It is rapidly becoming apparent that we are going to need two simple, new terms to be able to use in discussion of the evolution of progressive prostate cancer after “standard” forms of androgen deprivation therapy (ADT) have failed to work. So … anyone got good, scientifically sound suggestions?
In the first place, the term, “castration-resistant prostate cancer” is clearly no longer accurate (whether it was ever a good term or not). This term was coined, not so long ago, to describe men who had progressive disease after treatment with:
- “Standard” ADT, meaning bilateral orchiectomy (surgical castration) or single-agent, continuous LHRH agonist therapy or continuous LHRH + antiandrogen therapy or almost any form of intermittent ADT and
- Continous use of LHRH + antiandrogen therapy in any man who had stopped responding to single-agent LHRH therapy or any form of intermittent ADT and
- Subsequent antiandrogen withdrawal
However, it is now clear that such men are not necessarily “castration resistant” (i.e., unresponsive to hormonal therapies) because many of them clearly still respond to therapy with the new hormonally active agents like abiraterone acetate and enzalutamide. We need a new term to describe this set of men (who are still naive to drugs like abiraterone acetate and enzalutamide). Other terms that have been use to describe this condition in the past (regardless of whether the patients had metastatic disease or not) include “hormone refractory prostate cancer” (HRPC) and “androgen-independent prostate cancer” (AIPC). Neither of these terms is going to be appropriate either.
The other set of patients who are going to need to be defined are those men who have progressive disease after all known forms of hormonal manipulation, including all those described above as well as men progressing after treatment with drugs like
- Ketoconazole and itraconazole
- Low-dose estrogens
- Abiraterone acetate
It may be that we should resusciate the term “hormone refractory” to imply this set of patients, but there may be better terms. As just one example, the hormonal axis on which all hormonal therapy for prostate cancer is based is the so-called “hypothalamic–pituitary–adrenal” (HPA) axis. If a patient becomes refractory to all attempts to manipulate the functions of that axis, perhaps we should define their condition as “HPA axis therapy resistant” or “HPA axis therapy refractory” prostate cancer (HTRPC ).
Anyway … now’s your chance to get creative!