Usefulness of robot‐assisted radical prostatectomy in a patient with oligometastatic castration‐resistant prostate cancer

INTRODUCTION: The patients with prostate cancer and low‐volume osseous metastases who underwent local definitive therapies had lower risks of cancer‐specific mortality. The usefulness of local definitive therapy for metastatic prostate cancer remains unclear. CASE PRESENTATION: A 76‐year‐old man visited a private hospital with a chief complaint of left lower limb pain. His serum prostate‐specific antigen level was 365.156 ng/mL. Histological evaluation led to the initial diagnosis of adenocarcinoma of Gleason score 4 + 4 and clinical stage T3a N1 M1b. Although androgen deprivation therapy was performed, he developed metastatic castration‐resistant prostate cancer 6 months after the initial treatment. Therefore, he received enzalutamide and attained a serum prostate‐specific antigen level of 0.002 ng/mL 7 months after the second treatment. We performed robot‐assisted radical prostatectomy 1 year after diagnosis. Histopathological examination revealed that prostate cancer cells disappeared into the prostate. CONCLUSION: Robot‐assisted radical prostatectomy in selected patients with metastatic castration‐resistant prostate cancer may improve oncological outcomes.