Hormonal factors in vulvar cancer. A case-control study.

As part of a case-control study of vulvar cancer, we examined the role of reproductive history, menstrual history, exogenous estrogen use and body mass in the etiology of this disease. A total of 330 women with vulvar squamous cell cancer (259 in situ, 81 invasive), aged 18-79 years, who were diagnosed with this tumor during 1980-1990 were interviewed. Their responses were compared to those of 1,010 women who were selected from the general population by means of random digit dialing. Cases and controls did not differ regarding age at menopause, parity, number of prior pregnancies or number of prior births, history of miscarriage or use of noncontraceptive estrogens. Women diagnosed with vulvar cancer were slightly more likely to have experienced menarche at < 12 years (odds ratio [OR] = 1.8, 95% confidence interval [CI] = 1.2-2.7, in situ cancer; OR = 1.6, 95% CI = 0.8-3.1, invasive cancer), to have excess weight (invasive cancer only, OR = 2.9, 95% CI = 1.5-5.8 for highest tertile of Quetelet's index) and, among gravid women, to have had their first pregnancy after age 24 (in situ cancer only, OR = 1.5, 95% CI = 0.9-2.5). These data, together with similar results from previous studies and quantitative studies of hormone receptors in vulvar tissue, suggest that in situ and invasive vulvar cancer are not strongly hormone dependent tumors.