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 as a standard chemotherapeutic regimen, the long term efficacy of adjuvant XELOX (oral capecitabine plus intravenous oxaliplatin) in Asian colorectal cancer (CRC) patients remains anecdotal. Moreover, uncertainties persist as to whether pharmacogenetic differences in Asian populations preclude equally tolerable and effective administration of these drugs.

Method: One hundred consecutive patients with resected colorectal cancer received adjuvant XELOX (oxaliplatin 130 mg/m2 on day 1 plus capecitabine 900 mg/m2 twice daily on day 1 to 14 every 3 weeks for 8 cycles) at Queen Mary Hospital, Hong Kong. Endpoints monitored during follow-up were disease-free survival (DFS) and disease recurrence, overall survival (OS) and adverse events (AEs).

Results: The median patient age was 56 years, 56% were diagnosed with rectal cancer and 44% with colonic cancer. After a median follow-up of 4.3 years (95% confidence interval, 3.2-4.7), 24 recurrences were confirmed including 13 patients who died due to progressive disease. Four-year DFS was 81% in colon cancer patients and 67% in rectal cancer 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 were neuropathy (91%), hand-foot syndrome (49%) and diarrhea (46%), while the commonest grade 3/4 AEs were neutropenia (11%) and diarrhea (10%).

Conclusion: These results confirm the favourable long term survival benefit with good tolerability in using adjuvant XELOX in treating East Asian colorectal cancer patients.