Three versus six months of adjuvant oxaliplatin-fluoropyrimidime chemotherapy for colorectal cancer: final results of the phase 3 SCOT trial

Adjuvant chemotherapy for colorectal cancer (CRC) with oxaliplatin and fluoropyrimidine was traditionally given for 6 months but is associated with cumulative peripheral neuropathy. The multinational phase 3 noninferiority SCOT trial investigated treatment reduction from 6 to 3 months, and reported noninferior disease-free survival with reduced toxicity and improved quality of life with 3 months of treatment in 6,088 patients. Final overall survival (OS) results of the study, with 38 months of additional follow-up, have now been reported. Patients with high-risk stage II and stage III CRC were assigned 1:1 to receive 3 or 6 months of either CAPOX of FOLFOX. With a median follow-up of 113 months and 1,255 OS events, 5-year OS rate was 82.4% in both groups (HR 0.96; 95% CI 0.8-1,07), proving noninferiority of 3 months versus 6 months of treatment. Noninferiority of 3 months of treatment for OS was also shown in 1,087 patients with rectal cancer. The duration effect was regimen-dependent with noninferiority shown for CAPOX but not for FOLFOX. The authors conclude that SCOT has shown noninferiority for OS with 3 months of adjuvant chemotherapy, which should be recommended for most patients.