High-risk human papillomavirus seems not involved in DES-related and of limited importance in nonDES related clear-cell carcinoma of the cervix
Objective: Over 90% of all cervical adenocarcinoma are caused by a transforming infection with a high-risk type human papillomavirus (hrHPV). Previous studies demonstrated that the association between hrHPV positivity and cervical clear-cell adenocarcinoma (CCAC) varies between 0% and 100%. As approximately 60% of all CCAC are associated with intra-uterine diethylstilbestrol (DES) exposure, we determined in a cohort of both DES-exposed and DES-unexposed women the prevalence of hrHPV infections, and the potential etiological role of hrHPV by additional analysis of p16INK4a and p53 expression. Methods: Representative slides of 28 women diagnosed with CCAC were tested for hrHPV by two PCR methods (the clinically validated GP5+/6+ PCR and the very sensitive SPF10PCR/LiPA25). Fifteen women were DES-exposed, 10 unexposed and of 3 women DES-exposure was unknown. Twenty-one cases with sufficient material were immuno-histochemically stained for p16INK4a and p53. Results: Seven tumors, of which four DES-exposed and two unexposed tested positive for hrHPV with GP5+/6+ PCR. Thirteen tumors, of which five DES-exposed and seven unexposed, tested positive with SPF10PCR/ LiPA25. In one women with unknown exposure, a CCAC tested positive in both assays. Only three cases, none in DES-exposed women, and all positive with both hrHPV assays, revealed diffuse p16INK4a immuno-staining and weak p53 staining as well, supporting indisputable hrHPV involvement. Conclusions: Although the prevalence of hrHPV was high, only two DES-unrelated CCAC (25%) and one tumor in a woman with unknown exposure could be attributed to hrHPV.