Dietary inflammatory index, risk and survival among women with endometrial cancer

Purpose Chronic inflammation has been implicated in endometrial carcinogenesis yet the impact of potentially modifiable exposures that might affect inflammation, like diet, has been understudied. This study examined the association between the dietary inflammatory index (DII (R)), a literature-derived tool to assess the inflammatory potential of diet, and risk of developing, and survival after a diagnosis of endometrial cancer (EC). Methods This study included data from 1,287 women with EC and 1,435 population controls who participated in the Australian National Endometrial Cancer Study. Energy-adjusted DII (E-DII) scores were calculated from pre-diagnostic dietary intake obtained using a semi-quantitative food frequency questionnaire. Logistic regression was used to assess the association between E-DII scores and risk of EC and proportional-hazards models were used for survival analyses. Results Higher E-DII scores, reflecting a more pro-inflammatory diet, were not associated with risk of EC [adjusted odds ratio (OR) 0.98, 95% CI 0.77-1.24, p-trend = 0.7]. However, in stratified analyses, higher E-DII scores were associated with increased risk of EC among very obese (BMI 35 + kg/m(2)) women (OR 1.60, 95% CI 0.80-3.21, p-trend = 0.049, p-interaction = 0.045). After a median follow-up of 7.2 years there were 160 deaths, of which 110 (69%) were from EC. We found no association between E-DII score and survival. Conclusion Greater inflammatory potential of pre-diagnostic diet was not associated with EC risk or survival. Secondary stratified analysis suggested greater inflammatory potential may be associated with EC risk in very obese women.