Outcomes of Salvage Whole-gland Cryoablation for Radiation-resistant PCa

Oncological and Functional Outcomes for Men Undergoing Salvage Whole-gland Cryoablation for Radiation-resistant Prostate Cancer (2023)

A study from Duke.

"Abstract

Background: There is no consensus on the optimal approach for salvage local therapy in radiation-resistant/recurrent prostate cancer (RRPC).

Objective: To investigate oncological and functional outcomes for men treated with salvage whole-gland cryoablation (SWGC) of the prostate for RRPC.

Design, setting, and participants: We retrospectively reviewed our prospectively collected cryosurgery database between January 2002 and September 2019 for men who were treated with SWGC of the prostate at a tertiary referral center.

Intervention: SWGC of the prostate.

Outcome measurements and statistical analysis: The primary outcome was biochemical recurrence-free survival (BRFS) according to the Phoenix criterion. Secondary outcomes included metastasis-free survival, cancer-specific survival, and adverse events.

Results and limitations: A total of 110 men with biopsy-proven RRPC were included in the study. Median follow-up for patients without biochemical recurrence (BCR) after SWGC was 71 mo (interquartile range [IQR] 42.3-116). BRFS was 81% at 2 yr and 71% at 5 yr. A higher prostate-specific antigen (PSA) nadir after SWGC was associated with worse BRFS. The median International Index of Erectile Function-5 score was 5 (IQR 1-15.5) before SWGC and 1 (IQR 1-4) after SWGC. Stress urinary incontinence, strictly defined as the use of any pads after treatment, was 5% at 3 mo and 9% at 12 mo. Clavien-Dindo grade ≥3 adverse events occurred in three patients (2.7%).

Conclusions: In patients with localized RPPC, SWGC achieved excellent oncological outcomes with a low rate of urinary incontinence, and represents an alternative to salvage radical prostatectomy. Patients with fewer positive cores and lower PSA tended to have better oncological outcomes following SWGC.

Patient summary: For men with prostate cancer that persists after radiotherapy, a freezing treatment applied to the whole prostate gland can achieve excellent cancer control. Patients who did not have elevated prostate-specific antigen (PSA) at 6 years after this treatment appeared to be cured."

Djin

I believe radioresistant/radioresistance are the accepted terms.

"Radiation therapy (RT) is commonly used for the treatment of localized prostate cancer (PCa). However, cancer cells often develop resistance to radiation through unknown mechanisms and pose an intractable challenge. Radiation resistance is highly unpredictable, rendering the treatment less effective in many patients and frequently causing metastasis and cancer recurrence." from "Profiles of Radioresistance Mechanisms in Prostate Cancer" (2018)

I don't know what the limit of resolution is for PSMA-identified lesions, but I would think that as a second shot following unsuccessful RT of the prostate, one would want to go ahead and treat the whole prostate. I'm thinking that viable microlesions could remain in untreated prostate tissue after focal cyro.

Djin