Background:
Early-onset colorectal cancer (EOCRC) is increasing globally, but data from tropical and underserved regions like the Brazilian Amazon remain scarce. Understanding local epidemiological trends and patient profiles is crucial for guiding context-specific prevention and early detection strategies in low- and middle-income countries.
Objectives:
To describe the clinical and sociodemographic profile of CRC patients, with emphasis on early-onset cases (≤49 years); to assess temporal trends of early-onset and late-onset (≥50 years) CRC from 2001 to 2024; to investigate birth cohort effects; and to compare behavioral and clinical factors between age groups.
Methods:
We conducted a retrospective analysis of a hospital-based cancer registry at Ophir Loyola Hospital in Belém, Brazil (2001–2024). A total of 2,847 incident CRC cases were included. EOCRC was defined as diagnosis before 50 years of age. Descriptive statistics, chi-square/Fisher's exact tests, and age-period-cohort (APC) analysis were performed using R software version 4.3.1.
Results:
EOCRC represented 28.8% (n=820) of all cases and showed a significant annual percent change (APC) of +1.94% (p<0.05). The sharpest increase was in the 40-49 age group (APC=+3.2%, p<0.05). Late-onset CRC showed an increase of +3.03% per year. Compared to late-onset patients, early-onset cases had higher education levels (31.5% completed high school vs. 16.9%, p<0.001), were more frequently single or in a stable union (48.9% vs. 20.9%, p<0.001), and reported a stronger family history of cancer (38.2% vs. 32.5%, p=0.008). Smoking and alcohol consumption patterns also differed significantly (p<0.001). Tumor sidedness did not differ between groups (p=0.230), with a predominance of left-sided tumors (64.8% of early-onset cases). A marked birth cohort effect was observed, indicating a progressively higher risk among individuals born from the 1960s onwards.
Conclusions/Implications:
Early-onset colorectal cancer represents a substantial and growing burden in the Brazilian Amazon, with the most pronounced increase among adults aged 40-49. Distinct sociodemographic and familial risk profiles highlight a generational shift in CRC presentation. These findings underscore the urgent need for tailored awareness campaigns, early clinical suspicion, and reconsideration of age thresholds for screening in similar underserved tropical regions.