The Rising Incidence of Early-Onset Colorectal Cancer.

Background: The incidence of early-onset (diagnosis before age 50) colorectal cancer (EOCRC) is increasing in some high-income countries. In this study, we examined the trends in EO-CRC incidence in Germany.

Methods: We obtained data on CRC (ICD-10 C18-C20) incidence from the Centre for Cancer Registry Data (excluding cases reported via death certificate only) and on mortality from the official cause of death statistics for 1999-2018 from registries with sufficient incidence coverage. To assess time trends for persons aged 20-49 we calculated the average annual percent changes (AAPC) and corresponding 95% confidence intervals (95% CI). The incidence analyses were stratified by sex, site (proximal colon, distal colon, rectum), age group (20-29, 30-39, and 40-49) and tumor size (T).

Results: EO-CRC accounted for 5.1% (9529 cases) of all colorectal cancers in the selected German regions. The EO-CRC incidence rose annually by 1.16% (95% CI: [0.51; 1.81]) in men and 1.32% [0.80; 1.84] in women. The incidence of proximal colon cancer increased in both sexes (men: AAPC = 3.26 [2.00; 4.53]; women: AAPC = 2.99 [2.17; 3.83]), while the incidence of distal colon cancer remained unchanged.

Conclusion: The incidence of EO-CRC in Germany is rising. The reasons are probably multifactorial, reflecting the changing prevalence of early life exposure to risk and protective factors.