Effect of dietary inflammatory index on the risk for cancer recurrence and mortality in Korean women with breast cancer

Abstract

Dietary inflammatory index (DII), a new tool for assessing the inflammatory potential of the diet has been shown to be associated with breast cancer incidence and survival. However, the association between DII and cancer recurrence and mortality has not been studied in breast cancer patients. Therefore, the present study investigated the hypothesis that DII was positively associated with risk for cancer recurrence and overall mortality among breast cancer patients. Women who underwent breast cancer surgery were recruited consecutively from June 2000 to August 2017. Among 511 patients included in the study, there were 88 patients with cancer recurrence and 44 patients were died during follow–up. Dietary intake was estimated using the 24-hour recall, and DII score was calculated using 34 foods/nutrients. The DII was significantly higher in patients with than without recurrence of cancer, and positively associated with risk for cancer recurrence (T3 vs. T1 = 2.347; 95% CI = 1.17, 4.71) and overall mortality (T3 vs. T1 = 3.049; 95% CI = 1.08, 8.83) after adjusting for confounding factors. Disease-free survival and overall survival were significantly lower in patients with the higher than lower DII scores. In addition, the DII was positively associated with risk for cancer recurrence according to prognostic factors, such as <50 years old, premenopausal status, BMI ≥25 kg/m2, HR+, tumor size >2 cm and presence of lymph node metastasis. The present study suggested that anti-inflammatory diets could decrease the risk of cancer recurrence and overall mortality in breast cancer patients, particularly with younger age, premenopausal status, obesity, HR+, tumor size >2 cm and presence of lymph node metastasis.