Sex difference in alcohol consumption associated with colorectal cancer risk in Quzhou, China: A nested case-control study

Objective: Colorectal cancer (CRC) incidence has been increasing worldwide over time. This study investigated whether drinking was associated with CRC risk. Methods: We designed a case-control study nested in a mass CRC screening program in Quzhou, China. Cases were newly diagnosed CRC in 2020-2022. Controls were randomly sampled using frequency match. Drinking variables included drinking status, frequency, duration, and others. Logistic regressions were used to estimate odds ratio (OR) and 95 % confidence interval (CI). Results: The crude OR (cOR) (95 % CI) of drinking between 153 cases and 650 controls was 1.46 (0.99, 2.16) in current drinkers, 3.31 (1.44, 7.60) in former drinkers, 1.82 (1.21, 2.74) in drinking 6-7 days/week, and 3.48 (1.29, 9.37) in drinking 1-19 years. Stratifying by sex, all drinking variables in women but not all in men were consistently associated with CRC risk. The adjusted OR (aOR) (95 % CI) was 1.01 (0.59, 1.74) in current drinking men, 2.27 (0.78, 6.64) in former drinking men, and 4.24 (1.61, 11.13) in current drinking women. The aOR (95 % CI) of drinking whisky was 0.19 (0.04, 0.83), 1.89 (0.86, 4.17), 2.25 (1.05, 4.83), and 1.82 (0.85, 3.92) in men drinking <= 0.5, >0.5-<= 1.0, >1.0-<= 1.5, and >1.5 Liter/week (P-trend = 0.011), and 3.80 (1.03, 14.00) and 9.92 (2.01, 49.00) in women drinking <= 0.5 and >0.5 Liter/week (P-trend = 0.001), respectively. Conclusions: There was sex difference in drinking associated with increased risk of CRC which association was stronger in women than that in men. Men's association between drinking whisky and CRC risk was J-shaped.