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制品公司涉及的臨床宫颈癌普查试验在印度-有夸大HPV检测和贬低细胞学检测的倾向,误导读者

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The paper HPV screening for cervical cancer in rural India published in N Engl J Med.(one of the most important journal of medicine in the world) 2009 Apr 2;360(14):1385-94.

The conclusion of the paper: In a low resource setting, a single round of HPV testing was associated with a significant reduction in the numbers of advanced cancers or deaths from cervical cancer.Furthermore, the study abstract asserted, "No significant reductions in the numbers of associated deaths were observed in the cytology testing group or in the VIA group, as compared with the control group".

 

In other words, this clinical trial in India demostrate HPV testing can reduce the rate of cervical cancer and its related death, but Pap cytology and VIA have no reduction of cervical cancer related death, same as no any test group (control).

The authors manupulated the statistical numbers and made the results they hope to have.

Why? Industry-company involved the clinical trials. Interests are what people are looking for.

 

I pasted the original abstract here and also Dr. Austin and I wrote the editorial commentary.

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本帖最后由 于 2009-07-19 09:11:00 编辑  N Engl J Med. 2009 Apr 2;360(14):1385-94.Click here to read

HPV screening for cervical cancer in rural India.

在印度农村地区进行HPV筛查宫颈癌

International Agency for Research on Cancer, Lyon, France. sankar@iarc.fr

BACKGROUND: In October 1999, we began to measure the effect of a single round of screening by testing for human papillomavirus (HPV), cytologic testing, or visual inspection of the cervix with acetic acid (VIA) on the incidence of cervical cancer and the associated rates of death in the Osmanabad district in India. METHODS: In this cluster-randomized trial, 52 clusters of villages, with a total of 131,746 healthy women between the ages of 30 and 59 years, were randomly assigned to four groups of 13 clusters each. The groups were randomly assigned to undergo screening by HPV testing (34,126 women), cytologic testing (32,058), or VIA (34,074) or to receive standard care (31,488, control group). Women who had positive results on screening underwent colposcopy and directed biopsies, and those with cervical precancerous lesions or cancer received appropriate treatment. RESULTS: In the HPV-testing group, cervical cancer was diagnosed in 127 subjects (of whom 39 had stage II or higher), as compared with 118 subjects (of whom 82 had advanced disease) in the control group (hazard ratio for the detection of advanced cancer in the HPV-testing group, 0.47; 95% confidence interval [CI], 0.32 to 0.69). There were 34 deaths from cancer in the HPV-testing group, as compared with 64 in the control group (hazard ratio, 0.52; 95% CI, 0.33 to 0.83). No significant reductions in the numbers of advanced cancers or deaths were observed in the cytologic-testing group or in the VIA group, as compared with the control group. Mild adverse events were reported in 0.1% of screened women. CONCLUSIONS: In a low-resource setting, a single round of HPV testing was associated with a significant reduction in the numbers of advanced cervical cancers and deaths from cervical cancer.

背景:1999年10月,在印度的Osmanabad区,我们开始衡量效果地进行单轮HPV筛查检测、细胞学检测、或直视下醋酸检查宫颈癌的发生率和与宫颈癌相关的死亡率。方法:本组随机分组实验,52个村庄进行分组,共有31746名年龄介于30到达9岁的健康女性,被随机分配到4个组,每组有13个村庄。分组随机指定接受HPV检测(34126名妇女)、细胞学检测(32058名妇女)、或直视下醋酸检查(VIA)(34074名妇女)或接受标准护理(31488名妇女,对照组)。对筛查结果为阳性进行阴道镜下活检。以及对那些有宫颈癌前病变和癌进行适当的治疗。结果:在HPV检测组,被诊断为宫颈癌症127例(其中39例为STAGEII及以上);而相对于对照组[在HPV组检测晚期癌症的风险比:0.47;95%的可信区间(CI):0.32-0.69]为118例(其中82例有晚期的病变)。在HPV检测组中有34例死于癌症,而对照组有64例(风险比:0.52;95%的可信区间:0.38-0.83)。细胞学检测组或VIA组在晚期癌症或死亡病例的数据同对照组比较没有显著的减少。在筛查的妇女中被报道轻度不良反应为0.1%。结论:在低资源环境中,一个单轮的HPV检测在减少晚期宫颈癌和死亡的宫颈癌人数有显著的相关性。

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本帖最后由 于 2009-07-19 12:11:00 编辑  
CytoJournal 2009,  6:12

Test group biases and ethical concerns mar New England Journal of Medicine articles promoting HPV screening for cervical cancer in rural India

新英格兰医学杂志发表的文章中在印度农村地区进行HPV筛查宫颈癌的试验组的偏见和伦理问题


 Department of Pathology, Magee-Womens Hospital of University of Pittsburgh Medical Center, 300 Halket Street, Pittsburgh, PA 15213, USA

Date of Submission 16-Apr-2009
Date of Acceptance 03-Jun-2009
Date of Web Publication 16-Jul-2009

Correspondence Address:
R Marshall Austin
Department of Pathology, Magee-Womens Hospital of University of Pittsburgh Medical Center, 300 Halket Street, Pittsburgh, PA 15213
USA

©



The study conclusions, released from prepublication embargo by the New England Journal of Medicine (NEJM) at 5:00 PM on April 1, 2009, were dramatic. "In a low resource setting, a single round of HPV testing was associated with a significant reduction in the numbers of advanced cancers or deaths from cervical cancer." Furthermore, the study abstract asserted, "No significant reductions in the numbers of associated deaths were observed in the cytology testing group or in the VIA group, as compared with the control group." [1]

200941日下午5:00点,这项研究的结论被新英格兰医学杂志(NEJM)从预发表的禁止期到发表,是戏剧性的。“在低资源环境中,一个单轮的HPV检测在减少晚期宫颈癌和死亡的宫颈癌人数有显著的相关此外,研究摘要断言:“与对照组比较细胞学检测组或VIA(直视下醋酸检查)组在晚期癌症或死亡病例的数据同对照组比较没有显著的减少”.
Simultaneously, at 5:00 PM on April 1, 2009, a press release from Qiagen, a Netherlands Holding Company and a manufacturer of the digene HPV test, stated: "Landmark study in New England Journal of Medicine shows HPV testing significantly reduces deaths from cervical cancer, compared to other methods including Pap." [2] It is now known that the manufacturer received pre-embargo access to contents of the article and the accompanying editorial. The NEJM customer service office confirmed on April 14 that pre-embargo release was not from the journal.

