Grant: Project Grant - PA: Breast Cancer Research

Pregnancy-associated breast cancer is rare overall with about 120 cases each year in Canada. But, for Canadian women that develop breast cancer under the age of 30, at least one in five will develop breast cancer during pregnancy or in the following one year. In one study, 30% of pregnancy-associated breast cancer patients were born with a mutation in the BRCA1 gene. In this project we will test the idea that these BRCA1 mutations disturb the process of cell division that occurs naturally when the pregnant breast is preparing to produce milk. We propose that this change in how the cell division process is controlled in late pregnancy is caused by an accompanying change in their breast tissue. Importantly, the altered cell division that occurs normally in late pregnancy affects the very same cells from which these hard to treat breast cancers are thought to arise. To study this hypothesis, we will examine mammary cells isolated from genetically modified mice, immortalized human mammary cells with experimentally introduced mutations, and mammary cells isolated from female human donors carrying BRCA1 mutations. To accomplish this, we have assembled a multidisciplinary research team with internationally recognized expertise in the multiple disciplines required to achieve the goal of the proposed studies. We believe new prophylactic drug treatments for BRCA1 mutation carriers and novel insight into the normal development of alveolar cells are plausible future applications for the findings from our proposed studies.