Clinical significance of circulating tumor cells in squamous cell lung cancer patients.

BACKGROUND: Squamous cell carcinoma (SCC) of the lung represents 20-30% of non-small cell lung cancers (NSCLC) and is associated with a poor prognosis. OBJECTIVE: This study aims to investigate the presence of circulating tumor cells (CTCs) in squamous cell lung cancer patients and what its role might be in providing prognostic information. METHODS: Serial blood samples from 100 patients both before and after initiation of one cycle of standard chemotherapy were analyzed using CellSearch system. RESULTS: Of 105 patients enrolled, 100 were evaluable. >= 2 CTCs per 7.5 mL of blood were present in 29% of patients at baseline before chemotherapy, and 9% patients have more than 5 CTCs. Based on the current literature, the CTC measurements were dichotomized as 2-4 versus >= 5 CTCs. In the univariate analysis, CTC count >= 5 at baseline and CTC count >= 5 at both time points (before and after one cycle of chemotherapy) were significantly associated with a poor PFS and OS outcome. Both factors remained independent poor prognostic markers in the stepwise multivariate analysis. CONCLUSION: Our study indicate that the CTC count is a prognostic factor for PFS and OS outcomes in Chinese patients with locally advanced SCC of the lung.