Clinical significance of detecting survivin-expressing circulating cancer cells in patients with non-small cell lung cancer.

We previously demonstrated that the detection of circulating cancer cells (CCC) expressing survivin mRNA could provide valuable information for predicting metastasis and recurrence in breast cancer. The objective of this study was to investigate the significance of detecting survivin-expressing CCC on the clinical outcomes of patients with non-small cell lung cancer (NSCLC). Peripheral blood samples collected from 143 NSCLC patients and 177 healthy volunteers were quantitatively evaluated using a technique developed in our laboratory that detected reverse transcription-polymerase chain reaction (RT-PCR) products based on a hybridisation-enzyme linked immunosorbant essay (ELISA), which we called RT-PCR ELISA. The presence of survivin-expressing CCC was detected in 63 cancer patients (44.1%) and was significantly associated with pathological T classification, nodal status, and disease stages (all P<0.001). During a follow-up period of 36 months, patients who had positive survivin expressions at the time of the initial assay test had a higher relapse rate and shorter survival time when compared to those who had negative survivin expressions (all P<0.001). Through multivariate analysis, the detection of survivin-expressing CCC was found to be an independent predictor for cancer recurrence (HR=43.5; 95% CI=2.67-70.9; P=0.008) and survival (HR=1.35; 95% CI=1.02-4.31; P=0.049). Thus, detection of survivin-expressing CCC could be used in the prediction of disease recurrence as well as in the prognosis of NSCLC.