Circulating endothelial cells in non-small cell lung cancer patients treated with carboplatin and paclitaxel.

Introduction: Circulating endothelial cells (CECs) increase in cancer patients and play an important role in tumor neovascularization.

Methods: This study was designed to investigate the role of CEC as a marker for predicting the effectiveness of a carboplatin plus paclitaxel based first line chemotherapy in advanced non-small cell lung cancer (NSCLC).

Results: The CEC count in 4 ml of peripheral blood before starting chemotherapy (baseline value) was significantly higher in NSCLC patients, ranging from 32 to 4501/4 ml (n = 31, mean +/- SD = 595 +/- 832), than in healthy volunteers (n = 53, 46.2 +/- 86.3). We did not detect a significant correlation between the CEC count and estimated tumor volume. CECs were significantly decreased by chemotherapy as compared with pretreatment values (175.6 +/- 24 and 173.0 +/- 24, day +8, +22, respectively). We investigated the correlation between baseline CEC and the clinical effectiveness of chemotherapy. CEC values are significantly higher in patients with clinical benefit (partial response and stable disease, 516 +/- 458, 870.8 +/- 1215, respectively) than in progressive disease patients (211 +/- 150). Furthermore, a statistically significant decrease in CECs, on day 22, was observed only in patients with partial response. Patients who had a baseline CEC count greater than 400/4 ml showed a longer progression-free survival (>400, 271 days [range: 181-361] versus <400, 34 [range: 81-186], p = 0.019).

Conclusion: CEC is suggested to be a promising predictive marker of the clinical efficacy of the CBDCA plus paclitaxel regimen in patients with NSCLC.