We currently have several treatments for men with Metastatic Castration Resistant Prostate Cancer (mCRPC) that prolong survival. However, we don’t understand the optimum sequencing of these drugs. Personalized medicine is beginning to use genetic predictors to to help make treatment decisions so that expensive potentially toxic therapies can be avoided in men who have minimal chance of ever having any benefit.
In reality, the actual use of these genetic predictors hasn’t yet become a part of the average clinical practice of most doctors. They are thing to write about, but not what most of us actually have available from our doctors. Given this, we have a great need to also develop practical methods of identifying men who are unlikely to respond to a particular treatment so that a more appropriate therapy can be used.
In a study presented at the 2015 ASCO Meeting, researchers reported on a detailed analysis of men with mCRPC receiving multiple lines of therapy. Their goal was to identify a cohort of men who will have limited benefit from abiraterone to see if there are any consistencies among them which could instruct us on who might not respond to Abiraterone (Zytiga).
In a retrospective analysis of 47 consecutive men with mCRPC treated in a single cancer center was conducted. The men were treated sequentially with androgen deprivation (Luteinizing Hormone Releasing Hormone agonist/LHRHa or orchidectomy), bicalutamide (Casodex), docetaxel (Taxotere) plus prednisone followed by abiraterone (Zytiga).
They found that men who had less than or equal to 18 months to progression while on a LHRHa, no response to bicalutamide and less than or equal to 6 months response to docetaxel were more likely to experience a shorter progression-free and overall survival from abiraterone than men not falling into these data points.
J Clin Oncol 33, 2015 (suppl; abstr e16103);
Rhian Sian Davies, Christian Smith, Ricky Dylan Frazer, Mick Button, Jacob Tanguay, Jim Barber, Nachi Palaniappan, John Staffurth, Jason Francis Lester.
Joel T. Nowak, M.A., M.S.W.
All I have is this present moment. The past and the future are only ideas.