Lack of accruals

Patients with hormone sensitive oligometastatic prostate cancer (≤ 5 metastatic tumours outside of regional pelvic nodes with no more than 3 in any organ system) and no previous treatment to prostate will be treated with intermittent androgen deprivation therapy +/- chemotherapy, stereotactic radiotherapy to all metastases, and either radical prostatectomy or radiotherapy.

Investigators propose to do a randomized feasibility trial comparing RP vs RT to the prostate in the setting of hormone sensitive oligometastatic prostate cancer. SBRT will be used to treat all of the metastases, and this will be combined with an intermittent ADT approach. Adding systemic chemotherapy will be allowed. Given the past difficulties of randomizing patients between RP and RT in localized prostate cancer studies (like SPIRIT), investigators feel a small feasibility project is the first step. In the setting of metastatic disease, where radical treatment is not routine standard of care, we hope that patients will be more inclined to accept randomization. If patients do not accept their assigned randomization (ie they prefer RP even though they are randomized to RT, or vice versa), they will still be treated with their prostate intervention of choice and followed for their outcomes.

Inclusion Criteria:

• Able to provide informed consent.
• Histologic confirmation of prostate adenocarcinoma.
• Stage IV disease with ≤ 5 metastases outside of the pelvis.
• ≤ 3 metastases in any one organ system.
• ECOG performance 0-1.
• All metastatic tumours amenable to SBRT.
• Patient eligible for either RP or RT to the prostate.

Exclusion Criteria:

• Castration resistant prostate cancer.
• Previous RP or RT to prostate.
• Inability to treat all metastases with SBRT.
• Prior malignancy within the past 5 years, excluding non-melanoma skin cancer, in-situ cancer, superficial bladder cancer, chronic lymphocytic leukemia or low grade lymphoma which is being observed.