The Different Outcomes And Mechanism Of Prostate Cryosurgery For Metastatic Prostate Cancer With Different Metastatic Volume

Androgen deprivation therapy(ADT)is the standard treatment for patients with metastatic prostate cancer(PCA).Previous study suggested that the patients with metastatic PCA would benefit from local treatment of the primary tumor.Radical prostatectomy and radiation therapy used to serve as local treatments for primary tumors in metastatic PCA.The outcomes and mechanism of cryosurgery in metastatic PCA with different metastatic volume remains unclear.The research will assess the outcomes and mechanism of prostate cryosurgery for metastatic PCA with different metastatic volume by 2 retrospective analysis and a randomized controlled trial,aimed to provide theoretical evidence for cryosurgery in metastatic PCA treatment.Methods1.The clinical data of 69 patients with oligometastatic PCA were retrospectively analyzed:23 men treated by ADT alone(the control group),23 men plus radiation therapy(the radiation group),and 23 men plus cryosurgery(the cryosurgery group).Progression-free survival(PFS),PSA kinetics and local complications were compared between these three groups.2.The clinical data of 44 metastatic PCA patients with high metastatic volume were retrospectively analyzed.16 patients received ADT alone(the ADT group).15 patients received ADT plus docetaxel chemotherapy(the chemotherapy group).13 patients received cryosurgery combined with docetaxel chemotherapy and ADT(the cryosurgery group).PFS,PSA kinetics and local complications were compared.3.From January 2015 to September 2017,the metastatic PCA patients meeting the criterions were randomized by 1:1 ratio into the cryosurgery group or the control.The patients in the cryosurgery group received cryosurgery plus ADT.The patients in the control received ADT alone.Circulating tumor cells(CTCs)and PFS were compared at pretherapy,3-month posttherapy and 1-year posttherapy respectively.The patients were divided into low and high metastatic volume patients for subgroup analysis.Cox proportional hazards regression analysis was used to identify predictors for PFS.Results1.The patients with oligometastatic PCA in the cryosurgery group and radiation therapy group had longer PFS than those in the control;no significant difference was seen between the cryosurgery group and the radiation therapy group.The patients in the cryosurgery group had lower PSA nadir and less complications than those in the radiation therapy group and the control.2.The metastatic PCA patients with high metastatic volume in the cryosurgery group and in the chemotherapy group had significantly longer PFS than those in the ADT group;no significant difference was seen between the cryosurgery group and the chemotherapy group.PSA response rate was higher in the cryosurgery group and the chemotherapy group than the ADT group.Local complications were less in the cryosurgery group than the chemotherapy group and the ADT group.3.Forty participants finished the randomized controlled trial,each group had 20 participants.CTCs were less in the cryosurgery group than the control group at 3-month posttherapy and 1-year posttherapy.CTCs in the cryosurgery group decreased gradually at pretherapy,at 3-month posttherapy and 1-year posttherapy.The patients in the cryosurgery group had significantly longer PFS than those in the ADT group.Subgroup analysis showed:the cryosurgery group had longer PFS than the control in the patients with low metastatic volume;no significant difference was seen between the two group in the patients with high metastatic volume Cox multivariate analysis associated shorter PFS with the following factors:without cryosurgery,Gleason score ≧8,T stage ≧T3a,bone metastases>3,PSA≧100 ng/ml,CTCs positive at 3-month posttherapy and CTCs positive at 1-year posttherapy.Conclusions1.Cryosurgery might improve PFS and delay time to CRPC as well as radiation therapy in oligometastatic PCA patients.The patients in the cryosurgery group had lower PSA nadir and less complications than those in the radiation therapy.2.Chemotherapy plus ADT could improve PFS in the metastatic PCA patients with high metastatic volume.Cryosurgery combined with chemotherapy and ADT could not improve PFS furthermore,but could improve PSA kinetics and reduce local complications.3.CTC was a prognosis factor in metastatic PCA patients.Cryosurgery plus ADT could reduce CTCs and improve PFS than ADT alone in the metastatic PCA patients with low metastatic volume,no similar effect was seen in the metastatic PCA patients with high metastatic volume.