Prognostic Factors and Real-World Outcomes in Patients Aged 65 Years and Older with Stage II and III Colon Cancer
Zeliha Birsin1, Selin Cebeci1, Seda Jeral1, Vali Aliyev1, Nebi Serkan Demirci1, Özkan Alan11Department of Medical Oncology, Faculty of Medicine, Istanbul University-Cerrahpaşa, Istanbul, Türkiye
Objectives: Colon cancer is common among older adults, yet this population is underrepresented in clinical trials. This study aimed to evaluate real-world outcomes and prognostic factors in patients aged ?65 years with stage II and III colon cancer. Methods: This retrospective cohort study included aged ?65 years with stage II or III colon cancer who underwent curative-intent resection between 2010 and 2024. Clinical, pathological, and treatment-related variables were collected. Relapse-free survival (RFS) and overall survival (OS) were analyzed using Kaplan–Meier and Cox regression methods. Results: Of the study population (n:218), 45% were younger than 70 years and 55% were aged ?70 years (median age: 70). Adjuvant chemotherapy was administered to 66% overall, but less frequently in older patients (59% vs. 73%, p=0.027). Oxaliplatin-based regimens were rarely used in stage II disease (3%) but commonly given in stage III (68%, p<0.001). Treatment-related toxicity occurred in 52% of patients, without significant differences between age groups (p=0.937). In the overall cohort, age ?70 was associated with significantly worse OS (median OS 8.95 vs. 13.3 years, logrank p=0.021), while RFS did not differ significantly (5-year RFS 64% vs. 76%, p=0.067). In stage II disease, neither age nor receipt of adjuvant chemotherapy significantly influenced OS or RFS (both p>0.05), whereas T4 tumor stage independently predicted shorter OS (p=0.047). In stage III disease, older age (?70; HR: 2.03, p=0.043), advanced nodal stage (HR: 2.21, p=0.013), and BMI <25 (HR: 2.14, p=0.002) were independent predictors of worse OS, while age was not independently associated with RFS (p>0.05). The addition of oxaliplatin did not provide a measurable survival benefit (p>0.05). Conclusion: In elderly patients with colon cancer, age did not affect OS or RFS in stage II disease. In stage III, however, older age was an independent adverse factor for OS but not for RFS, while oxaliplatin did not provide additional survival benefit. These findings highlight the importance of individualized treatment decisions based on both tumor characteristics and patient factors. Keywords: Adjuvant Chemotherapy, Colon Cancer, Elderly Oncology, Prognostic Factors, Real-world Data
Cite This Article
Birsin Z, Cebeci S, Jeral S, Aliyev V, Demirci N, Alan Ö. Prognostic Factors and Real-World Outcomes in Patients Aged 65 Years and Older with Stage II and III Colon Cancer. EJMI. 2025; 9(4): 227-239
Corresponding Author: Zeliha Birsin