与此同时,200941日下午5:00点,一个由荷兰控股公司和digene病毒检测的制造商Qiagen公司发了一份新闻稿指出: “在新英格兰医学杂志发表具有划时代意义的研究表明HPV检测能显著降低宫颈癌的死亡率,相对于包括巴氏在内的其他方法。”现在已经知道,制造商在预发表禁止期内获得了文章的内容和社论。新英格兰医学杂志客户服务办公室证实说:在414日之前是预发表禁止期而不是从杂志上获得。
A close look at the NEJM paper suggests that unexpected biases might have occurred in some of the test group arms of the study which sought to compare a single round of cervical cancer screening with HPV testing, cytology, and visual inspection with acetic acid (VIA) among over 131,746 "healthy women between the ages of 30 and 59 years" in rural India. In fact, the study acknowledged that the positive predictive value (PPV) for detecting CIN 2 - 3 was 19.3% in the cytologic testing group, higher than 11.3% in the HPV testing group, and study results indicate that essentially the same numbers of cervical cancers were detected after positive screening test results in the cytology arm (88) as in the HPV arm (87). Cervical cancer detection rates were 0.344% in the cytologic testing group and 0.321% in the HPV testing group [Table 1]. Among cervical cancers detected after a positive screening test, more cervical cancers were detected in the earliest and most favorable Stage (IA) in the cytology arm (58/88, 65.9%) than in the HPV arm (45/87, 51.7%), and there were fewer advanced (Stage II+) screening-detected cervical cancers in the cytology arm (10/88, 11.4%) than in the HPV arm (14/87, 16.1%) [Table 1]. The preliminary 2005 publication of study data had earlier reported that cytology had a higher detection rate for CIN 2 - 3 (1.0%) than for HPV testing (0.7%) and observed the following: "Our present findings indicate that the detection rates of HPV testing did not show any improvement over cytology. Furthermore, the currently available test (HC2) is expensive and requires a relatively sophisticated laboratory operation." [3] Only the individuals performing HPV testing are specifically described in the 2005 report as having been trained "intensively." What new information then led to the quite different study conclusions reported in the 2009 publication and the simultaneous manufacturer's press release?
仔细观察了新英格兰医学杂志的该文章表明:意想不到的偏见发生在一些试验组中,该研究试图比较在印度农村地区“30岁到59岁之间的健康妇女超过131746人群中,用单一轮的HPV检测进行宫颈癌筛查、细胞学筛查和直视下醋酸(VIA)筛查。事实上,这项研究获取诊断CIN2-3的阳性预测值( PPV ):细胞学筛查组为19.3 %,高于HPV筛查组的11.3 %。研究结果表明:阳性的筛查结果在细胞学筛查组(88例)与HPV筛查组(87例)基本上是相同的宫颈癌检出。宫颈癌检出率细胞学筛查组为0.344 % ,而HPV筛查组为0.321% [1 ] 。在筛查阳性之后的子宫颈癌诊断中,更多更早期和更有意义阶段(IA期)的宫颈癌在细胞学筛查组(58/88 65.9 %)比HPV筛查组(45 /8751.7 %),而更少的晚期(Stage II+)癌,细胞学筛查组( 10/88 11.4 %)比HPV筛查组( 14/87 16.1 % ) [1 ] 2005年公布的初步研究数据报告:细胞学有较高的检出率在CIN2-31.0%)相比HPV检测(0.7%),并注意到了以下内容:我们目前的研究结果显示,HPV的检出率没有出现任何改善细胞学检测。此外,现有的测试( HC2 )非常昂贵,而且需要一个相对先进的实验室作业”[ 3 ]。在2005年的报告中指出只有专门被密集”训练有素的人才能进行HPV检测。有什么新信息导致了完全不同的研究结论在2009年并同时与生产商的新闻稿发表呢?
The 2009 publication employed the well-recognized "intention-to-treat-principle" in which all eligible patients assigned to a study arm are included in the final analyses for each study arm, whether or not the patients adhere to the research protocol management strategy. [4] Therefore, the final study analyses included in each arm cervical cancer patients who had not been screened, 32 in the HPV arm and 42 in the cytology arm [Table 2]. Since there were 10 more unscreened cancer patients and 5 more cervical cancer deaths in the cytology arm than in the HPV arm and since these unscreened cancer patients predictably had higher rates of cervical cancer, more advanced stages, and less favorable outcomes, the net effect of the inclusion of the larger number of unscreened cervical cancer patients in the cytology arm was to make the cytology arm appear more like the unscreened control arm of the study. Of 54 cervical cancer-related deaths in the cytology cohort, 27 deaths were in the "assigned but not screened" group and another 18 deaths were in patients who had abnormal cytology results. For cervical cancer deaths in the HPV arm, 19% fewer deaths (22) were in the "assigned but not screened" group, and 33% fewer deaths (12) occurred in women with abnormal screening HPV test results. Given the higher PPV and specificity of cytology compared to HPV testing, the outcomes suggest that follow-up colposcopic examinations, tissue sampling procedures, and treatments were not equally effective in the two groups. Significantly inconsistent adherence to management strategies in different study arms may also introduce study bias in investigations, even in studies applying the intention-to-treat-principle. [4]
2009年出版采用公认的意向处理原则,使所有符合研究条件的患者都分配到一个研究组包括在列入最后分析的每一个研究组。不论患者是否坚持研究的意向管理[ 4 ]。因此,最终的研究分析所包含每一组的子宫颈癌患者谁没有被筛选, 在HPV组中有32例和细胞学组有42[2 ] 。由于多了10例未经筛查的宫颈癌患者和多了5例宫颈癌死亡患者在细胞学组比HPV组,由于这些未经筛查患者预示了较高的子宫颈癌比率、更晚期的阶段和不良的预后,其净效应的列入了大量未经筛查的宫颈癌患者在细胞学组中,使细胞学组看起来更象未经筛查的对照组。在细胞学组54例宫颈癌死亡病例中, 27例死亡是分配但没筛查组和另外18例死亡患者有异常的细胞学结果。子宫颈癌死亡的HPV组,死亡人数减少19 %(22例)是在分配但不筛查组,死亡人数减少33 %(12例)发生在妇女异常HPV检测结果。给出了细胞学较高的阳性预测值(PPV)和特异性比HPV检测,结果表明:后续阴道镜检查、组织活检和治疗在两组中不是等同。明显不遵守研究的管理在不同的研究组中可能引入偏见的调查研究,即使是在研究过程中运用意向处理原则。

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本帖最后由 于 2009-07-19 14:48:00 编辑

