A large cohort study1 finding that the risk of dying of breast cancer was increased threefold after a DCIS diagnosis may cause patients diagnosed with DCIS to ask what they can do to reduce that risk. Currently, there is little that most patients can do. “The lifetime risk of death following DCIS is approximately 3%, and this level of risk is too low to recommend chemotherapy,” the study authors wrote.
“I don’t advocate chemotherapy for people with 3% mortality rates,” the study’s corresponding author, Steven A. Narod, MD, told The ASCO Post. Dr. Narod is Canada Research Chair in Breast Cancer, Women’s College Research Institute, and Professor, University of Toronto. “Chemotherapy prevents 3 out of 10 deaths, and that’s okay, but not if your risk of dying is 3%, because it would be preventing less than 1%. Chemotherapy is it is too toxic,” he said.
“If there were a drug with mild side effects, or a drug like aspirin, then we would give it,” Dr. Narod said. “But there is no way I am going to give 100 women chemotherapy to prevent 1 death from breast cancer.”
Higher Risk
“There were some women (ie, those younger than 40 years and/or Black) for whom the mortality rate approached 10%, and at this level, chemotherapy might be considered,” the study found. “One could make the argument for chemotherapy among these women,” Dr. Narod said, but that should be done on a patient-by-patients basis. There is not enough evidence to warrant a recommendation that young Black women with DCIS should have chemotherapy, he added.
“I would consider tamoxifen,” Dr. Narod added, although he is concerned about the lack of data on tamoxifen and death from breast cancer. He also pointed out, “The average risk of dying of breast cancer for women with a DCIS is 3%, so that should be reassuring.”
DISCLOSURE: Dr. Narod reported no conflicts of interest.
REFERENCE
1. Giannakeas V, Sopik V, Narod SA: Association of a diagnosis of ductal carcinoma in situ with death from breast cancer. JAMA Netw Open 3:e2017124, 2020.
