HUMAN PAPILLOMAVIRUS DNA-SEQUENCES IN ADENOCARCINOMA OF THE UTERINE CERVIX IN INDIAN WOMEN

Background. Infection with human papillomavirus (HPV) is considered to be the principal causal agent in the development of squamous cell car cinoma of the uterine cervix. Although adenocarcinoma of the cervix or iginates adjacent to the squamous epithelial neoplastic lesions, the e tiopathogenesis of adenocarcinoma is not yet clearly understood. Recen t studies have raised more controversy, rather than answering the ques tion of whether specific HPV infection also plays a role in the develo pment of adenocarcinoma of the cervix. Molecular DNA hybridization tec hniques were used to detect HPV types prevalent in both adenocarcinoma and squamous cell carcinoma of the uterine cervix, which is the most common cancer in Indian women. Methods. Histologically confirmed, form aldehyde-fixed, paraffin-embedded tissue sections from 12 cases of ade nocarcinoma and 30 cases of squamous cell carcinoma of the uterine cer vix were analyzed retrospectively for the presence of HPV DNA types 6b , 11, 16, and 18 by both Southern blot hybridization and in situ hybri dization. Results. Of 12 adenocarcinomas, 5 (41.67%) tumors were posit ive for HPV DNA. All five cases were positive for HPV 16, and two (16. 6%) of these were hybridized again to the HPV 18-specific DNA probe. A ll tumors were negative for HPV 6b and 11. In addition, no biopsy spec imens were positive after hybridization with a mixed probe of HPV 31, 33, 35, 39, and 45. These results were compared to those obtained for 30 squamous cell carcinomas of the cervix. Although 20 (66%) were excl usively positive for HPV 16 and 6 (20%), more tumors were of HPV 16 re lated types as detected under nonstringent conditions of hybridization , only one (3%) was positive for HPV 18. The results of in situ hybrid ization were found to be in good agreement with those of Southern blot ting. Conclusions. HPV 16 is the type present almost exclusively in sq uamous cell carcinoma of Indian women. A higher frequency of HPV 16 in adenocarcinoma of Indian women, in contrast to HPV 18, as reported fr om other regions, may be attributed to geographic variation rather tha n to histologic differences only, and both HPV 16 and 18 may be presen t in adenocarcinoma of the uterine cervix.