Role of Prognostic Nutritional Index (PNI) as a Prognostic Marker for Early Postoperative Complications in Gastrointestinal Malignancy

Gastrointestinal malignancies are among the leading causes of cancer-related morbidity and mortality. Surgery remains the mainstay of treatment, but postoperative complications are common, particularly in patients with compromised nutritional and immune status. The Prognostic Nutritional Index (PNI), derived from serum albumin and lymphocyte count, has been proposed as a simple tool to assess preoperative risk. A retrospective observational study was conducted at Nepal Mediciti Hospital, including patients ≥18 years who underwent elective surgery for histologically proven gastrointestinal malignancy between January and December 2024. PNI was calculated using Onodera’s formula. The primary outcome was early postoperative complications within 30 days. Fifty-three patients met the inclusion criteria (mean age 60.9 ± 7.5 years; 52.8% male). Colorectal resections (56.6%) were the most common surgeries. The mean PNI was 49.5 ± 10.8. ROC analysis yielded an area under the curve of 0.66, and the cutoff value was set at 45. Nineteen patients (35.8%) developed at least one early complication, with surgical site infection (20.8%) most frequent. Complications occurred in 57.9% of patients with PNI <45 compared with 23.5% of those with PNI ≥45 (p=0.017). Preoperative PNI was significantly associated with early postoperative complications in gastrointestinal malignancy. A cutoff of 45 effectively stratified patients into high- and low-risk groups. As a simple and inexpensive marker based on routine laboratory values, PNI can be integrated into preoperative assessment to identify patients who may benefit from nutritional optimization and enhanced perioperative care.