Men with castration-resistant prostate cancer (CRPC) treated with abiraterone may experience PSA surge, but it has no long-term impact on outcome, according to Italian investigators.
In a retrospective study of 330 CRPC patients (median age 74 years) being treated with abiraterone, Vincenza Conteduca, MD, PhD, of Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST), IRCCS, Meldola, Italy, and colleagues monitored PSA levels at baseline every 4 weeks. They defined PSA surge as a PSA increase within the first 8 weeks from the start of abiraterone therapy of more than 1% from baseline followed by a PSA decline.
The cohort included 281 patients previously treated with chemotherapy and 49 chemotherapy-naïve patients.
The investigators identified PSA surge in 20 (7%) chemotherapy patients and 2 (4%) chemotherapy-naïve patients (4%), Dr Conteduca’s team reported online ahead of print in The Prostate. For the patients experiencing PSA surge, the timing of PSA peak from baseline was a median of 5 weeks; the median PSA rise from baseline was 21%.
During an overall median follow-up was 23 months, the investigators observed no significant differences in progression-free and overall survival between the patients with and without PSA surge.
Multivariable analysis revealed no baseline factors associated with PSA surge.
“Physicians and patients should be aware of PSA surge challenge to prevent a premature discontinuation of potentially effective therapy with abiraterone,” they concluded.
Conteduca V, Caffo O, Lolli C, et al. Long-term clinical impact of PSA surge in castration-resistant prostate cancer patients treated with abiraterone. Prostate 2017; published online ahead of print on April 20. doi: 10.1002/pros.23357