Perioperative Circulating Tumor Cells (CTCs), MCTCs, and CTC-White Blood Cells Detected by a Size-Based Platform Predict Prognosis in Renal Cell Carcinoma

Research progress on the multi-omics and survival status of circulating tumor cells

In the dynamic process of metastasis, circulating tumor cells (CTCs) emanate from the primary solid tumor and subsequently acquire the capacity to disengage from the basement membrane, facilitating their infiltration into the vascular system via the interstitial tissue. Given the pivotal role of CTCs in the intricate hematogenous metastasis, they have emerged as an essential resource for a deeper comprehension of cancer metastasis while also serving as a cornerstone for the development of new indicators for early cancer screening and new therapeutic targets. In the epoch of precision medicine, as CTC enrichment and separation technologies continually advance and reach full fruition, the domain of CTC research has transcended the mere straightforward detection and quantification. The rapid advancement of CTC analysis platforms has presented a compelling opportunity for in-depth exploration of CTCs within the bloodstream. Here, we provide an overview of the current status and research significance of multi-omics studies on CTCs, including genomics, transcriptomics, proteomics, and metabolomics. These studies have contributed to uncovering the unique heterogeneity of CTCs and identifying potential metastatic targets as well as specific recognition sites. We also review the impact of various states of CTCs in the bloodstream on their metastatic potential, such as clustered CTCs, interactions with other blood components, and the phenotypic states of CTCs after undergoing epithelial-mesenchymal transition (EMT). Within this context, we also discuss the therapeutic implications and potential of CTCs.

Prognostic value of circulating tumor cells associated with white blood cells in solid cancer: a systematic review and meta-analysis of 1471 patients with solid tumors

BACKGROUND

The clinical relevance of circulating tumor cell-white blood cell (CTC-WBC) clusters in cancer prognosis is a subject of ongoing debate. This study aims to unravel their contentious predictive value for patient outcomes.

METHODS

We conducted a comprehensive literature search of PubMed, Embase, and Cochrane Library up to December 2022. Eligible studies that reported survival outcomes and examined the presence of CTC-WBC clusters in solid tumor patients were included. Hazard ratios (HR) were pooled to assess the association between CTC-WBC clusters and overall survival (OS), as well as progression-free survival (PFS)/disease-free survival (DFS)/metastasis-free survival (MFS)/recurrence-free survival (RFS). Subgroup analyses were performed based on sampling time, treatment method, detection method, detection system, and cancer type.

RESULTS

A total of 1471 patients from 10 studies were included in this meta-analysis. The presence of CTC-WBCs was assessed as a prognostic factor for overall survival and PFS/DFS/MFS/RFS. The pooled analysis demonstrated that the presence of CTC-WBC clusters was significantly associated with worse OS (HR = 2.44, 95% CI: 1.74-3.40, P < 0.001) and PFS/DFS/MFS/RFS (HR = 1.83, 95% CI: 1.49-2.24, P < 0.001). Subgroup analyses based on sampling time, treatment method, detection method, detection system, cancer type, and study type consistently supported these findings. Further analyses indicated that CTC-WBC clusters were associated with larger tumor size (OR = 2.65, 95% CI: 1.58-4.44, P < 0.001) and higher alpha-fetoprotein levels (OR = 2.52, 95% CI: 1.50-4.22, P < 0.001) in hepatocellular carcinoma. However, no significant association was found between CTC-WBC clusters and TNM stage, depth of tumor invasion, or lymph node metastasis in the overall analysis.

CONCLUSIONS

CTC-WBC clusters are negative predictors for OS and PFS/DFS/MFS/RFS in patients with solid tumors. Monitoring CTC-WBC levels may provide valuable information for predicting disease progression and guiding treatment decisions.

Circulating biomarkers in perioperative management of cancer patients

Owing to the advances in surgical technology, most solid tumours can be controlled by surgical excision. The priority should be tumour control, while some routine perioperative management might influence cancer progression in an unnoticed way. Moreover, it is increasingly recognized that effective perioperative management should include techniques to improve postoperative outcomes. These influences are elucidated by the different functions of circulating biomarkers in cancer patients. Here, circulating biomarkers with two types of clinical functions were reviewed: (i) circulating biomarkers for cancer progression monitoring, for instance, those related to cancer cell malignancy, tumour microenvironment formation, and early metastasis, and (ii) circulating biomarkers with relevance to postoperative outcomes, including systemic inflammation, immunosuppression, cognitive dysfunction, and pain management. This review aimed to provide new perspectives for the perioperative management of patients with cancer and highlight the potential clinical translation value of circulating biomarkers in improving outcomes.

