摘要:Malnutrition, which commonly occurs in perioperative patients with cancer, leads to decreased muscle mass, hypoalbuminemia, and edema, thereby increasing the patient’s risk of various complications. Thus, the nutritional management of perioperative patients with cancer should be focused on to ensure that surgical treatment is safe and effective, postoperative complications are prevented, and mortality is reduced. Pathophysiological and drug-induced factors in elderly patients with cancer are associated with the risk of developing malnutrition. Pathophysiological factors include the effects of tumors, cachexia, and anorexia of aging. Metabolic changes, such as inflammation, excess catabolism, and anabolic resistance in patients with tumor-induced cancer alter the body’s ability to use essential nutrients. Drug-induced factors include the side effects of anticancer drugs and polypharmacy. Drug–drug, drug–disease, drug–nutrient, and drug–food interactions can significantly affect the patient’s nutritional status. Furthermore, malnutrition may affect pharmacokinetics and pharmacodynamics, potentiate drug effects, and cause side effects. This review outlines polypharmacy and malnutrition, the impact of malnutrition on drug efficacy, drug–nutrient and drug–food interactions, and intervention effects on polypharmacy or cancer cachexia in elderly perioperative patients with cancer.