Associations of dietary patterns with kidney cancer risk, kidney cancer-specific mortality and all-cause mortality among postmenopausal women.

BACKGROUND: The empirical dietary index for hyperinsulinemia (EDIH) and empirical dietary inflammatory pattern (EDIP) are novel measures of dietary quality associated with insulin hypersecretion or chronic inflammation, respectively, whereas the Healthy Eating Index (HEI-2015) measures adherence to the Dietary Guidelines for Americans (DGA). We evaluated associations of EDIH, EDIP and HEI-2015 on the risk of both kidney cancer development and mortality. METHODS: We calculated the dietary scores from baseline food frequency questionnaires among 115,830 participants aged 50-79 years in the Women's Health Initiative. Multivariable-adjusted Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (95%CI) for kidney cancer risk, kidney cancer-specific mortality and all-cause mortality, per 1-standard deviation increment in dietary pattern scores. RESULTS: Higher EDIH was associated with greater risk of kidney cancer development [HR, 1.12; 95%CI, (1.01,1.23)], kidney cancer-specific death [1.22(0.99,1.48)], and all-cause mortality, [1.05(1.02,1.08)]. Higher HEI-2015 was associated with lower risk of kidney cancer development, [0.85(0.77, 0.94)], kidney cancer-specific death, [0.84(0.69,1.03)] and all-cause mortality, [0.97(0.95,1.00)]. However, EDIP was not significantly associated with outcomes. Associations did not differ by BMI categories. CONCLUSIONS: Low-insulinemic dietary patterns and higher quality diets, are worthy of testing in dietary pattern intervention trials for kidney cancer prevention and improved survivorship.

Associations of Dietary Patterns with Colorectal Adenomas in the Prostate, Lung, Colorectal, and Ovarian Cancer Cohort.

BACKGROUND: Most colorectal cancers arise from adenomas, and although insulinemic and inflammatory dietary patterns have been associated with colorectal cancer risk, these dietary patterns have not been studied in relation to adenoma risk. METHODS: Using data from 21,192 participants in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer screening cohort, we calculated the Empirical Dietary Index for Hyperinsulinemia (EDIH), Empirical Dietary Inflammatory Pattern (EDIP), and overall dietary quality measured via the Healthy Eating Index (HEI-2015), from food frequency questionnaires (FFQ). In multivariable-adjusted logistic regression, we investigated associations of these dietary indices with adenoma (any adenoma, advanced adenoma, n = 19,493) and recurrent adenoma (n = 1,699). RESULTS: EDIH was not associated with adenoma or advanced adenoma but was marginally associated with recurrent adenoma. The OR (95% CI) comparing highest (lowest insulinemic) versus lowest (most hyperinsulinemic) quintiles was 0.76 (0.55-1.05) after multivariable adjustment including BMI. EDIP and HEI-2015 were not associated with any of the three outcomes. CONCLUSIONS: In the PLCO cohort, we did not observe substantial associations between dietary patterns and risk of colorectal adenomas. IMPACT: Pending confirmation in larger prospective studies, our findings suggest that these dietary patterns may not substantially affect colorectal cancer risk via the adenoma-carcinoma sequence.