The Role of Percentage of Prostate-specific Antigen Reduction After Focal Therapy Using High-intensity Focused Ultrasound for Primary Localised Prostate Cancer. Results from a Large Multi-institutional Series

Abstract

Focal therapy (FT) for prostate cancer (PCa) is emerging as a novel therapeutic approach for patients with low to intermediate-risk disease, in order to provide acceptable oncological control, whilst avoiding the side effects of radical treatment. Evidence regarding the ideal follow up strategy, and the significance of PSA kinetics post treatment is needed. In this study we aimed at assessing the value of the percentage of PSA reduction (%PSA reduction) after FT in predicting the likelihood of any additional treatment, or any radical treatment. We retrospectively analysed a multicentre cohort of 688 men receiving FT for PCa. Overall, the rates of any additional treatment, and of any radical treatment rate were 30% and 13%, respectively. Median follow-up was 41 months. The median %PSA reduction after FT was 73%. At Cox multivariable analysis, %PSA reduction was an independent predictor of any additional treatment (hazard ratio [HR]: 0.97; p<0.001) and of any radical treatment (HR: 0.96; p<0.001) after FT. For %PSA reduction > 90%, the probability of any additional treatment within 5 years was 20%. Conversely, for %PSA reduction < 10% the probability of receiving any additional treatment within 5 years was roughly 70%. This study is the first to assess the role of %PSA reduction in the largest multicenter cohort of men receiving FT for PCa. Given the lack of standardized follow-up strategies in FT field, the use of the %PSA reduction should be considered. Patient summary:The %PSA reduction is a useful tool to assess men following FT. It can assist the urologist in setting up an appropriate follow-up and during post-FT patients counselling.

Intraoperative Digital Analysis of Ablation Margins (DAAM) by Fluorescent Confocal Microscopy to Improve Partial Prostate Gland Cryoablation Outcomes

“…All patients included in the present study had a reduction of PSA > 75% at three months of follow-up. Even if the percentage of PSA reduction represents only a surrogate of the oncological outcome, Stabile et al recently showed it is inversely associated with disease recurrence and the need for additional treatment, thus potentially useful as a proxy of treatment efficacy [16].…”

“…Surgical and intraoperative biopsy complications were reported using the Clavien-Dindo Classification [15]. Finally, PSA values at three months after therapy were used to compute the percentage of PSA reduction (derived from the ratio between PSA at three months and preoperative PSA) [16].…”

Development and internal validation of multivariable prediction models for biochemical failure after MRI-guided focal salvage high-dose-rate brachytherapy for radiorecurrent prostate cancer

“…We argue that this might be a better predictor than PSA nadir, given its dependence on pre-salvage PSA. Furthermore, PSA nadir is also influenced by other factors, such as prostate volume [12]. In another study by Peters et al, univariable analysis showed that age was associated with BF in 62 patients treated with whole-gland brachytherapy.…”

“…Assuming a 0.05 acceptable difference in apparent and adjusted R-squared, an expected R-squared of 0.15, an overall event rate of 0.2 (200 events per 1000 person-years follow-up), and a shrinkage factor of 0.8, would allow for seven candidate variables with 150 patients and 61 events [25]. For model 1, six candidate variables were selected for multivariable testing based on clinical knowledge and literature [12,17,18]. For model 2, three additional variables were tested, thereby accepting a small increase in chance of overfitting.…”

“…In this setting, focal therapy, targeting the recurrent lesion while sparing healthy prostate tissue, is an attractive treatment option with the aim of postponing initiation of androgen deprivation therapy (ADT) [5,8]. The main potential advantage of focal over whole-gland salvage treatments is the reduced chance of side-effects and quality of life deterioration, without affecting oncological outcomes [9][10][11][12][13][14][15].…”