According to a recent study published in the International Journal of Radiation Oncology • Biology • Physics, patients with prostate cancer that have persistent prostate specific antigen (PSA) after prostatectomy should receive earlier and more aggressive radiotherapy.
The study entitled “Prostate-Specific Antigen Persistence After Radical Prostatectomy as a Predictive Factor of Clinical Relapse-Free Survival and Overall Survival: 10-Year Data of the ARO 96-02 Trial,” provided a 10-year post-treatment analysis of the German ARO 96-02 prospective clinical trial, which compared a wait-and-see (WS, arm A) versus an adjuvant radiation therapy (ART, arm B) approach for patients with node negative prostate cancer who had a prostatectomy and achieved undetectable PSA levels. Moreover, the study conducted by Thomas Wiegel and colleagues reports the clinical outcome of patients who after 12 years of follow-up had persistent PSA post-radical prostatectomy and received aggressive radiotherapy (SRT, arm C).
A total of 388 patients with prostate cancer were recruited from 1997 to 2004. All of the patients had radical prostatectomy. From the total 307 participants who achieved undetectable PSA levels, 159 patients were randomized to arm A (WS), and 148 to arm B (ART). The remaining 74 patients that did not achieve undetectable PSA levels were assigned to complete arm C (SRT).
Using the Kaplan-Meier method, the authors found that patients who had persisting PSA after radical prostatectomy also had higher preoperative PSA values, tumor stages, Gleason scores, and more positive surgical margins than patients in study arms A and B.
Results also revealed that compared with patients who had undetectable PSA levels, arm-C patients had worse clinical outcomes, with a 10-year relapse free survival rate of 67% versus 86% and 83% for arm A and arm B, respectively.
“After patients undergo radical prostatectomy, the marker for PSA should fall below detection limits. Our analysis demonstrates that patients who have detectable PSA post-prostatectomy may benefit from more aggressive, early and uniform treatment that could improve survival outcomes,” Thomas Wiegel, MD, director of the radiation oncology department at University Hospital Ulm in Ulm, Germany, and lead author of the study, said in news release. “The impact of PSA persistence on 10-year overall survival is evident based on this new analysis. Improved imaging or surrogate markers beyond PSA are desirable to distinguish risk groups among men with PSA persistence. Larger, prospectively randomized clinical trials should examine additional treatment options to come to a standardized therapy for prostate cancer patients with PSA persistence.”
Based on these findings, the research team suggests that detectable PSA after radical prostatectomy appears to be an indicator of clinical progression for prostate tumors. This indicator correlates with higher distant metastases and worse overall survival. Thus, the researchers suggest that larger prospective studies are necessary to understand patients’ treatment needs.