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Other aspects of the study data also support the hypothesis that bias was introduced in the study group arms during treatment of patients who developed cervical cancer. For example, the death rate for clinically detected cervical cancer patients in the HPV test-negative group of the HPV arm was 0% as compared to 40.9% among clinically detected cancer patients in the cytology-negative group of the cytology arm [Table 3]. Remarkably, the 0% death rate occurred in the HPV group despite the fact that 62.5% of the HPV test-negative cervical cancers were "advanced stage" (Stage II+). Among patients with positive screening results, similar unexpected outcome differences are also evident [Table 1]. Even though the numbers of cervical cancers in both screen-detected groups were essentially the same (HPV 87; cytology 88), more favorable Stage IA screen-detected cancers were detected in the cytology arm (58) than in the HPV arm (45). Also, fewer unfavorable Stage II+ cancers were screen detected in the cytology arm (10) than in the HPV arm (14). Even after acknowledging the higher negative predictive value of HPV testing reflected in [Table 3], deaths in the HPV arm were unexpectedly one-third lower (12) than in the more stage-favorable cytology arm (18). The 2005 publication [3] states that "Women with suspected invasive cancer were referred to the surgical oncology department of NDMCH (Nargis Dutt Memorial Cancer Hospital) for investigations and treatment with surgery and radiation." The study also notes that "The most common form of treatment for invasive carcinoma in the intervention arm was radical hysterectomy followed by radical radiotherapy." No data are reported on the extent of similarities or differences in cancer treatments between the test group arms. The effect of the bias of unexpectedly favorable treatment outcomes in the HPV arm contributes to the study conclusion that HPV screening (rather than some other factor) preferentially prevented cervical cancer deaths. The NEJM report does acknowledge that "both practitioners and subjects were aware of the study group assignments." [1]

其他方面的研究数据也支持这样的假设,即偏见被引入在治疗期间谁进展为宫颈癌的患者研究组中。例如:与临床诊断宫颈癌患者的死亡率在HPV检测结果是阴性组占HPV组中0%相比,临床诊断宫颈癌患者的死亡率在细胞学结果阴性组占细胞学组中40.9 [3 ] 。值得注意的是,在0 %的死亡率发生在人乳头状瘤病毒组,尽管实际上62.5 %的HPV检测结果阴性的宫颈癌是晚期Stage II+)。在患者阳性筛查结果中,类似的意外结果也有很明显的差异性[1 ] 。尽管在这两个筛查组中获得的子宫颈癌的人数基本上是相同的(HPV87人 、细胞学88人 ) ,但是更多更早期和更有意义阶段(IA期)的宫颈癌在细胞学筛查组(58)比HPV筛查组(45),而更少的晚期(Stage II+)癌,细胞学筛查组( 10)比HPV筛查组(14。即使在获得较高的阴性预测值的HPV检测组反应[3 ] ,死亡人数在HPV组( 12 )出意外的比更早期和更有意义阶段的细胞学组 18 )低三分之一。 2005年出版[ 3 ]指出:被怀疑浸润癌的女性转移到肿瘤外科部NDMCH Nargis杜特纪念肿瘤医院)进行随访、治疗、手术和放疗。这项研究同时指出:最常见的治疗浸润癌在干预组进行根治性子宫切除术之后,进行放射治疗。无数据报告在试验组之间进行程度相似或不同的癌症治疗。意外的偏见性的在HPV组进行优先治疗结果的影响有助于研究结论:HPV筛查(而不是其他的一些因素)优先阻断了宫颈癌的死亡。
The NEJM publication reports that the study was supported by the Bill and Melinda Gates Foundation, through the Alliance for Cervical Cancer Prevention (ACCP). The paper also states that "no potential conflict of interest was reported." However, questions have been raised in the peer-reviewed literature as to whether or not the Gates Foundation and the ACCP might have in effect "become enamored with the promise of science and new technologies at the expense of delivering available preventives today". [5] Questions have also been raised about the partnership between AACP's coordinating organization and the HPV test manufacturer. [5-7] Similarly, the Gates Foundation was recently acknowledged as having funded a large project supporting publication of a special supplemental issue of the journal Vaccine entitled "Overview of Human Papillomavirus-Based and Other Novel Options for Cervical Cancer Screening in Developed and Developing Countries." [8] The HPV test manufacturer is also listed as providing corporate support, [8] acknowledged as "critical for meetings and travel." The two lead authors of the NEJM article and one of the NEJM editorial writers are specifically listed among the large number of international contributors. The presence of not even a single cytopathologist among the very large number of contributors supported for international travel and meetings clearly suggests an anticytology bias for the proceedings, one perhaps mirrored in the NEJM. The two selected authors of the accompanying NEJM editorial [9] also turn out to have co-authored no fewer than 34 PUBMED-cited publications with the former Vice President for Research and Development and Chief Scientific Officer of the HPV test manufacturer. Industry co-authorship was recently cited as the second most common conflict-of-interest in high impact journals such as NEJM. [10]

Although the NEJM study upon first inspection may be interpreted as applying primarily to low-resource settings where even very limited screening and diagnostic testing are difficult to support, the accompanying editorial, [9] press release [2] and media coverage all strive to suggest otherwise. According to the editorial writers, "The implications of the study in rural India are immediate and global." [9] According to the New York Times (NYT), the study indicates broadly that a "new DNA test outperforms the  Pap smear More Details." [11] Strangely absent from any of the commentary, however, has been any concern that the study included a "control" group of 31,506 "healthy women" who were allowed to largely go without any screening at all during the study, one approved by both local and international "institutional scientific and ethical committees." [3] Sixty-four women in the "control" group died of cervical cancer along with another 70 unscreened women "assigned to undergo screening," numbers of cervical cancer deaths substantially in excess of the number which occurred in widely criticized experiments conducted at New Zealand's Auckland National Women's Hospital in the latter half of the last century. [12] The deaths of so many unscreened study "control" subjects made the NYT-quoted comment by a Stanford gynecologist, "The study is another nail in the coffin for Pap smears," seem particularly insensitive and ironic. [11]

The unexpected increase in the presence of cervical cancer in both the unscreened cytology and VIA arms of the study was a key foundation for the authors' surprising statement that "no significant reductions in the numbers of advanced cancers or deaths were observed in the cytologic-testing group or in the VIA group, as compared with the control group." [1] When unscreened study cancer victims are included in the "control" group, it becomes clear that significant reductions in advanced stage cervical cancers occurred in virtually all screening group arms [Table 4]. The comparative reductions in advanced stage cervical cancer after a single round of (less expensive) conventional cytology are not significantly different from those achieved with a single round of (more expensive) HPV testing (P = 0.2655), even before taking into consideration other study biases. Furthermore, the study's cytology screeners were trained for only 3 months, one-fourth of the usual year-long training for cytotechnologists. This was almost certainly suboptimal to confront the challenging conditions in the rural Osmanabad district. Pap screening, when successfully implemented, reduces cervical cancer rates by 60 - 90% within 3 years of introduction to populations that have not been screened; these reductions in incidence and mortality are consistent and dramatic across populations. [5,13] Even a single round of screening with conventional cytology and limited training in rural India appears to have been remarkably effective, despite the published interpretations of study data in the NEJM. As noted by many of the same authors in their 2005 publication, "Our results clearly show that good quality cytology can be implemented even in a rural setting of a developing country with reasonable investment, while HPV testing does not give any better detection of CIN2/3 lesions, despite the higher investments." [3] Careful reading of the 2009 publication data and assessments of the numerous internal biases suggest that the widely reported conclusions may be significantly misleading.

