A new study from researchers at the Comprehensive Cancer Center found that a tool commonly used by doctors to estimate the risk of a woman’s breast cancer returning after surgery is not very effective at explaining risk to patients. As a result, women with breast cancer may not find these tools helpful when deciding whether to have chemotherapy.
The tool itself is very useful to doctors, many of whom print out information from it for patients when they are discussing chemotherapy. Nearly all women diagnosed with early stage breast cancer will have surgery, but many also will consider chemotherapy to help prevent the cancer from coming back.
“Even when patients are given the information they need, they have to be able to understand it well enough to make the right choice. We’re making patients work too hard,” says lead study author Brian Zikmund-Fisher, research assistant professor of general medicine at the Medical School and a researcher at the VA Ann Arbor Healthcare System.
The currently available risk-assessment tool presents risk statistics in a bar graph format that compares four different potential choices: hormonal therapy alone, chemotherapy alone, both hormonal and chemotherapy, or no treatment at all. The researchers found that it is more difficult for women to find and focus on the benefit of adding chemotherapy to hormonal therapy.
“The main benefit of additional treatments such as chemotherapy after surgery is long-term risk reduction,” says Zikmund-Fisher, a member of the Center for Behavioral and Decision Sciences in Medicine.
“But chemotherapy does not provide much benefit for some, and those women can potentially avoid unnecessary side effects by skipping chemotherapy. So understanding how large or small the risk reduction is can help women make the right choice.”
In the study, published Dec. 15 in the journal Cancer, researchers surveyed 1,619 women, presenting them with a hypothetical breast cancer diagnosis. All women were given identical risk factors for recurrence. The women viewed one of four graphical formats to describe how chemotherapy would reduce the risk of dying from a return of cancer.
When respondents saw the risk information in the bar graph format that current risk-assessment tools use, only 51 percent correctly understood how much their chance of surviving would increase if they took chemotherapy. When women were shown a simpler graph that showed only the two key options, 65 percent were accurate. When the simpler graph used a pictograph format that showed a set of 100 small rectangles to represent the possible outcomes, 77 percent were able to correctly report the benefit of chemotherapy.
The researchers hope that eventually these risk tools will incorporate better ways to show these risks to both doctors and patients.
Additional authors on the study are Angela Fagerlin and Dr. Peter Ubel of the Medical School.
