Capecitabine/oxaliplatin, a safe and active first-line regimen for older patients with metastatic colorectal cancer: post hoc analysis of a large phase II study

PURPOSE: The tumor-activated fluoropyrimidine capecitabine achieves response rates superior to those of bolus 5-fluorouracil/leucovorin (5-FU/LV) as first-line treatment for metastatic colorectal cancer (CRC), with favorable safety and fewer hospitalizations. Capecitabine is also at least as effective as bolus 5-FU/LV in the adjuvant setting, again with a favorable safety profile. Improved outcomes with capecitabine versus bolus 5-FU/LV in the adjuvant setting have been shown in overall trial populations and in patients aged >or= 70 years. Capecitabine/oxaliplatin (XelOx) is a safe and active combination for the first-line treatment of metastatic CRC. PATIENTS AND METHODS: This post hoc analysis of a large phase II trial compared data from older and younger patients treated with first-line XelOx: oxaliplatin 130 mg/m(2) intravenously on day 1 followed by oral capecitabine 1,000 mg/m(2) twice daily for 14 days every 3 weeks. RESULTS: The median age of the overall population (N = 96) was 64 years (range, 34-79 years), including 52 younger patients (< 65 years of age) and 44 older patients (>or= 65 years of age). Both age groups received a median of 8 cycles (range, 1-26 cycles) of XelOx. The XelOx regimen had similar high activity in both groups, with response rates of 58% (95% CI, 43%-71%) and 52% (95% CI, 37%-68%) in younger and older patients, respectively. In addition, time to disease progression and overall survival were similar in both groups (P > 0.5 for both outcomes). The XelOx regimen also had a favorable safety profile, with no clinically relevant differences between older and younger patients. The overall incidence of adverse events (including grade 3/4), dose reductions, and withdrawals because of adverse events were similar in both groups. CONCLUSION: In the context of an aging population, XelOx provides a highly effective and tolerable first-line treatment for patients with metastatic CRC.