Malnutrition in cancer surgery: A retrospective study on screening practices and outcomes

Preoperative nutrition risk screening and referral for optimization are recommended for patients undergoing cancer surgery; however, despite high-risk individuals being identified, referral remains variable. This study aimed to determine the prevalence of preoperative undernutrition risk and body mass index (BMI)-defined overnutrition, assess referral rates to registered dietitians or prehabilitation among at-risk patients, and explore associations with postoperative outcomes within an Enhanced Recovery After Surgery center.

Charts of patients with thoracic or abdominal cancer attending the preoperative clinic from July 2, 2019, to July 20, 2020, were retrospectively reviewed. Reduced appetite and unintentional weight loss were considered risk factors for undernutrition, and overnutrition was defined as BMI ≥ 30 kg/m². Outcomes included prevalence of undernutrition risk and overnutrition, referrals, 30-day postoperative complications, and length of stay. Multivariable analyses adjusted for cancer type, age, sex, neoadjuvant therapy, and number of comorbidities.

Among 519 patients, 25% reported unintentional weight loss, 11% reduced appetite, 8% both risk factors, and 24% were overnourished. Thirty-seven percent of patients with both risk factors and 72% with one risk factor were not referred for preoperative optimization. Compared with those with one or no risk factors, patients with both had longer length of stay (incidence rate ratio, 1.8; 95% CI, 1.4-2.4) and higher odds of postoperative complications (odds ratio, 2.2; 95% CI, 1.1-4.5). BMI-defined overnutrition was not associated with adverse postoperative outcomes.

One in three patients presented with at least one risk factor for undernutrition, yet many were not referred for optimization. Undernutrition risk was associated with worse postoperative outcomes, highlighting gaps in nutrition screening and referral pathways.