Breast cancer: Burden, epidemiology and priority interventions

In 2020, an estimated 2.3 million people were diagnosed with breast cancer, making it the commonest cancer among women worldwide. This chapter reviews trends over the past 20 years, key risk factors including high body mass index, alcohol use and unhealthy diet, as well as reproductive and family history, particularly BRCA gene variants. In addition to public health interventions to reduce exposure to modifiable risk factors, health systems need to be adequately resourced to ensure that breast cancer is diagnosed and treated early (including through screening programmes whenever feasible) and that quality treatment and care are available for women with breast cancer. The role of oestrogen or progesterone receptors in the diagnosis and treatment of breast cancer is described as are the implications of BRCA mutations when it comes to counselling for women with a family history of breast cancer. Treatment options including surgery, radiation and systemic chemo-, hormone- and targeted immuno- therapy are outlined. The need to ensure that those with advanced cancer have access to palliative care is also emphasized. The importance of networks of care, including with centres of excellence is highlighted, as is ensuring that early diagnosis, treatment and palliative care are included in universal health care benefit packages.