VANCOUVER, B.C. — Low-grade squamous intraepithelial lesions were likely to regress in women older than 30 years who were not infected with types of human papillomavirus associated with a high risk for cervical cancer, a longitudinal study found.
Of 412 women with untreated cervical low-grade squamous intraepithelial lesions (L-SIL), only women who tested positive for high-risk human papillomavirus (HPV) developed cervical intraepithelial neoplasia grades 2 or 3 (CIN 2/3) during 2 years of follow-up, Christine C. Clavel, Ph.D., said at the 22nd International Papillomavirus Conference.
HPV testing is approved in the United States to help triage women with Pap results showing atypical squamous cells of undetermined significance, or as an adjunct to Pap smears for screening women older than age 30. The study suggests that it also might be helpful by allowing a longer interval between follow-ups in women with L-SIL and a negative HPV test, said Dr. Clavel of the University of Reims (France) Hospital Center.
At baseline, 87% of the 412 women and 80% of those older than 35 years tested positive for high-risk HPV types. Colposcopy and biopsies found 21 cases of CIN 2/3 at baseline and an additional 12 cases during the 2-year follow-up, all in women who initially tested positive for high-risk HPV, she said at the conference, sponsored by the University of California, San Francisco.
Half of the high-risk HPV infections cleared over a median of 9 months in the cohort as a whole and in the subset of women older than 35 years. Cytologic lesions cleared over time in 66% of the total cohort and in 68% of women older than 35.
“There was a significant correlation observed between an initial negative high-risk HPV test, the regression of cytologic lesions, and the absence of CIN 2/3 in follow-up,” Dr. Clavel said.
Women with L-SIL who test negative for high-risk HPV might safely be followed 12 months later by repeat cytology and HPV testing, she said. This would include approximately 13% of all women with L-SIL, 20% of these over age 35 with L-SIL, or 24% of women over age 45 with L-SIL. In women older than 45 years, misclassification of L-SIL increases and leads to a decrease in detection of L-SIL at colposcopy, she noted.
Using HPV testing plus Pap smears to follow HPV-negative women with L-SIL could significantly decrease the number of women sent to colposcopy, compared with follow-up using cytology alone, Dr. Clavel said.