2025-08-14 カロリンスカ研究所(KI)
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<関連情報>
- https://news.ki.se/rising-colorectal-cancer-among-young-adults-in-sweden
- https://www.sciencedirect.com/science/article/pii/S0923753425009202
早期発症大腸がんの発生傾向と長期生存率:スウェーデン全国規模の研究 Incidence Trends and Long-Term Survival in Early-Onset Colorectal Cancer: A Nationwide Swedish Study
Shabane Barot, Annelie Liljegren, Caroline Nordenvall, Johannes Blom, Cecilia Radkiewicz
Annals of Oncology Available online: 13 August 2025
DOI:https://doi.org/10.1016/j.annonc.2025.07.019
ABSTRACT
Background
Early-onset colorectal cancer (EOCRC, diagnosis before age 50) is increasing globally. However, survival comparisons with late-onset colorectal cancer (CRC) are inconsistent, and long-term excess mortality remains poorly understood. This Swedish population-based study aimed to evaluate trends in incidence, survival, and long-term excess mortality in early- versus late-onset CRC.
Materials and methods
We identified all incident colorectal adenocarcinomas recorded in the Swedish National Cancer Register from 1993 to 2019. Incidence trends were quantified using annual percentage changes (APCs) and relative survival differences were assessed using excess mortality rate ratios (EMRRs), both from Poisson regression models with 95% confidence intervals (CIs).
Results
A total of 47,864 right-sided colon, 40,664 left-sided colon and 47,082 rectal cancer cases were included. EOCRC patients were more frequently diagnosed with metastatic disease, compared to late-onset CRC. EOCRC incidence increased across all subsites, with APCs ranging from 2.04 (95% CI 1.51-2.56) for rectal to 2.64 (95% CI 2.02-2.37) for right-sided colon cancer, while an increase among late-onset cases was observed only for right-sided colon cancer. Crude 5-year relative survival was similar across age groups, but after full adjustment (including metastatic stage), EOCRC was associated with better survival, with EMRRs ranging from 0.76 (95% CI 0.68-0.84) for rectal cancer to 0.83 (95% CI 0.74-0.92) for right-sided colon cancer. Notably, excess mortality remained elevated 5-10 years post-diagnosis in both age groups.
Conclusions
EOCRC incidence is increasing in Sweden, aligning with global trends. Although younger patients were more often diagnosed at an advanced stage of disease, they had similar crude survival and better stage-adjusted survival, compared to older patients. The persistent long-term excess morality in both groups, even during periods when CRC patients are typically considered statistically cured, highlights the need for extended follow-up and tailored survivorship care.
