Gene expression profiling tests can help patients avoid unnecessary chemotherapy treatments, but a new study of breast cancer patients in Canada suggests that many patients have a muddled understanding of how these tests work and may be likely to put faith in the results they want to hear.
According to a new study in Current Oncology, many women place great importance on and trust in gene expression profiling tests, but have mixed levels of understanding about their function and "misapprehensions" are common.
"Patients often viewed their [gene expression profiling] results as providing information that was more scientifically valid, uniquely personalized and emotionally significant than any other information they had received," says study co-author Yvonne Bombard, a genomics and health services researcher at the Li Ka Shing Knowledge Institute of St. Michael's Hospital, in a statement. "For many, the test was a transformational element that empowered them, allowed them to feel confident in their decisions and may even have rescued them from unnecessary chemotherapy."
In a study interview, one patient said that the profiling test "would actually take something concrete from my body and it would use a finer scientific way of actually deciding ... what treatment would best benefit me. It would not be based on others people's statistics, mortality rates. … It would define my risk factors."
Another patient says her test assessment showed that there was "zero" reason for her to take chemotherapy and called it "the greatest gift I've ever been given."
When Bombard asked participants why they did not consider the test's limitations, she found they had "emotional reasons" for not wanting to know more about the test results and likens the trust they had in the tests to 'magical thinking.'
"I didn't ask. … I think I just wanted to take it at face value," another patient says. "I think I was so happy about what I was seeing on that paper and hearing from her that I didn't question it."
Another patient summed up the way she accepted her results as "a willful… suspension of disbelief."