Grant: Project Grant

Cancer patients are particularly prone to have blood clots and/or irregular heart beats, and blood thinners are medications used to treat and prevent blood clots that may lead to stroke, death and other complications. There is a new class of blood thinners called "direct oral anticoagulants" that are used more and more often in cancer patients. This new class of blood thinners has the advantage of being able to be taken by mouth and no need for frequent monitoring. However, these drugs could still thin patients' blood too much and cause bleeding problems, especially when they interact with other drugs including cancer therapies. A worrying interaction between this new class of blood thinners and several different classes of cancer drugs is suspected to lead to dangerous blood thinning and internal bleeding, but there have not been studies to investigate this. We are proposing this study that will examine the risk of bleeding in older patients who were prescribed direct oral anticoagulants and certain breast cancer therapies that could have interactions from large healthcare databases in Ontario. Our study will be the first and largest of its kind ever done and the results will immediately provide information for patients and their doctors.