Jennifer C. Molokwu, Anna Prizment, Aaron R. Folsom
Date of Defense:
Kidney (renal cell) cancer accounts for approximately 3-4% of all new cases of primary cancer diagnosed in the United States. A relationship between kidney cancer and female reproductive factors has been hypothesized but supporting evidence is inconsistent. We measured risk factors for kidney cancer and reproductive characteristics in a group of 37,440 post menopausal women in Iowa. From 1986 to 2003, 165 cases of incident kidney cancer were identified through a statewide cancer registry. After adjustment for age and other risk factors, past use of estrogen showed an increased risk of renal cancer (RR 1.56; 95% CI 1.13-2.17) when compared to no use. Women with no live birth (RR 1.91, p=0.02) and women with 3-4 live births (RR 1.62, p=0.02) also had an increased risk of kidney cancer when compared with women who had 1-2 live births. There was also a lower risk of kidney cancer with greater lifetime duration of ovulation. In conclusion, greater exposure to estrogen may increase the risk for kidney cancer.