Malnutrition modifies the response to multimodal prehabilitation: a pooled analysis of prehabilitation trials

Patients with colorectal cancer are at risk of malnutrition before surgery. Multimodal prehabilitation (nutrition, exercise, stress reduction) readies patients physically and mentally for their operation. However, it is unclear whether extent of malnutrition influences prehabilitation outcomes. We conducted a pooled analysis from five 4-week multimodal prehabilitation trials in colorectal cancer surgery (prehabilitation: n = 195; control: n = 71). Each patient's nutritional status was evaluated at baseline using the Patient-Generated Subjective Global Assessment (PG-SGA; higher score, greater need for treatment of malnutrition). Functional walking capacity was measured with the 6-minute walk test distance (6MWD) at baseline and before surgery. A multivariable mixed effects logistic regression model evaluated the potential modifying effect of PG-SGA on a clinically meaningful change of ≥19 m in 6MWD before surgery. Multimodal prehabilitation increased the odds by 3.4 times that colorectal cancer patients improved their 6MWD before surgery as compared with control (95% confidence interval (CI): 1.6 to 7.3; P = 0.001, n = 220). Nutritional status significantly modified this outcome (P = 0.007): Neither those patients with PG-SGA ≥9 (adjusted odds ratio: 1.3; 95% CI: 0.23 to 7.2, P = 0.771, n = 39) nor PG-SGA <4 (adjusted odds ratio: 1.3; 95% CI: 0.5 to 3.8, P = 0.574, n = 87) improved in 6MWD with prehabilitation. In conclusion, baseline nutritional status modifies prehabilitation effectiveness before colorectal cancer surgery. Patients with a PG-SGA score 4-8 appear to benefit most (physically) from 4 weeks of multimodal prehabilitation. Novelty: Nutritional status is an effect modifier of prehabilitation physical function outcomes. Patients with a PG-SGA score 4-8 benefited physically from 4 weeks of multimodal prehabilitation.