Early use of chemotherapy in metastatic prostate cancer – an overview of current evidence

This study examined evidence for the benefits of adding chemotherapy early to hormone therapy for metastatic prostate cancer. Authors concluded that early evidence indicates a survival benefit with the addition of chemotherapy for metastatic prostate cancer.

Androgen deprivation therapy (ADT) is a type of hormone therapy that targets male hormones (such as testosterone) active in cancer growth. ADT is currently the standard of care for advanced prostate cancer and cancer that has spread to distant organs (metastatic). Treatment response to ADT is estimated to be about 80%. Over time, however, many men eventually become resistant (no longer respond) to ADT. When cancer continues to spread despite ADT, this is referred to as metastatic castration-resistant prostate cancer (mCRPC).

Chemotherapy, such as docetaxel (Taxotere), is often the standard-of-care treatment for mCRPC. However, recent evidence is suggesting that adding chemotherapy to ADT early may improve survival for men with metastatic prostate cancer (mPC). This is in contrast to waiting until cancer progresses and becomes hormone-resistant.

The aim of this study was to review evidence on the benefits of adding chemotherapy early to ADT.

In an early study, 385 patients recently diagnosed with mPC were randomly assigned to be treated with either ADT alone or ADT with docetaxel. Average overall survival (time from treatment until death from any cause) was improved by 4.7 months with the addition of chemotherapy. However, this increase was not statistically significant.

In a larger study involving 790 men with mPC, average overall survival was 57.6 months in the group receiving ADT with docetaxel. This was significantly longer compared to men treated with ADT alone (44 months). The survival benefit was particularly pronounced for men with a greater amount of distant cancer spread.

Another study included 2,962 men with high-risk locally advanced prostate cancer (tumor protruding into neighbouring tissue) or mPC. Men were randomly assigned to be treated with ADT either with or without docetaxel. Results showed a 10-month increase in overall survival with the addition of chemotherapy. Overall, mortality risk was 22% lower for men treated with ADT and docetaxel.

Authors reported early results indicating a survival benefit when chemotherapy is added to ADT for men with mPC. Authors also advised that more studies are needed to examine the best timing of chemotherapy for advanced prostate cancer.