Preoperative Prognostic Nutritional Index was not predictive of short-term complications after laparoscopic resection for rectal cancer

Abstract

Background and aim: Prognostic Nutritional Index (PNI) is a useful tool to predict short-term results in patients undergoing surgery for gastrointestinal cancer. Few studies have addressed this issue in colorectal cancer or specifically in rectal cancer. We evaluated the prognostic relevance of preoperative PNI on morbidity of patients undergoing laparoscopic curative resection for rectal cancer (LCRRC).

Methods: PNI data and clinico-pathological characteristics of LCRRC patients (June 2005-December 2020) were evaluated. Patients with metastatic disease were excluded. Postoperative complications were evaluated using the Clavien-Dindo classification.

Results: A total of 182 patients were included in the analysis. Median preoperative PNI was 36.5 (IQR 32.8-41.2). Lower PNI was associated with females (p=0.02), older patients (p=0.0002), comorbidity status (p<0.0001), and those who did not receive neoadjuvant treatment (p=0.01). Post-operative complications occurred in 53 patients (29.1%), by the Clavien-Dindo classification: 40 grades I-II and 13 grades III-V. Median preoperative PNI was 35.0 (31.8-40.0) in complicated patients and 37.0 (33.0-41.5) in uncomplicated patients (p=0.09). PNI showed poor discriminative performance regarding postoperative morbidity (AUC 0.57) and was not associated with postoperative morbidity (OR 0.97) at multivariable analysis.

Conclusions: Preoperative PNI was not associated with postoperative morbidity after LCRRC. Further research should focus on different nutritional indicators or hematological/immunological biomarkers.

Keywords: Laparoscopy; Morbidity; Nutritional index; Post-operative complications; Rectal cancer.