Body mass index in early adulthood and endometrial cancer risk for mismatch repair gene mutation carriers

Win AK, Dowty JG, Antill YC, English DR, Baron JA, Young JP, Giles GG, Southey MC, Winship I, Lipton L, Parry S, Thibodeau SN, Haile RW, Gallinger S, Le Marchand L, Lindor NM, Newcomb PA, Hopper JL, Jenkins MA (2011) Body mass index in early adulthood and endometrial cancer risk for mismatch repair gene mutation carriers. Obstet Gynecol 117:899-905

OBJECTIVE: To investigate the association of body mass index (BMI) in early adulthood and endometrial cancer risk for carriers of a germline mutation in a DNA mismatch repair gene. METHODS: We estimated the association between BMI at age 18-20 years and endometrial cancer risk for mismatch repair gene mutation carriers and, as a comparison group, noncarriers using 601 female carriers of a germline mutation in a mismatch repair gene (245 MLH1, 299 MSH2, 38 MSH6, and 19 PMS2) and 533 female noncarriers from the Colon Cancer Family Registry using a weighted Cox proportional hazards regression. RESULTS: During 51,693 person-years of observation, we observed diagnoses of endometrial cancer for 126 carriers and eight noncarriers. For carriers, there was no evidence of an association between BMI at age 20 years and endometrial cancer (adjusted hazard ratio 0.73 per 5 kg/m(2); 95% confidence interval [CI], 0.40-1.34; P=.31). For noncarriers, endometrial cancer risk increased by 74% for each 5-kg/m(2) increment in BMI (adjusted hazard ratio 1.74; 95% CI 1.27-2.37; P<.001). the="" hazard="" ratio="" for="" bmi="" and="" endometrial="" cancer="" for="" noncarriers="" was="" greater="" than="" for="" carriers="" (p=".04)." conclusion:="" the="" effect="" of="" body="" mass="" on="" endometrial="" cancer="" risk="" depends="" on="" the="" woman's="" mismatch="" repair="" gene="" mutation="" carrier="" status,="" suggesting="" obesity-independent="" endometrial="" carcinogenesis="" for="" carriers.="" level="" of="" evidence:="">