Colorectal cancer (CRC) is a major global health concern, with older patients often experiencing malnutrition, which affects treatment outcomes. The Geriatric Nutritional Risk Index (GNRI) is a simple tool for assessing the nutritional status in older adults. This study evaluated the association between the preoperative GNRI and long-term prognosis in elderly patients with CRC.

This multicenter retrospective cohort study analyzed 1,176 patients ≥65 years old who underwent curative resection for stage 0-III colorectal adenocarcinoma between 2001 and 2020. Patients were categorized into high-GNRI (hG; GNRI ≥98, n=770) and low-GNRI (lG; GNRI <98, n=406) groups. The overall survival (OS) and recurrence-free survival (RFS) were compared between groups using a Kaplan-Meier analysis and Cox proportional hazards models.

The lG group had significantly more females, right-sided colon cancers, and advanced T-stage tumors and significantly more frequent postoperative complications than the hG group. A multivariate analysis identified GNRI as an independent prognostic factor for both the OS and RFS. Respective 3-year OS rates were 91.4% and 80.6%, and respective 3-year RFS rates were 84.8% and 73.8% in the hG and lG groups. Hematogenous recurrence was significantly more common in the lG group than in the hG group (16.7% vs. 10.5%, p=0.003).

The preoperative GNRI was an independent prognostic factor for long-term outcomes in older patients with CRC. This easily calculated index provides valuable complementary information to traditional staging systems and can be readily implemented in clinical practice to identify high-risk patients who may benefit from intensive perioperative management.