Importance of Detecting Early Metastasis in CRPC

The Prostate Cancer Radiographic Assessments for Detection of Advanced Recurrence (RADAR) Group was a multidisciplinary collaboration tasked with reviewing the currently available imaging guidelines for metastatic castration-resistant prostate cancer (CRPC). This review found a lack of consensus on eligibility criteria, type of imaging modality, or the frequency of scanning for detecting metastatic disease.

One of the suggestions from the review, explained Daniel P. Petrylak, MD, who was a member of RADAR, was to start looking for metastases when a patient’s PSA reached 2, and then again at every doubling point thereafter. While there are recommendations, there are no absolute guidelines at this point as to when patients should be imaged, says Petrylak. Since many of these patients are being followed through urology, another goal of the report was to prod urologists to look for early metastatic disease, as multiple therapies are now available.

Prior to the development of metastatic disease, the treatment of a typical patient with M0 prostate cancer is very challenging, since there aren't any therapies approved specifically for this distinct population. According to NCCN, the only options at present are observation or enrollment in a clinical trial. Several phase III clinical trials are available for patients in the M0 setting, including:

• The SPARTAN trial exploring ARN-509 in men with M0 CRPC (NCT01946204)
• The ARAMIS trial is examining the efficacy and safety of ODM-201 in men with high-risk M0 CRPC (NCT02200614)
• The PROSPER trial is investigating the efficacy and safety of enzalutamide in patients with M0 CRPC (NCT02003924)