PSA kinetics following primary focal cryotherapy (hemiablation) in organ-confined prostate cancer patients

We aim to evaluate prostate-specific antigen (PSA) trends in post-primary focal cryotherapy (PFC) patients.

This was an institutional review board-approved retrospective study of PFC patients from 2010 to 2015. Patients with at least one post-PFC PSA were included in the study. Biochemical recurrence (BCR) was determined using the Phoenix criteria. PSA bounce was also assessed. We analyzed rates of change of PSA over time of post-PFC between BCR and no BCR groups. PSA-derived variables were analyzed as potential predictors of BCR.

A total of 104 PFC patients were included in our analysis. Median (range) age and follow-up time were 66 (48-82) years and 19 (6.3-38.6) months, respectively. Four (3.8%) patients experienced PSA bounce. The median percent drop in first post-PFC PSA of 80.0% was not associated with BCR (p = 0.256) and may indicate elimination of the index lesion. The rate of increase of PSA in BCR patients was significantly higher compared to patients who did not recur (median PSA velocity (PSAV): 0.15 vs 0.04 ng/ml/month, p = 0.001). Similar to PSAV (HR 9.570, 95% CI 3.725-24.592, p < 0.0001), PSA nadir ≥ 2 ng/ml [HR (hazard ratio) 1.251, 95% CI 1.100-1.422, p = 0.001] was independently associated with BCR.

A significant drop in post-PFC PSA may indicate elimination of the index lesion. Patients who are likely to recur biochemically have a significantly higher PSAV compared to those who do not recur. Nadir PSA of less than 2 ng/ml may be considered the new normal PSA in focal cryotherapy (hemiablation) follow-up.

World journal of urology. 2017 Nov 17 [Epub ahead of print]

Michael Kongnyuy, Shahidul Islam, Alfred K Mbah, Daniel M Halpern, Glenn T Werneburg, Kaitlin E Kosinski, Connie Chen, David J Habibian, Jeffrey T Schiff, Anthony T Corcoran, Aaron E Katz

Department of Urology, NYU-Winthrop Hospital, 1300 Franklin Ave, Garden City, Mineola, NY, 11530, USA. ., Department of Biostatistics, NYU-Winthrop Hospital, Mineola, NY, USA., University of South Florida College of Public Health, Tampa, FL, USA., Department of Urology, NYU-Winthrop Hospital, 1300 Franklin Ave, Garden City, Mineola, NY, 11530, USA., Stony Brook University School of Medicine, Stony Brook, NY, USA., St George's University School of Medicine, True Blue, Grenada.