| Papanicolaou en Base Líquida |
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| HPV DNA Testing likely to become primary cervical cancer screening tool as vaccine use expands, predict international experts |
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| Expert Consensus Published by Vaccine Journal, Released at HPV Conference |
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Prague, Czech Republic – Sept. 11, 2006 – Experts speaking at the world’s leading conference on the human papillomavirus (HPV) predicted that countries that widely implement the new HPV vaccine will eventually switch to DNA testing for the virus as their primary screening tool to identify women at risk of cervical cancer, Digene Corp. (Nasdaq: DIGE) reported. HPV is the cause of cervical cancer, and Digene markets the only FDA-approved and CE-marked HPV test, which detects 13 high-risk types of the virus.
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| The consensus presented at the 23rd Annual International Papillomavirus Conference was developed by more than 100 experts in HPV, cervical cancer screening and vaccination, and was simultaneously published in a special supplement to Vaccine.
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| “Even after vaccination programs have been instituted and reasonable levels of coverage obtained, cervical cancer screening cannot be discontinued,” said Thomas C. Wright, MD, lead author of the panel’s conclusions and Associate Professor of the Division of Gynecologic Pathology College of Physicians and Surgeons at Columbia University in New York. “However, it will be important to re-evaluate how we screen. It is likely that the current approach of frequent screening using cytology (Pap testing) will prove to be too expensive and inefficient for many countries that also implement HPV vaccination – particularly for those that publicly fund most of their healthcare. Most countries that introduce HPV vaccination will eventually want to switch to HPV DNA testing as the primary screening test, due (in part) to its better performance.” |
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A working group led by Eduardo Franco, MD, Professor in the Departments of Oncology and Biostatistics at Canada’s McGill University, concluded that simply doing Paps more frequently would not be a viable strategy, because the ability to accurately identify women with pre-cancerous or cancerous conditions using cytology is expected to decline as HPV vaccines are more widely used. This is because, the group said, the Pap relies on a “highly subjective” interpretation of changes seen in cervical cell samples – contributing to its already high false-negative rate and the need for frequent re-testing. As widespread vaccination of women results in a lower incidence of abnormal cells, the “signal-to-noise” ratio will decrease -- potentially leading to greater tedium and fatigue in the laboratory, and a greater number of mistakes.
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| “The evidence in favor of HPV testing for screening is substantial. HPV testing is based on a highly standardized and validated assay system that suffers from none of the vagaries that typically affect Pap cytology,” said Dr. Franco. “HPV testing is not prone to subjective interpretation and would thus maintain its high performance characteristics under low-lesion conditions.” |
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| Dr. Franco’s working group concluded that HPV testing is the most suitable tool for routine screening, and that cytology should be reserved for follow-up evaluation of women who are found to have high-risk types of HPV. Currently, the Digene HPV Test is approved in the United States for use along with the Pap in women 30 and over. |
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| Another benefit of widespread use of HPV DNA testing cited by the experts is the ability to track HPV infection over time as the vaccine becomes more widely used – particularly if coupled with genotyping technology now under development by Digene and others to determine which specific high-risk types of the virus are present. “HPV DNA testing could provide an effective strategy to monitor long-term protection among vaccinated women,” wrote Dr. Wright. |
