The survival benefit of oxaliplatin-based adjuvant chemotherapy, improving over time and with the disease severity, was confirmed at 10 years in patients with stage 2 to 3 colon cancer, a new study published online ahead of print in the Journal of Clinical Oncology has shown.1
The MOSAIC study evaluated adjuvant FOLFOX4 (oxaliplatin, fluorouracil, leucovorin) in patients with stage 2 to 3 resected colon cancer.
Results showed that 3-year disease-free survival and 6-year overall survival were improved with adjuvant oxaliplatin. In this analysis, researchers present 10-year overall survival data and overall survival and disease-free survival by mismatch repair (MMR) status and BRAF mutation status.
Researchers analyzed survival data after 10 years of follow-up for 2246 patients and assessed MMR status and BRAF mutation status in 1008 samples.
Results showed that after a median follow-up of 9.5 years, the 10-year overall survival rates in the LV5FU2 (bolus/infusion fluorouracil plus leucovorin) and FOLFOX4 arms were 67.1% and 71.7%, respectively (HR, 0.85; P = .043) in the entire population.
Overall survival rates for patients with stage 2 colon cancer were 79.5% vs 78.4% for LV5FU2 and FOLFOX, respectively (HR, 1.00; P = .980), and 59.0% vs 67.1%, respectively, for those with stage 3 disease (HR, 0.80; P = .016).
Researchers found that having MMR-deficient (dMMR) tumors was an independent prognostic factor (HR, 2.02; 95% CI, 1.15 – 3.55; P = .014), but BRAF mutation was not prognostic for overall survival (P = .965). The analysis also demonstrated an overall survival benefit and disease-free survival benefit with adjuvant FOLFOX in those with dMMR tumors or BRAF mutation.
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“These updated results support the use of FOLFOX in patients with stage 3 disease, including those with dMMR or BRAF mutation,” the authors conclude.
- André T, de Gramont A, Vernerey D, et al. Adjuvant fluorouracil, leucovorin, and oxaliplatin in stage II to III colon cancer: updated 10-year survival and outcomes according to BRAF mutation and mismatch repair status of the MOSAIC study [published online ahead of print November 2, 2015]. J Clin Oncol. doi: 10.1200/JCO.2015.63.4238.