HPV DNA Testing Likely To Become Primary Cervical Cancer Screening Tool As Vaccine Use Expands, Predict International Experts
News reports that 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. reported. Human Papillomavirus (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.
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.
“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.”
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.
“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.”
According to the U.S. Food and Drug Administration (FDA)
Digene Hybrid Capture 2 High-Risk HPV DNA Test – P890064 S009 A004
This is a brief overview of information related to FDA’s approval to market this product. See the links below to the Summary of Safety and Effectiveness and product labeling for more complete information on this product, its indications for use, and the basis for FDA’s approval.
Product Name: Digene Hybrid Capture 2 High-Risk HPV DNA Test
Manufacturer: Digene Corporation
Address: 1201 Clopper Road, Gaithersburg, MD 20878
Approval Date: March 31, 2003
Approval Letter Link
What is the HPV DNA TEST?
The Digene HC2 High-Risk HPV DNA Test is a laboratory test used to show the presence or absence of the genetic (DNA) material from the Human Papilloma Virus (HPV), in cells from a woman’s cervix. (The cervix is the lower part of the uterus or womb.) When HPV genetic material is found in these cells, it sometimes indicates the potential or the presence of disease. The cervical cells are usually obtained during a Pap Test (“pap smear”), when cells are obtained by gently scraping the surface of the cervix.
How does it work? The test causes the release of DNA from the cervical cells: Normal DNA and, if present, HPV DNA. Probe molecules are added that combine with the DNA to form what is called DNA-Probe-Hybrid. This Hybrid recognizes many types of high-risk HPVs.
Then, light-producing antibodies are added and combine with the DNA-Probe Hybrid. The amount of light produced above a certain level indicates the presence of HPV. Anything below that level indicates either the absence of HPV or HPV-levels that are too low to detect.
When is it used? The HPV-DNA Test is used only in conjunction with Pap Testing. The test is used:
* When a woman’s Pap Test results are mildly abnormal. The HPV-DNA Test is then used to tell whether or not HPV is present at high enough levels to indicate that an HPV infection exists. If she has an HPV infection, she may be tested further to be sure that she does not have serious cervical abnormalities.
* When women over age 30 have HPV infections that do not disappear over time. These women may be at greater risk for developing cervical disease. Women over 30 with a positive Pap Test and a positive HPV-DNA Test have a higher than average risk of cervical cancer and may need to be tested more frequently. Only a small percentage of HPV infections, however, lead to cancer.
Note: Women with normal Pap test results and an absence of HPV infection are at very low risk for developing cervical cancer but should be tested at regular intervals, as prescribed by a doctor. There is not enough information currently to tell us how long women with normal Pap Test results remain at low risk. There is also not enough information to decide how frequently an HPV-infected woman should be tested.
Additional information: Summary of Safety and Effectiveness and labeling will be available at: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cftopic/pma/pma.cfm?num=p890064s009