Changes in skeletal muscle mass during palliative chemotherapy in patients with advanced lung cancer

BACKGROUND: Sarcopenia is a defining feature of cancer cachexia associated with physical decline, poor quality of life and poor prognosis. Thus, maintaining muscle mass is an important aim of cachexia treatment. Many patients at risk for developing cachexia or with cachexia experience side effects of chemotherapy that might aggravate the development of cachexia. However, achieving tumor control might reverse the catabolic processes causing cachexia. There is limited knowledge about muscle mass changes during chemotherapy or whether changes in muscle mass are associated with response to chemotherapy. PATIENTS AND METHODS: In this pilot study, patients with advanced non-small cell lung cancer (NSCLC) receiving three courses of palliative chemotherapy were analyzed. Muscle mass was measured as skeletal muscle cross sectional area (SMCA) at the level of the third lumbar vertebrae using CT images taken before and after chemotherapy. RESULTS: In total 35 patients, 48% women, mean age 67 years (range 56-86), participated; 83% had stage IV disease and 71% were sarcopenic at baseline. Mean reduction in SMCA from pre- to post-chemotherapy was 4.6 cm2 (CI 95% -7.3--1.9; p<0.002), corresponding to a 1.4 kg loss of whole body muscle mass. Sixteen patients remained stable or gained SMCA. Of these, 14 (56%) responded to chemotherapy, while two progressed (p=0.071). Maintaining or gaining SMCA resulted in longer median overall survival (loss: 5.8 months, stable/gain: 10.7 months; p=0.073). Stage of disease (p=0.003), treatment regimen (p=0.023), response to chemotherapy (p=0.007) and SMCA change (p=0.040), but not sarcopenia at baseline, were significant prognostic factors in the multivariate survival analyses. CONCLUSION: Almost half of the patients had stable or increased muscle mass during chemotherapy without receiving any cachexia treatment. Nearly all of these patients responded to the chemotherapy. Increase in muscle mass, but not sarcopenia at baseline, was a significant prognostic factor.