Early-Stage Prostate Cancer Treatment: Examining Long-Term Complications

Announcer:
Welcome to On the Frontlines of Prostate Cancer on ReachMD. On this episode, we’ll hear from Dr. Joseph Unger, who is not only a biostatistician and health services researcher, but also an Associate Professor in the Cancer Prevention Program within the Public Health Services Division at Fred Hutchinson Cancer Research Center. He’ll be discussing his study on long-term adverse effects and complications after prostate cancer treatment. Let’s hear from Dr. Unger now.

Dr. Unger:
So our primary objective was to estimate the long-term complications rate following treatment for early-stage prostate cancer, and this is really critical to understand because early-stage prostate cancers are predominantly low risk. Although prostate cancer will affect more than 50 percent of men in their lifetime, only about two to three percent will actually die of the disease, so treatment for early-stage prostate cancer is going to have both potential advantages and disadvantages. On the one hand, it may reduce or eliminate the risk of developing an advanced-stage prostate cancer at a later time, but on the other hand, most early-stage prostate cancers do not progress to the advanced stage and may simply reside harmlessly for the remainder of a man’s life, which could be decades. So the treatment for early-stage prostate cancer also comes with decided disadvantages at the same time, such as short and long-term urinary and sexual complications and even more rare but very serious complications. 

For our methods, we were able to employ a novel linkage between two large data sources. We linked two large prostate cancer prevention trials to Medicare claims data to identify the development of prostate cancer, the receipt of prostate cancer treatment, and the complications from those treatments. So our strategy had some distinct advantages over prior studies. First, prior studies have generally almost entirely—to my knowledge—lacked a valid control group. Because our database was comprised of men who were initially healthy, without prostate cancer, we were able to compare those who ultimately received prostate cancer treatment to a control cohort of older men. This is vital because older men develop some conditions due to natural aging, especially urinary and sexual complications. So in our study we were able to compare treated to untreated men to understand the extent to which patterns of complications were actually attributable to the prostate cancer treatment itself or just to naturally getting older. And prior studies have not been able to do that. Prior studies also had small sample sizes, analyzed only a few complications, and/or had limited follow-up. In contrast, our study examined a broad-spectrum of different types of complications all the way out to 12 years after treatment in order to better understand the long-term impact of the prostate cancer treatment. 

The results were that even after accounting for age-related symptoms and disease, prostate cancer treatment was associated with substantial risks of complications in the 12 years after treatment, especially urinary and sexual complications. Patients receiving prostatectomy had more than a six-fold increased risk of one or more complications compared to a control cohort, and patients receiving radiation therapy had more than a three-fold increased risk of one or more complications compared to controls. Although complications from radiation therapy were less common compared to prostatectomy overall, as I noted, they also included serious complications, like radiation cystitis or radiation proctitis and even potentially life-threatening conditions like bladder cancer. 

These findings have some very pronounced implications for prostate cancer care in our view. Treatment for early-stage prostate cancer comes with substantial risks of treatment-related complications. These findings indicate that men should be better informed about the potential risks of prostate cancer treatment complications when they’re deciding whether or not to receive treatment. It is notable that, to our knowledge, no national organization currently includes quantitative information on prostate cancer treatment-related risks in their guidance, so such information should be made widely available to encourage what would be truly informed decision-making about whether to treat an early-stage prostate cancer or to choose another option, such as active surveillance.

Announcer:
That was Dr. Joseph Unger discussing his study on the long-term adverse effects and complications after prostate cancer treatment. To access this and other episodes in our series, visit On the Frontlines of Prostate Cancer on ReachMD.com, where you can Be Part of the Knowledge. Thanks for listening!