Circulating Tumor Cells In Patients Undergoing Androgen Deprivation Therapy With Versus Without Cryosurgery For Metastatic Prostate Cancer: : A Retrospective Analysis

Background: The study aimed to assess the value of circulating tumor cells (CTCs) as a prognostic and treatment response marker in patients undergoing androgen deprivation therapy (ADT) plus cryosurgery vs. ADT alone for metastatic prostate cancer (mPCA).Methods: This retrospective analysis included 43 patients with mPCA: 23 receiving ADT alone (control) and 20 receiving additional cryosurgery (cryosurgery group).CTCs and progression-free survival(PFS) were compared between the two groups. Cox proportional hazards regression was conducted to identify variables associated with PFS.Results: Median PFS was 35 months (IQR: 33-37) in the cryosurgery group vs. 30 months (IQR: 27-32) in the control (p<0.001). CTCs count was significantly lower in the cryosurgery group at both 3 months (z=2.170, p=0.030) and 12 months (z=2.481; p=0.013). In comparison to the baseline, the number of CTCs at both 3 and 12 months was lower in the cryosurgery group (p=0.004 and p<0.001, respectively), but not in the ADT alone group. In multivariate Cox regression, shorter PFS was associated with baseline PSA ≧100 ng/ml (HR 6.584, 95%CI: 5.309-8.166), biopsy Gleason score≧8 (HR 2.064, 95%CI: 1.608-2.650), clinic T stage＞T2b (HR 5.021, 95%CI: 3.925-6.421), number of bone metastases＞3 (HR 3.421, 95%CI: 2.786-4.202), positive CTCs at 3 months post-treatment (HR 6.833, 95%CI: 5.176-9.022), positive CTCs 1 year post-treatment (HR 6.051, 95%CI: 4.347-8.424). Prostate cryosurgery was associated with longer PFS(HR 0.062, 95%CI: 0.048-.080). Conclusions: CTC was a prognostic and treatment response marker for mPCA. ADT plus cryosurgery could reduce CTCs and prolong PFS vs. ADT alone in mPCA patients with low metastatic volume.