(HealthDay News) — The number of cervical precancers (CIN2+ cases) in the United States declined from 2008 to 2016, likely in part because of prevention with the human papillomavirus (HPV) vaccine, according to research published in the April 19 issue of the U.S. Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report.
Nancy M. McClung, Ph.D., from the CDC in Atlanta, and colleagues analyzed data from the Human Papillomavirus Vaccine Impact Monitoring Project, a population-based CIN2+ surveillance system, to characterize rates of CIN2+ among women aged ≥18 years from 2008 to 2016.
The researchers found that from 2008 to 2016, the rate of CIN2+ per 100,000 women declined significantly in women aged 18 to 19 years and 20 to 24 years, but increased significantly in women aged 40 to 64 years. In 2008, an estimated 216,000 U.S. women were diagnosed with CIN2+, more than half of whom (55 percent) were women aged 18 to 29 years. By comparison, in 2016, an estimated 196,000 CIN2+ cases were diagnosed, more than a third of which (36 percent) were in women aged 18 to 29 years. During the study period, an estimated three-quarters of CIN2+ cases (76 percent) were attributable to HPV types targeted by the vaccine currently used in the United States.
“These estimates of CIN2+ cases likely reflect changes in CIN2+ detection resulting from updated cervical cancer screening and management recommendations, as well as primary prevention through HPV vaccination,” the authors write.