Case–Control Study of the Metabolic Syndrome and Metabolic Risk Factors for Endometrial Cancer

BACKGROUND: Metabolic syndrome may predict endometrial cancer risk better than diabetes, hypertension, dyslipidemia, dysglycemia, or weight alone, but few studies have examined this issue. METHODS: We conducted a population-based case-control study in Alberta, Canada (2002-2006) that included 515 incident endometrial cancer cases and 962 frequency age-matched controls. Data were collected through in-person interviews, anthropometric measurements, and 8-hour fasting bloods drawn either pre- or postsurgery. Bloods were analyzed using quantitative colorimetric or absorbance-based assays (ELISA), specific to metabolic syndrome markers. Metabolic syndrome was defined using harmonized guidelines requiring presence of ≥ 3 of the following risk factors: waist circumference ≥ 88 cm, triglycerides ≥ 150 mg/dL, high-density lipoprotein cholesterol <50 mg/dL, treatment of previously diagnosed hypertension, and fasting blood glucose ≥ 100 mg/dL. OR and 95% CIs for endometrial cancer risk with presence of metabolic syndrome and individual metabolic syndrome components were estimated using logistic regression analysis. RESULTS: Metabolic syndrome was significantly more prevalent among cases (62%) than controls (38%). A statistically significant increased risk for endometrial cancer was observed for metabolic syndrome (OR = 1.53; 95% CI: 1.17-2.00), as well as for some of the individual components of metabolic syndrome including waist circumference ≥ 88 cm (OR = 1.57; 95% CI: 1.18-2.08), hypertension (OR = 1.57; 95% CI: 1.18-2.09), and fasting blood glucose ≥ 100 mg/dL (OR = 1.31; 95% CI: 1.03-1.67). Some evidence for effect modification by menopausal status and body mass index was also found. CONCLUSION: Metabolic syndrome is clearly associated with increased endometrial cancer risk. IMPACT: Targeting the entire metabolic syndrome may optimize endometrial cancer risk reduction.