Obesity and Age at Diagnosis of Endometrial Cancer

OBJECTIVE: Obesity is an established risk factor for development of endometrial cancer. We hypothesized that obesity might also be associated with an earlier age at endometrial cancer diagnosis, because mechanisms that drive the obesity-endometrial cancer association might also accelerate tumorigenesis. METHODS: A retrospective chart review was conducted of all cases of endometrial cancer diagnosed from 1999 to 2009 at a large medical center in New York City. The association of body mass index (BMI) with age at endometrial cancer diagnosis, comorbidities, stage, grade, and radiation treatment was examined using analysis of variance and linear regression. Overall survival by BMI category was assessed using Kaplan-Meier method and the log-rank test. RESULTS: A total of 985 cases of endometrial cancer were identified. The mean age at endometrial cancer diagnosis was 67.1 years (+/- 11.9 standard deviation) in women with a normal BMI, whereas it was 56.3 years (+/- 10.3 standard deviation) in women with a BMI greater than 50. Age at diagnosis of endometrioid-type cancer decreased linearly with increasing BMI (y=67.89-1.86x, R-2=0.049, P<.001). This association persisted after multivariable adjustment (R-2=0.181, P=.02). A linear association between BMI and age of nonendometrioid cancers was not found (P=.12). There were no differences in overall survival by BMI category. CONCLUSIONS: Obesity is associated with earlier age at diagnosis of endometrioid-type endometrial cancers. Similar associations were not, however, observed with nonendometrioid cancers, consistent with different pathways of tumorigenesis.