Today most doctors rely on their personal evaluation or objective response criteria (OR) of a man to know when docetaxel chemotherapy has stopped working. The earlier this determination can be accurately made the quicker an alternative treatment can e put into place. Personal evaluations without any validated tools are unreliable and never consistent among doctors. Errors are made which will lead to poorer outcomes.

Circulating tumor cell (CTC) counts have been looked at and seem to yield positive results for making this type of clinical decision in men who are taking both abiraterone (Zytiga) and enzalutamide (Xtandi). Some new research has found that CTCs also display a superior prognostic value for overall survival (OS) compared to objective response criteria (OR) in men with metastatic castration-resistant prostate cancer (mCRPC).

The researchers used the CellSearch™ system and evaluated 122 samples during docetaxel chemotherapy.
They found that CTC counts appear to be an earlier and more sensitive predictor for survival and treatment response than current OR approaches and may provide complementary information toward individualized treatment strategies.

J Cancer Res Clin Oncol. 2015 Feb 24. Epub ahead of print. doi: 10.1007/s00432-015-1936-z; Thalgott M, Heck MM, Eiber M, Souvatzoglou M, Hatzichristodoulou G, Kehl V, Krause BJ, Rack B, Retz M, Gschwend JE, Andergassen U

Joel T. Nowak, M.A., M.S.W.