To what extent is male excess risk of advanced colorectal neoplasms explained by known risk factors? Results from a large German screening population. Issue 11 (31st July 2021)

• Record Type: Journal Article
• Authors: Niedermaier, Tobias; Heisser, Thomas; Gies, Anton; Guo, Feng; Amitay, Efrat L.; Hoffmeister, Michael; Brenner, Hermann
• Is Part Of: International journal of cancer. Volume 149:Issue 11(2021)
• Page Start: 1877
• Page End: 1886
• Publication Date: 2021-07-31
• Subjects: colorectal neoplasia -- distal colon -- male sex -- prevalence -- proximal colon; Cancer -- Periodicals; Cancer -- Prevention -- Periodicals; 616.994
• DOI: 10.1002/ijc.33742
• Languages: English
• ISSNs: 0020-7136

Abstract

Abstract: Colorectal cancer (CRC) incidence and prevalence of its precursors are substantially higher among males than among females in most countries but the reasons for the male excess risk are incompletely understood. We aimed to assess to what extent it is explained by known risk factors. Prevalence of advanced neoplasia (AN, ie, CRC or advanced adenoma) and CRC risk and preventive factors were ascertained among 15 985 participants of screening colonoscopy aged 55‐79 years in Germany. Logistic regression was used to calculate odds ratios (ORs) for the association between male sex and AN with and without adjustment for known risk and preventive factors. In age‐adjusted comparisons, men had 2‐fold increased risk for AN compared to women (OR = 1.98, 95% confidence interval [CI] 1.79‐2.19). After comprehensive adjustment for medical, lifestyle and dietary factors, the OR was reduced to 1.52 (95% CI 1.30‐1.77), suggesting that these factors accounted for 47% of male excess risk. Male excess risk increased from proximal colon to distal colon and rectum, with age‐adjusted ORs (95% CI) of 1.63 (1.38‐1.91), 2.13 (1.85‐2.45) and 2.36 (1.95‐2.85), respectively, and with the proportion of excess risk explained by covariates being lower for AN in the rectum (26%) than for AN in the proximal (52%) or distal colon (46%). Male excess risk was somewhat lower (age‐adjusted OR 1.87) and explained excess risk was smaller (36%) when men were compared to women who never used hormone replacement therapy. In conclusion, most of the male excess risk and the potential to overcome it remain to be explored by further research. Abstract : What's new? The prevalence of precursor lesions for colorectal cancer (CRC), advanced colorectal neoplasia (AN) is higher among males than females. Whether this difference is explained by variations in certain risk factors remains unclear. In this study, the authors found that male excess risk of AN was twice as high in men than women. About half of excess CRC risk among males could be attributed to medical, lifestyle, and dietary factors. Proportions of explained excess risk increased from the rectum to the distal and proximal colon. The findings warrant further investigation of factors contributing to AN and CRC risk in males.