Efficacy and Tolerability of Adjuvant Oral Capecitabine plus Intravenous Oxaliplatin (XELOX) in Asian Patients with Colorectal Cancer: 4-Year Analysis

Background: Although FOLFOX (infusional fluorouracil/leucovorin plus oxaliplatin) is established asa standard chemotherapeutic regimen, the long term efficacy of adjuvant XELOX (oral capecitabine plusintravenous oxaliplatin) in Asian colorectal cancer (CRC) patients remains anecdotal. Moreover, uncertaintiespersist as to whether pharmacogenetic differences in Asian populations preclude equally tolerable and effectiveadministration of these drugs.
Method: One hundred consecutive patients with resected colorectal cancerreceived adjuvant XELOX (oxaliplatin 130 mg/m2 on day 1 plus capecitabine 900 mg/m2 twice daily on day 1 to14 every 3 weeks for 8 cycles) at Queen Mary Hospital, Hong Kong. Endpoints monitored during follow-up weredisease-free survival (DFS) and disease recurrence, overall survival (OS) and adverse events (AEs).
Results: Themedian patient age was 56 years, 56% were diagnosed with rectal cancer and 44% with colonic cancer. After amedian follow-up of 4.3 years (95% confidence interval, 3.2-4.7), 24 recurrences were confirmed including 13patients who died due to progressive disease. Four-year DFS was 81% in colon cancer patients and 67% in rectalcancer patients (p=0.06 by log-rank test). For the cohort as a whole, OS was 90% at 3 years and 84% at 5 years.Treatment-related AEs led to early withdrawal in four patients. The commonest non-hematological AEs wereneuropathy (91%), hand-foot syndrome (49%) and diarrhea (46%), while the commonest grade 3/4 AEs wereneutropenia (11%) and diarrhea (10%).
Conclusion: These results confirm the favourable long term survivalbenefit with good tolerability in using adjuvant XELOX in treating East Asian colorectal cancer patients.