Preoperative Cachexia as a Predictor of Postoperative Morbidity and a Target for Home-Based Prehabilitation in Resectable Gastric Cancer

<b>Background:</b> Gastric cancer (GC) is one of the most common malignancies, requires aggressive treatment, as has a high incidence of complications. The high prevalence of cachexia and comorbidity among GC patients has led to the development of the "prehabilitation" concept. We aimed to investigate the prognostic value of cachexia in the "Western" patient population with resectable GC and to evaluate its utility as an indicator for a home-based prehabilitation program. <b>Methods:</b> This cohort study included 147 patients who underwent surgical treatment for GC from 2019 to 2023. A multivariable analysis was conducted to study the impact of cachexia on postoperative outcomes in 122 patients with resectable GC. The prehabilitation group included 25 patients with cachexia who underwent a 2-week-long multimodal prehabilitation program prior to surgery. The functional results, as well as the 30-day incidence of postoperative complications and 90-day mortality, were evaluated. <b>Results:</b> There were 76 (51.7%) patients with cachexia. Multivariate analysis revealed that cachexia was a significant predictor of all postoperative complications (OR = 5.48, 95% CI 1.85-18.39, <i>p</i> = 0.001), severe postoperative complications (OR = 15.87, 95% CI 3.05-131.81, <i>p</i> < 0.001) and surgical site infection (SSI) (OR = 8.03, 95% CI 1.89-49.09, <i>p</i> = 0.038). Patients in the prehabilitation group had a lower incidence of SSI than in the control group (8.3% vs. 23.5%, <i>p</i> = 0.049). <b>Conclusions:</b> Preoperative cachexia is a potentially modifiable predictor of complications after gastric cancer surgery, and its identification may help define high-risk patients for proactive multimodal prehabilitation.