OBJECTIVE: We evaluated the prognostic value of TD counts and incorporated them with the number of positive lymph nodes to develop a revised nodal staging. SUMMARY BACKGROUND DATA: The current American Joint Committee on Cancer (AJCC) staging on colon cancer includes the tumor deposits (TDs) only for node-negative patients, as N1c, and their counts are not considered. METHODS: We included consecutive patients with stage III colorectal cancer who underwent curative resections between January 2010 and December 2019. The patients were grouped as TD 0, TD 1, TD 2, or TD ≥ 3 based on their TD counts. Disease-free survival and overall survival were compared. RESULTS: Out of 2,446 eligible stage III patients, 658 (26.9%) had TDs. Among them, 500 (76.0%) patients concurrently had positive lymph nodes (LNs). TD counts were significantly related to worse DFS and OS regardless of pT stages or the number of positive LNs. The patients were restaged based on the integrated number of TD counts and LNs. The N3 stage, which had ten or more integrated TDs and positive LNs, was newly classified. Among the patients who completed six months of adjuvant chemotherapy, those upstaged to N2 from an initial stage of N1 experienced significantly worse DFS than those confirmed as N1, and it was comparable to N2 patients. The newly N3-staged patients showed significantly worse DFS than the patients initial staged as N2. CONCLUSIONS: Revised N staging using the integrated number of TD counts and positive LNs could predict DFS more accurately than current staging. It would also draw greater attention to high-risk stage III colon cancer staged as N3.
OBJECTIVE: We evaluated the prognostic value of TD counts and incorporated them with the number of positive lymph nodes to develop a revised nodal staging. SUMMARY BACKGROUND DATA: The current American Joint Committee on Cancer (AJCC) staging on colon cancer includes the tumor deposits (TDs) only for node-negative patients, as N1c, and their counts are not considered. METHODS: We included consecutive patients with stage III colorectal cancer who underwent curative resections between January 2010 and December 2019. The patients were grouped as TD 0, TD 1, TD 2, or TD ≥ 3 based on their TD counts. Disease-free survival and overall survival were compared. RESULTS: Out of 2,446 eligible stage III patients, 658 (26.9%) had TDs. Among them, 500 (76.0%) patients concurrently had positive lymph nodes (LNs). TD counts were significantly related to worse DFS and OS regardless of pT stages or the number of positive LNs. The patients were restaged based on the integrated number of TD counts and LNs. The N3 stage, which had ten or more integrated TDs and positive LNs, was newly classified. Among the patients who completed six months of adjuvant chemotherapy, those upstaged to N2 from an initial stage of N1 experienced significantly worse DFS than those confirmed as N1, and it was comparable to N2 patients. The newly N3-staged patients showed significantly worse DFS than the patients initial staged as N2. CONCLUSIONS: Revised N staging using the integrated number of TD counts and positive LNs could predict DFS more accurately than current staging. It would also draw greater attention to high-risk stage III colon cancer staged as N3.