Cervical Cancer: Less-Frequent Screening Needed After HPV Vaccine, Study Finds
A new study has found that women may only need cervical cancer screening every 5-10 years, instead of currently recommended three years screening. Cervical cancer is a malignant tumor of the lower-most parts of the uterus that can be better treated, or even prevented, by PAP smear screenings and human papillomavirus (HPV) vaccines.
Researchers who were part of the study from Harvard T.H. Chan School of Public Health found that less-intensive screening is needed among women who have been vaccinated against HPV, which causes almost all cases of cervical cancer, because the risk of these women developing cervical cancer is quite low. The study was published Monday in the Journal of the National Cancer Institute (JNCI).
"This analysis enabled us to examine what would happen if we shifted from the current way we screen for cervical cancer — essentially, recommending the same type of screening for all women — to screening that takes into account whether women have been vaccinated against HPV and therefore face a substantially lower risk of cervical cancer," Jane Kim, professor of health decision science at Harvard Chan School said. "We found that continuing intensive screening among HPV-vaccinated women yields excessive costs and harms with little to no health benefit."
According to recommendations since 2012, all women in the U.S. should be screened for cervical cancer every three years, beginning at age 21 with a Pap test (which checks for abnormal cells in the cervix), with the option of switching to a combination of Pap test and HPV testing (known as "cotesting") every five years beginning at age 30.
For the latest study, researchers developed a disease simulation model that calculated the risks and benefits of various screening protocols. This model projected the health and economic effects of three different types of HPV vaccines that are currently approved for use, two of which have been available since 2006. The main aim of the study was to find the biggest health benefit in the most cost-effective way.
According to the model, women with the lowest risk of cervical cancer—those vaccinated with the new "nonavalent" HPV vaccine (HPV-9) would only need screening four times in their life, every 10 years, starting at age 30 or 35. Those vaccinated with earlier versions of the HPV vaccine—the bivalent and quadrivalent vaccines (HPV-2 and HPV-4) would need screening every five years starting at age 25 or 30.
However, the study was conducted on women who were fully vaccinated in pre-adolescence (as recommended) and fully compliant with screening protocols.
HPV-9 vaccine targets seven types of HPV that cause nearly 90 percent of all cervical cancers, while bivalent and quadrivalent vaccines (HPV-2 and HPV-4) target two HPV types that cause roughly 70% of cervical cancers.
Signs and symptoms of cervical cancer:
Abnormal vaginal bleeding, such as bleeding after vaginal intercourse, bleeding after menopause, bleeding and spotting between periods.
Having (menstrual) periods that are longer or heavier than usual.
An unusual discharge from the vagina − the discharge may contain some blood and may occur between periods or after menopause.
Pain during intercourse.