Study highlights long-term risks of prostate cancer treatment

The risks of adverse effects and complications from treatment for prostate cancer are substantial and continue for years after treatment ends.

The largest comprehensive analysis reporting long-term risks from such treatment relative to the risks faced by a control group of untreated men has just been published in the journal JAMA Oncology.

In the 12 years following treatment, men whose initial treatment was a prostatectomy (removal of all or part of the prostate) had a risk of urinary or sexual complications more than seven times higher than that faced by untreated men.

For men whose first treatment was radiotherapy, the risk of such complications that was almost three times that of untreated men. Additionally, men in the radiotherapy group faced three times the risk of a bladder cancer diagnosis.

The report – by researchers from the SWOG Cancer Research Network, a clinical trials group funded by the National Cancer Institute (NCI), part of the National Institutes of Health (NIH), along with researchers from the NCI – argues that men need to have access to risk numbers such as these when deciding whether to even be screened for prostate cancer.

“This study throws down a major gauntlet to all physicians to give patients this information before they even begin the process of drawing a PSA test,” said the paper’s senior author Ian M. Thompson, Jr., MD, of CHRISTUS Santa Rosa Health System and The University of Texas Health Science Center at San Antonio. A PSA test measures the blood level of a protein called prostate-specific antigen.

Roughly 30 million men in the U.S. are in the age range (55-69 years) for which the U.S. Preventive Services Task Force recommends discussing PSA testing with their doctor. Making an informed decision requires that they have a clear understanding of the magnitude of the potential risks and benefits of screening, and of each step that might follow it, which can include a biopsy and one or more treatments if prostate cancer is found.

One challenge in determining the risk of adverse effects from prostate cancer treatment is that for some of these conditions, such as erectile dysfunction, the incidence increases with age. So, a true measure of risk can be determined only by comparing men treated for prostate cancer with untreated men of similar age in the general population. The JAMA Oncology study does just that.

“Past studies of prostate cancer treatment complications have had small sample sizes, limited follow up, or the absence of a valid control group. Our study is distinguished by long follow-up, out to 12 years, looking at a broad spectrum of key complications. Critically, we were able to compare treated men to a representative control group of untreated men, which prior studies have not included.” – Joseph Unger, PhD., lead author