Objective: Our randomized controlled trial previously demonstrated improved staging accuracy with targeted nodal assessment and ultrastaging (TNA-us) in colon cancer (CC). Our objective was to test the hypothesis that TNA-us improves disease-free survival (DFS) in CC.
Methods: In this randomized trial, targeted nodal assessment and ultrastaging resulted in enhanced lymph node diagnostic yield associated with improved staging accuracy, which was further associated with improved disease-free survival in early colon cancer.
Results: Clinical parameters of the control (n = 94) and TNA-us (n = 98) groups were comparable. Median (interquartile range) lymph node yield was higher in the TNA-us arm: 16 (12-22) versus 13 (10-18); P = 0.002. Median follow-up was 46 (29-70) months. Overall 5-year DFS was 61% in the control arm and 71% in the TNA-us arm (P = 0.11). Clinical parameters of node-negative patients in the control (n = 51) and TNA-us (n = 55) groups were comparable. Lymph node yield was higher in the TNA-us arm: 15 (12-21) versus 13 (8-18); P = 0.03. Five-year DFS differed significantly between groups with node-negative CC (control 71% vs TNA-us 86%; P = 0.04). Survival among stage II CC alone was higher in the TNA-us group, 83% versus 65%; P = 0.03. Adjuvant chemotherapy use was nearly identical between groups. TNA-us stratified CC prognosis; DFS differed significantly between ultrastaged and conventionally staged node-negative patients [control pN0 72% vs TNA-us pN0(i-) 87%; P = 0.03]. Survival varied according to lymph node yield in patients with node-negative CC [5-year DFS: <12 lymph nodes = 57% vs 12+ lymph nodes = 85%; P = 0.011] but not in stage III CC.
Conclusions: TNA-us is associated with improved nodal diagnostic yield and enhanced staging accuracy (stage migration), which is further associated with improved DFS in early CC. This study is registered at clinicaltrials.gov under the registration number: NCT01623258.