NEW YORK, NY--(Marketwired - Apr 2, 2014) - Patients underdoing adjuvant radiation therapy for localized prostate cancer may benefit from a significantly reduced course of androgen deprivation therapy (ADT). In comparing the outcomes of 18-month and 36-month ADT courses, Canadian researchers found comparable disease-free survival rates and reduced side effects. The findings suggest that halving the traditional 36-month dosing could reduce costs and improve patients' quality of life without jeopardizing treatment benefits.
To more aggressively target cancer cells, androgen blockade therapy is commonly added to standard pelvic radiotherapy in patients with high-risk, node-negative prostate cancer. Based on a study of 630 men, researchers report that halving the ADT course to 18 months safely and comparably addresses node and bone metastases. New York robotic prostate surgeon, David B. Samadi, MD, is encouraged by these findings.
"Long-term use of androgen blockades can lead to low testosterone and impotence," said Dr. Samadi, Chairman of Urology and Chief of Robotic Surgery at Lenox Hill Hospital. "Prostate cancer treatment side effects and their duration are of top concern when patients evaluate prostate cancer treatments such as robotic prostatectomy, radiation therapy and hormone therapy."
The study was conducted across 10 Canadian centers from October 2000 through January 2008. Radiation patients were randomly assigned to 18 months and 36 months of simultaneous androgen blockade therapy. In a multivariate analysis, all participants had similar PSA levels, Gleason scores and disease stages. At five- and 10-year follow-ups, the differences in mortality and biochemical failure rates between the 18-month and 36-month groups were not statistically significant. Pelvic node metastases and bone metastases were also comparable.
Researchers are hopeful that the 18-month mark may represent a threshold beyond which no additional ADT benefit is realized. If so, patients could face a shorter duration of side effects such as erectile dysfunction (ED). Findings were presented at the 2013 Genitourinary Cancers Symposium, http://meetinglibrary.asco.org/content/107219-134
The quality of life data from the study are under continued review and likely will be published in a follow-up report later this year.
Radiation therapy and hormone therapy for prostate cancer are disease management modalities. Whereas robotic surgery removes the cancer from the body, radiation and hormone therapy treat it in place. Side effects of hormone therapy may include bone weakening and cancer treatment-induced bone loss, acute kidney injury, erectile dysfunction, fatigue and depression.