Circulating tumor cells as a prognostic factor in patients with small cell lung cancer

Abstract

The detection of circulating tumor cells (CTCs) in peripheral blood is currently an important field of study. Detection of CTCs by the OBP-401 assay (TelomeScan®) has previously been reported to be useful in the diagnosis, prognosis and evaluation of therapeutic efficacy in breast and gastric cancer. The aim of the present study was to evaluate the OBP-401 assay as a novel method of detecting CTCs of small cell lung cancer (SCLC) patients and to evaluate whether CTC count is associated with prognosis. Prospectively, 30 consecutively diagnosed SCLC patients who had commenced chemotherapy or chemoradiotherapy were enrolled as subjects of the current study. Peripheral blood specimens were collected from the SCLC patients prior to and following the initiation of treatment and the viable CTCs were detected in the specimens following incubation with a telomerase-specific, replication-selective, oncolytic adenoviral agent, which was carrying the green fluorescent protein gene. CTCs were detected in 29 patients (96%). The group of 21 patients with a CTC count of <2 cells/7.5 ml prior to treatment (baseline) had a significantly longer median survival time than the group of eight patients with a CTC count of ≥2 cells/7.5 ml prior to treatment (14.8 and 3.9 months, respectively; P=0.007). The results of a multivariate analysis showed that the baseline CTC count was an independent prognostic factor for survival time (hazard ratio, 3.91; P=0.026). Among the patients that achieved a partial response to treatment, patients who had a CTC count of <2 cells/7.5 ml following two cycles of chemotherapy tended to have a longer median progression-free survival compared with patients who had a CTC count of ≥2 cell/7.5 ml (8.3 and 3.8 months, respectively; P=0.07). Therefore, CTCs may be detected via OBP-401 assay in SCLC patients and the CTC count prior to treatment appears to be a strong prognostic factor.

The clinical utility of circulating tumour cells in patients with small cell lung cancer

“…Since this discovery both epitope dependent and epitope independent enrichment methods have detected an abundance of CTCs in SCLC patients, compared to other tumour types. Between 70-95% of patients with SCLC have detectable CTCs (22)(23)(24)(25)(26)(27)(28)(29)(30).…”

Circulating Tumor Cells in Diagnosing Lung Cancer: Clinical and Morphologic Analysis

“…However, our resuts should be corroborated by larger future studies especially for patients having small nodules. [1], prostate [2], colon-rectal [3], and lung cancer [4][5][6]. Presently, the standard invasive procedures for diagnosing lung lesion are bronchoscopic or computed tomography-guided tissue sampling (solid biopsy).…”

Liquid biopsies in lung cancer: The new ambrosia of researchers

“…In addition, the presence of circulating cells is associated with a significantly higher risk of lymph node metastasis but not with tumor histology in NSCLC [37]. Recently it has been proved the prognostic value of CTC enumeration in patients with SCLC [8,38]. The reduction of CTC count higher than 89% after one chemotherapy cycle improves prognostic accuracy and is associated with lower risk of death.…”