Factors predicting oncologic outcomes in patients with fewer than 12 lymph nodes retrieved after curative resection for colon cancer.

Objective: The aim of this study was to determine which clinicopathological factors influenced the long-term survival after potentially curative resection of patients with colon cancer having fewer than 12 retrieved lymph nodes.

Methods: Prospective data were collected from 179 patients who had fewer than 12 resected lymph nodes after curative resection for stages I-III colon cancer. The oncological outcomes and the risk factors for recurrence were analyzed, focusing on lymph node ratio (LNR).

Results: The median number of harvested lymph nodes was 7 (range, 1-11). The LNR was associated significantly with T category and lymphovascular invasion. Multivariate analysis revealed that tumor diameter (P = 0.006), perineural invasion (P = 0.043), LNR (P = 0.002), and preoperative carcinoembryonic antigen (CEA) level (P = 0.013) were the independent predictors for 5-year disease-free survival; T category (P = 0.032), postoperative chemotherapy (P = 0.001), LNR (P = 0.007), and preoperative CEA level (P = 0.023) were the independent predictors for 5-year overall survival.

Conclusions: The LNR and preoperative CEA level may be reliable predictors of recurrence and survival after curative surgery in patients with colon cancer who have less than 12 lymph nodes examined.