Cervical Cancer Screening Declines, Fewer Lesions Detected

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Since the introduction of human papillomavirus (HPV) vaccines in the United States in 2006 and recent changes in cervical cancer screening guidelines, rates of high-grade cervical lesions among young women have decreased, according to the results of a study published in Cancer.

Between 2008 and 2012, there were large declines in the detection of high-grade cervical lesions-grade 2 or 3 cervical intraepithelial neoplasia (CIN) and adenocarcinoma in situ-among 18- to 20-year-old women.

“We think that the decreases in high-grade lesions in this group reflect changes in screening but also may be partially due to HPV vaccination,” said Susan Hariri, PhD, of the US Centers for Disease Control and Prevention (CDC), in a statement.

There were also modest decreases in 21- to 29-year-old women. The rates among 30- to 39-year-old women did not change.

As part of the CDC-led HPV vaccine impact monitoring project (HPV-IMPACT), which started in 2008, Hariri and colleagues analyzed 9,119 health records of 18- to 39-year-old women from parts of California, Connecticut, New York, Oregon, and Tennessee.

High-grade cervical lesions are without symptoms and are detected through a routine cervical screening exam. The lesions may lead to cancer and are predominantly caused by a persistent HPV infection.

Current recommendations state that women between the ages of 21 and 29 should be screened every 3 years with a Pap smear. Starting at age 30 and until age 65, a combination of a Pap smear and HPV test is recommended every 5 years. 

The incidence of CIN2 lesions, the most common diagnosis, ranged from 41.4% in California to 57.9% in Connecticut.

In line with guidelines, screening rates among 18- to 20-year-old women decreased by 67% in Oregon, 80% in New York, and 88% in California. Screening in this age group declined to less than 10% in all regions by 2012.

Among 21- to 29-year-old women, relative screening rate declines were 13% in Oregon, 26% in New York, and 27% in California.

The impact of HPV vaccination on the frequency of high-grade lesions will take many more years to understand, according to the study authors.

In editorial accompanying the study, Harinder Brar, MD and Allan Covens, MD, both of the University of Toronto, called the study significant as it is a first window into the incidence trends of high-grade cervical lesions after the introduction of the HPV vaccine.

“The study highlights that while preliminary data demonstrates a drop in… incidence rates, the results may be confounded by the changes in cervical screening guidelines,” wrote the editorial authors.