Women who have been vaccinated against the human papillomavirus (HPV) might need fewer cervical cancer screenings than previously thought, a new study argues. And the frequency of said screenings depends on the kind of vaccine a woman has received.
Those who have been immunized with earlier forms of the HPV vaccine need cervical cancer screening once every five years, starting at age 25 or 30, the research says. This kind of vaccine protects against the two strains of the sexually-transmitted virus most likely to cause cancer, US News and World Report says.
Women who have received the latest vaccine, which protects against seven strains of HPV that might cause cancer, need screening only once every 10 years, from age 30 to 35 until 65.
Both these screening procedures are looser than current recommendations, which mandate cervical cancer exams every three years from the age of 21, with a Pap test until the age of 30. After this, the regimen is a combination of HPV and Pap tests every five years.
Jane Kim, a professor of health decision science at the Harvard T.H. Chan School of Public Health and lead researcher on the study, says,
Under no circumstances are the currently recommended strategies in any way preferred in these two groups of vaccinated women.
Kim adds, “I’m hoping this brings awareness to the policy makers that there needs to be a revision, hopefully to provide people with information among those with a good sense of what their vaccine status is, at least.”
But the American Cancer Society might not change its cervical cancer screening guidelines anytime soon, according to Debbie Saslow, senior director of HPV-Related and Women’s Cancers. She says there are too few women getting the HPV vaccine in the country, and monitoring immunization is quite poor.
In order for the ACS to consider changing its recommendations, vaccine rates need to go up and happen on time, Saslow says.
The HPV virus causes almost all cases of cervical cancer. The earlier vaccines are expected to prevent 70% of cervical cancer in women worldwide, while the newer kind could prevent up to 90% of cases, the researchers note.
The Harvard team came up with a disease simulation model that could estimate the risks and benefits of the current and prospective screening standards, factoring in how HPV vaccines work.
The study concludes that since women who have received the vaccine are at a low risk of developing cervical cancer, less-intensive screening can be encouraged. Too much screening can open up a whole new avenue of false positives and unnecessary tests, as well as additional health costs.
The researchers also state that Pap smears for HPV-vaccinated women were not needed, and HPV tests were enough.
But Saslow says more research is needed on the discussion of how effective HPV vaccines are in preventing cervical cancer. Since the vaccine was made available only in 2006, not enough women have reached the proper age to get screened, much less show long-term effects. Revising the guidelines “probably won’t become an issue for us for five years,” she says.
The study was published in the Journal of the National Cancer Institute.