Abstract
BACKGROUND: The Japan Clinical Oncology Group (JCOG) 1006 was a phase III trial of patients with clinical T3/T4 colon cancer comparing the no-touch isolation technique ('No Touch') with the conventional technique ('Conventional'). The planned primary analysis at 3 years failed to confirm the superiority of the No Touch over the 'Conventional'. The present study aimed to compare the 'No Touch' and 'Conventional' using long-term (6-year) follow-up data. METHODS: Patients aged 20-80 years who had a clinical classification of T3-4, N0-2, and M0 with histologically proven colon cancer were randomly assigned (1 : 1) to undergo open surgery using 'Conventional' or 'No Touch' techniques. The primary endpoint was disease-free survival. RESULTS: In total, 853 patients from 30 institutions were assigned to the 'Conventional' (427) or 'No Touch' (426) groups between June 2011 and November 2015. The 6-year disease-free survival was 70.3% and 69.4% for 'Conventional' and 'No Touch' arms respectively (HR 1.030; 95% c.i. 0.813 to 1.304; one-sided P = 0.60). The 6-year overall survival was 89.4% and 86.6% respectively (HR 1.276; 95% c.i. 0.902 to 1.807). The 6-year relapse-free survival was 78.9% and 75.0% respectively (HR 1.209; 95% c.i. 0.920 to 1.589). The 6-year liver relapse-free survival was 85.1% and 80.2% respectively (HR 1.311; 95% c.i. 0.961 to 1.787). CONCLUSION: Long-term follow-up data did not support the superiority of 'No Touch' over 'Conventional' technique in patients with stages II and III colon cancer. These study findings indicate that the conventional technique is still standard surgery for managing colon cancers. TRIAL REGISTRATION NUMBER: UMIN000004957.