Circulating tumour cells as biomarkers of prostate, bladder, and kidney cancer

Circulating tumour cells (CTCs) have been validated as prognostic biomarkers of prostate cancer. These data have been generated with a number of different methods for CTC detection including the FDA-approved CellSearch testNovel CTC assays have also been developed to help identify which prostate cancer patients are most likely to respond to androgen-pathway targeted therapies, such as abiraterone and enzalutamideCTCs have also been studied as prognostic biomarkers of bladder cancer. These data have mostly been generated using the CellSearch testOne potential area of clinical application of CTCs in patients with urothelial carcinoma is the identification of patients with non-muscle-invasive bladder cancer who have been clinically understaged and are unlikely to benefit from intravesical therapyCTCs have been less well studied as biomarkers of kidney cancer. This is related to the fact that renal cell carcinoma expresses low levels of EpCAM, a cell surface maker that is used by many CTC isolation methodsAlternative methods for CTC isolation that employ specific markers for kidney cancer have shown early promise