Photo by Dean Forbes
Men trying to decide how to have their early stage prostate cancer treated may get incomplete or biased advice from doctors and patient-education materials, according to a new review led by Drs. Steve Zeliadt and Scott Ramsey of the Public Health Sciences Division.
Zeliadt, Ramsey and colleagues found that men with prostate cancer generally make treatment decisions based on differences in the information they receive rather than their own preferences. The review of 69 prostate-cancer decision-making studies suggests that a lack of medical evidence and consistent, comprehensive messages about therapeutic options compel men to turn to a wide variety of popular and biased sources, which influence their decisions. This approach often results in treatments that do not generally reflect patients' goals, such as maintaining urinary continence or quality of life. The study was published in the March 27 online publication of the journal Cancer.
Zeliadt said they conducted the study to better understand the differences in U.S. prostate-cancer treatment and survival rates. "In the United States, there appears to be a lot of disparity in treatment, with black men, men from rural areas and men with lower socioeconomic status receiving less aggressive treatments," he said. "There are also big gaps here in prostate-cancer mortality that remain unexplained. This work was conducted as a first phase in understanding why treatment disparity exists, how personal preferences contribute to treatment disparity, and if the disparity in treatment is a major factor contributing to poorer survival for some groups of men — most notably black men."
In the largest study the authors reviewed, which involved 1,000 patients, approximately 42 percent of the patients defined effective treatment as one that extended expected survival or delayed disease progression, while 45 percent said effectiveness meant preservation of quality of life. In contrast, 90 percent of physicians defined effectiveness as extending expected survival.
Despite new treatment options for prostate cancer, there is little evidence-based consensus in the oncology community about the most effective treatment. Surgeon-urologists will often recommend surgery, while radiation oncologists think radiation therapy is best. Newly diagnosed patients must still balance existing information about risks and benefits of available therapies with their own treatment objectives.
"As a culture, we just don't like not knowing. So we tend to ignore that there is no information, and we find some way of being encouraging about treatment," Zeliadt said. "Over and over and over again in these studies, men would bring up the issue of treatment side effects. But when it came down to it, side effects played a very small role among the factors that made them decide. Ironically, that is the only area for which we have a lot of information."
The review showed that cancer eradication or control was the foremost objective of treatment for men. Many men are not content to wait and see, so they must choose from different forms of surgery or radiation treatment. While their goal is to eradicate the cancer, there's not a lot of evidence pointing to the superiority of one treatment over another.
The studies report a gap between patient treatment objectives and the evidence supporting the efficacy of the treatment chosen. Men's concerns about controlling the cancer correlated directly with the aggressiveness of the treatment they chose, regardless of actual disease severity. Yet, in choosing treatment, patients did not consistently rely on scientific evidence of a therapy's efficacy to control disease or prolong life. As few as one in four patients in one study relied on evidence of a treatment efficacy for their decision.
Physicians and family, as well as race and culture may affect patients' decisions, but the degree of their respective influence varies in the literature and is often poorly measured, according to the review. Notably, physicians tended to present therapies in ways that were both confusing and dismissive of patient concerns about risks. This either biased patients' decisions or turned patients to other sources of information.
Review of patient-education materials found that most contain biases toward active treatment, minimize the role of watchful waiting, and underestimate the likelihood and impact of side effects, the authors said.
Two new studies
Finally, the researchers found the studies failed to show how and if patients critically analyze the quality of information they receive. It is very likely, the authors said, that patients "have significant limitations in their ability to identify biased information, as well as in their ability to weigh complex information about the outcomes that are important to them."
Ramsey and Zeliadt are now conducting two prospective studies looking at prostate-cancer decision making. One study is recruiting 850 newly diagnosed patients from Washington, Oregon and California. The second study is recruiting 570 families from South Carolina, Texas and California.
Study co-authors include Dr. David Penson, University of Southern California/Norris Cancer Center, and Drs. Ingrid Hall, Donatus Ekwueme, Leonard Stroud and Judith Lee, Centers for Disease Control and Prevention. The work was funded by the National Cancer Institute and the Centers for Disease Control and Prevention.