Osteopontin as a marker of weight loss in lung cancer.

Although the role of osteopontin (OPN) in tumorigenesis and invasiveness is well-known, its role in systemic consequences of lung cancer has not been studied yet. The objective of the current study was to assess the value of osteopontin as a marker of weight loss in relation to systemic inflammation in non-small cell lung cancer (NSCLC) patients. A total of 63 male NSCLC patients (stage III and IV) and 25 age and sex-matched controls were included. The NSCLC patients were further divided into subgroups depending on whether they had > 5% weight loss in the last 6 months or not. Serum OPN and TNF-α concentrations were measured by ELISA using commercially available kits. Serum C-reactive protein (CRP) concentration was measured by the turbidimetric method. OPN (p = 0.001) and CRP (p < 0.001) concentrations were significantly higher in lung cancer patients compared to controls whereas TNF-α concentrations were similar in cancer and control groups (p = 0.063). There were 33 NSCLC patients (52.4%) with weight loss. Serum OPN concentration was found to be higher in this weight-losing group (p = 0.042). CRP concentration was also higher in the weight-losing group but the difference was not statistically significant (p = 0.246). TNF-α concentrations were similar in both subgroups (p = 0.094). In correlation tests, there was a positive correlation between OPN and CRP (r = 0.299, p = 0.044), but no correlation was detected between OPN and TNF-α (r = − 0.009, p = 0.930). A negative correlation was detected between OPN and BMI (r = − 0.246, p = 0.048). In addition to being an indicator of systemic inflammation in lung cancer patients, osteopontin may also be an indicator of weight loss.