Postoperative radiotherapy for men who have persistently elevated PSA levels following radical prostatectomy (RP) for prostate cancer is associated with improved survival among patients with adverse pathologic characteristics, according to a new study.
In addition, persistently elevated PSA after RP is not always associated with a poor prognosis.
Giorgio Gandaglia, MD, of IRCCS Ospedale San Raffaele and Vita-Salute San Raffaele University in Milan, Italy, and colleagues studied 496 men who underwent RP and lymph node dissection at 2 referral centers from 1994 to 2014 and had persistently elevated PSA (0.1 to 2 ng/mL at 6 to 8 weeks after RP. The group consisted of 251 men who underwent postoperative radiotherapy and 245 who did not.
The median follow-up for survivors was 110 months, the investigators reported in a paper published online ahead of print in European Urology. In all, 49 patients died from prostate cancer.
The 10-year CSM-free survival was 88%. Receipt of postoperative radiotherapy was associated with a survival benefit only among patients with a CSM risk of 30% or higher. Patients with a CSM risk less than 30% should be initially managed expectantly, according to the researchers.
Among the 245 patients who did not receive postoperative radiotherapy, those in pathologic grade group 4 or higher had a nearly 7-fold higher risk of CSM than those in pathologic grade 3 or lower.
Pathologic grade group and pathologic stage independently predicted CSM. In multivariable analysis, a pathologic grade group of 4 or higher was associated with a significant 2.7-fold higher risk of CSM compared with a pathologic grade group of 3 or less. A pathologic tumor stage of T3b/4 versus T2-pT3a was associated with a significant 2.3-fold higher risk of CSM.
The association between CSM-free survival and PSA at 6 to 8 weeks differed by the baseline risk of CSM, as defined by pathologic characteristics. The effect of increasing PSA was evident only in patients with a CSM risk of 10% or more. “Increasing PSA levels should be considered as predictor of mortality exclusively in men with worse pathologic characteristics,” the investigators concluded.
Gandaglia G, Boorjian SA, Parker WP, et al. Impact of postoperative radiotherapy in men with persistently elevated prostate-specific antigen after radical prostatectomy for prostate cancer: A long-term survival analysis. Eur Urol 2017; published online ahead of print.