The human papilloma virus (HPV) is common in humans but it can lead to infection and even cancer so there have been calls to get people vaccinated. 4,000 women will die each year from cervical cancer, which is linked to HPV, and HPV can also cause genital warts and more rare forms of cancer. The two vaccines in use, made by GlaxoSmithKline and Merck, prevent about 70 percent of cervical cancer cases and the CDC estimates that 7,000 HPV-associated cancers might be prevented each year with HPV vaccines but uptake has been limited because medical professionals don't like that there have been tens of thousands of adverse reaction reports.
A new study finds that the HPV test alone may be valuable. A study
in the Journal of the National Cancer Institute finds that though co-testing for HPV and Pap testing for cervical cancer every 5 years for women aged 30-65 years is now recommended, HPV testing alone may provide better reassurance against cervical cancer than Pap testing alone and lead to the same confidence as cotesting, which is going to save a lot of money.
In a comparison of the three strategies, Julia C. Gage, Ph.D., M.P.H., of the Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, and colleagues analyzed data from the Kaiser Permanente Northern California (KPNC) large integrated health delivery system, which screened women age 30-64 since 2003 with both HPV and Pap testing.
Data were available through 2012, and over 1 million women were screened at approximately 3-year intervals, with a mean follow-up time of 4.36 years. For each testing strategy, they estimated the cumulative risk of cervical cancer after a negative test result.
The researchers found that the 3-year cancer risks after a negative HPV-alone test result were lower than those for a Pap-alone negative result. In addition, the 3-year cancer risks after a negative HPV-alone test result were similar to the 5-year cancer risk for a co-test negative result.
Gage et al. write "In conclusion, we find that primary HPV testing every 3 years might provide as much, if not more, reassurance against precancer and cancer, compared to primary Pap testing every 3 years and cotesting every 5 years." However, the authors note that a screening program based on only one or the other test alone, rather than a cotesting program like that at KPNC, might give somewhat different estimates. They urge studies of screening programs in different health-care settings and populations to identify the optimal screening strategy and interval.
In an accompanying editorial, Jane J. Kim, of the Harvard School of Public Health, Department of Health Policy and Management, Center for Health Decision Science, Boston, MA, also cautions that the data reflect management based on co-testing and notes that the HPV test approved for primary screening specifically assays the two highest-risk HPV types (16 and 18) that account for 70% of cervical cancers but pools the assay for the other 12 HPV strains.
However, despite these caveats, Kim concludes that the authors "…provide timely evidence from the United States that HPV primary testing can provide equal or more reassurance against cancer risk than strategies currently recommended by guidelines."