Lymph Node Status and Long-Term Oncologic Outcomes After Colon Resection in Locally Advanced Colon Cancer

Locally advanced colon cancer is associated with poor prognosis. The aim of this report was to examine the association between the lymph node status and prognosis of locally advanced colon cancer. Perioperative and oncologic outcomes were studied in patients who had undergone colectomy for colon cancer between June 2004 and December 2018. Locally advanced colon cancer was defined as stage T4a/T4b cancer. The long-term oncologic results were investigated in patients with non-metastatic locally advanced colon cancer. Of 195 patients operated for locally advanced colon cancer, 83 (42.6%), 43 (22.1%), and 69 (35.3%) had pN0, pN1, and pN2 disease, respectively. Preoperative serum levels of CEA and CA 19-9, as well as incidence of distant metastases were significantly higher in patients with pN2 compared to those with pN0 and pN1. In non-metastatic setting, a trend towards higher incidence of recurrence was observed in node-positive patients. Nodal stage was a significant predictor for survival in the univariable analysis but non-significant after adjusting for confounders. Subgroup analyses among the patients with T4a and T4b cancer did not demonstrate any association between the nodal stage and survival. Preoperative CA 19-9 > 37 U/ml and adjuvant chemotherapy were the only prognostic factors in T4a and T4b colon cancer, respectively. Although a trend towards higher incidence of recurrence was observed in node-positive locally advanced colon cancer, nodal stage was not associated with survival. Adjuvant chemotherapy should be strongly considered in T4b stage colon cancer.