Daniel P. Petrylak, MD: Sequencing Therapies in mCRPC

Daniel P. Petrylak, MD, Professor of Medicine (Medical Oncology) and of Urology, Professor and Co-Director, Signal Transduction Research Program, Yale Cancer Center, notes that this patient has symptomatic metastatic castration-resistant prostate cancer (CRPC).

First, bicalutamide should be discontinued. Approximately 20% to 30% of patients will respond to antiandrogen withdrawal, as evidenced by PSA declines and, in some patients, improvement in symptoms. This generally occurs 4 to 6 weeks after treatment. It takes approximately 6 weeks for this effect to be noted.

It is important to know whether or not the patient is on narcotic analgesics, as well as whether the patient has visceral disease, Petrylak notes. This is an important decision point for subsequent treatments. A CT scan of the chest/abdomen/pelvis would be appropriate for restaging, Petrylak adds.

If the patient is not on narcotic analgesics or has no evidence of visceral disease on CT scan, immunotherapy would be appropriate. Of course, if the patient has rapidly progressing disease or bone pain it may not be appropriate to wait for anti-androgen withdrawal. There’s been no evidence that this strategy has any effect on survival, Petrylak adds.

For symptomatic patients with bone metastases, first-line treatment options would include chemotherapy with docetaxel, other treatment options would include isotope therapy with radium-223, as well as other hormonal manipulations with abiraterone/prednisone or enzalutamide. This patient also should be on a bone-targeting agent, such as denosumab or zoledronic acid.