New insights into side effects can help prostate cancer patients choose treatments
For many men newly diagnosed with early-stage prostate cancer, concerns about potential quality-of-life issues often guide treatment decisions. A new study led by UNC Lineberger Comprehensive Cancer Center researchers identifies distinct patterns of side effects that patients could use to guide their choices.
In the Journal of the American Medical Association, the study examines quality-of-life outcomes for the treatment choices most patients will face. Those choices include active surveillance, radical prostatectomy, external beam radiation treatment, and brachytherapy, a treatment that involves inserting radioactive seeds into the prostate.
"Patients diagnosed with early-stage prostate cancer—and that's the vast majority of patients with this disease—face many treatment options that are thought to be similarly efficacious," said Ronald C. Chen, MD, MPH, UNC Lineberger member and associate professor in the UNC School of Medicine Department of Radiation Oncology. "Therefore, the quality-of-life differences among these options become an important consideration when patients are trying to make their decisions."
The study is needed as prostate cancer treatment technologies have advanced, and as active surveillance has emerged as an important strategy for sparing low-risk prostate cancer patients unnecessary side effects. Active surveillance involves regular testing to check for cancer growth rather than immediate treatment. Many patients with low-risk prostate cancer on active surveillance may be able to avoid treatment for several years or altogether. The American Society of Clinical Oncology has endorsed active surveillance for most men with low-risk prostate cancer.
"There has not been a large-scale comparison of the quality-of-life impact for these modern options, until now," Chen said. "Existing quality of life studies have studied older types of surgery and radiation that are no longer used, and patients need updated information regarding the impact of modern treatment options so they can make informed decisions about the choices they face today."
For the study, UNC Lineberger researchers surveyed 1,141 men in North Carolina who were diagnosed with early-stage prostate cancer between January 2011 and June 2013. They compared patients' self-reported quality of life related to bowel, urination, and sexual function across four strategies: active surveillance; prostatectomy; external beam radiotherapy; and brachytherapy. Almost all prostatectomy patients received robotic surgery, and almost all external beam radiotherapy patients received intensity-modulated radiation, reflecting modern treatment technologies.
Prostatectomy was linked to higher sexual dysfunction and urinary leakage than the other options. At two years after treatment, more than 57 percent of men who had normal sexual function prior to treatment reported poor sexual function after surgery, compared with 27 percent who reported poor sexual function after external beam radiation, 34 percent after brachytherapy, and 25 percent after active surveillance.
"With modern robotic surgery, sexual dysfunction and urinary incontinence continue to be some of the side effects that surgery can cause," Chen said. "While we do see improvement over time, even at the two-year point, surgery still causes more of these issues than other treatments."
Meanwhile, other treatment choices were linked to worse scores for other side effects. External beam radiotherapy and brachytherapy cause more short-term urinary tract obstruction and irritation, while external beam radiotherapy was linked to more short-term bowel symptoms.
For the group of men who chose active surveillance, urinary issues and sexual function worsened over time. This is likely partly due to aging, and partly due to some men who experienced cancer progression that necessitated treatments that caused these side effects.
"At the two-year time point, patients who chose radiotherapy or brachytherapy actually had quality-of-life results similar to patient who chose active surveillance, and that may be surprising to some patients," Chen said. "With advances in treatment technologies for both surgery and radiation, patients and physicians today must base their decisions on the quality-of-life results of modern treatments, not on results for outdated treatment modalities that caused much more side effects historically."
Overall, Chen said the data can help patients weigh their treatment options based on their own baseline health and on their priorities.
"With all of the modern treatment options, patients should have accurate and realistic expectations about the frequency of side effects from treatment," Chen said. "We found that the different treatment options have trade-offs in side effects. Each patient can look at these data to see what they care about most."