Comparing Radiation Therapies for Gleason 5 Prostate Cancer
Posted: Monday, March 23, 2020
According to the results of a retrospective analysis published in European Urology, there appears to be no significant survival benefit to men who have Gleason grade group 5 prostate cancer with the use of whole-pelvis versus prostate-alone external-beam radiotherapy (EBRT), with or without a brachytherapy boost. Amar U. Kishan, MD, of UCLA Jonsson Comprehensive Cancer Center, and colleagues based their work on the outcomes of 1,170 patients with biopsy-proven Gleason 5 prostate cancer treated in the United States and Norway between 2000 and 2013. However, they did find that pelvic radiation resulted in a longer duration of prostate-specific antigen (PSA) control.
Prostate cancer of this grade is linked to a high risk of nodal metastases, the authors wrote. A total of 734 men were treated with EBRT (41% whole-pelvis), and 436 men were given EBRT with a brachytherapy boost (73% whole-pelvis).
At a median follow-up of 5.6 years, the adjusted 5-year biochemical recurrence–free survival rates with whole-pelvis radiotherapy in the EBRT and EBRT-plus-brachytherapy-boost groups were 66% and 88%, respectively, and 58% and 78%, respectively, without whole-pelvis radiotherapy. The 88%/78% difference was significant (P = .02)—in other words, PSA levels were controlled longer—but the 66%/58% difference was not (P = .40). Furthermore, whole-pelvis radiotherapy was not significantly associated with improved distant metastasis–free survival or prostate cancer–specific survival in the EBRT group or in the group that received EBRT and a brachytherapy boost, the team explained.
Nonetheless, continued “strategies to optimize whole-pelvis radiotherapy are warranted,” concluded Dr. Kishan and co-investigators. “Potentially…the [adjunctive] use of advanced imaging techniques [could] identify occult nodal disease.”
Disclosure: The study authors reported no conflicts of interest.