[Adjuvant treatment of colon cancer MOSAIC study's main results]. / Traitement adjuvant du cancer du côlon: principaux résultats de l'étude MOSAIC.

Oxaliplatin in combination with 5-fluorouracil/leucovorin (LV5FU) improves the response rate and survival of patients with metastatic colorectal cancer. The objective of the Mosaic study was to evaluate the efficacy of this association in the adjuvant treatment of stage II and III colon cancer. This international study, including 2,246 patients, compared the efficacy of standard treatment with LV5FU2 alone to that of oxaliplatin-LV5FU (Folfox4 regimen) following R0 resection of the primary tumour. Both treatments were administered every two weeks for six months. At 3-year follow-up, the risk of relapse was decreased by 23% in the Folfox4 group (p = 0.002). The protocol was well tolerated, with an identical overall mortality during treatment (0.5%) in both groups. The main specific complication, peripheral sensory neuropathy was reversible in the great majority of cases. A new analysis at 4-year follow-up (median 48.6 months) confirmed the superior efficacy of the Folfox4 regimen compared to the standard treatment, the reduction in relapse risk being 24% (p = 0.0008). On the strength of these results, oxaliplatin was granted a marketing authorization for the indication adjuvant treatment of stage III colon cancer. Based on the data currently available, physicians should consider adjuvant treatment for stage II patients, making each individual decision for treatment on a case-by-case basis.

Oxaliplatin, fluorouracil, and leucovorin as adjuvant treatment for colon cancer.

BACKGROUND: The standard adjuvant treatment of colon cancer is fluorouracil plus leucovorin (FL). Oxaliplatin improves the efficacy of this combination in patients with metastatic colorectal cancer. We evaluated the efficacy of treatment with FL plus oxaliplatin in the postoperative adjuvant setting. METHODS: We randomly assigned 2246 patients who had undergone curative resection for stage II or III colon cancer to receive FL alone or with oxaliplatin for six months. The primary end point was disease-free survival. RESULTS: A total of 1123 patients were randomly assigned to each group. After a median follow-up of 37.9 months, 237 patients in the group given FL plus oxaliplatin had had a cancer-related event, as compared with 293 patients in the FL group (21.1 percent vs. 26.1 percent; hazard ratio for recurrence, 0.77; P=0.002). The rate of disease-free survival at three years was 78.2 percent (95 percent confidence interval, 75.6 to 80.7) in the group given FL plus oxaliplatin and 72.9 percent (95 percent confidence interval, 70.2 to 75.7) in the FL group (P=0.002 by the stratified log-rank test). In the group given FL plus oxaliplatin, the incidence of febrile neutropenia was 1.8 percent, the incidence of gastrointestinal adverse effects was low, and the incidence of grade 3 sensory neuropathy was 12.4 percent during treatment, decreasing to 1.1 percent at one year of follow-up. Six patients in each group died during treatment (death rate, 0.5 percent). CONCLUSIONS: Adding oxaliplatin to a regimen of fluorouracil and leucovorin improves the adjuvant treatment of colon cancer.