Different nutritional assessment tools as predictors of postoperative complications in patients undergoing colorectal cancer resection

Background & aims: Malnutrition in patients with colorectal cancer contributes to increased postoperative complications. The aim of the study was to evaluate the prognostic value of several nutritional assessment parameters: body mass index versus percentage of weight loss grading system (BMI/%WL); Patient-Generated Subjective Global Assessment (PG-SGA); standardized phase angle (SPA) by BIA; muscle strength by handgrip strength; muscle mass by computerized tomography; and the combination of muscle mass and strength in patients undergoing resection surgery.

Methods: Patients diagnosed with cancer of the colon or rectum, who were over 18 years old and were scheduled to undergo surgical treatment were invited to participate. Postoperative complications were assessed from the first day post-surgery until discharge. Complications classified as Grade II or above according to the Clavien-Dindo classification were considered. Chi-square test or Fisher's exact test, bivariate analysis, Poisson regression and receiver operator characteristic (ROC) curve were utilized and p < 0.05 was considered significant.

Results: 84 patients were evaluated, with 28 (33.3%) presenting with Grade II postoperative complications. SPA showed no association with postoperative complications (p = 0.199). In multivariate analysis, low skeletal muscle mass showed a relative risk (RR) of 1.80 (CI: 1.02-3.17), BMI/%WL equal or higher than grade 3 had a RR of 1.90 (95% CI: 1.22-3.39). PG-SGA classified as malnutrition showed a RR of 2.08 (95% CI: 1.06-4.06); and low muscle mass plus low muscle strength showed a RR 2.13 (95% CI: 1.23-3.69). Low strength alone was not associated with postoperative complications after controlling for confounding factors (p = 0.16; 95% CI: 0.83-2.77). Low muscle mass in combination with low strength showed the highest predictive power for postoperative complications (AUC: 0.68; CI: 0.56-0.80).

Conclusions: BMI/%WL > grade 3, PG-SGA defined malnutrition, low muscle mass and low muscle mass plus low strength were independent risk factors for complications controlling for confounding factors. However, low muscle mass in combination with low muscle strength were the strongest variables associated with complications.

Clinical trials identification number: NCT02901132 (www.clinicaltrials.gov).