Prognostic value of EpCAM/MUC1 mRNA-positive cells in non-small cell lung cancer patients

The aim of this study was to assess the prognostic value of EpCAM/MUC1 mRNA-positive circulating tumor cells (CTCs) in patients with non-small cell lung cancer (NSCLC). The presence of EpCAM/MUC1 mRNA-positive CTCs was evaluated in 74 NSCLC patients before the initiation of any therapy, from which 61 patients with surgical resection of tumor were also evaluable for EpCAM/MUC1 mRNA-positive CTC analysis after surgery, by quantitative real-time PCR assay. Sixty patients with benign lung disease (BLD) entered this study as controls. The results showed that blood levels of EpCAM and MUC1 mRNA in NSCLC patients before and after surgery were significantly higher than those in BLD patients (P = 0.001 and P = 0.015, respectively, for EpCAM; P = 0.003 and P = 0.026, respectively, for MUC1), and the levels of the two gene mRNA in NSCLC patients significantly decreased after surgery (P = 0.025 and P = 0.033, respectively). Disease recurrence significantly increased in NSCLC patients with EpCAM/MUC1 mRNA-positive CTC preoperation and postoperation (P = 0.004 and P = 0.001, respectively). Disease-free survival and overall survival significantly reduced in patients with EpCAM/MUC1 mRNA-positive CTC preoperation and postoperation (P = 0.012 and P = 0.002, respectively, for preoperation; both P < 0.001 for postoperation). Multivariate analysis demonstrated that the presence of EpCAM/MUC1 mRNA-positive CTCs before and after surgery was an independent factor associated with disease recurrence. In conclusion, the detection of EpCAM/MUC1 mRNA-positive CTCs in the blood before and after surgery is useful for predicting a poor prognosis in NSCLC patients who undergo curative surgery.