Assessment of body composition and impact of sarcopenia and sarcopenic obesity in patients with gastric cancer.

Malnutrition is a critical problem in patients with gastric cancer (GC); however, no universally accepted marker that is convenient for clinical use has been defined. Recently, body composition has attracted considerable attention as a means to assess nutrition status in patients with cancer. The clinical role of skeletal muscle mass has also been increasingly recognized. In patients with GC, sarcopenia, which is the loss of skeletal muscle mass, was found to be significantly associated with increased post-surgical complications including hospital stay, healthcare costs, and poor survival. In addition, sarcopenic obesity, which combines the health risks of obesity and sarcopenia, is recognized as a strong risk factor for poor short- and long-term outcomes following gastrectomy. The mechanism linking sarcopenia to worse postoperative outcomes remains unclear; however, skeletal muscle has been found to act as an endocrine organ that produces substances affecting the immune system. In addition, sarcopenia was reported to be associated with toxicity and termination of chemotherapy. Patients with sarcopenia may be unable to react appropriately to the stress of gastrectomy and perioperative chemotherapy. To improve the short- and long-term outcomes of patients with GC and sarcopenia, adequate energy and protein intake are necessary during resistance training. In the present study, we performed a literature review and presented a method to evaluate body composition, the relationship between skeletal muscle mass and GC, and perioperative nutrition and exercise therapy for patients with sarcopenia.