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References   Top

1. Sankaranarayanan R, Nene BM, Shastri SS, Jayant K, Muwonge R, Budukh AM, et al . HPV screening for cervical cancer in rural India. N Engl J Med 2009;360:1385-94.   Back to cited text no. 1    
2. Press Release. Source: Qiagen. Landmark study in the New England Journal of Medicine shows HPV testing significantly reduces deaths from cervical cancer, compared to other methods including Pap. Wednesday April 1, 2009, 5:00 PM EDT.   Back to cited text no. 2    
3. Sankaranarayanan R, Nene BM, Dinshaw KA, Mahe C, Jayant K, Shastri SS; et al . A cluster randomized controlled trial of visual, cytology, and human papillomavirus screening for cancer of the cervix in rural India. Int J Cancer 2005;116:617-23.   Back to cited text no. 3    
4. Montori VM, Guyatt GH. Intention-to-treat principle. CMAJ 2001;165:1339-41.  Back to cited text no. 4  [PUBMED]  [FULLTEXT]
5. Suba EJ, Donnelly AD, Furia LM, Huynh ML, Raab SS. Cervical cancer prevention for all the world′s women: genuine promise resides in skilled quality management rather than novel screening approaches. Diagn Cytopathol 2007;35:187-91.   Back to cited text no. 5    
6. Suba EJ, Murphy SK, Donnely AD, Furia LM, Huynh LM, Raab SS. Systems analysis of real worlds obstacles to successful cervical cancer prevention in developing countries. Am J Public Health 2006;96:480-7.  Back to cited text no. 6    
7. Suba EJ, Frable WJ, Raab SS. Cost-effectiveness of cervical cancer screening in five developing countries. N Enlg J Med 2006;354:1535-6.   Back to cited text no. 7    
8. Cuzick J, Arbyn M, Sankaranarayanan R, Tsu V, Ronco G, Mayrand MH, et al. Overview of human papillomavirus-based and other novel options for cervical cancer screening in developed and developing countries. Vaccine 2008;26S:K29-41.  Back to cited text no. 8    
9. Schiffman M, Wacholder S. From India to the world: a better way to prevent cervical cancer. N Engl J Med 2009;360:1453-5.  Back to cited text no. 9  [PUBMED]  [FULLTEXT]
10. Jaqsi R, Sheets N, Jankovic A, Motomura AR, Amarnath S, Ubel PA. Frequency, nature, effects and correlates of conflicts of interest in published Clinical Cancer Research. Cancer 2009;115:2783-91.  Back to cited text no. 10    
11. McNeil, DG. New DNA test outperforms Pap smear. New York Times. April 7, 2009.   Back to cited text no. 11    
12. McCredie MR, Sharples KJ, Paul C, Baranyai J, Medley G, Jones RW, et al. Natural history of cervical intraepithelial neoplasia and risk of invasive cancer in women with cervical intraepithelial neoplasia 3: a retrospective cohort study. Lancet Oncol 2008;9:425-34.   Back to cited text no. 12  [PUBMED]  [FULLTEXT]
13. Agency for Healthcare Research and Quality. Screening for cervical cancer: File inventory. Available from: http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid¼hstat3.section.4193. [accessed on 2009 Apr 14].  Back to cited text no. 13    

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5 楼    发表于2009-07-17 19:21:00举报|引用
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 Welcome every one write your oppinion.

Our editorial comment paper is relative long. I will appreciate it if some one with good English can translate it in Chinese.

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6 楼    发表于2009-07-17 19:25:00举报|引用
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 Besides our comment, there are some other short comments for this paper. I will paste them here late.
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7 楼    发表于2009-07-17 19:43:00举报|引用
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 All the following comment letters were published in NEJM.

The new england journal of medicine

 

correspondence

 

 

HPV Screening for Cervical Cancer in Rural India


To the Editor: Sankaranarayanan et al. (April 2 issue)1 report no significant differences in rates of detection of high-risk cervical neoplasia among women who underwent screening by cytologic testing, testing for human papillomavirus (HPV) with the Hybrid Capture II assay, or visual in­spection of the cervix with acetic acid (VIA). Re­ductions in mortality from cervical cancer were observed only among women screened by HPV testing. The unexpected lack of a correlation be­tween detection rates reported for the screening tests and subsequent mortality rates requires care­ful consideration. Sankaranarayanan et al. ac­knowledge that unidentified differences in follow-up care, rather than differences in the performance of screening tests, account for differences in mor­tality between women screened by VIA in their current study and women screened by VIA in an earlier study.2 The same logic, applied to the cur­rent data, suggests that unidentified differences in follow-up care, rather than nonsignificant dif­ferences among screening-test detection rates, account for differences in mortality among the groups of women who underwent screening. Within the political structures of many develop­ing countries, there is genuine lack of support for

cervical-cancer prevention efforts,3 which may be further eroded by the questionable conclusion that only an unaffordable screening option is better than none at all.1

Eric J. Suba, M.D.

Kaiser Permanente Medical Center San Francisco, CA 94115 eric.suba@kp.org

Edmund S. Cibas, M.D.

Harvard Medical School Boston, MA 02115

Stephen S. Raab, M.D.

University of Colorado Health Sciences Center Aurora, CO 80045

1.        Sankaranarayanan R, Nene BM, Shastri SS, et al. HPV screen­ing for cervical cancer in rural India. N Engl J Med 2009;360: 1385-94.

2.        Sankaranarayanan R, Esmy PO, Rajkumar R, et al. Effect of visual screening on cervical cancer incidence and mortality in Tamil Nadu, India: a cluster-randomised trial. Lancet 2007;370: 398-406.

3.        Suba EJ, Murphy SK, Donnelly AD, Furia LM, Huynh ML, Raab SS. Systems analysis of real-world obstacles to successful cervical cancer prevention in developing countries. Am J Public Health 2006;96:480-7.

 

 

 

 

 

 

To the Editor: The study by the Indian Council of Medical Research showed that a down-staging effect of VIA and a reduction in the case fatality rate still hold in the Indian subcontinent.1 The discrepancy between the authors’ earlier findings and the current findings with regard to the bene­fits of VIA calls for more explanation.2

Jain Ankit, M.D.

Kidwai Memorial Institute of Oncology Bangalore 560030, India ankitjaindm@gmail.com

Jain Prakriti, M.B., B.S., D.G.O.

Bhagwan Mahaveer Jain Hospital Bangalore 560052, India

K.C. Lakshmaiah, M.D., D.M.

Kidwai Memorial Institute of Oncology Bangalore 560030, India

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8 楼    发表于2009-07-17 19:46:00举报|引用
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To the Editor: In a previous article,1 Sankara­narayanan et al. reported a decrease in cervical-cancer mortality with the use of VIA and the “screen and treat” approach, whereas the current article calls for multiple visits and treatment only of women with grade 2 or 3 cervical intraepithe­lial neoplasia confirmed on biopsy. In the current report, there is no discussion of this difference between the two studies.

