More than a third of men with early prostate cancer who participated in a study analyzing treatment choice received therapies that might not be appropriate, based on pre-existing problems with urinary, bowel or sexual function.
The prevalence of these treatments' "mismatches" could reflect patients' unwillingness to discuss such problems with their physicians.
The study was led by James Talcott, MD, SM, of the Center for Outcomes Research at Massachusetts General Hospital (MGH) Cancer Center.
"Prostate cancer patients experience the same fears and hard decisions as all cancer patients do, but prostate cancer treatment directly affects very personal things that most people aren't comfortable talking about - urinary, bowel and sexual function," he said.
He added: "In this case, however, having that information matters because the three major treatments available to patients have different patterns of potential side effects. Knowing if patients already have problems in these areas should help guide treatment decisions."
For early prostate cancer the standard treatment options are external radiation therapy; brachytherapy, in which tiny radioactive particles are implanted into the prostate gland; and prostatectomy, surgical removal of the prostate gland.
Both treatments have similar levels of effectiveness, but each presents a different risk of side effects - external radiation can lead to bowel dysfunction, brachytherapy may lead to urinary problems, and surgery can damage nerves involved in sexual function.
For patients who already have problems in these areas, therapies that could worsen their symptoms are usually not recommended.
Also, approaches such as nerve-sparing prostate-removal surgery, designed to preserve normal functions, would not be appropriate for patients for whom those functions have already been lost.
The research team enrolled patients treated for early prostate cancer at four Boston centers over a six-year period, to investigate the frequency of treatment mismatches.
Study participants completed a questionnaire before beginning treatment and subsequent questionnaires at intervals of 3, 12, 24 and 36 months after they entered the study. They also gave the researchers - who were not involved in their clinical care - permission to review their medical records.
The questionnaires were designed to assess urinary incontinence and other urinary problems, along with bowel and sexual dysfunction. Participants were also asked to assess their level of distress with any symptoms they experienced.
Amongst, 440 patients who completed the entire study, 389 or 89 percent reported having some level of urinary, bowel or sexual problem before beginning treatment.
Those participants were classified into four groups. Group 1 was patients with serious symptoms in a single area, for whom decisions would be expected to be the most straightforward. Group 2 included less serious symptoms that would count against a single treatment option. Group 3 had problems in several areas but still had one potentially appropriate treatment. Group 4 included those patients with significant dysfunction in all three areas, for whom none of the treatment options would be recommended.
Results showed similar levels of treatment mismatches in all groups - 34 percent in Group 1, 37 percent in Group 2, and 40 percent in Group 3. Among Group 4 patients - those with dysfunction in all three areas - only 5 percent chose watchful waiting, a strategy in which they receive no treatment but are followed closely by their medical team.
When choosing therapies, patients take many considerations into account. The surveys asked about several factors that might affect those decisions, none of which could account for the mismatched choices.
Patients reporting pre-existing conditions were more likely to have problems after treatment if they had received a mismatched treatment, as it was expected.
"It could be that treatment choices are determined by factors other than those we asked about, or patients may decide to go ahead with mismatched treatments for their own reasons, knowing the risks," Talcott said.
He added, "But it also could be that the open, frank conversations patients should have with their doctors aren't taking place or that doctors aren't making it clear to patients why they should be forthright about urinary, bowel or sexual problems they are having."
He and his colleagues revealed that patients may be more open about addressing sensitive topics on a questionnaire than they are in conversation and suggest that factoring such a questionnaire into treatment decisions could reduce mismatches, a strategy they hope to study in the future.
The study will appear in the January 1, 2007 issue of the journal Cancer and is being released online.