Home-based self-collected vaginal specimens detect more cervical lesions and cancers than cytology
Vaginal self-collection for Hybrid Capture®-based HPV testing increases screening coverage and is more sensitive than Pap smear shows a Mexican study published today online in the Lancet
Hilden, Germany, and Gaithersburg, Md., November 2, 2011 - Promising findings published today online in the Lancet[i] from a community-based, randomized equivalence trial undertaken by public health authorities in Mexico to investigate DNA home testing for human papillomavirus (HPV) compared with cytology (evaluation of cells) based on Pap smears. The study indicated that the relative sensitivity of HPV molecular testing was 3.4 times higher than cytology. Additionally, 4.2 times more invasive cancers were detected. The home testing study adds support to previous evidence[ii] that adding self-collection to the screening setup can increase the coverage rate of cervical cancer prevention programs, especially in underserved regions in developing and developed countries. The study was funded by the Instituto Nacional de Salud Pública (INSP), the Health Ministry of Mexico and QIAGEN.
"HPV testing is lower in cost, easier to implement, and has lower false-negative rates than cytology. Testing of self-collected vaginal samples offers increased coverage and acceptability," commented the lead study author, Dr. Eduardo Lazcano-Ponce, professor at the Centro de Investigación en Salud Poblacional of INSP in Morelos, Mexico.
The trial included 25,061 women of low socioeconomic status between 26 to 65 years from 540 rural communities in Morelos, Guerrero, and Mexico State, Mexico. They were randomly allocated to HPV DNA testing of a vaginal sample self-collected at home or cervical cytology at the nearest health center. Eight community nurses visited the self-collection women at home and instructed them how to use the digene® cervical sampler, a conical-shaped brush, to take the sample. The study used the digene® HPV test based on Hybrid Capture 2, which is considered the gold standard for HPV testing and already has been clinically validated in trials including more than one million women worldwide. The primary endpoint was CIN2 or worse, detected by colposcopy. Any woman having a positive result for either of the tests was referred to colposcopy.
The participation rate was higher in women randomized to the HPV group (9,202 of 9,371, 98%) than in the cytology group (11,054 of 12,731, 87%). Importantly, in the HPV group more invasive cancers were detected than with cytology (28 vs. 8). With a lower positive predictive value for HPV testing (PPV CIN2 or worse 12.2% vs. 90.5%) the identification of appropriate triage methods is crucial. The study adds: "Because women at these sites will be screened only a few times in their lives, the high sensitivity of a HPV screen is of paramount importance."
Based on data from several national trials including Hybrid Capture technology, Mexico is the first country to implement frontline HPV testing with cytology triage as a national cervical cancer prevention program. Dr. Nubia Munoz, Colombian Cancer Institute, Bogota, Colombia, and Dr. Rolando Herrero, Prevention and Implementation Group, International Agency for Research on Cancer, Lyon, France, conclude in an accompanying editorial in the Lancet: "The experience shows what can be achieved when scientific judgment guides public health policy."
"The value of HPV DNA testing in cervical cancer screening and disease detection has been proven again and again for both the developed and developing worlds. Self-collection for HPV DNA testing could become an important way for national cervical cancer prevention programs worldwide to increase coverage rates," said Dr. Helge Lubenow, Head of the Molecular Diagnostic Business at QIAGEN. "Our digene HPV testing solutions have been used in several trials for self-collection, and we support any approach that helps to include populations that are difficult to reach as here are most cases of cancer to be found."
About cervical cancer and the digene® HPV test
Worldwide, cervical cancer affects approximately 500,000 women annually and, after breast cancer, is the second-most-common malignancy found in women. Since the cause of cervical cancer - HPV - is known and women who have it can be identified, it is a highly preventable and treatable disease if women have access to organized prevention programs. The World Health Organization estimates that only about five percent of women in the developing world have been screened for cervical disease in the previous five years compared to 75 percent in the developed world. In the U.S., the digene HPV Test is approved for use together with a Pap test in women 30 years and older. In Europe, it is approved as an initial general population screening test either alone or together with a Pap test. It is also used as a follow-up to inconclusive Pap test results. For more information about HPV and cervical cancer, visit www.theHPVtest.com.
About self-collected samples
HPV testing offers the ability for women to self-collect a specimen that can be sent to a laboratory for testing; this cannot be done with a pap smear. Specimens are self-collected in either a clinical setting or in a home. Several health authorities, e.g. in the Netherlands and Mexico, have already investigated the effectiveness of self-collected specimens to determine if it could increase the coverage and effectiveness of their cervical cancer screening program and reach women who today are unscreened. Trials in both countries have shown very promising results and both have used the digene HPV test as the test for screening. Therefore, self-collection could be a useful addition to cervical cancer screening programs and when new algorithms are implemented that incorporate HPV DNA testing. This is true for both developing countries as well as in the developed world. Currently the digene HPV test is validated using digene Cervical Sampler and is not validated for use with self-collected specimens.
QIAGEN N.V., a Netherlands holding company, is the leading global provider of sample and assay technologies. Sample technologies are used to isolate and process DNA, RNA and proteins from biological samples such as blood or tissue. Assay technologies are used to make such isolated bio-molecules visible. QIAGEN has developed and markets more than 500 sample and assay products as well as automated solutions for such consumables. The company provides its products to molecular diagnostics laboratories, academic researchers, pharmaceutical and biotechnology companies, and applied testing customers for purposes such as forensics, animal or food testing and pharmaceutical process control. QIAGEN's assay technologies include one of the broadest panels of molecular diagnostic tests available worldwide. This panel includes the digene HPV Test, which is regarded as a "gold standard" in testing for high-risk types of human papillomavirus (HPV), the primary cause of cervical cancer, as well as a broad suite of solutions for infectious disease testing and companion diagnostics. QIAGEN employs about 3,700 people in over 35 locations worldwide. Further information about QIAGEN can be found at http://www.qiagen.com/.
QIAGEN Media Contacts:
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[i] Lazcano-Ponce, E. et al. (2011) Self-collection of vaginal specimens for human papillomavirus testing in cervical prevention (MARCH): a community-based randomised controlled trial. Lancet 378. Published Online November 2, 2011 DOI:10.1016/S0140-6736(11)61522-5.
[ii] Gök, M. et al. (2011) Experience with high-risk human papillomavirus testing on vaginal brushbased
self-samples of non-attendees of the cervical screening program. Int J Cancer. doi: 10.1002/ijc.26128.