Prospective Exploratory Study of the Clinical Significance of Circulating Tumor Cells in Patients With Small Cell Lung Cancer Exposed to Prophylactic Cranial Irradiation.

Lei Deng,Zhouguang Hui,Wenqing Wang,Ye Zhang,Zongmei Zhou,Wen Zhang,Kaitai Zhang,Lin Feng,Luhua Wang

doi:10.3389/fonc.2020.575394

Abstract

ObjectiveCirculating tumor cells (CTCs) can predict the efficacy of anti-cancer treatments and indicate prognosis. Here we investigate the significance of CTCs in relation to the prediction of treatment efficacy and prognosis in patients with small cell lung cancer (SCLC) who have received prophylactic cranial irradiation (PCI).MethodsCTCs were detected in 20 patients with SCLC before and after PCI using the oHSV1-hTERT-GFP method. The primary endpoints were progression-free survival (PFS) and overall survival (OS).ResultsEleven patients had limited-stage SCLC, and nine had extensive-stage SCLC. All patients completed chemo-radiotherapy and received PCI. The median baseline CTC count before PCI was 12. After PCI, the median CTC count was 4. The median follow-up time for all enrolled patients was 39.2 months. The median PFS and OS were significantly reduced in patients with ≥4 CTCs after PCI compared to those with <4 CTCs (PFS, 28.1 months vs. not reached, p = 0.001; OS, not reached vs. not reached, p = 0.029). Seven of the 10 patients with ≥4 CTCs after PCI failed after treatment, whereas the10 patients with <4 CTCs after PCI remained alive without tumors. The median PFS and OS were significantly improved in patients who exhibited a rate of CTC decline of ≥58% after PCI compared with patients who exhibited a decline rate of <58% (PFS, 26.4 months vs. not reached, p = 0.006; OS, not reached vs. not reached, p = 0.029).ConclusionIn SCLC patients who receive PCI, the CTC count and rate of CTC decline after PCI significantly correlate with prognosis.

Highlights

Small cell lung cancer (SCLC) accounts for 10% to 15% of all lung cancers, with the majority presenting at a stage of extensive disease and poor prognosis [1]
Seven of the 10 patients with ≥4 Circulating tumor cells (CTCs) after prophylactic cranial irradiation (PCI) failed after treatment, whereas the10 patients with
The median progression-free survival (PFS) and overall survival (OS) were significantly improved in patients who exhibited a rate of CTC decline of ≥58% after PCI compared with patients who exhibited a decline rate of

Summary

Introduction

Small cell lung cancer (SCLC) accounts for 10% to 15% of all lung cancers, with the majority presenting at a stage of extensive disease and poor prognosis [1]. According to the National Comprehensive Cancer Network (NCCN) guidelines, prophylactic cranial irradiation (PCI) is recommended for patients with limited-stage SCLC who respond well to chemoradiotherapy and for patients with extensive-stage SCLC who have received effective chemotherapy treatment. PCI reduces the 3-year cumulative incidence of brain metastasis and increases the 3-year overall survival (OS) rate [2, 3]. A recent study from Japan found that PCI reduced the incidence of brain metastasis but failed to improve the OS in patients with extensive-stage SCLC who underwent effective chemotherapy [4]. There has been some controversy over whether SCLC patients who are effectively treated with chemoradiotherapy should undergo active follow-up consisting of magnetic resonance imaging (MRI) or PCI [5, 6]. The identification of molecular markers that can be used for early prediction of therapeutic efficacy and to guide individualized treatment of SCLC represents an important research direction

Methods

Results

Conclusion