Andrew T. Kunzmann

Metabolic Syndrome and the Risk of Breast, Endometrial, and Ovarian Cancer among Postmenopausal Women in the UK Biobank

Abstract Background: There is some evidence that metabolic syndrome (MetS) is associated with postmenopausal breast and gynecologic cancer. However, results from previous studies have been inconsistent and varied by the definition of MetS used. Methods: Using data from the UK Biobank, the association between MetS, according to three definitions, and the risk of breast, endometrial, and ovarian cancer was assessed among postmenopausal women with serologic biomarker data. Cox proportional hazards regression was used to calculate HRs with 95% confidence intervals (CI), adjusting for a range of confounders. Results: In total, 4,791 breast cancers, 820 endometrial cancers, and 582 ovarian cancers were diagnosed. For all definitions, MetS was associated with a higher risk of breast cancer (harmonized definition; HR, 1.11; 95% CI, 1.04–1.19) and endometrial cancer (harmonized definition; HR, 2.18; 95% CI, 1.86–2.55) but not ovarian cancer (harmonized definition; HR, 1.08; 95% CI, 0.88–1.31). Assessment of the individual MetS components revealed that only abdominal obesity was consistently associated with breast cancer, whereas all components were associated with a higher risk of endometrial cancer. Conclusions: In this cohort, MetS and all MetS components were individually associated with a higher risk of endometrial cancer, but only abdominal obesity was consistently associated with an increased risk of breast cancer. No associations were observed between MetS and ovarian cancer risk. Impact: These findings underline the need for further mechanistic research to clarify potential causal relationships and to better inform public health strategies to address the increasing obesity-related cancer burden, particularly endometrial cancer in postmenopausal women.

Weight Change and Incident Distal Colorectal Adenoma Risk in the PLCO Cancer Screening Trial

Abstract Background Although obesity is a known risk factor, the impact of weight change on colorectal adenoma risk is less clear and could have important implications in disease prevention. We prospectively evaluated weight change in adulthood and incident colorectal adenoma. Methods We assessed weight change during early-late (age 20 years to baseline, ie, ages 55-74 years), early-middle (20-50 years), and middle-late (50 years-baseline) adulthood using self-reported weight data in relation to incident distal adenoma in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (cases = 1053; controls = 16 576). For each period, we defined stable weight as greater than −0.5 kg to less than or equal to 1 kg/5 years, weight loss as less than or equal to −0.5 kg/5 years, and weight gain as greater than 1-2, greater than 2-3, or greater than 3 kg/5 years. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression; all tests were 2-sided. Results Compared with stable weight, weight loss during early-late adulthood was associated with reduced adenoma risk (OR = 0.54, 95% CI = 0.34 to 0.86), particularly among those who were overweight or obese at age 20 years (OR = 0.39, 95% CI = 0.18 to 0.84). Results were similar for early-middle adulthood but less pronounced for middle-late adulthood. Weight gain greater than 3 kg/5 years during early-late adulthood was associated with increased risk (OR = 1.30, 95% CI = 1.07 to 1.58, Ptrend < .001). Findings appeared stronger among men (OR for >3 kg/5 years = 1.41, 95% CI = 1.11 to 1.80) than women (OR = 1.09, 95% CI = 0.79 to 1.50, Pinteraction = .21). Conclusions Weight loss in adulthood was associated with reduced adenoma risk, particularly for those who were overweight or obese, whereas weight gain greater than 3 kg/5 years increased risk. Findings underscore the importance of healthy weight maintenance throughout adulthood in preventing colorectal adenoma.