Heterogeneity of Circulating Tumor Cell-Associated Genomic Gains in Breast Cancer and Its Association with the Host Immune Response

New insights into the correlations between circulating tumor cells and target organ metastasis

Organ-specific metastasis is the primary cause of cancer patient death. The distant metastasis of tumor cells to specific organs depends on both the intrinsic characteristics of the tumor cells and extrinsic factors in their microenvironment. During an intermediate stage of metastasis, circulating tumor cells (CTCs) are released into the bloodstream from primary and metastatic tumors. CTCs harboring aggressive or metastatic features can extravasate to remote sites for continuous colonizing growth, leading to further lesions. In the past decade, numerous studies demonstrated that CTCs exhibited huge clinical value including predicting distant metastasis, assessing prognosis and monitoring treatment response et al. Furthermore, increasingly numerous experiments are dedicated to identifying the key molecules on or inside CTCs and exploring how they mediate CTC-related organ-specific metastasis. Based on the above molecules, more and more inhibitors are being developed to target CTCs and being utilized to completely clean CTCs, which should provide promising prospects to administer advanced tumor. Recently, the application of various nanomaterials and microfluidic technologies in CTCs enrichment technology has assisted to improve our deep insights into the phenotypic characteristics and biological functions of CTCs as a potential therapy target, which may pave the way for us to make practical clinical strategies. In the present review, we mainly focus on the role of CTCs being involved in targeted organ metastasis, especially the latest molecular mechanism research and clinical intervention strategies related to CTCs.

Factors influencing the diagnostic and prognostic values of circulating tumor cells in breast cancer: a meta-analysis of 8,935 patients

Background

Circulating tumor cells (CTCs) could serve as a predictive biomarker in breast cancer (BC). Due to its high heterogeneity, the diagnostic and prognostic values of CTC are challenging.

Methods

We searched published studies from the databases of PubMed, Cochrane Library, Embase, and MEDLINE. The detection capability and hazard ratios (HRs) of CTCs were extracted as the clinical diagnosis and prognosis evaluation. Subgroup analyses were divided according to the detection methods, continents, treatment periods, therapeutic plans, and cancer stages.

Results

In this study, 35 publications had been retrieved with 8,935 patients enrolled. The diagnostic efficacy of CTC detection has 74% sensitivity and 98% specificity. The positive CTC detection (CTC+ ) would predict worse OS and PFS/DFS in both mid-therapy and post-therapy (HROS, 3.09; 95% CI, 2.17–4.39; HRPFS/DFS, 2.06; 95% CI, 1.72–2.47). Moreover, CTC+ indicated poor survival irrespective of the treatment phases and sampling times (HROS, 2.43; 95% CI, 1.85–3.19; HRPFS/DFS, 1.82; 95% CI, 1.66–1.99). The CTC+ was associated with poor survival regardless of the continents of patients (HROS = 2.43; 95% CI, 1.85–3.19).

Conclusion

Our study suggested that CTC+ was associated with a worse OS and PFS/DFS in the Asian population. The detection method, the threshold level of CTC+ , therapeutic approaches, and sampling times would not affect its diagnostic and prognostic values.

The dawn of spatial omics

Spatial omics has been widely heralded as the new frontier in life sciences. This term encompasses a wide range of techniques that promise to transform many areas of biology and eventually revolutionize pathology by measuring physical tissue structure and molecular characteristics at the same time. Although the field came of age in the past 5 years, it still suffers from some growing pains: barriers to entry, robustness, unclear best practices for experimental design and analysis, and lack of standardization. In this Review, we present a systematic catalog of the different families of spatial omics technologies; highlight their principles, power, and limitations; and give some perspective and suggestions on the biggest challenges that lay ahead in this incredibly powerful-but still hard to navigate-landscape.

A clinically feasible circulating tumor cell sorting system for monitoring the progression of advanced hepatocellular carcinoma

BACKGROUND

Hematogenous metastasis is essential for the progression of advanced hepatocellular carcinoma (HCC) and can occur even after patients receive multidisciplinary therapies, including immunotherapy and hepatectomy; circulating tumor cells (CTCs) are one of the dominant components of the metastatic cascade. However, the CTC capture efficiency for HCC is low due to the low sensitivity of the detection method. In this study, epithelial cell adhesion molecule (EpCAM)/vimentin/Glypican-3 (GPC3) antibody-modified lipid magnetic spheres (LMS) were used to capture tumor cells with epithelial phenotype, mesenchymal phenotype and GPC3 phenotype, respectively, in order to capture more CTCs with a more comprehensive phenotype for monitoring tumor metastasis.

RESULTS

The novel CTC detection system of Ep-LMS/Vi-LMS/GPC3-LMS was characterized by low toxicity, strong specificity (96.94%), high sensitivity (98.12%) and high capture efficiency (98.64%) in vitro. A sudden increase in CTC counts accompanied by the occurrence of lung metastasis was found in vivo, which was further validated by a clinical study. During follow-up, the rapid increase in CTCs predicted tumor progression in HCC patients. Additionally, genetic testing results showed common genetic alterations in primary tumors, CTCs and metastatic tissues. The proportion of patients predicted to benefit from immunotherapy with the CTC detection method was higher than that for the tissue detection method (76.47% vs. 41.18%, P = 0.037), guiding the application of clinical individualized therapy.

CONCLUSIONS

The Ep-LMS/Vi-LMS/GPC3-LMS sequential CTC capture system is convenient and feasible for the clinical prediction of HCC progression. CTCs captured by this system could be used as a suitable alternative to HCC tissue detection in guiding immunotherapy, supporting the clinical application of CTC liquid biopsy.