Bhaumik Brahmbhatt

MBBS

Mayo Clinic

Senior Associate consultant

PLCO (Learn more about this study)

PLCO-593

Mar 16, 2020

Association of colorectal polyps with dietary inflammation during screening colonoscopy in Men and Women

Colorectal cancer is the third most commonly diagnosed cancer in both men and women in the United States. Colorectal cancer arises from colonic polyps. The major types of colonic polyps associated with colorectal cancer development are adenomatous (tubular, villous, and tubulovillous) and serrated (hyperplastic, sessile or traditional) polyps with varying degrees of dysplasia. There is evidence that colonic inflammation plays a major role in colon polyp and colorectal cancer development. However, the use of anti-inflammatory agents for the prevention of colonic polyps and colorectal cancer is controversial, although there is some suggestion that its use may lower colorectal cancer risk.

Accumulating evidence have shown diet affect cytokine levels and inflammation. Diet rich in trans-fat and sugar is associated with increased circulating levels of pro-inflammatory cytokines IL-6 and TNFα . Recently, the Empirical Dietary Inflammatory Index (EDII) was developed and validated to assess inflammatory potential of diet based on the Food Frequency Questionnaire (FFQ). Here we propose to investigate the association between diet-derived inflammation, as measured by the EDII, and the risk of colon polyp and colorectal cancer formation during screening or surveillance colonoscopy . Previous studies from the PLCO (Prostate, lung, Colorectal and Ovarian) cancer database showed increased risk of colorectal cancer who had advanced adenoma at diagnostic colonoscopy. Higher inflammatory scores, reflecting greater inflammatory potential of diet, were associated with increased incidence of colorectal cancer. Previous studies using Nurses health study and Health Professionals Follow-up study also showed that pro-inflammatory diet patterns is associated with a higher risk of colorectal cancer by 32% (pooled hazard ration [HR], 1.32; 95% CI, 1.12-1.55;P < .001). Data on energy-adjusted dietary inflammatory index developed based on FFQ responses are available in the PLCO database and has been studies in relation to pancreatic cancer risk in the PLCO population. The relationship of dietary inflammatory index scores risk of colonic polyps is unknown. Furthermore, the association between dietary inflammatory index score and colorectal cancer risk is not clear. Dietary inflammation has been proven to cause increase in incidence of colorectal cancer, this study will give more knowledge about dietary inflammation and colon polyps and if proven which prevent colorectal cancer and propose to address these gaps in knowledge with the following aims and hypothesis.

Methods: We propose to use data from the PLCO study population. The presence of colon polyps with subsequent colonoscopy are determined also will be derived from the PLCO database. We will obtained the energy-adjusted DII scores from the PLCO database then determine its relationship with incidence of colon polyps or colorectal cancer. The DII scores will be categorized into quantiles with the lowest quantiles as the reference and assess also as a continuous variable. The energy-adjusted DII scores will be calculated using the FFQ-derived dietary nutrients.

Statistical Analysis:
Descriptive statistics at baseline will be assess using Students’ t-test for continuous variables and χ2 tests for categorical variables. Multivariable adjusted Cox proportional hazard models will be used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).