Impact of skeletal muscle mass in patients with recurrent gastric cancer

BACKGROUND: We retrospectively examined the relationship among skeletal muscle mass index (SMI), prognosis, and chemotherapy side effects in patients with recurrent gastric cancer (RGC). METHODS: Sixty-seven patients who developed recurrence after undergoing curative gastrectomy for gastric cancer at Tottori University Hospital and received palliative chemotherapy were included in this study. Pretreatment computed tomography was performed to measure the skeletal muscle mass (SMM) and cross-sectional SMM at the third lumbar vertebra. We focused on haematologic toxicity (neutropenia, thrombocytopenia, and anaemia), febrile neutropenia, and gastrointestinal toxicity (diarrhoea, vomiting, and stomatitis) as the side effects of chemotherapy. RESULTS: Median SMIs for males and females (43.9 and 34.7 cm(2)/m(2), respectively) were used as cutoff values. The patients were classified into high (SMI(High); n = 34) and low SMI groups (SMI(Low); n = 33). The SMI(Low) group included more patients treated with monotherapy (P = 0.016) compared with the SMI(High) group, had a significantly lower number of chemotherapy lines (P = 0.049), and had a significantly higher incidence of grade 3 or 4 side effects (P = 0.010). The median survival rate was significantly higher in the SMI(High) group (17.8 vs 15.8 months; P = 0.034). In the univariate analysis, body mass index, SMI, histological type, and prognostic nutritional index were identified as prognostic indicators. The multivariate analysis identified SMI (P = 0.037) and histological type (P = 0.028) as independent prognostic factors. CONCLUSION: The incidence of grade 3 or 4 side effects was significantly higher in patients with SMI(Low) RGC. SMI was a useful prognostic marker of RGC.