Assessment of the Clinical Utility of Circulating Tumor Cells at Different Time Points in Predicting Prognosis of Patients With Small Cell Lung Cancer: A Meta-Analysis

Abstract

Objectives Numerous studies have elucidated that circulating tumor cells (CTCs) have significant prognostic value in various solid tumors. However, the prognostic value of CTCs in small cell lung cancer (SCLC) remains controversial. The current study was performed to investigate the prognostic significance of different time points of CTCs in SCLC. Methods PubMed, EMBASE, Web of Science, and Cochrane Library databases were retrieved for eligible studies. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to investigate the association between CTCs level and overall survival (OS) and progression-free survival (PFS) in SCLC. Furthermore, subgroup analyses, sensitivity analysis, Begg’s and Egger’s tests were also conducted. Results Sixteen cohort studies with 1103 participants were eligible for this meta-analysis. Our results revealed that higher pretreatment CTCs level was significantly correlated with worse OS in SCLC no matter CellSearch (HR, 2.95; 95%CI, 1.56-5.58; P = .001) or other methods (HR, 2.37; 95%CI, 1.13-4.99; P = .023) was used to detect CTCs. Higher pretreatment CTCs status detected by CellSearch was associated with shorter PFS (HR, 3.75; 95%CI, 2.52-5.57; P < .001), while there was no significant association when other methods were adopted to CTC detection (HR, 2.04; 95%CI, .73-5.68; P = .172). Likewise, we observed that higher post-therapy CTCs level detected by both CellSearch (HR, 2.99; 95%CI, 1.51-5.93; P = .002) and other methods (HR, 4.79; 95%CI, 2.03-11.32; P < .001) was significantly correlated with decreased OS in SCLC. However, higher post-therapy CTCs count detected by CellSearch was not correlated with worse PFS (HR, 1.80; 95%CI, .83-3.90; P = .135). Sensitivity analysis demonstrated that the pooled data were still stable after eliminating studies one by one. However, significant publication bias was observed between pretreatment CTCs level detected by CellSearch and OS of SCLC. Conclusion Dynamic monitoring of CTCs level could be a non-invasive and effective tool to predict the disease progression and prognosis in patients with SCLC.

Soluble biomarkers to predict clinical outcomes in non-small cell lung cancer treated by immune checkpoints inhibitors

“…CTCs seem highly promising for clinical cancer management, based on their non-invasive, easily repeatable, and dynamic real-time monitoring analysis ( 145 ). Additional CTC markers have been explored in NSCLC patients treated by ICI.…”

Extracellular Vesicles and Circulating Tumour Cells - complementary liquid biopsies or standalone concepts?

“…Furthermore, at this juncture, we have a real field to maneuver, as many studies have indicated that both structures with high sensitivity and specificity can be used as a liquid biopsy in the diagnosis and prognosis of patients' outcomes and responses to treatment [36,44,91]. Nevertheless, many meta-analyses have confirmed the unique diagnostic and prognostic value of CTCs [92][93][94][95]. The same properties are attributed by meta-analyses to circulating EVs [96][97][98][99].…”

New biochemical, immune and molecular markers in lung cancer: Diagnostic and prognostic opportunities

“…134 The analysis of CTC number at baseline and at different time points in the course of SCLC was referred to for the prediction and monitoring of the response to chemotherapy. 135 Circulating tumor cells obtained from plasma samples may be also used for the detection of specific mutations related to lung cancer, such as EGFR 136 and KRAS, 137 with a higher sensitivity than ctDNA. Moreover, specific gene rearrangements can be detected in CTCs with promising acurracy.…”