Associations Between Pre- and Post-Diagnosis Dietary Inflammatory Patterns and Ovarian Cancer Survival: Results From the Ovarian Cancer Follow-Up Study.

Background: Dietary factors impact systemic inflammation, which not only correlates with poorer outcomes in patients with ovarian cancer (OC), but also promotes cancer development through increased cell division, genetic alterations, and malignant transformation of epithelial cells at inflammatory sites. However, evidence between dietary inflammatory patterns and OC survival remains sparse.

Objective: The aim of this study was to examine associations between pre- and post-diagnosis dietary inflammatory patterns, including their changes, and overall survival (OS).

Design: This study analyzed data from the hospital-based prospective, longitudinal cohort study: the Ovarian Cancer Follow-Up Study. Dietary intake information was collected at baseline (pre-diagnosis) and 12 months after diagnosis (post-diagnosis) using a 111-item food frequency questionnaire. Three inflammatory dietary scores were analyzed: dietary inflammatory index (DII), inflammatory score of the diet (ISD), and empirical dietary inflammatory pattern. The dietary inflammatory scores were calculated for each person and categorized in tertiles.

Participants/setting: Participants included 560 patients aged 18 through 79 years, who were newly diagnosed with OC, recruited at the Shengjing Hospital of China Medical University between 2015 and 2022.

Main outcome measures: OS time was defined as the interval between the histologic diagnosis of OC and the date of death from any cause or the date of last follow-up (February 16, 2023) for patients who were still alive.

Statistical analyses performed: Differences in general and clinical characteristics according to the tertile of inflammatory dietary pattern scores were assessed using χ² test for categorical variables and Student t test or Kruskal-Wallis test for continuous variables. Cox proportion hazard models were used to calculate hazard ratios (HRs) and 95% CIs for the associations of the pre- and post-diagnosis inflammatory dietary patterns with OS.

Results: High pre-diagnosis DII, ISD, and empirical dietary inflammatory pattern scores were associated with worse OS (HR_{tertile3vs tertile1} 1.84; 95% CI 1.12 to 3.01; HR_{tertile3vs tertile1} 1.70; 95% CI 1.04 to 2.79; and HR_{tertile3vs tertile1} 1.64; 95% CI 1.14 to 2.35, respectively). High post-diagnosis DII and ISD scores were related to worse OS (HR_{tertile3vs tertile1} 2.71; 95% CI 1.15 to 6.40 and HR_{tertile3vs tertile1} 2.84; 95% CI 1.25 to 6.49). Compared with those who maintained stable scores (change ± 20%), patients whose DII or ISD scores increased (>20%) from pre- to post-diagnosis had worse OS (DII: HR 2.00; 95% CI 1.30 to 3.08; ISD: HR 1.56; 95% CI 1.10 to 2.21), whereas patients whose empirical dietary inflammatory pattern score decreased (>20%) had better OS (HR 0.67; 95% CI 0.45 to 0.99). Moreover, compared with persistently low scores, patients who changed from low pre-diagnosis to high post-diagnosis scores had worse OS (DII: HR 2.47; 95% CI 1.54 to 3.94; ISD: HR 2.88; 95% CI 1.81-4.57).

Conclusions: Pre- and post-diagnosis adherence to inflammatory dietary patterns was associated with poor OC survival.