The current data cast doubt on VIA, which is an invaluable asset to cervical-cancer prevention in developing countries. The benefit of VIA in low-resource settings is that it can be used to detect cervical precancer inexpensively and that it en­ables the examiner to institute immediate and appropriate therapy. This strategy decreases the risk that a patient with a potentially precancerous lesion will be lost to follow-up.

We strongly believe that the lack of survival benefit reported in the current article should not preclude the lifesaving results of screen-and-treat programs that have been demonstrated previ­ously.

Miriam L. Cremer, M.D., M.P.H.

Basic Health International San Salvador, El Salvador mlcremer@hotmail.com

Elizabeth Conlisk, Ph.D.

Hampshire College Amherst, MA 01002

Juan C. Felix, M.D.

University of Southern California Los Angeles, CA 90033

Dr. Felix reports receiving lecture fees from Qiagen and Ho-logic. No other potential conflict of interest relevant to this letter was reported.

1. Sankaranarayanan R, Esmy PO,  Rajkumar R, et al. Effect of visual screening on cervical cancer incidence and mortality in Tamil Nadu, India: a cluster-randomised trial. Lancet 2007;370: 398-406.

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9 楼    发表于2009-07-17 19:48:00举报|引用
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 To the Editor: Interest in implementing cervi­cal-cancer prevention services in developing na­tions will probably peak as a result of the power­ful evidence reported by Sankaranarayanan et al. Unfortunately, expenditures on health care and

health care–related development assistance may shrink because of the ongoing global financial downturn.1 In this scenario, the integration of cervical-cancer prevention services with other population-based health care programs may pro­vide valuable opportunities for cost-effective ini­tiation, expansion, and sustainability of these services.

Programs for the prevention and treatment of human immunodeficiency virus (HIV) infection and the acquired immunodeficiency syndrome (AIDS) are being implemented in many develop­ing nations, where cervical-cancer incidence and mortality rates are also high. HIV–AIDS pro­grams are slowly but substantially contributing to improved health infrastructures and increasing access to health care.2 Integration of cervical-cancer prevention services within HIV–AIDS pro­grams is an excellent opportunity to target women at highest risk for cervical cancer, as we recently showed in Zambia.3,4 Such efforts hold the promise of both saving lives from an emi­nently preventable cancer and strengthening the broader primary care context that is so essential for the sustainability

of vertical health programs.

Mulindi H. Mwanahamuntu, M.B., B.S., M.Med.

University Teaching Hospital Lusaka, Zambia

Vikrant V. Sahasrabuddhe, M.B., B.S., Dr.P.H.

Vanderbilt University Institute for Global Health Nashville, TN 37203 vikrant.sahasrabuddhe@vanderbilt.edu

Groesbeck P. Parham, M.D.

Center for Infectious Disease Research in Zambia Lusaka, Zambia

1.        Parry J, Humphreys G. Health amid a financial crisis: a com­plex diagnosis. Bull World Health Organ 2009;87:4-5.

2.        El-Sadr WM, Hoos D. The president’s emergency plan for AIDS relief — is the emergency over? N Engl J Med 2008;359: 553-5.

3.        Mwanahamuntu MH, Sahasrabuddhe VV, Pfaendler KS, et al. Implementation of ‘see-and-treat’ cervical cancer prevention services linked to HIV care in Zambia. AIDS 2009;23:N1-N5.

4.        Pfaendler KS, Mwanahamuntu MH, Sahasrabuddhe VV, Mu­denda V, Stringer JS, Parham GP. Management of cryotherapy­ineligible women in a “screen-and-treat” cervical cancer preven­tion program targeting HIV-infected women in Zambia: lessons from the field. Gynecol Oncol 2008;110:402-7.

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10 楼    发表于2009-07-17 19:50:00举报|引用
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To the Editor: Sankaranarayanan et al. found that a single DNA screening test for cervical-cancer–related HPV strains can be cost-effective in a resource-limited setting. An additional strat­egy could stretch a public health budget even fur-

ther, increasing the number of early cancers de­tected by extending screening to more women. In 1943, Dorfman1 proposed a clever pooling ap­proach for screening military recruits for syphi­lis. His idea was that if the available assay per­forms well under a dilution of 1:k, then one can assay pools of specimens, each based on k per­sons, testing only individual specimens if their pool tested positive. To screen N persons in a population with a low prevalence, α, the number of assays one would need to conduct, on average, would be only

1

[κ+1−(1−α)κ].

In the study by Sankaranarayanan et al., α was approximately 0.10. Suppose an assay tolerates a dilution of 1:3 and the budget permits N assays. Pooling in groups of three would require (0.6)N assays, and the number of women who could be screened would be (1/0.6)N, or 1.67N. Further gains would accrue if women who presented for screening could be grouped according to risk, with individual-level assays reserved for high-risk women and pooling used for lower-risk women.

Clarice R. Weinberg, Ph.D.

National Institute of Environmental Health Sciences Research Triangle Park, NC 27709

1. Dorfman R. The detection of defective members of large populations. Ann Math Stat 1943;14:436-40.

ther, increasing the number of early cancers de­tected by extending screening to more women. In 1943, Dorfman1 proposed a clever pooling ap­proach for screening military recruits for syphi­lis. His idea was that if the available assay per­forms well under a dilution of 1:k, then one can assay pools of specimens, each based on k per­sons, testing only individual specimens if their pool tested positive. To screen N persons in a population with a low prevalence, α, the number of assays one would need to conduct, on average, would be only

1

[κ+1−(1−α)κ].

In the study by Sankaranarayanan et al., α was approximately 0.10. Suppose an assay tolerates a dilution of 1:3 and the budget permits N assays. Pooling in groups of three would require (0.6)N assays, and the number of women who could be screened would be (1/0.6)N, or 1.67N. Further gains would accrue if women who presented for screening could be grouped according to risk, with individual-level assays reserved for high-risk women and pooling used for lower-risk women.

Clarice R. Weinberg, Ph.D.

National Institute of Environmental Health Sciences Research Triangle Park, NC 27709

1. Dorfman R. The detection of defective members of large populations. Ann Math Stat 1943;14:436-40.

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11 楼    发表于2009-07-17 19:55:00举报|引用
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 The following is the correspondence from NEJM authors of the paper in india trial to above comments published in NEJM

The Authors Reply: Suba et al., Ankit et al., and Cremer et al. call for more explanation regarding the lack of significant reductions in mortality from cervical cancer during the 8-year follow-up period after VIA screening or cytologic testing in our study. Although interstudy differences are not new, the discrepant results after VIA screen­ing in the two randomized trials in India1 have caused concern, especially in some countries that are beginning to implement VIA-based screen-and-treat programs.

