Flow Cytometric Methods for Circulating Tumor Cell Isolation and Molecular Analysis

Detection of circulating tumor cells in non-metastatic prostate cancer through integration of a microfluidic CTC enrichment system and multiparametric flow cytometry

Prostate cancer (PCa) is the second most common cancer among men and the fifth leading cause of cancer death. Circulating tumor cell (CTC) enumeration and characterisation in PCa has been shown to provide valuable information on prognosis of disease, therapy management and detection of resistance. Here, Cellsway's microfluidic platform for high-throughput enrichment of intact CTC populations was used to isolate CTCs from the blood of 20 localised PCa patients and 10 healthy donor samples to evaluate the clinical performance of the technology. To enumerate and characterise CTCs, a multi-parameter flow cytometry analysis was performed on the enriched CTC suspension using CTC-specific biomarkers. CTCs were detected in 17 of 20 patient samples, which corresponds to 85% CTC positivity. The median CTC count per 7.5 ml blood was 2 (1-9). In 80% of patients (n = 16), the number of CTCs ranged from 1 to 5, and in 5% of patients (n = 1) the number of CTCs was above 5. No CTCs were observed in the blood samples of 10 healthy volunteers, demonstrating the high specificity and low risk of false positives of the technology.

Immune Resistance Mechanisms and the Road to Personalized Immunotherapy

What does the future of cancer immunotherapy look like and how do we get there? Find out where we've been and where we're headed in A Report on Resistance: The Road to personalized immunotherapy.

"Friends and foes" of multiple myeloma measurable/minimal residual disease evaluation by next generation flow

Next Generation Flow (NGF) represents a gold standard for the evaluation of Minimal Residual Disease (MRD) in Multiple Myeloma (MM) patients at any stage of treatment. Although the assessment of MRD is still not universally employed in clinical practice, numerous studies have demonstrated the strength of MRD as a reliable predictor of long-term outcome, and its potential to supersede the prognostic value of CR. The possibility to acquire millions of events, in combination with the use of standard reagents and a good expertise in the analysis of rare populations, led to high chance of success and a sensitivity of 10-6 that is superimposable to the one of Next Generation Sequencing molecular techniques. Some minor bias, correlated to the protocols applied, to the quality of samples and to the high heterogeneity of plasma cells phenotype, may be overcome using standard protocols and having at disposition personnel expertise for MRD analysis. With the use of NGF we can today enter a new phase of the quantification of residual disease, switching from the definition of "minimal" residual disease to "measurable" residual disease. This review takes account of the principle "friends and foes" of Myeloma "Measurable" Residual Disease evaluation by NGF, to give insights into the potentiality of this technique. The optimization of the quality of BM samples and the analytic expertise that permits to discriminate properly the rare pathologic clones, are the keys for obtaining results with a high clinical value that could be of great impact and relevance in the future.

Does transrectal ultrasonography-guided biopsy of the prostate lead to possible further metastasis via circulating tumor cells?

Background/aim

We evaluate whether transrectal ultrasonography (TRUS)-guided prostate biopsy might lead to spillage of tumor cells into peripheral blood as a result of disruption of the epithelial barrier and ultimately result in metastasis.

Materials and methods

Eighty-eight patients underwent TRUS-guided prostate needle biopsy due to prostate-specific antigen (PSA) increase or abnormal digital rectal examination at the Samsun Research and Training Hospital (Samsun, Turkey) between April 2016 and September 2018. Approximately 10 mL of whole blood was collected from patients before, 1 week after, and 1 month after biopsy. Samples were analyzed for CD117 positivity and prostate-specific membrane antigen (PSMA) levels using flow cytometry. Patients with pathologically determined prostate cancer and without CD117 positivity before biopsy were included in the study. The study group thus consisted of 55 patients.

Results

Subjects’ PSA levels ranged from 2.3 to 40.0 ng/mL (median: 7.9 ng/mL), and their Gleason score was a median of 7 (range: 5–9). PSMA levels ranged between 9.3 ng/mL and 118.5 ng/mL and CD117 antigen levels between 0 and 5. We detected no CD117- positive cells in blood samples collected 7 days or 1 month after biopsy.

Conclusion

We detected no circulating tumor cells in the peripheral circulation following biopsy. Prostate needle biopsy seems to be a safe method in terms of spillage of tumor cells into blood circulation as a possible cause of further metastasis.

Single-Cell Proteomics for Cancer Immunotherapy

Cancer immunotherapy fights against cancer by modulating the immune response and is delivering encouraging results in clinical treatments. However, it is challenging to achieve durable response in all cancer patients during treatment due to the diversity and dynamic nature of immune system as well as inter- and intratumor heterogeneity. A comprehensive assessment of system immunity and tumor microenvironment is crucial for effective and safe cancer therapy, which can potentially be resolved by single-cell proteomic analysis. Single-cell proteomic technologies enable system-wide profiling of protein levels in a number of single cells within the immune system and tumor microenvironment, and thereby provide direct assessment of the functional state of the immune cells and tumor-immune interaction that could be used to evaluate efficacy of immunotherapy and to improve clinical outcome. In this chapter, we summarized current single-cell proteomic technologies and their applications in cancer immunotherapy.