Circulating endothelial cells and serum caspase-cleaved CK18 to predict for response and survival in non-small cell lung cancer patients receiving endostatin and paclitaxel-carboplatin combined chemotherapy

e18088 Background: Combinations of anti-angiogenic drugs with chemotherapeutics are widely used for cancers control. Whether can better efficacy of such a combinated modality be achieved and predicted earlier is a great challenge. Circulating endothelial cells (CECs) and cytokeratins (CKs) might have a role in tumour angiogenesis and in tumour cell death. Measurement of CECs and CKs in the blood of patients with tumors could be a simple, non-invasive approach to monitor or predict responses and survival to treatment. Methods: One hundred and seven patients with primary advanced non-small cell lung cancer (NSCLC) were enrolled, randomly assigned to either the endostatin treatment group (paclitaxel+ carboplatin+ endostatin) or the control group (paclitaxel+carboplatin). CEC count and serum CK8, caspase-cleaved CK18 (ccCK18) and uncleaved CK18 (CK18) were measured in the 107 subjects at before treatment (baseline), week 3, and week 6 of treatment, respectively. Results: Higher baseline CEC count was observed in patients with good tumor response (p=0.002 for all the 107 patents; p=0.000 in the treatment group). When compared with the baseline level, after 6 weeks therapy in the endostatin group, CECs decreased significantly (p=0.000), but the CKs levels increased. The increased levels of ccCK18 and CK18 at week 6 reached significance in the treatment group (p=0.001 and p=0.048, respectively). Tumor response showed strong correlation with the reduction extent of CECs (p=0.000) and the increase value of ccCK18 (p=0.040) after endostatin therapy. The best cut-off values of the changes of CECs and ccCK18 for prediction of survival were designed being 0.58/ul and 19.6ng/ml, respectively. Furthermore, obvious reduction of CECs and more rise of ccCK18 significantly correlated with the longer median survival (p= 0.013 and p = 0.016 for PFS, p = 0.009 and p=0.012 for OS, respectively). Conclusions: CECs and CKs would be the impressive biomarkers to explore for selecting NSCLC patients who might benefit from endostain in combination with paclitaxel plus carboplatin treatment.