Vimentin expression in circulating tumor cells (CTCs) associated with liver metastases predicts poor progression-free survival in patients with advanced lung cancer

Ying Wang,Lina Zhang,Fanbin Hu,Tongmei Zhang,Yanxia Liu,Peter Ping Lin,Li Tong,Baolan Li,Yuan Gao

doi:10.1007/s00432-019-03040-9

Abstract

ObjectiveTo investigate the presence of vimentin expression in CTCs and its clinical relevance in patients with advanced lung cancer.MethodsPeripheral blood was obtained from 61 treatment-naive patients with advanced lung cancer. Subtraction enrichment and immunostaining-fluorescence in situ hybridization (SE-iFISH) platform was applied to identify, enumerate and characterize CTCs based on cell size, aneuploidy of chromosome 8 (Chr8) and vimentin expression. Quantification and analysis of CTCs were performed on patients before chemotherapy administration and after two cycles of therapy.ResultsBefore treatment, CTCs were detected in 60 (98.4%) patients, small cell CTCs (≤ 5 µm of WBCs) accounted for 52.8% of the absolute CTCs number, while 12 (19.7%) of the included patients had detectable vimentin-positive CTCs (vim+ CTCs). Liver metastases were reported in 7 (11.5%) patients and were significantly correlated to the presence of Vim+ CTCs (p = 0.002), with a high positivity rate of 71.4% (5/7). Vim+ CTCs were mostly in small cell size and Chr8 aneuploidy (77.0% and 82.05%, respectively). Baseline small cell CTCs ≥ 2/6 ml, triploid CTCs ≥ 2/6 ml, Vim+ CTCs ≥ 1/6 ml were found to significantly correlate with poor progression-free survival (PFS) (p = 0.017, p = 0.009 and p = 0.001, respectively). After adjusting for clinically significant factors, baseline Vim+ CTCs ≥ 1/6 ml was the only independent predictor of poor PFS [hazard ratio (HR):2.756, 95% confidence interval (CI): 1.239–6.131; p = 0.013].ConclusionsThis study demonstrates an important morphologic, karyotypic and phenotypic CTCs heterogeneity in advanced lung cancer patients. The majority of Vim+ CTCs are in small size and Chr8 aneuploidy. Baseline presence of Vim+ CTCs is correlated with liver metastases and may help predict poor PFS.

Highlights

Lung cancer remains a leading cause of cancer death worldwide, approximately 1.8 million new cases and 1.6 million lung cancer deaths occured every year globally, among which a third occured in China (Chen et al 2016; Ferlay et al 2015)
epithelial to mesenchymal transition (EMT) endows tumor cells with invasive and metastatic abilities which in effect allow cells to penetrate into the lymph vasculature and circulate as single or clusters of CTCs (Nurwidya et al 2016), whilst CTCs exist in a dynamic EMT state in blood (Micalizzi et al 2017)
Univariate analysis of CTC subpopulations revealed that pretreatment small cell CTCs ≥ 2/6 ml, triploid CTCs ≥ 2/6 ml and Vim+ CTCs ≥ 1/6 ml were significantly associated with a shorter progression-free survival (PFS) (p = 0.017, p = 0.009 and p = 0.001, respectively)

Summary

Introduction

Lung cancer remains a leading cause of cancer death worldwide, approximately 1.8 million new cases and 1.6 million lung cancer deaths occured every year globally, among which a third occured in China (Chen et al 2016; Ferlay et al 2015). The high mortality of cancer patients is in most cases caused by metastatic disease but the underlying mechanisms regarding this complex process are incompletely elucidated (Wan et al 2013). EMT endows tumor cells with invasive and metastatic abilities which in effect allow cells to penetrate into the lymph vasculature and circulate as single or clusters of CTCs (Nurwidya et al 2016), whilst CTCs exist in a dynamic EMT state in blood (Micalizzi et al 2017). Human malignant carcinomas, including lung cancer, are highly heterogeneous, and their molecular characteristics evolve to induce metastasis and therapeutic resistance during disease progression (Amirouchene-Angelozzi et al 2017; Maley et al 2017; Messaritakis et al 2018; Nicholas and Charles 2015). Taking advantages of the well-established integrated SE-iFISH platform, CTCs with different morphologic, karyotypic and phenotypic characteristics can be efficiently isolated and effectively identified (Li et al 2018; Lin 2018)

Methods

Results

Conclusion