Prostate Cryoablation Combined with Metronomic Cyclophosphamide for Metastatic Prostate Cancer

The goal of this clinical trial is to explore whether androgen deprivation therapy combined with novel androgen receptor inhibitors, prostate cryoablation, and metronomic cyclophosphamide is superior to the current treatment regimen of androgen deprivation therapy plus novel androgen receptor inhibitors for patients with metastatic prostate cancer. It will also learn about the safety of prostate cryoablation, and metronomic cyclophosphamide for patients with metastatic prostate cancer. The main questions it aims to answer are:

Does prostate cryoablation, and metronomic cyclophosphamide delay the progression of metastatic prostate cancer? Does prostate cryoablation, and metronomic cyclophosphamide reduce symptomatic local events of metastatic prostate cancer?

Researchers will explore if androgen deprivation therapy combined with novel androgen receptor inhibitors, prostate cryoablation, and metronomic cyclophosphamide works to treat metastatic prostate cancer.

Participants will:

Receive treatment of androgen deprivation therapy and novel androgen receptor inhibitors until progression.

Receive prostate cryoablation surgery and take cyclophosphamide. Visit the clinic every 1-3 months for checkups and tests. Keep a diary of their symptoms.

This study aims to evaluate the efficacy and safety of combining prostate cryoablation and cyclophosphamide with androgen deprivation therapy plus novel androgen receptor inhibitors (apalutamide, rezvilutamide, or darolutamide) in patients with newly diagnosed, metastatic prostate cancer. By comparing with previous studies, it seeks to explore whether prostate cryoablation and cyclophosphamide treatment can confer survival benefits and reduce symptomatic local urinary events in these patients.

Patients with newly diagnosed, metastatic prostate cancer who meet the inclusion criteria after evaluation will receive treatment with androgen deprivation therapy plus a novel androgen receptor inhibitor (apalutamide, rezvilutamide, or darolutamide) in combination with prostate cryoablation and cyclophosphamide. Enrolled patients should start the novel androgen receptor inhibitor (apalutamide, rezvilutamide, or darolutamide) within 3 months of initiating androgen deprivation therapy and undergo prostate cryoablation within 6 months of starting androgen deprivation therapy. Cyclophosphamide treatment will begin one day after prostate cryoablation and continue for a total of six months.

The primary endpoint of the study is PSA progression-free survival. Secondary endpoints include: 1) radiographic progression-free survival, 2) time to progression to metastatic castration-resistant prostate cancer, 3) overall survival, 4) PSA nadir, 5) incidence of symptomatic local events, and 6) safety.

Eligibility Criteria:
Inclusion Criteria:

* Males between 18 and 80 years old;
* Histopathological confirmation of prostatic acinar adenocarcinoma;
* Diagnosed with metastatic prostate cancer at initial diagnosis according to the AJCC 8th edition staging criteria;
* No progression at the time of initiating of prostate cryoablation;
* ECOG score of 0-1;
* Can tolerate general anesthesia and prostate cryoablation surgery;
* No significant abnormalities .
* Able to understand this study and sign the informed consent form.

Exclusion Criteria:

* Serious illness not suitable to receive the treatment regimen;
* Other malignant tumors (within 5 years), except for non-melanoma skin cancer;
* Receipt of treatments other than treatment regimen of this study;
* Prostate cancer invading the rectum;
* with prostate volumegreater than 55ml after 6 months of androgen deprivation therapy .