The burden and histopathological characteristics of early-onset colorectal cancer: a retrospective cross-sectional study at Ethiopia’s largest tertiary hospital (2019–2024)

Abstract

PURPOSE: The global rise in early-onset colorectal cancer (EOCRC) is a growing concern, particularly in low-resource settings. However, comprehensive data from Ethiopia are limited. AIM: This study aimed to describe the clinicopathological profile and proportional hospital-based representation of EOCRC at Ethiopia's largest tertiary referral center. METHODS: We conducted a retrospective cross-sectional analysis of 630 histologically confirmed colorectal cancer (CRC) cases diagnosed at Tikur Anbessa Specialized Hospital between January 2019 and September 2024. EOCRC was defined as a diagnosis before the age of 50 years and late-onset CRC (LOCRC) as a diagnosis at the age of 50 years or older. Data on demographics, tumor location, histology, differentiation grade, and TNM stage were also extracted. Descriptive statistics, chi-square tests, and binary logistic regression were used for the analysis. RESULTS: Of the 630 CRC cases, 292 (46.3%) were EOCRC (mean age 36.1 years, SD 7.9). Rectal tumors were significantly more common in EOCRC (31.2% vs. 22.5%, p = 0.012), as were poorly differentiated/undifferentiated tumors (21.9% vs. 13.0%, p = 0.003). Metastasis at diagnosis was less frequent in the EOCRC group (27.4% vs. 66.3%, p < 0.001). Multivariable analysis identified rectal location (adjusted odds ratio (AOR) = 1.60, 95% confidence interval (CI) 1.11-2.30) and poor differentiation (AOR = 1.94, 95% CI 1.25-3.00) as independent predictors of EOCRC, while metastasis was inversely associated (AOR = 0.20, 95% CI 0.14-0.29). CONCLUSION: In this hospital-based sample, EOCRC constitutes a substantial proportion of CRC cases, with distinct clinicopathological features, including rectal predilection and aggressive histology. These findings highlight the need for heightened clinical suspicion in younger adults while acknowledging the influence of Ethiopia's young population structure on the observed proportions.