Preoperative Prognostic Nutritional Index Predicts Prolonged Postoperative Hospital Stay in Patients With Oral Cancer Undergoing Highly Invasive Surgery

ABSTRACT Aim To evaluate whether preoperative prognostic nutritional index (PNI) values predict prolonged postoperative hospital stay in patients with oral cancer undergoing highly invasive surgery. Methods We retrospectively evaluated background factors (age, sex, primary site, preoperative clinical stage, type of free flap, and the PNI) and postoperative hospital stay in patients with oral cancer who underwent radical resection and free flap reconstruction at our department between June 2007 and July 2023. Patients who remained hospitalized for postoperative treatment were excluded. The PNI was calculated from serum albumin levels and peripheral blood lymphocyte counts, and a cutoff value of 43 was used to categorize patients into two groups (PNI‐low/high). The length of postoperative hospital stay was compared between the groups. Results Ninety patients (55 males and 35 females) were included. A significant negative correlation was observed between the PNI and postoperative hospital stay. The median postoperative hospital stay was 51 days. Significant differences in hospital stay were observed for age, type of free flap, and the PNI; however, only the PNI remained a significant factor in the analysis of covariance. Kaplan–Meier analysis showed that postoperative hospital stay was significantly longer in the PNI‐low group than in the PNI‐high group. Conclusions Preoperative PNI was identified as an independent predictor of prolonged postoperative hospital stay in patients with oral cancer undergoing highly invasive surgery. These findings suggest that the PNI may serve as a simple and practical tool for preoperative risk stratification in clinical practice.