Serum interleukin-6 levels correlate with malnutrition and survival in patients with advanced non-small cell lung cancer

Aim: To investigate the level of interleukin-6 in advanced non-small cell lung cancer and to analyze the relationship with malnutrition and survival. Methods and study design: Seventy-one newly diagnosed advanced non-small cell lung cancer patients were enrolled in this prospective study. Malnutrition was defined by using subjective global assessment. Performance status was assessed by the Karnofsky scale. Serum levels of albumin, transferrin, C-reactive protein, lymphocytes/mm(3), lactate dehydrogenase and growth hormone were determined before treatment. The patients were followed, and the factors affecting survival were analyzed. Results: The mean follow-up after diagnosis was 180 days. IL-6 levels increased in 48 (68%) of 71 patients. According to the subjective global assessment, 28 (39%) patients were well nourished and 43 (61%) were malnourished. Of the 43 malnourished patients, 29 (41%) were moderately malnourished or suspected of being malnourished and 14 (20%) were severely malnourished. The IL-6 level was related to impaired performance status (P = 0.0001), severe malnutrition (P = 0.004), increased C-reactive protein (P = 0.013), higher growth hormone (P = 0.025) and transferrin (P = 0.03) levels. On univariate analysis, impaired performance status, moderate and severe malnutrition, decreased serum albumin and transferrin, a raised IL-6 and lactate dehydrogenase levels were the significant prognostic factors for survival. Multivariate analysis indicated that a raised IL-6, severe malnutrition and a low serum level of albumin were independent prognostic factors for survival in patients with advanced non-small cell lung cancer. Conclusions: lL-6 secretion may play a role in the pathophysiology of malnutrition in advanced lung cancer. Results show a relation between elevated IL-6 serum levels and malnutrition, poor performance status, acute phase response and shorter survival in patients affected by advanced non-small cell lung cancer.