VANCOUVER, B.C. — Women over age 50 with normal Pap results who don't have human papillomavirus probably can safely be excused from cervical screening, Marc F.D. Baay, Ph.D., said in a poster presentation at the 22nd International Papillomavirus Conference.
That would encompass 93% of women older than 50 years, said Dr. Baay of the University of Antwerp, Belgium.
Dr. Baay and his associates followed 513 women in three age groups for a median of 3 years with 1,952 Pap smears and testing for high-risk human papillomavirus (HPV) types. Results showed 41 transient infections and 9 persistent HPV infections, with only 2 of the persistent infections in women aged 50 and up, they reported at the conference, sponsored by the University of California, San Francisco.
HPV infection in 16% of 68 women aged younger than 30 years was transient in every case. HPV infection in 14% of 175 women aged 30–49 years and 6% of 270 women aged 50 years and older was persistent in 4% of women in the middle-age group and less than 1% of the women over age 50. Five out of the nine persistent infections were related to HPV 16. All women had normal cytology results at the time HPV was first detected.
Six of the nine women with persistent infections developed abnormal cytology during the follow-up study. Only one of these women was over age 50; she developed high-grade squamous intraepithelial lesions (HSIL) at age 52. A biopsy showed cervical intraepithelial neoplasia grade 0 (CIN0).
The other five abnormal Pap results in women with persistent HPV came from women aged 30–49 years. A biopsy in one woman with HSIL found CIN3. Among three cases of low-grade squamous intraepithelial lesions (LSIL), one regressed spontaneously, and a biopsy in another found cervical intraepithelial neoplasia grade 3 (CIN3). One woman with persistent HPV in this middle-age group developed atypical squamous cells of undetermined significance (ASCUS).
Low-grade abnormal cytology also was seen in 10 HPV-negative women (7 with ASCUS and 3 with LSIL), but these lesions all regressed spontaneously.
The study suggests that canceling cervical screening for HPV-negative older women with normal Pap results would carry only a limited risk of missing cervical abnormalities or the development of slow-growing cervical cancer, Dr. Baay said.