Radiation Plus Hormone Therapy Extends Survival in Patients With High-Risk Prostate Cancer
The addition of radiation to lifelong hormone therapy with oral antiandrogens vs antiandrogens alone reduced the prostate cancer–specific death rate by more than 50% at 10 and 15 years in men with locally advanced prostate cancer, according to an updated analysis of the Scandinavian Prostate Cancer Group’s Study VII. Results were presented at a press briefing in advance of the 2014 Genitourinary Cancers Symposium in San Francisco (Abstract 4).
Study Details
Earlier results of this study, published in 2009 after about 8 years of observation, demonstrated a 12% reduction in prostate cancer–specific mortality in patients with locally advanced prostate cancer initially treated with hormone therapy plus radiotherapy vs patients treated with hormone therapy alone.
“In 1996, when this study was initiated, standard therapy for locally advanced or high-risk prostate cancer was lifelong hormone therapy alone. This trial continues to show that adding radiotherapy substantially boosts long-term survival. The combination [of radiotherapy and hormone therapy] more than doubled the 10-year and 15-year survival rate and confirms that this approach should be a standard curative option for men with this type of prostate cancer with at least another 10-year life expectancy,” stated lead author Sophie Dorothea Fosså, MD, PhD, of Oslo University Hospital, Norway.
Dr. Fosså noted that lifelong hormone therapy is still considered standard treatment for locally advanced or high-risk prostate cancer.
In 1996, locally advanced prostate cancer (ie, extending through the prostate capsule) was considered inoperable, and surgery is still not used at some centers because it can be challenging to remove all the tumor tissue, she explained. Radiation can be directed at tissue outside the prostate and can attack cancer cells that extend through the capsule.
Benefit of Radiotherapy Confirmed
The updated analysis was conducted after 11 years of observation and was based on mortality data from the Norwegian and Swedish death registries. Among 439 men treated with antiandrogens alone, 118 deaths occurred vs 45 deaths among the 436 men who received combination therapy. The 10- and 15-year cancer-specific mortality rates were 18.9% and 30.7%, respectively, for the men treated with antiandrogens alone vs 8.3% and 12.4 %, respectively, for those who received both radiotherapy and antiandrogens.
“At 15 years, the difference between the two arms in prostate cancer–specific mortality became even greater,” Dr. Fosså noted. She pointed out that the 10-year 8.3% prostate cancer–specific mortality rate in the combination arm was similar to that after prostatectomy in comparable patients.
“However, the difference in overall mortality between the two arms was narrower because many patients died of other diseases,” she added.
The 10- and 15-year overall mortality in patients treated with antiandrogens alone was 35% and 57%, respectively, and 26% and 43%, respectively, in those treated with the combination of radiation plus antiandrogens.
Both treatment arms were associated with adverse events, including impaired sexual function and bowel problems. Dr. Fosså said that patients should be aware of the side effects of the treatment options so that they can make informed decisions based on their expected post-treatment quality of life.
The study authors reported no potential conflicts of interest.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