The reasons for the discrepancies are not entirely clear to us. There were no differences in the follow-up care among the study groups. That HPV testing had a higher sensitivity for detect­ing potentially progressive precursor lesions than that of cytologic testing or VIA is clear from our findings. Nevertheless, long-term follow-up of the study cohorts may clarify the current lack of effect after VIA or cytologic testing. Perhaps the health education provided to the control women had an effect on the burden of cervical cancer, resulting in

the absence of a significant detect­able difference in the rate of advanced disease or deaths from cervical cancer between the control group and the VIA or cytologic-testing groups. An underestimation of the number of cervical-cancer cases and deaths in the control group cannot be ruled out either, since cervical cancers were diagnosed in the control group in women with symptoms who were seeking diagnostic services, and health services in the Osmanabad district are underdeveloped. Some women with disease might not have sought clinical care, and such cases and deaths might have been missed because of the lack of hospital records for such patients.

The above possibilities may account for the apparent lack of effectiveness of VIA and cyto­logic screening at this time. However, since we plan to continue the follow-up of the study groups for cervical-cancer incidence and mortal­ity for several years, we will clarify the long-term effects of the interventions, including any delayed reductions in mortality in the cytologic-testing and VIA groups.

In reply to Mwanahamuntu et al. and Wein­berg: approaches to the screening of women older than 30 years of age that involve using fewer rounds of screening with a highly sensitive test and targeting early diagnosis among women who are positive for high-risk HPV types are al­ready good strategies to maximize the utiliza­tion of public health budgets. We hope that HPV testing will become affordable in all settings in the near future.

Rengaswamy Sankaranarayanan, M.D.

International Agency for Research on Cancer 69372 Lyon CEDEX 08, France sankar@iarc.fr

Kasturi Jayant, M.Sc.

Nargis Dutt Memorial Cancer Hospital Barshi 413 401, India

Surendra S. Shastri, M.D.

Tata Memorial Center Mumbai 400 012, India

1. Sankaranarayanan R, Esmy PO, Rajkumar R, et al. Effect of visual screening on cervical cancer incidence and mortality in Tamil Nadu, India: a cluster-randomised trial. Lancet 2007;370: 398-406.

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12 楼    发表于2009-07-17 19:55:00举报|引用
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科学就是要这样的认真态度。

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13 楼    发表于2009-07-17 20:09:00举报|引用
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本帖最后由 于 2009-07-17 20:10:00 编辑

We analized the India paper with very detailed  study of their data and background. Our comment paper is very long. There is limitation of word number for the letter to editor in NEJM. This is why we sent our comment paper to CytoJournal as a View Point. Our comment was just available online yesterday. We are waiting for the correspondence from Dr. Rengaswamy Sankaranarayanan,the author for the india trial paper.

By the way CytoJournal is the only one free online journal for cytology. Dr. DeMay is the Editors-in chief. Every one can get in to read the papers for free. You also can submit your studis for publication.

http://www.cytojournal.com/

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14 楼    发表于2009-07-17 20:18:00举报|引用
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 Ok. I spend more than one hour to paste these information here. Just hope more our Chinese physicians, researchers know some hot issues in the world.

Mao is right: class struggle is present every where. Ha, ha, just kidding.

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15 楼    发表于2009-07-17 22:14:00举报|引用
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 Just notice that I did not paste the tables in our comment we made based on the data from India HPV papers
CytoJournal 2009,  6:12   View Point

Test group biases and ethical concerns mar New England Journal of Medicine articles promoting HPV screening for cervical cancer in rural India

 Department of Pathology, Magee-Womens Hospital of University of Pittsburgh Medical Center, 300 Halket Street, Pittsburgh, PA 15213, USA

Table 1.  Cervical cancer cases, cancer stages, and deaths among cancers detected after positive screening tests

Groups

Controls

Cytology

HPV

No. of eligible patients

31,488

32,058

34,126

Assigned but not screened

NA

6509

6934

Screened patients

 

NA

25549

27129

Positive screening test detected Ca

NA

88

87

Ca detection rate

 

NA

0.344%

0.321%

Stage IA

 

NA

58/88

(65.9%)

45/87

(51.7%)

Stage IB

 

NA

20/88

(22.7%)

27/87

(28.7%)

Stage II+

 

NA

10/88

(11.4%)

14/87

(16.1%)

Stage unknown

NA

0/88

(0%)

4/87

(3.4%)

Deaths among positive screening Test detected Ca

NA

18/88

(20.5%)

12/87

(13.8%)

Ca detected among controls

118

NA

NA

Ca deaths among controls

64

 

 

Table 2. Cervical cancer cases, cancer stages, and deaths;                                                        cancers detected among assigned but not screened study women

Groups

Controls

Cytology

HPV

No of eligible patients

31,488

32,058

34,126

Assigned but not screened

NA

6509

6934

Ca detected among assigned but not screened women

NA

42

32

Stage IA

NA

0/42

(0 %)

2/32

(6.2%)

Stage IB

NA

5/42

(11.9%)

6/32

(18.8%)

Stage II+

NA

33/42

(78.6%)

20/32

(62.5%)

Stage unknown

NA

4/42

(9.5%)

4/32

(12.5%)

Ca deaths among assigned but not screened women

NA

27/42

(64.3%)

22/32

(68.8%)

Ca detected among controls

118

 

 

Ca deaths among controls

64

 

 


Table 3. Cervical cancer cases, cancer stages, and deaths among cancers detected after negative screening tests                                                         

Groups

Controls

Cytology

HPV

No. of eligible patients

31,488

32,058

34,126

Assigned but not screened

NA

6509

6934

Ca diagnosed in women with negative screening test results

NA

22

8

Stage IA

NA

2/22

(9.1%)

0/8

(0%)

Stage IB

NA

4/22

(18.2%)

2/8

(25.0%)

Stage II+

NA

15/22

(68.2%)

5/8

(62.5%)

Stage unknown

NA

1/22

(4.5%)

1/8

(12.5%)

Deaths among Ca diagnosed in  women with negative screening test results

NA

9/22

(40.9%)

0/8

(0%)

Ca detected among controls

118

 

 

Ca deaths among controls

64

 

 

Table 4. Advanced stage (II+) cervical cancers: unscreened control group and unscreened assigned study group vs. screened study group women

Groups

Controls & assigned but not screened

VIA

Cytology

HPV

No. of eligible patients

31,488

34,074

32,058

34,126

Assigned but not screened

20,752              (all arms total)

7309

6509

6934

Stage II+ Ca after positive screening test

NA

35

10

14

Stage II+ Ca

after negative

screening test

NA

19

15

5

Total screened

stage II+ Ca

NA

54

25

19

Stage II+ Ca after being assigned but not screened

85

NA

NA

NA

Stage II+ Ca

“Controls”

82

NA

NA

NA

Total

stage II+ Ca

controls &

assigned but not screened

167

NA

NA

NA

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16 楼    发表于2009-07-17 23:24:00举报|引用
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The paper HPV screening for cervical cancer in rural India published in N Engl J Med.(one of the most important journal of medicine in the world)(one of the most important journal of medicine in the world) 2009 Apr 2;360(14):1385-94.

