Treating Prostate Cancer That Has Come Back After Surgery With Apalutamide and Targeted Radiation Based on PET Imaging

This phase III trial tests two questions by two separate comparisons of therapies. The first question is whether enhanced therapy (apalutamide in combination with abiraterone + prednisone) added to standard of care (prostate radiation therapy and short term androgen deprivation) is more effective compared to standard of care alone in patients with prostate cancer who experience biochemical recurrence (a rise in the blood level of prostate specific antigen \[PSA\] after surgical removal of the prostate cancer).

A second question tests treatment in patients with biochemical recurrence who show prostate cancer spreading outside the pelvis (metastasis) by positron emission tomography (PET) imaging. In these patients, the benefit of adding metastasis-directed radiation to enhanced therapy (apalutamide in combination with abiraterone + prednisone) is tested.

Diagnostic procedures, such as PET, may help doctors look for cancer that has spread to the pelvis. Androgens are hormones that may cause the growth of prostate cancer cells. Apalutamide may help fight prostate cancer by blocking the use of androgens by the tumor cells. Metastasis-directed targeted radiation therapy uses high energy rays to kill tumor cells and shrink tumors that have spread. This trial may help doctors determine if using PET results to deliver more tailored treatment (i.e., adding apalutamide, with or without targeted radiation therapy, to standard of care treatment) works better than standard of care treatment alone in patients with biochemical recurrence of prostate cancer.