Following radical prostatectomy (RP) for prostate cancer, patients who have both a detectable PSA nadir and a shorter time to nadir (TTN) are at higher risk for biochemical recurrence of disease, a new study suggests.
A team led by Stephen J. Freedland, MD, of Cedars-Sinai Medical Center in Los Angeles, conducted a retrospective analysis of 1939 men from the SEARCH database who underwent RP from 1998 to 2015 and had PSA nadir values determined by ultrasensitive assay within 1–6 months post-RP.
Among men with an undetectable PSA nadir, TTN was unrelated to biochemical recurrence (BCR). Regardless of TTN, however, men with detectable nadir had a significantly increased risk of BCR. Compared with men who had an undetectable nadir and TTN of 3–6 months, those who had a TTN of 3–6 months and 1–2.99 months had a 1.8 and 3.7 times increased risk of BCR, respectively, Dr Freedland and his colleagues reported online ahead of print in Urology. Additionally, among patients who had detectable PSA at 1–3 months, 53% had a lower follow-up PSA 3–6 months after RP, with 32% having undetectable levels and 21% having lower but still detectable levels.
“With the widespread availability of early adjuvant therapies, it is essential to determine the risk of disease recurrence and progression early after surgery,” the authors concluded. “Using both the PSA nadir value and the time it takes to reach nadir can be valuable tools in predicting a patient’s BCR risk and potential need for early secondary therapy.”
With regard to patients for whom early post-operative PSA values are crucial in deciding on adjuvant radiation therapy or not, and the PSA is detectable but below the threshold for recurrence (0.2 ng/mL or less), Dr Freedland’s team noted that if their findings are confirmed in future studies, “it may be reasonable to give more time for the PSA to decline before documenting a nadir, which may spare some patients from needless radiation.”
Skove SL, Howard LE, Aronson WJ, et al. Timing of PSA nadir after radical prostatectomy and risk of biochemical recurrence. Urol 2017; published online ahead of print. doi: 10.1016/j.urology.2017.07.009.