Evre II-III kolorektal kanserinde oksaliplatin bazlı adjuvan tedavi rejimlerinin karşılaştırmalı sağkalım ve toksisite profilleri: iki merkezli retrospektif bir çalışma

Aims: Oxaliplatin-based chemotherapy is the standard adjuvant treatment for patients with stage III and high-risk stage II colorectal cancer (CRC). However, real-world data comparing the survival outcomes and toxicity profiles of commonly used regimens remain limited. To evaluate and compare the efficacy and tolerability of adjuvant FOLFOX, FLOX, and XELOX regimens in patients with resected stage III and high-risk stage II CRC treated in routine clinical practice. Methods: Patients with resected stage III and high-risk stage II CRC treated with adjuvant oxaliplatin-based chemotherapy at two tertiary centers between 1998 and 2025 were retrospectively screened. A total of 180 eligible patients were included. Disease-free survival (DFS) and overall survival (OS) were estimated using the Kaplan–Meier method and compared with the log-rank test. Multivariable Cox proportional hazards models were used to adjust for potential confounders. Treatment-related toxicities were graded according to CTCAE criteria.Results: Among 180 patients, the median DFS and OS for the entire cohort were 3.78 and 5.53 years, respectively. Median DFS estimates varied numerically across chemotherapy regimens, whereas median OS values were broadly comparable. Kaplan Meier log-rank analyses did not demonstrate statistically significant differences in DFS or OS between treatment groups. In multivariable Cox proportional hazards models adjusted for baseline clinical factors and treatment duration, chemotherapy regimen was not independently associated with OS. For DFS, however, the XELOX regimen was associated with a lower risk of recurrence compared with FOLFOX-6 (HR 0.51, 95% CI 0.28–0.94; p=0.031). Toxicity profiles varied significantly between regimens. Hematologic toxicities were more frequent with FOLFOX-6 and XELOX, whereas FOLFOX-4 showed comparatively lower rates of myelosuppression. Peripheral neuropathy was predominantly observed in the FOLFOX-6 and XELOX groups.Conclusion: Oxaliplatin-based adjuvant chemotherapy regimens achieved broadly comparable long-term survival outcomes in patients with stage III and high-risk stage II CRC. After adjustment for baseline characteristics, no regimen demonstrated a clear independent OS advantage. XELOX was associated with a modest DFS benefit without a corresponding improvement in OS. Toxicity profiles differed across regimens, particularly with respect to hematologic adverse events and peripheral neuropathy. Therefore, regimen selection in routine clinical practice should balance efficacy with patient-specific tolerability and comorbidity considerations.