Prognostic value of D3 lymph node dissection and nutritional status in colorectal cancer patients aged 80 years and older

PURPOSE: To evaluate the impact of D3 lymph node dissection and nutritional status on outcomes in patients aged ≥80 years with colorectal cancer. METHODS: We retrospectively analyzed patients aged ≥80 years who underwent curative resection for stage I-III colorectal cancer between April 2007 and February 2020. Patients were divided into D3 and non-D3 lymph node dissection groups. Propensity score matching was performed to reduce baseline differences. Short- and long-term outcomes, including overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS), were compared. Multivariate Cox regression analyses were used to identify independent prognostic factors, with particular attention to the prognostic nutritional index (PNI). Competing-risk analysis for cancer-specific death was also conducted. RESULTS: After propensity score matching, 272 patients (136 per group) were analyzed. The D3 group showed significantly better OS (5-year: 73.5% vs. 60.0%, P = 0.0039) and DFS (5-year: 69.5% vs. 56.1%, P = 0.0099) than the non-D3 group. CSS was not significantly different on Kaplan-Meier analysis; however, competing-risk analysis demonstrated a significantly lower cumulative incidence of cancer-specific death in the D3 group (5-year: 23.0% vs. 29.6%, P = 0.024). Multivariate analysis identified D3 dissection and PNI ≥ 45 as independent favorable prognostic factors for OS, DFS, and CSS. CONCLUSIONS: In patients aged ≥80 years with colorectal cancer, D3 lymph node dissection improved OS and DFS without increasing perioperative morbidity. Preoperative PNI was a strong predictor of long-term prognosis and may aid surgical decision-making in elderly patients.