Breast cancer is a multifaceted disease involving environmental, genetic, and lifestyle risk factors. Breast cancer also represents a collection of clinically heterogeneous diseases ranging from indolent to aggressive. Several differences have been observed in breast cancer epidemiology between populations.
A Global Scope
In 2020, there were 2.3 million women diagnosed with breast cancer and 685 000 deaths globally. As of the end of 2020, there were 7.8 million women alive who were diagnosed with breast cancer in the past five years, making it the world’s most prevalent cancer.
Age-standardized breast cancer mortality in high-income countries dropped by 40% between the 1980s and 2020. Countries that have succeeded in reducing breast cancer mortality have been able to achieve an annual breast cancer mortality reduction of 2-4% per year. If an annual mortality reduction of 2.5% per year occurs worldwide, 2.5 million breast cancer deaths would be avoided between 2020 and 2040.
In Africa, breast cancer is responsible for one in four diagnosed cancers and one in five cancer deaths in women. Incidence marked variation exists in the reported incidence of breast cancer worldwide – from 95 to 100 cases per 100 000 persons in North America, Northern Europe, and Australia to 13.5 - 30 per 100,000 women in sub-Saharan Africa (SSA). The breast cancer incidence in Africa continues to increase and is projected to double by 2050.
Breast cancer is the most common cancer in women in the United States (US), except for skin cancers and has a prevalence rate of about 30% (or 1 in 3) of all new female cancers each year.
The American Cancer Society's (ACS) estimates for breast cancer in the United States for 2022 are:
About 287 850 new cases of invasive breast cancer will be diagnosed in women.
About 51 400 new cases of ductal carcinoma in situ (DCIS) will be diagnosed.
About 43 250 women will die from breast cancer.
Breast cancer mainly occurs in middle-aged and older women. The median age at the time of breast cancer diagnosis is 62.