Background: Site-specific cancer frequencies and incidence rates are reported regularly by the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program, but not by histologic type within site. This report reviews data for 160,977 histologically or cytologically confirmed invasive and in situ cancers of the female genital tract.
Methods: Data were supplied by the SEER program for histologically confirmed cases of uterine corpus, uterine cervix, ovary, vulva, vagina, fallopian tube, and placental cancers diagnosed between 1973 and 1987. Histologic types were reviewed for race, age at diagnosis, incidence, stage, and survival.
Results: There were 89,943 invasive and 71,034 in situ neoplasms. Squamous carcinoma was the most common invasive malignancy of the cervix (77.1%), vulva (74.4%), and vagina (70.8%). Adenocarcinoma was the most frequent malignancy in the uterine corpus (81.5%) and ovary (86.6%), with these percentages reaching 91.6% for corpus and 86.9% for ovary if adenosquamous carcinoma and adenocarcinoma with squamous metaplasia are included. Cervical carcinoma in situ accounted for 91.0% of all in situ cancers. In situ cancers made up 78.5% of all cervical cancers, 35.1% of vaginal cancers, and 50.4% of vulvar cancers.
Conclusions: There are dominant histologic groups in each female genital tract site that are largely responsible for incidence and survival statistics. Within the groups, however, there are subtypes with differing features. Epidemiologic studies may provide more definite information by considering the effect of these subtypes in examining risk factors.