The Efficacy and Safety of Prostatectomy for Castration-Naive Oligometastatic Prostate Cancer

Inclusion Criteria:

* Patients must be ≥ 40 and ≤75 years of age.
* All patients must have a histologically or cytologically diagnosis of prostate cancer.
* All patients must have been diagnosed oligometastatic prostate cancer which meet the following criteria. (1) ≤5 metastatic lesions are found by imaging examination (2)No visceral metastasis was found (3) The diameter of a single lesion ≤5cm or the surface area ≤250cm2.
* Patients previously treated with surgical castration or androgen deprivation therapy must maintain a testosterone level of \<50ng/dl or \<1.7nmol/L during treatment. Also the treatment duration should be less than 9 months. Patients were previously treated with at least 6 cycles of abiraterone.
* PSA\<2ng/ml before enrollment.
* There was no PSA progression or radiographic progression during previous treatment.
* Primary lesion must be eligible for radical prostatectomy based on random radiographic assessment. ( Preoperative clinical staging \<T4 or achievable complete resection agreed by experienced surgeons is deemed as eligible for radical prostatectomy)
* Eastern Cooperative Oncology Group (ECOG) physical condition score ≤ 1.
* Patients must have adequate hematologic function, within 28 days prior to registration as evidenced by: white blood cell (WBC) ≥ 4.0 × 109 /L, platelets≥ 100 × 109 / L, hemoglobin ≥ 9g / dL, and international normalized ratio (INR) \< 1.5.
* Patients must have adequate hepatic function, within 28 days prior to registration, as evidenced by: total bilirubin (TBIL)≤1.5 x upper limit of normal (ULN),and SGOT (AST) and SGPT (ALT) ≤ 2.5 x ULN.
* Patients must have adequate renal function, within 28 days prior toregistration, as evidenced by serum creatinine ≤2×ULN
* Patients must participate voluntarily and sign an informed consent form(ICF), indicating that they understand the purpose and required procedures of the study, and are willing to participate in. Patients must be willing to obey the prohibitions and restrictions specified in the research protocol.

Exclusion Criteria:

* Patients with neuroendocrine, small cell, or signet ring cell histological features are not eligible.
* Patients with visceral metastasis or more than 5 metastatic lesions are excluded.
* Patients were diagnosed metastatic castration-naive prostate cancer for more than 9 months or showed biochemical or radiographic progression before enrollment.
* Patients with unresectable primary lesion before enrollment based on CT/MRI.
* Patients received local treatments such as pre-focal treatment, radiotherapy and palliative endoscopic resection.
* Patients with severe or uncontrolled concurrent infections are not eligible.
* Patients must not have New York Heart Association Class III or IV congestive heart failure at the time of screening. Patients must not have any thromboembolic event, unstable angina pectoris, myocardial infarction within 6 months prior to registration.
* Patients must not have uncontrolled severe hypertension, persistent uncontrolled diabetes, oxygen-dependent lung disease, chronic liver disease, or HIV infection.
* Patients must not have had other malignancies other than prostate cancer in the past 5 years, but cured basal cell or squamous cell skin cancers can be enrolled.
* Patients with mental illness, mental disability or inability to give informed consent are not eligible.