Older adults with late stage dementia are likely to lack the capacity to make decisions regarding care and treatment on their own, and subsequently these decisions may rely on a proxy decision-maker. In most cases, a carer will assume the role of decision maker, and this will involve navigating which services and treatments are most appropriate for women with a breast cancer diagnosis. The Mental Capacity Act (2005) sets out the guidelines for safeguarding individuals who are unable to make an informed decision, and this act is underpinned by the principle that any decision should be made in their best interests. Little is currently known about how treatment decisions are made for older women with breast cancer, and there are limited treatment recommendations tailored specifically towards older women with dementia and a breast cancer diagnosis. This research will reflect on the needs of caregivers involved in making proxy treatment decisions in breast cancer care.