Hysterectomy, oophorectomy, and risk of renal cell Carcinoma

Background: Female hormones may play roles during renal cell carcinoma (RCC) carcinogenesis. The aims of this study were to investigate associations between hysterectomy, oophorectomy, and risk of RCC and to assess whether the associations were modified by exogenous estrogen, commonly used among women who have undergone hysterectomy. Methods: Postmenopausal women (n ¼ 144,599) ages 50–79 years at enrollment (1993–1998) in the Women's Health Initiative were followed for a mean of 15.9 years. Hysterectomy and oophorectomy were self-reported. Incident RCC cases were confirmed by physician review of medical records and pathology reports. Multivariable Cox proportional hazards modeling was used to estimate hazard ratios (HR) and 95% confidence intervals (CI), adjusting for potential confounders. Results: A total of 583 women developed RCC during follow-up. We observed that hysterectomy, regardless of oophorectomy status, was significantly associated with an increased risk of RCC (HR, 1.28; 95% CI, 1.03–1.60). The association appeared to be more pronounced in women with age at hysterectomy younger than 40 years (HR, 1.34; 95% CI, 1.01–1.80) or older than 55 years (HR, 1.52; 95% CI, 1.01–2.29). Oophorectomy was not significantly associated with risk of RCC. There was no evidence that exogenous estrogen use modified the association between hysterectomy and risk of RCC. Conclusions: In this large prospective study, we showed that women with a history of hysterectomy had 28% increased risk of RCC, and this finding was not modified by exogenous hormone use. Impact: If our findings are confirmed, women should be made aware of increased risk of RCC when considering hysterectomy.