The American Society of Clinical Oncology (ASCO) and Cancer Care Ontario (CCO) has issued a joint clinical practice guideline on treating men with metastatic castration-resistant prostate cancer (CRPC).

The guideline includes recommendations on systemic therapies that are indicated for use alongside androgen deprivation, addressing survival and quality of life benefits, side effects, and cost considerations for each.

"We have seen unprecedented progress against advanced prostate cancer recently, with six new treatments approved in the last couple of years," said Ethan Basch, MD, co-chair of the ASCO/CCO Expert Panel that developed the guideline.

"There are a lot of nuances about treatment selection in terms of disease stage and what prior therapies the patient received. We hope this guideline will help doctors and patients make informed treatment decisions."

Many men with hormone-sensitive metastatic prostate cancer ultimately develop CRPC.

While continuing on androgen deprivation therapy, such men now have a range of additional treatments available that have the potential to improve their survival and quality of life.

In releasing this guideline, ASCO/CCO prominently included quality of life considerations in the development of recommendations.

"Including quality of life data in the guideline helps people understand how the different treatments will make them feel," said Andrew Loblaw, MD, co-chair of the ASCO/CCO Expert Panel that developed the guideline and head of the genitourinary disease site group for CCO.

"We also have to be conscious of cost, because it can affect access to treatment and quality of life."

Key guideline recommendations:

• Continue androgen deprivation therapy (pharmaceutical or surgical) indefinitely.
• Abiraterone/prednisone, enzalutamide, or radium-223 (for men whose cancer spread predominantly to the bones) should be offered in addition to androgen deprivation therapy, as all three treatments are associated with improved survival, quality of life, and favourable balance of benefits and harms. 
• If chemotherapy is being considered, docetaxel/prednisone should be offered but side effect risks should be discussed.
• Cabazitaxel may be offered to men whose disease worsens despite treatment with docetaxel, accompanied by discussion of side effect risks.​
• Sipuleucel-T may be offered to men with no symptoms or minimal symptoms.​
• Mitoxantrone may be offered, accompanied by discussion of limited clinical benefit and side effect risk.
• Ketoconazole or antiandrogens (bicalutamide, flutamide, nilutamide) may be offered, accompanied by discussion of limited clinical benefit.
• Bevacizumab, estramustine, or sunitinib should not be offered. 
• Palliative care should be offered early to all patients in discussion of treatment options.

Although insufficient clinical evidence was available to recommend the optimal sequence in which treatments should be given, ongoing clinical trials are exploring this question, as well as potential benefits of combining various treatments.

The guideline builds upon prior recommendations from ASCO and CCO that were based on a systematic review of 28 randomised clinical trials published between 1979 and 2004.

An additional 28 randomised clinical trials on systemic therapies have been identified since 2004, including targeted therapies and immunotherapies, for the treatment of metastatic CRPC.

These additional randomised trials inform the current recommendations.

The guideline, Systemic Therapy in Men with Metastatic Castration-Resistant Prostate Cancer (CRPC): American Society of Clinical Oncology and Cancer Care Ontario Clinical Practice Guideline, was published in the Journal of Clinical Oncology and is available here.

Source: ASCO