The conclusion of the paper: In a low resource setting, a single round of HPV testing was associated with a significant reduction in the numbers of advanced cancers or deaths from cervical cancer.Furthermore, the study abstract asserted, "No significant reductions in the numbers of associated deaths were observed in the cytology testing group or in the VIA group, as compared with the control group".

 

In other words, this clinical trial in India demostrate HPV testing can reduce the rate of cervical cancer and its related death, but Pap cytology and VIA have no reduction of cervical cancer related death, same as no any test group (control).

The authors manupulated the statistical numbers and made the results they hope to have.

Why? Industry-company involved the clinical trials. Interests are what people are looking for.

 

I pasted the original abstract here and also Dr. Austin and I wrote the editorial commentary.

印度乡村宫颈癌HPV筛查的论文发表于《新英格兰医学杂志》(2009 Apr 2;360(14):1385-94.)。该杂志是全世界医学杂志中最著名的杂志之一。

发表于该杂志的这篇文章得出的结论是:在医疗资源欠发达地区,单一的HPV检测可明显减少进展期宫颈癌及其死亡率。而且,这篇论文的摘要指出:“与对照组比较,细胞学检查或醋酸检查没有明显减少宫颈癌的发生及其死亡率。”

换句话说,印度的这个临床实验证实了HPV检测能减少宫颈癌及其死亡率,但与未进行任何检测一样(对照组),宫颈涂片和醋酸实验却不能减低宫颈癌相关的死亡。

这些作者对统计数字进行了人为控制,使得结果成为他们所希望的。

为什么?这是因为有企业参与了这项临床实验。这正是这些人所希望的。

这里我贴出了原始摘要,也贴出了我和Austin博士写给编辑部的评论。

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17 楼    发表于2009-07-19 05:01:00举报|引用
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 Thank Dr. Huang for your translation.
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19 楼    发表于2009-07-19 20:55:00举报|引用
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本帖最后由 于 2009-07-19 20:57:00 编辑  

Test group biases and ethical concerns mar New England Journal of Medicine articles promoting HPV screening for cervical cancer in rural India

The study conclusions, released from prepublication embargo by the New England Journal of Medicine (NEJM) at 5:00 PM on April 1, 2009, were dramatic. "In a low resource setting, a single round of HPV testing was associated with a significant reduction in the numbers of advanced cancers or deaths from cervical cancer." Furthermore, the study abstract asserted, "No significant reductions in the numbers of associated deaths were observed in the cytology testing group or in the VIA group, as compared with the control group." [1] Simultaneously, at 5:00 PM on April 1, 2009, a press release from Qiagen, a Netherlands Holding Company and a manufacturer of the digene HPV test, stated: "Landmark study in New England Journal of Medicine shows HPV testing significantly reduces deaths from cervical cancer, compared to other methods including Pap." [2] It is now known that the manufacturer received pre-embargo access to contents of the article and the accompanying editorial. The NEJM customer service office confirmed on April 14 that pre-embargo release was not from the journal.

A close look at the NEJM paper suggests that unexpected biases might have occurred in some of the test group arms of the study which sought to compare a single round of cervical cancer screening with HPV testing, cytology, and visual inspection with acetic acid (VIA) among over 131,746 "healthy women between the ages of 30 and 59 years" in rural India. In fact, the study acknowledged that the positive predictive value (PPV) for detecting CIN 2 - 3 was 19.3% in the cytologic testing group, higher than 11.3% in the HPV testing group, and study results indicate that essentially the same numbers of cervical cancers were detected after positive screening test results in the cytology arm (88) as in the HPV arm (87). Cervical cancer detection rates were 0.344% in the cytologic testing group and 0.321% in the HPV testing group [Table 1]. Among cervical cancers detected after a positive screening test, more cervical cancers were detected in the earliest and most favorable Stage (IA) in the cytology arm (58/88, 65.9%) than in the HPV arm (45/87, 51.7%), and there were fewer advanced (Stage II+) screening-detected cervical cancers in the cytology arm (10/88, 11.4%) than in the HPV arm (14/87, 16.1%) [Table 1].

The preliminary 2005 publication of study data had earlier reported that cytology had a higher detection rate for CIN 2 - 3 (1.0%) than for HPV testing (0.7%) and observed the following: "Our present findings indicate that the detection rates of HPV testing did not show any improvement over cytology. Furthermore, the currently available test (HC2) is expensive and requires a relatively sophisticated laboratory operation." [3] Only the individuals performing HPV testing are specifically described in the 2005 report as having been trained "intensively." What new information then led to the quite different study conclusions reported in the 2009 publication and the simultaneous manufacturer's press release?

The 2009 publication employed the well-recognized "intention-to-treat-principle" in which all eligible patients assigned to a study arm are included in the final analyses for each study arm, whether or not the patients adhere to the research protocol management strategy. [4]Therefore, the final study analyses included in each arm cervical cancer patients who had not been screened, 32 in the HPV arm and 42 in the cytology arm [Table 2].Since there were 10 more unscreened cancer patients and 5 more cervical cancer deaths in the cytology arm than in the HPV arm and since these unscreened cancer patients predictably had higher rates of cervical cancer, more advanced stages, and less favorable outcomes, the net effect of the inclusion of the larger number of unscreened cervical cancer patients in the cytology arm was to make the cytology arm appear more like the unscreened control arm of the study.Of 54 cervical cancer-related deaths in the cytology cohort, 27 deaths were in the "assigned but not screened" group and another 18 deaths were in patients who had abnormal cytology results. For cervical cancer deaths in the HPV arm, 19% fewer deaths (22) were in the "assigned but not screened" group, and 33% fewer deaths (12) occurred in women with abnormal screening HPV test results.

