When I was first diagnosed with metastatic prostate cancer one of the first questions that I asked my doctor was whether it made sense for me to start chemotherapy immediately. I very clearly remember him telling me that there was absolutely no evidence that starting chemotherapy at this early stage would do anything to extend my life. I went along with him, but I do admit that I was cynical.
Having now survived many years and spending these years learning about this disease I do have to admit that he was right. I have learned that what seems logical might not be actually what is real. Evidence is the best guide.
Today, it was released that hormone therapy along with docetaxel (chemotherapy) might improves overall survival in prostate cancer. Preliminary results from an NIH-supported clinical trial showed that some men with hormone-sensitive metastatic prostate cancer who received docetaxel at the start of standard hormone therapy lived longer than men who received hormone therapy alone.
The study known as E3805 was a randomized controlled clinical trial that enrolled 790 men with metastatic prostate cancer between July 2006 and November 2012. All men received initial ADT, either ADT alone or ADT with docetaxel every 3 weeks for 18 weeks.
Early results showed a significant improvement in the overall survival for men who received ADT plus docetaxel compared to ADT alone (3-year survival rates of 69.0% vs. 52.5%, respectively).
However, there is an important caveat as the majority of benefit was limited to men receiving both ADT and chemotherapy who had significant metastasis (3-year survival rates of 63.4% vs. 43.9%, respectively). As the result the investigators noted that the use of chemotherapy in combination with ADT should be limited to men with high-extent (multiple metastases) metastatic prostate cancer.
There are plans for further follow-up on patients with less extensive metastasis who participated in E3805 in order to define the effect of this treatment combination.
These results are significant as they will be practice changing. Clinicians will now have to consider giving chemotherapy much earlier in men with significant disease. Where they are going to get tripped up is in deciding if prior to administering chemotherapy with all its toxic effects should Provenge, Zytiga or Xtandi be used?
Joel T Nowak, M.A., M.S.W.