Improving earlier diagnosis and precision medicine for reduced mortality of breast cancer in Kenya Data show breast cancer rates are rising in Kenya with scant molecular pathology studies performed. Mortality is high in Kenya compared to the UK and cancer registry data estimate that breast cancer is the second leading cause of cancer death-making it a significant public health problem and loss of economic productivity. Advances in genomic and molecular technologies have transformed our understanding of breast cancer and provide a way to more accurately classify cancers into similar distinct types based on their genetic characteristics. Breast cancer survival has improved significantly in the UK over the last 20 years, but in lower income countries such as Kenya, increasing survival remains a significant challenge likely through a combination of issues. A major barrier to reduce mortality in low and middle-income countries (LMICs), such as Kenya, are multifaceted. However, two major challenges are late stage at diagnosis and limited capacity for accurate molecular tumour subtyping of breast cancer to identify women who would most benefit from endocrine therapies (a form of precision  medicine). Hence, a multidisciplinary approach combining expertise in epidemiology, surgery, oncology, pathology, and molecular genetics, could provide new insights into the risk factors of the disease relevant to the Kenya population, as well as new avenues for combatting the high mortality in Kenya. The observation that tumours release DNA into circulating blood, provides a potential means for earlier and more accurate diagnosis of cancer in low and middle resource countries like Kenya. DNA from the tumour that gets in the blood stream could be used as a test to provide minimally invasive diagnosis of cancer. To design effective approaches to improve health-care, consistent with the MRC 2014-2019 strategic plan we aim to  1) Collect data to inform research priorities that are most likely to deliver improved health outcomes, through the use of molecular defined disease datasets including tumour tissues and blood samples; 2)Bring the benefits of excellent research to all sections of society, in collaboration with academic and other research partners; 3) Develop new innovations through the use of new health data-to improve and inform cancer control and treatment programs and enhance economic development in Kenya. This pump-priming award would allow for knowledge exchange and provide a foundation for improved molecular epidemiology studies that would inform development of improved surveillance, diagnostic and treatment paradigms for breast cancer in Kenya. Through this multinational consortium we envision this proposal to provide future opportunities to train and build capacity for molecularly defined health data collection in Kenya and more broadly other countries in sub-Saharan Africa. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.