Phenotyping of rare circulating cells in the blood of non-metastatic breast cancer patients using microfluidic Labyrinth technology

Label-free technologies for isolating rare circulating cells in breast cancer patients are widely available; however, they are mostly validated on metastatic patient blood samples. Given the need to use blood-based biomarkers to inform on disease progression and treatment decisions, it is important to validate these technologies in non-metastatic patient blood samples. In this study, we specifically focus on a recently established label-free microfluidic technology Labyrinth and assess its capabilities to phenotype a variety of rare circulating tumor cells indicative of epithelial-to-mesenchymal transition as well as cancer-associated macrophage-like (CAML) cells. We specifically chose a patient cohort that is non-metastatic and selected to undergo neoadjuvant chemotherapy to assess the performance of the Labyrinth technology. We enrolled 21 treatment naïve non-metastatic breast cancer patients of various disease stages. Our results indicate that (i) Labyrinth microfluidic technology is successfully able to isolate different phenotypes of CTCs despite the counts being low. (ii) Invasive phenotypes of CTCs such as transitioning CTCs and mesenchymal CTCs were found to be present in high numbers in stage III patients as compared to stage II patients. (iii) As the total load of CTCs increased, the mesenchymal CTCs were found to be increasing. (iv) Labyrinth was able to isolate CAMLs with the counts being higher in stage III patients as compared to stage II patients. Our study demonstrates the ability of the Labyrinth microfluidic technology to isolate rare cancer-associated cells from the blood of treatment naïve non-metastatic breast cancer patients, laying the foundation for tracking oncogenic spread and immune response in patients undergoing neoadjuvant chemotherapy.

The Number of Intraoperative Intestinal Venous Circulating Tumor Cells Is a Prognostic Factor for Colorectal Cancer Patients

Purpose

To assess the association between intestinal venous blood (IVB) circulating tumor cells (CTCs) and clinicopathological parameters in stage I-III colorectal cancer (CRC) patients.

Methods

Participants were retrospectively retrieved, who were admitted to our hospital or took annual physical exams between December 1, 2015 and December 31, 2018. A negative enrichment-immunofluorescence in situ hybridization (NE-imFISH) technique was used to isolate and identify CTCs. Receiver operating characteristic (ROC) curves and Youden index values were used to determine the critical CTC cutoff value for the diagnosis of CRC. Kaplan-Meier and log-rank methods were used to conduct survival analyses, and multivariate Cox regression analyses were employed for multivariate corrections to comprehensively evaluate the value of CTCs in the diagnosis of CRC. Relationships between IVB CTCs, clinicopathological parameters, and prognosis were then analyzed based upon patient postoperative follow-up data.

Results

In total, we retrieved 282 patients including 48 healthy controls, 72 patients with benign colorectal tumors, and 162 CRC patients. CRC patients exhibited significantly higher numbers of CTCs relative to control patients or those with benign disease. CTC numbers in CRC patient peripheral blood (PB) and IVB were closely associated with tumor node metastasis (TNM) staging (P < 0.01), carbohydrate antigen-125 (CA-125) levels (P < 0.001), and KRAS (Kirsten rat sarcoma virus oncogene) mutation status (P < 0.001). The disease-free survival (DFS) of patients in the CTC-negative group was significantly longer than that of patients in the CTC-positive group (24.60 ± 13.31 months vs. 18.70 ± 10.19 months, P < 0.05), with the same being true with respect to their overall survival (OS) (30.60 ± 12.44 months vs. 35.25 ± 11.57 months, P < 0.05). A multivariate analysis revealed that the detection ≥2 CTCs/3.2 ml was independently associated with poorer DFS and OS. CTC counts were independently predictive of CRC patients TNM staging, CA-125, and KRAS mutation status in both univariate and multivariate Cox proportional hazards regression analyses.

Conclusion

CTCs are valuable biomarkers that can be monitored to predict CRC patient disease progression.