Salvage partial gland ablation for recurrent prostate cancer following primary partial gland ablation: Functional and oncological outcomes.

Introduction And Objective: Partial gland ablation (PGA) for localised prostate cancer (CaP) aims to eradicate clinically significant tumours while preserving healthy tissue, thereby decreasing the likelihood of side effects compared to whole-gland approaches. Although salvage radical prostatectomy (sRP) is a well-described salvage option in cases of PGA failure, the evidence supporting salvage PGA (sPGA) is limited. We hereby report the oncologic and functional outcomes of patients treated with sPGA following initial treatment with primary PGA (pPGA).

Methods: We describe the findings of a retrospective review of patients who had a CaP recurrence after pPGA and then underwent sPGA, at 3 medical centers in Ontario, Canada, between 2005 and 2017. Oncological outcomes following sPGA were assessed for biochemical recurrence (BCR) and biopsy-proven recurrence (BPR). Functional outcomes were described using the international prostate symptom score (IPSS), international index of erectile function (IIEF), and rates of urinary incontinence (use of >1 pad/day).

Results: We identified 25 patients who underwent sPGA following pPGA (hemiablation in 48% and zonal ablation in 52% of the patients). The median length of time was 16.8 months (interquartile range [IQR] 14.0-19.1) from pPGA to sPGA and 47.06 months (IQR 19.9-171.3) from pPGA to date of last follow up. High intensity focused ultrasound (HIFU) was the only modality used in all patients. At baseline, the median age was 65 years (IQR 52-77) and median prostate specific antigen (PSA) level was 7.46 ng/mL (IQR 1-25). The median time from pPGA to BPR was 12.7 months (IQR 5.19-36). At BPR following pPGA, 4 patients (17%) had CaP grade group (GG) 1, 10 patients (42%) had GG2, 6 patients (25%) had GG3, and 4 patients (17%) had GG4 disease, with a median PSA of 3.58 ng/mL (IQR 0.67-19). The median length of follow up after sPGA was 27.3 months (IQR 14.5-86.3). Following sPGA, 13/25 patients (52%) had BCR with median time to recurrence of 14 months (IQR 2.5-82.15), with a recurrence-free survival of 24.5 months (95% confidence interval: 15.3-not reached). Of those 13 patients, 4 were managed with sRP, 4 were managed with salvage radiotherapy, 3 were managed with androgen-deprivation therapy, 1 had a third PGA with HIFU, and 1 was managed with active surveillance. The mean change from baseline to last follow up in IPSS and IIEF scores was +1.3 (P = 0.66) and -2.3 (P = 0.32), respectively. Urinary incontinence was reported by 9% of patients at baseline, with only one additional patient developing incontinence following sPGA.

Conclusion: Our present study demonstrates that after a median follow-up of 27 months, sPGA for recurrent CaP following pPGA provides disease control in up to 50% of patients with nonsignificant detrimental effects on functional outcomes. Appropriate patient selection and adequate staging are important to consider before offering PGA to patients.