Significance of serum interleukin-6 in patients treated with radiotherapy for hepatocellular carcinoma.

Abstract

254 Background: Interleukin-6 (IL-6) is reported to contribute to aggressive tumor growth and resistance to treatment. In several cancers including esophagus, head and neck, and pancreas, high IL-6 is associated with poor treatment outcome after radiotherapy (RT). However, reports about significance of IL-6 in RT for HCC were rare. The aim of this study was to investigate the significance of serum IL-6 with treatment outcome in patients treated with RT for HCC. Methods: For patients treated with RT for HCC, blood samples were collected prospectively, before start and after completion of RT schedule. Serum IL-6 levels were measured with enzyme-linked immunosorbent assay kit. Patients’ clinical profiles were recorded. Results: Between September 2008 and October 2009, 51 patients were included in this study. Median follow-up duration was 12.3 months (range, 0.5-62.3). Baseline serum IL-6 level was 31.63 pg/ml and patients who had treatment history before RT showed higher baseline serum IL-6 levels than treatment (Tx)-naïve patients (53.09 vs. 15.35, p=0.028). Baseline IL-6 levels were higher in patients showing infield failure (59.70 vs. 14.96, p=0.022) and extrahepatic failure (40.50 vs. 17.88, p=0.072). In patients who had treatment history before RT, higher baseline IL-6 levels were associated with both infield and extrahepatic failure (p=0.014, p=0.032, respectively) in. However, this significance was not found in Tx-naïve patients. Higher baseline IL-6 levels were associated with short infield PFS (p<0.0001) in entire patients and in patients who had treatment history before RT. After RT, serum IL-6 level decreased but it was not significant (29.54 pg/ml, p=0.794). And variation of serum IL-6 level was not associated with treatment failure. Conclusions: Baseline serum IL-6 levels seem significant in predicting treatment outcome in patients treated with RT for HCC. High baseline serum IL-6 levels were associated with infield and extrahepatic failure, especially in patients who had treatment history before RT.