Prenatal Diethylstilbestrol Exposure and High-grade Squamous Cell Neoplasia of the Lower Genital Tract.
The link between prenatal DES exposure and vaginal and cervical clear cell adenocarcinoma in young women was established in the early 1970s. Parentally DES exposed women are also shown to have a two times higher risk of cervical and vaginal squamous cell neoplasia (a possible precursor to cancer) compared with unexposed women. The current analysis set out to determine whether the increased risk for squamous cell neoplasia of the vagina and cervix continued with age among the DES exposed and whether DES-exposed women should continue to receive annual Pap smears.
To answer this question, we analyzed data from 4,062 DES exposed women and 1,837 unexposed women in the DES Follow-Up Study. We found that 145 (or 5.3%) of the exposed women had pathology-confirmed cervical intraepithelial neoplasia (CIN2+) compared with 33 (or 2.6%) among the unexposed women. Even after considering other possible factors that may cause CIN2, the DES-exposed women had a CIN2+ risk that was two times higher than the unexposed women. This risk remained elevated until women reached their mid-40s, confirming the appropriate recommendation of annual screening of prenatally DES-exposed women through the age of at least 44 years, and possibly beyond.