Diet-Driven Inflammation and Insulinemia and Risk of Interval Breast Cancer

Association between Inflammatory Dietary Pattern and Mammographic Features

BACKGROUND

The empirical dietary inflammation pattern score (EDIP), which measures the ability of the diet to regulate chronic inflammation, is associated with both higher adiposity and breast cancer (BC) risk. Mammographic density (MD) is an important risk factor for BC.

OBJECTIVE

We examined the associations between EDIP and mammographic features overall and stratified by menopausal status, and assessed the extent to which these associations are mediated by adiposity.

METHODS

We included 4145 participants without BC in the Nurses' Health Study (NHS) and NHSII. Cumulative average EDIP was assessed by food frequency questionnaires every 4-6 y. We assessed MD parameters (percent MD, dense area, and nondense area) and V (measure of grayscale variation). MD parameters were square-root transformed. Multivariable-adjusted linear regression models were used to analyze the associations between EDIP score and MD parameters. Baron and Kenny's regression method was used to assess the extent to which the associations of EDIP and mammographic traits were mediated by BMI.

RESULTS

In multivariable-adjusted models, EDIP was significantly inversely associated with percent MD [top compared with bottom quartile, β = -0.57; 95% confidence interval (CI): -0.78, -0.36]. Additional adjustment for BMI attenuated the association (β = -0.15; 95% CI: -0.34, 0.03), with 68% (β = 0.68, 20; 95% CI: 0.54, 0.86) mediation via BMI. In addition, EDIP was positively associated with nondense area after adjusting for BMI and other covariates. No associations were observed for dense area and V measure. Results were similar when stratified by menopausal status.

CONCLUSIONS

EDIP score was inversely associated with percent MD and positively associated with nondense area, and these associations were largely mediated by BMI.

Empirical dietary inflammatory pattern could increase the odds of breast cancer: a case-control study

BACKGROUND

It has been shown that chronic inflammation is a significant factor in cancer development and progression. The current study aimed to investigate whether a higher score on the empirical dietary inflammatory pattern (EDIP), which indicates a more pro-inflammatory diet, is related to higher odds of breast cancer in Iranian women.

METHODS

In the present case-control study, subjects in the case (n = 133) and control (n = 265) groups were chosen from the hospitals in Tehran, Iran. The cases consisted of women with newly diagnosed breast cancer, while the controls were selected from other parts of the same hospital and had no history of cancer or hormone therapy. Individuals whose reported energy intake deviated by three standard deviations above or below the mean energy intake of the population were excluded from the study. A reliable and valid semi-quantitative food frequency questionnaire was used to determine the participants' dietary intake. Additionally, the association between breast cancer and EDIP was evaluated by logistic regression analysis in both crude and adjusted models.

RESULTS

The median scores of EDIP in the case and control groups were 0.65 and 0.61, respectively. The findings also indicated that, in the adjusted model, the odds of developing breast cancer significantly increased in the last tertile of EDIP compared to the first tertile (odds ratio (OR) = 1.859; 95% confidence interval (CI): 1.059-3.265; P = 0.031). Additionally, after adjusting for potential confounders, higher odds of breast cancer were observed in the last tertile of EDIP compared to the first tertile in postmenopausal women (OR = 2.516; 95% CI: 1.081-5.856; P = 0.033).

CONCLUSIONS

The current study indicated that individuals with a higher pro-inflammatory diet score were more likely to develop breast cancer.

Body Mass Index Is Inversely Associated with Risk of Postmenopausal Interval Breast Cancer: Results from the Women's Health Initiative

Interval breast cancer refers to cancer diagnosed after a negative screening mammogram and before the next scheduled screening mammogram. Interval breast cancer has worse prognosis than screening-detected cancer. Body mass index (BMI) influences the accuracy of mammography and overall postmenopausal breast cancer risk, yet how is obesity associated with postmenopausal interval breast cancer incidence is unclear. The current study included cancer-free postmenopausal women aged 50-79 years at enrollment in the Women's Health Initiative who were diagnosed with breast cancer during follow-up. Analyses include 324 interval breast cancer cases diagnosed within one year after the participant's last negative screening mammogram and 1969 screening-detected breast cancer patients. Obesity (BMI ≥ 30 kg/m2) was measured at baseline. Associations between obesity and incidence of interval cancer were determined by sequential logistic regression analyses. In multivariable-adjusted models, obesity was inversely associated with interval breast cancer risk [OR (95% CI) = 0.65 (0.46, 0.92)]. The inverse association persisted after excluding women diagnosed within 2 years [OR (95% CI) = 0.60 (0.42, 0.87)] or 4 years [OR (95% CI) = 0.56 (0.37, 0.86)] of enrollment, suggesting consistency of the association regardless of screening practices prior to trial entry. These findings warrant confirmation in studies with body composition measures.