Studying gene expression could reduce risk of “over-treatment” for breast cancer
Diagnosis of early stage breast cancer can lead to aggressive treatment strategies, with many women showing Stage I and Stage II tumours receiving immediate chemotherapy. However, a new assay that looks at expression of 21 different risk genes suggests that such forceful early intervention may not be necessary for all patients.
“Through years of research discoveries, it became clear that we were over-treating many women with breast cancer, especially those with early-stage disease. In addition to chemotherapy’s obvious side effects, there were also long-term complications for these women as survivors,” explained Carlos Barcenas of the MD Anderson Cancer Center.
While promising, the new research still needs to be validated as part of an ongoing international clinical trial. The results published in the journal Cancer suggest that women with intermediate risk recurrence scores from the 21-gene expression assay had similar cancer outcomes, regardless of whether they receive chemotherapy or not.
While the findings dramatically changed care for women with a low RS, many questions remain regarding the management of women with an intermediate RS, defined by this trial as a score of 11-25. The conversation to give or not give chemotherapy is one Barcenas often has in his clinic, he said.
“This study evolved out of my patients’ frustration that I could not provide a definitive answer to their paramount question: ‘Do I need chemotherapy?'” said Barcenas.
While not practice changing, the findings do give Barcenas more information when discussing the benefits of chemotherapy in early-stage breast cancer patients, should their RS score be 11-25.
“Our research is likely the most comprehensive data we will have about this patient population until the international randomized trial is published,” said Barcenas. “Hopefully our findings will serve as a discussion point between physicians and patients as they are making critical decisions regarding a woman’s breast cancer care.”