The Study: The interim results of the CHAARTED trial were the first of a series showing exciting new treatment options for metastatic prostate cancer. As a reminder, the trial randomized men with metastatic (de novo or recurrent), hormone-sensitive prostate cancer to ADT +/- docetaxel x 6 cycles. Now the final results are out in JCO. About two-thirds of patients had high-volume (HV) disease, defined as visceral mets and/or >3 bone mets with at least one of those outside the spine/pelvis—trust us, this gets important in a second. Adding docetaxel extended median overall survival (OS) by a whopping 10 months. BUT men with HV disease drove the survival benefit with a 17 month (!) improvement in median OS, as opposed to no significant difference among those with low volume disease. These HV guys achieved nearly double the times to both castration resistance and clinical progression. Men with de novo metastatic disease also appeared to derive a bigger benefit.
Bottom Line: Adding docetaxel to ADT seems to seriously benefit men with de novo and/or high-volume metastatic disease. Perhaps, men with recurrent low-volume metastatic disease (and variant HSD3B1?) would benefit more from ADT + abiraterone. Stay tuned.