Efficacy of oxaliplatin in the treatment of colorectal cancer.

Colorectal cancer is one of the leading causes of cancer death. The mainstay of chemotherapy in colorectal cancer patients for the past 40 years has been fluorouracil (5-FU). Oxaliplatin (Eloxatin) is a novel platinum compound with promising activity in colorectal cancer. As a single agent, oxaliplatin has produced response rates of 12% to 24% in patients with previously untreated advanced colorectal cancer, and 10% to 11% in patients with relapsed or refractory advanced colorectal cancer. In phase II trials, oxaliplatin combined with 5-FU, with or without leucovorin, was associated with response rates of 60% and higher when used as front-line therapy, and when used in patients with relapsed or refractory advanced colorectal cancer, response rates ranged from 25% to 50%. In the front-line setting, two randomized trials of 5-FU and leucovorin, with or without oxaliplatin, demonstrated that the addition of oxaliplatin significantly increases response rate and time to tumor progression, but not survival, over 5-FU plus leucovorin alone. The reasons for this discrepancy are unclear, and several possibilities are being considered. Additional phase III trials are underway to clarify the contribution of oxaliplatin in the treatment of patients with locally advanced and metastatic colorectal cancer.