Agreement between PG-SGA category and fat-free mass in colorectal cancer patients

Low fat-free mass (FFM) is associated with adverse outcomes in colorectal cancer (CRC) patients. Patient-Generated Subjective Global Assessment (PG-SGA) is a widely used tool developed to detect patients with malnutrition or at risk of malnutrition. The aim of this study was to investigate the agreement between PG-SGA category and FFM in patients with non-metastatic CRC.

Ninety-seven patients were included and categorized as well nourished (PG-SGA:A, n = 67) or malnourished (PG-SGA:B, n = 30). No patients were severely malnourished (PG-SGA: C). Bioelectrical impedance analysis (BIA) was used to assess FFM. Low FFM was defined as low fat-free mass index (FFMI) according to cut-off values recently proposed by The European Society for Clinical Nutrition and Metabolism (ESPEN).

Twenty-nine percent of the patients were identified with low FFMI. The proportion with low FFMI was significantly higher among patients classified as malnourished by PG-SGA compared to well nourished (p = 0.015). The sensitivity was however low, as the PG-SGA categorization classified only 50.0% of the patients with low FFMI as malnourished (PG-SGA B). Using the PG-SGA scores (cut-off point > 4), the sensitivity increased to 60.7%. Physical examination in the PG-SGA identified only 64.3% of the patients with low FFMI as muscle depleted.

Our results indicate a low agreement between PG-SGA category and low FFMI among patients with non-metastatic CRC. In clinical practice, PG-SGA should be supplemented by muscle mass assessments by BIA or other methods in order to detect low FFM in this patient group.