Given the higher PPV and specificity of cytology compared to HPV testing, the outcomes suggest that follow-up colposcopic examinations, tissue sampling procedures, and treatments were not equally effective in the two groups.Significantly inconsistent adherence to management strategies in different study arms may also introduce study bias in investigations, even in studies applying the intention-to-treat-principle

实验组偏倚和伦理问题导致《新英格兰医学杂志》中《印度乡村宫颈癌的HPV筛查》一文有重大问题

200941日下午5点,来自于NEJM提前出版的一篇研究结论非常引人注目。“在医疗资源欠发达地区,单一的HPV检测可明显减少进展期宫颈癌及其死亡率。”而且,这篇论文的摘要指出:“与对照组比较,细胞学检查或醋酸检查没有明显减少宫颈癌的发生及其死亡率。”与此同时,Qigen公司于200941日下午5点举行了一场新闻发布会,该公司为一家荷兰控股公司,生产digeneHPV检测试剂盒,他们在发布会上宣布:“新英格兰医学杂志上一项重大研究显示,与其他方法包括Pap相比,HPV检测可明显降低宫颈癌死亡。”现在很明显制造商在文章发布前就已获得了这篇文章的内容和相应的评论。NEJM客户服务部414日证实了未发表前发布的内容不是来自于杂志。

这篇论文的研究目的是比较单一的HPV检测、细胞学和醋酸实验对宫颈癌筛查的影响,该项研究人群为印度乡村中131346名年龄为30-59岁健康女性。但认真阅读这篇NEJM论文,就会发现该研究中一部分实验组存在着料想不到的偏倚。实际上,该项研究发现细胞学检查检测CIN2-3的阳性预测值(PPV)为19.3%,高于HPV检测组的11.3%。该研究结果显示细胞学组(88例)和HPV组(87例)有阳性筛查检测结果后实际诊断的宫颈癌数量本质上是相同的。细胞学组宫颈癌检出率为0.344%HPV检测组宫颈癌检出率为0.321%(见表1)。在筛查获得阳性结果后的宫颈癌检出者中,最早期和最佳分期(IA)的宫颈癌检出率在细胞学组中(58/8865.9%)高于HPV(45/87, 51.7%)。筛查检测为II期以上进展期的宫颈癌在细胞学组(10/88, 11.4%)低于HPV(14/87, 16.1%)(表1)。

早期2005年一项研究资料显示细胞学对CIN2-3检出率(1.0%)高于HPV组(0.7%)。注意下面的一句话:“我们目前研究显示HPV检测对宫颈癌的检出率并不高于细胞学检查,而且,目前HPV检测方法(HC2)价格较高,需要一个相对高级的实验室操作。”由于进行了集中培训,仅有行HPV检测者才被特异性地纳入2005年研究报告中。那么什么新的信息可导致2009年出版的文章中得出明显不同的研究结论,又是什么导致制造商能同时举行新闻发布会?
2009年发表的文章应用了众所周知的“意向治疗原则”,即所有被研究者被指派到某一个研究组,而每个研究组被包括在最后的结果分析中,而不管病人是否符合研究议定书管理策略。因此,每组中最后的研究分析包括可那些没有进行筛查的宫颈癌病人,其中HPV32例,细胞学组42例(表2)。由于在细胞学组中有10个未筛查的宫颈癌病人和5个宫颈癌死亡者,高于HPV组,同时因这些未筛查的宫颈癌病人预期有较高的宫颈癌发生率,更加进展的临床分期和较差的预后,因而大量未筛查的宫颈癌病人在细胞学组中,这样结果的净效应是细胞学组更像本研究中未筛查对照组。细胞学组54例宫颈癌相关的死亡者中,27例为“指定的但没有进行筛查者”,另外18例死亡者有异常的细胞学结果。HPV组宫颈癌死亡者中,19%为“指定的但没有进行筛查者”,33%发生于有异常的HPV检测结果。

考虑到与HPV检测相比,细胞学具有较高的阳性预测值和特异性,结果提示在二组中进行随访性阴道镜检查、活检和治疗的效应是不相等的。很明显在不同的研究组中不遵守管理策略也可能导致调查研究中的研究偏倚,甚至在应用意向治疗原则的研究中。

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20 楼    发表于2009-07-19 21:40:00举报|引用
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这次内容实在太长太多,所以只能一段一段翻译,有兴趣者大家认领。

 Other aspects of the study data also support the hypothesis that bias was introduced in the study group arms during treatment of patients who developed cervical cancer. For example, the death rate for clinically detected cervical cancer patients in the HPV test-negative group of the HPV arm was 0% as compared to 40.9% among clinically detected cancer patients in the cytology-negative group of the cytology arm [Table 3]. Remarkably, the 0% death rate occurred in the HPV group despite the fact that 62.5% of the HPV test-negative cervical cancers were "advanced stage" (Stage II+). Among patients with positive screening results, similar unexpected outcome differences are also evident [Table 1]. Even though the numbers of cervical cancers in both screen-detected groups were essentially the same (HPV 87; cytology 88), more favorable Stage IA screen-detected cancers were detected in the cytology arm (58) than in the HPV arm (45). Also, fewer unfavorable Stage II+ cancers were screen detected in the cytology arm (10) than in the HPV arm (14). Even after acknowledging the higher negative predictive value of HPV testing reflected in [Table 3], deaths in the HPV arm were unexpectedly one-third lower (12) than in the more stage-favorable cytology arm (18). The 2005 publication [3] states that "Women with suspected invasive cancer were referred to the surgical oncology department of NDMCH (Nargis Dutt Memorial Cancer Hospital) for investigations and treatment with surgery and radiation." The study also notes that "The most common form of treatment for invasive carcinoma in the intervention arm was radical hysterectomy followed by radical radiotherapy." No data are reported on the extent of similarities or differences in cancer treatments between the test group arms. The effect of the bias of unexpectedly favorable treatment outcomes in the HPV arm contributes to the study conclusion that HPV screening (rather than some other factor) preferentially prevented cervical cancer deaths. The NEJM report does acknowledge that "both practitioners and subjects were aware of the study group assignments." [1]

该项研究资料的其它方面也支持了这个假说,即偏倚被引入到那些已进展为宫颈癌病人接受治疗的研究小组中。例如,HPV组中HPV检测阴性组临床检查处的宫颈癌病人死亡率为0%,而细胞学组中细胞学阴性组中临床检出的宫颈癌病人死亡率为40.9%(表3)。但是值得注意的是,尽管HPV组中死亡率为0%,但事实是62.5%HPV检测阴性的宫颈癌是处于“进展期”(II期及以上)。在阳性筛查结果的病人中,相似的意外结果差异也非常明显【表1】。 即使在该2组筛查中宫颈癌的数量本质上是相同的(HPV87例,细胞学88例),但筛查检出的IA期癌在细胞学组(58)高于HPV组(45)。而预后不好的II期及以上的癌在细胞学组的检出数为10例,低于HPV组(14例)。虽然从表3中可看出HPV检测具有较高的阴性预测值,但HPV组宫颈癌死亡人数比较高分期预后的细胞学组出乎意料地低1/32005年出版的文章指出:“那些怀疑为浸润性癌的女性被推荐到NDMCH肿瘤外科进行检查和手术及放疗。”该研究也指出:“干扰组中大多数浸润性癌最常见的治疗方法是根治性子宫切除术和放疗。”在检测组中有关癌症治疗的相似性或差异性的程度没有资料报道。HPV组这种意想不到的较好治疗后果的偏倚,其结果是导致该研究得出了HPV筛查(而不是其它因素)可优先防止宫颈癌死亡的结论。这篇NEJM论文的作者也承认“研究者和受试者都知道该研究的实验分组。”

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