Confusing Risk Information Leads To Poor Cancer Treatment Choices
A new study from researchers at the University of Michigan 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 this tool and give it to patients when they are discussing chemotherapy. Nearly all women diagnosed with early stage breast cancer will have surgery, but many will also consider chemotherapy to help prevent the cancer from coming back.
"The main benefit of additional treatments such as chemotherapy after surgery is long-term risk reduction. But chemotherapy does not provide much benefit for some women, 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," says lead study author Brian Zikmund-Fisher, Ph.D., research assistant professor of general medicine at the U-M Medical School and a researcher at the VA Ann Arbor Healthcare System.
The currently available risk-assessment tools present 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 problem, Zikmund-Fisher points out, is that most women are really only choosing between two options: For women whose cancers are sensitive to the hormone estrogen, hormonal treatments provide large benefits with few side effects. The real question is whether chemotherapy is also necessary.
Because the tool shows statistics about all four options, however, the researchers found that it is more difficult for women to find and focus on the number that most matters to their choice: the benefit of adding chemotherapy to hormonal therapy.
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.