Colon to Rectum
Aliment Pharmacol Ther. 2022;55(4):412–21
Long-term colorectal cancer incidence and mortality after adenoma removal in women and men
Background: Women and men with colorectal adenomas are at increased risk of colorectal cancer (CRC) and colonoscopic surveillance is recommended. However, the long-term cancer risk remains unknown.
Aims: To investigate CRC incidence and mortality after adenoma removal in women and men
Methods: The authors identified all individuals who had adenomas removed in Norway from 1993 to 2007, with follow-up through 2018. They calculated standardized incidence ratios (SIRs) and incidence-based mortality ratios (SMRs) with 95% confidence intervals (CIs) for CRC in women and men using the female and male population for comparison, and defined high-risk adenomas as ≥ 2 adenomas, villous component, or high-grade dysplasia.
Results: The cohort comprised 40,293 individuals. During median follow-up of 13.0 years, 1079 women (5.5%) and 866 men (4.2%) developed CRC; 328 women (1.7%) and 275 men (1.3%) died of CRC. CRC incidence was more increased in women (SIR = 1.64, 95% CI: 1.54–1.74) than in men (SIR = 1.12, 95% CI: 1.05–1.19). CRC mortality was increased in women (SMR = 1.13, 95% CI: 1.02–1.26) and reduced in men (SMR = 0.79, 95% CI: 0.71–0.89). Women with high-risk adenomas had an increased risk of CRC death (SMR = 1.37, 95% CI: 1.19–1.57); women with low-risk adenomas (SMR = 0.90, 95% CI: 0.76–1.07) and men with high-risk adenomas had a similar risk (SMR = 0.89, 95% CI: 0.76–1.04), while men with low-risk adenomas had a reduced risk (SMR = 0.70, 95% CI: 0.59–0.84).
Conclusions: After adenoma removal, women had an increased risk of colorectal cancer death, while men had a reduced risk, compared to the general female and male populations. Sex-specific surveillance recommendations after adenoma removal should be considered.