Arash Etemadi

National Cancer Institute

Research Fellow

PLCO (Learn more about this study)

PLCO-236

Oct 11, 2016

The association between meat and meat-related compounds intake and colorectal cancer incidence

The association between red and processed meat intake with all cancers has been studied in the past. Previous studies have shown an association between dietary intake of red and processed meat and meat mutagens and a number of malignancies such as renal cell carcinoma, bladder, pancreas, colon, prostate, esophagus, liver, and endometrium. These compounds include heme iron, nitrate and nitrites, polycyclic aromatic hydrocarbons (PAHs), and heterocyclic amines (HCAs).
We will use data on meat intake calculated in grams per day based on frequency and portion size information obtained from the DHQ. Total meat intake as well as the categories of meat such as red meat, white meat and processed meat will be used as exposure variables. Data from the CHARRED database has been used to estimate daily intake of meat-mutagens DiMeIQx, 2-amino-3,8-dimethylimidazo[4,5-’]quinozaline (MeIQx), PhIP, B(a)P and an overall meat-mutagenic activity index. Daily intake of heme iron has been computed using a previously developed NCI database based on measurements of heme iron content of a variety of fresh and processed meats, multiplied by the reported DHQ meat consumption. Meat and meat-mutagen exposure variables will be examined both continuously as well as categorically (categorized into quantiles based on the distribution of the entire cohort as well as sex-specific quantiles).
We will use Cox proportional hazards regression to estimate the strength of association between meat intake and colorectal cancer risk. Hazards ratios (HRs) and their 95% confidence intervals will be estimated. Follow-up time will be calculated from the date of receipt of the baseline questionnaire through colorectal cancer diagnosis, death or censoring date, whichever is earlier. The following variables will be assessed as possible confounders: age, BMI, race, smoking history, total energy intake, alcohol intake, total fat intake, total protein intake, total and saturated fat intake, screening history, and physical activity. We To account for the potential effect of duration of follow-up, we will stratify the meat, meat-mutagen intake association by time of follow-up. The analyses will be stratified by cancer site (proximal colon, distal colon, rectum).