Prognostic value of HALP score, Prognostic Nutritional Index (PNI), and Lymph Node Ratio (LNR) in right-sided colon adenocarcinoma: a retrospective single-center cohort analysis with clinico-pathological correlations

Introduction Preoperative systemic immunonutritional indices offer cost-effective, host-centric prognostic insights. This study evaluated the independent long-term prognostic utility of the Prognostic Nutritional Index (PNI), Hemoglobin–Albumin–Lymphocyte–Platelet (HALP) score, and Lymph Node Ratio (LNR) in patients with right-sided colon adenocarcinoma (RCC) following standardized D3 lymphadenectomy. Methods A retrospective cohort analysis was conducted on 232 consecutive patients who underwent curative radical resection for RCC between 2020 and 2025. Optimal cut-off values were determined via time-dependent ROC curve analysis at 36-month survival using the Youden Index. Long-term survival distributions were assessed using the Kaplan–Meier method, and independent prognostic factors were identified through multivariable Cox regression models with internal bootstrap validation (1000 resamples). Results The median harvested lymph node yield was 37 (IQR: 27–47.25). Time-dependent ROC analysis identified LNR as the most accurate prognostic marker (AUC = 0.817), followed by continuous PNI (AUC = 0.648) and HALP (AUC = 0.628). Kaplan–Meier tracking verified that low HALP (< 39.17, p = 0.006), low PNI (< 42.65, p < 0.001), and LNR variances provided significant survival discrimination. In fully adjusted multivariable Cox analysis, preoperative continuous PNI retained robust independent protective weight (HR: 0.931, 95% CI: 0.896–0.966, p = 0.005; conferring a 6.9% lower mortality hazard per single-unit increase), alongside advanced TNM stage (HR: 2.188, p < 0.001) and poor differentiation (HR: 3.330, p < 0.001). Conversely, the prognostic significance of LNR and HALP was attenuated. Conclusions Preoperative continuous PNI provides valuable independent prognostic insights complementing standard anatomical staging in RCC. Notably, ratio-based metrics lost independent prognostic variance in this cohort characterized by exceptionally high nodal yields.