Objectives:
To evaluate the association between PSA nadir level and time to nadir (TTN) with biochemical recurrence (BCR) risk after radical prostatectomy (RP) in the SEARCH database.
Methods:
Retrospective analysis of 1,939 men from the SEARCH database treated with RP between 1998–2015 with available ultrasensitive PSA nadir within 1–6 months after RP. Uni- and multivariable analyses of PSA nadir and TTN with time from nadir to BCR were done with Cox models (adjusted for demographics, tumor features and preoperative PSA).
Results:
Among men with an undetectable PSA nadir, the TTN was unrelated to BCR (1–2.9 vs. 3–6 months: HR 0.86, p=0.46). Regardless of TTN, men with detectable nadir had increased risk of BCR (TTN 3–6 months: HR 1.81, p=0.024; TTN 1–2.99 months: HR 3.75, p<0.001 vs. undetectable nadir and TTN 3–6 months). Among men with a detectable PSA at 1–3 months, 53% had a lower follow-up PSA 3–6 months after RP which was undetectable in 32% and lower but still detectable in 21%.
Conclusions:
In the post-RP setting, men with both a detectable nadir and a shorter TTN had an increased risk of BCR. Intriguingly, about half of the men with a detectable PSA in the first 3 months after RP had a lower follow-up PSA between 3 and 6 months after RP. If confirmed in future studies, this has important implications for patients considering adjuvant therapy based upon post-operative PSA values in the first 3 months after RP.