Propensity Score Matching (PSM) Comparison of Salvage Focal to Salvage Total Cryoablation of the Prostate
We compared oncological efficacy and functional outcomes for focal (SFC) versus total (STC) salvage cryoablation of the prostate.
In 400 men with recurrent disease after primary radiotherapy, we matched 100 treated with SFC to 300 treated with STC using propensity score matching with nearest neighbor method. Matching variables included age at time of treatment, pre-treatment PSA, Gleason sum, and neoadjuvant androgen deprivation therapy status. Primary outcomes were progression-free survival (PFS) using Phoenix criteria and post-treatment biopsy status. Secondary outcomes included post-treatment urinary incontinence, erectile dysfunction (ED), rectal fistulae, and urinary retention.
Median age of the study cohort was 72 (IQR.68-76) and median pre-treatment PSA 5.2 ng/ml (IQR, 3-8.7) and median Gleason Sum of 7 (IQR.6-7). There was a modest, non-significant improvement in 2-year PFS for STC compared to SFC (81.4% vs. 72.7%, p= 0.09) (Figure 1) but no significant difference in the prevalence of persistent cancer on post-treatment biopsy (26.2% vs. 35.3%, p=0.46). STC was associated with a lower probability of posttreatment, transient urinary retention (17.7% vs. 8%. p=0.02). There were no significant differences in post-treatment urinary incontinence (28.4% vs. 23.3% ,p=0.39), rectal fistulae (2% vs 3%, p=0.56) or new-onset ED (49% vs. 57.6%, p=0.47).
Compared to focal, whole gland salvage cryoablation was associated with a modest improvement in 2-year progression free survival and equivalent morbidity. Focal salvage cyroabaltion as opposed to whole gland therapy should be considered selectively, if at all, in men with exceptional sexual function even after primary radiation.