Adjuvant Therapy(3 vs. 6 Months) With the FOLFOX 4 or XELOX for Stage II or Stage III Colon Cancer

Six months of adjuvant chemotherapy with 5-FU and oxaliplatin for patients with stage III colon cancer is the world-wide standard of care, based on the MOSAIC and C-07 trials. However, it leads to significant cost, toxicity, and inconvenience. In particular, the onset of oxaliplatin induced cumulative dose-dependent neuropathies is a significant issue. The ability to maintain efficacy with a reduced duration of therapy would have clear advantage to patients, to providers, and to the health care system. Multiple large trials in the 1990s demonstrated that the previous standard of 12 months of therapy could be reduced to 6 months. A single small trial with 5-FU alone demonstrated similar outcomes for 3 versus 6 months of therapy. Thus, it is proposed to definitively evaluate the non-inferiority of 3 months of oxaliplatin-based adjuvant chemotherapy versus the current standard of 6 months. The primary endpoint will be disease-free survival (DFS). It is essential to have sufficient power to eliminate the possibility of clinically meaningful inferiority of 3 months of therapy: a huge number of patients will be necessary. Previous efforts and experience have conclusively demonstrated that in colon cancer, a single, global trial is impractical. Consequently, an international, prospective pooled analysis will be performed, gathering data of independent trials run in different countries, to answer the single primary hypothesis that 3 months of adjuvant therapy with FOLFOX/XELOX is non-inferior to the current standard of 6 months. Among six planned countries, the Greek intergroup will conduct one of these trials.