Sarcopenia increases the risk of post-operative recurrence in patients with non-small cell lung cancer

BACKGROUND: Sarcopenia is among the most prevalent and serious cancer-related symptom, and is strongly correlated with a poor prognosis. Moreover, it reportedly predicts poor prognosis after surgery in patients with lung cancer. However, it is unclear whether sarcopenia directly affects post-operative recurrence. The purpose of this study was to evaluate whether sarcopenia can be a risk indicator for post-operative recurrence, and whether it suppresses anti-tumor immunity, in a cohort of patients with resected non-small cell lung cancer. METHODS: This study retrospectively reviewed the data of 256 consecutive patients who underwent curative lobectomy and lymph node dissection for non-small cell lung cancer at our institution. The psoas muscle mass index was calculated as the total psoas muscle area at the third lumbar vertebral level/height(2) (cm(2)/m(2)). Sarcopenia was defined by a psoas muscle mass index of under 5.03 cm(2)/m(2) and 3.17 cm(2)/m(2) in male and female patients, respectively. Post-operative prognosis and cumulative incidence of recurrence rates were calculated. RESULTS: The 5-year overall survival and disease-free survival rates post-surgery were 59.5% and 38.6%, respectively, in patients with sarcopenia versus 81.1% and 72.1%, respectively, in patients without sarcopenia (p < 0.001). The 5-year cumulative incidence of recurrence rate in patients with sarcopenia was significantly higher than those without sarcopenia (49.9% versus 22.4%, respectively) in every pathological stage. Pathological stages II and III (hazard ratio, 3.36; p = 0.004), histological type (hazard ratio, 2.31; p = 0.025), and sarcopenia (hazard ratio, 2.52; p = 0.001) were independent risk factors for post-operative recurrence according to multivariate analysis. CONCLUSION: Sarcopenia is a risk indicator for post-operative recurrence in patients with non-small cell lung cancer.