Postoperative Nutritional Status is Predictive of the Survival Outcomes in Patients Undergoing Resection of Stage III Colorectal Cancer

Background Preoperative nutritional status is reportedly associated with the clinical outcomes in patients with colorectal cancer (CRC), although it remains inconclusive whether the preoperative nutritional status that may improve after surgery is truly predictive of the survival outcomes of patients with CRC. Methods Clinical records of patients with stage III CRC (n = 821) in whom curative resection had been achieved were retrospectively reviewed and the prognostic impact of nutritional status, determined by the controlling nutritional status (CONUT) score, was analyzed. Results The CONUT undernutrition grade was significantly associated with the overall survival rate (OS) in the original population (P < 0.0001). By adopting a cut-off value of CONUT score of >= 2 and adjustment for clinical variables using the inverse probability treatment weighting methods, the group with a preoperative CONUT score of >= 2 showed a worse OS as compared to the groups with a preoperative CONUT score of < 2 (P = 0.037). However, sub-analysis based on the dynamic changes in the CONUT score revealed that sustained malnutrition in the postoperative period was more frequent among patients with preoperative CONUT score of >= 2, and that the OS and recurrence-free survival rate (RFS) were significantly correlated with the "postoperative" nutritional status, irrespective of the preoperative nutritional status. Patients who showed improvements of the nutritional status after surgery showed a significantly longer OS and RFS. Conclusions Sustained undernutrition or worsening of the nutritional status after colectomy may be associated with a worse OS and RFS after curative resection in patients with stage III CRC.