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UNC study looks at frequency of common side effects of prostate-cancer treatment

Surveys of more than 1,100 prostate cancer patients confirm there are definite patterns to the side effects of different treatment options for the disease, information patients and doctors can put to use as they decide on their care strategy, researchers at UNC Chapel Hill say.

Publishing this morning in the Journal of the American Medical Asssociation, a group led by oncologist Ronald Chen says the findings speak to the reality that since the common forms of treatment for the disease have similar results for life expectency, the “quality of life effects of different treatment options [are] a central consideration for many men” after diagnosis.

Giving further weight to it conclusions, a second research group based at Vanderbilt University published in the same journal on Tuesday, on a similar study with results Chen said “are completely congruent” with the UNC team’s.

Now, “the issue is about translating research numbers in a way patients can actually understand, to help them make decisions,” Chen said.

Chen and his colleageus used a survey that from January 2011 to June 2013 questioned men who’d been diagnosed with prostate cancer but who had yet to start treatment. It sought to assess the then-current state of their sexual, urinary and bowel function, for use in later comparisons.

Some 1,141 of the men then went through treatment, the vast majority electing to have their prostate surgically removed or to receive one of a couple of different forms of radiation therapy. The remaining 27.5 percent of the survey participants opted for “active surveillance” of the disease, with doctors monitoring the development of their tumors via regular biopsies instead of trying immediately to remove them via surgery or radiation.

Two years later, the patients again answered questions about sexual, urinary and bowel function. After sorting the responses into the appropriate treatment groups, the researchers compared the new numbers to the old ones.

One fairly clear-cut pattern emerged, namely that surgery had lingering negative effects on the sexual front. At the start, 130 men reporting normal function there elected to have their prostates removed. Two years on, 57.1 percent of them reported “poor” function, which the paper said represented “no erections capable of intercourse or a lot of difficulty getting and keeping an erection.”

On the flip side, it was fairly common for patients who elected to undergo one of the various forms of radiation treatment to report urinary or bowel problems.

For example, 26 men with normal urinary opted for “brachytherapy” -- essentially, having a small radiation source implanted next to the tumor -- and two years all but five or so of them were reporting having more trouble with urinary tract obstructions or irritation.

The more common choice of having radiation beamed at the tumor had more or less a 50-50 chance of being followed by similar problems in men who started with normal function, much more rarely extending to incontinence. Bowel problems were more common, with only 42.7 percent of the 76 men who started with normal function on that front still reporting it two years after electing beamed-radiation therapy.

Active surveillance had its downsides too, in terms of sexual function and urinary obstructions and irritation particularly. But they tended to show up after a year, timing that coincided with recommnded biopsy schedules. After two years, average quality of life scores in clinical terms were not “meaningfully different between this group and” the men who elected “active treatment,” the paper said.

In terms of actually fighting cancer, all four of the main strategies have about the same effect, which Chen attributes to the success of screening and diagnostic regimes that tend to catch prostate cancer early on. Because of that, “quality of life and how treatment affects quality of life becomes a really important issue men can use for their decision-making process” about the potential trade-offs, he said.

The UNC study focused on patients from North Carolina, while the parallel one from Vanderbilt asked somewhat different questions of men from places like California and Georgia, Chen said. But given how the results line up, doctors can “give a lot of information” to their patients, updated for relatively recent developments on the medical-technology front like the use of robotics in surgery, he said.

Ray Gronberg: 919-419-6648, @rcgronberg

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