The Rise of Early-Onset Colorectal Cancer: Clinical Characteristics and Outcomes in a Young Patient Population

Emad Tashkandi Department of Medicine, College of Medicine, Umm Al-Qura University, Makkah, Saudi ArabiaCorrespondence: Emad Tashkandi, Department of Medicine, College of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia, Email [email protected]: The incidence of early-onset colorectal cancer (EOCRC), defined as diagnosis at age ≤ 50 years, is rising globally. Despite younger age and presumed clinical fitness, EOCRC often presents at advanced stages and displays distinct biologic and treatment profiles.Methods: We conducted a retrospective cohort study of patients aged ≤ 50 years with histologically confirmed colorectal adenocarcinoma treated at a tertiary cancer center in Saudi Arabia from 2015 to 2021. Clinical, pathologic, molecular, and treatment data were extracted. Survival outcomes were analyzed using Kaplan–Meier methods, and prognostic factors were assessed via Cox regression models.Results: Among 97 patients (mean age 43 ± 5 years; 56% male), 34% presented with metastatic disease and 75% had left-sided or rectal tumors. Obesity was prevalent in 24% of cases. Surgical resection was performed in 79% of patients, of whom 47% received adjuvant chemotherapy. First-line systemic therapy was administered in 39%, but attrition limited progression to subsequent lines. Median overall survival (OS) was 20 months (interquartile range [IQR], 11– 30). Progression-free survival (PFS) declined from 8 months in first-line to 4 months in third-line therapy. On multivariable analysis, obesity was independently associated with worse OS (hazard ratio [HR] 6.63, p = 0.035).Conclusion: Despite favorable performance status, EOCRC frequently presents with advanced disease and limited systemic therapy durability. Obesity emerged as an independent adverse prognostic factor. These findings reinforce EOCRC as a biologically distinct entity, underscoring the need for tailored screening strategies, early intensification of therapy, and molecularly guided care.Plain Language Summary:: Colorectal cancer used to be thought of as a disease affecting older adults, but more young people under the age of 50 are now being diagnosed. In this study, we looked at 97 patients treated at a cancer center to learn more about how the disease affects younger individuals. We found that many of them were diagnosed at a late stage, and that obesity and cancer spread at diagnosis were linked to shorter survival. Even though younger patients are often healthier, not all received the full recommended treatment. These results show the need to raise awareness, start screening earlier, and develop treatment plans tailored to younger patients. Our findings could help shape future research, policies, and clinical practices for this growing group of patients.Keywords: early-onset colorectal cancer, survival outcomes, tumor biology, prognostic factors, treatment patterns