The field of CTC enrichment has seen many emerging technologies in recent
years, which have resulted in the identification and monitoring of clinically
relevant, CTC-based biomarkers that can be analyzed routinely without invasive
procedures. Several molecular platforms have been used to investigate the
molecular profile of the disease, from high throughput gene expression analyses
down to single cell biological dissection.
The established presence of CTC heterogeneity nevertheless constitutes a
challenge for cell isolation as the several subpopulations can potentially
display different molecular characteristics; in this scenario, careful
consideration must be given to the isolation approach, whereas methods that
discriminate against certain subpopulations may result in the exclusion of CTCs
that carry biological relevance. In the context of prostate cancer (PC), CTC
molecular interrogation can enable longitudinal monitoring of key biological
features during treatment with substantial clinical impact, as several
biomarkers could predict tumor response to AR signaling inhibitors (abiraterone,
enzalutamide) or standard chemotherapy (taxanes). Thus, CTCs represent a
valuable opportunity to personalize medicine in current clinical practice.