According to recent global cancer estimates from the International Agency for Research on Cancer (IARC), female breast cancer has become the most commonly diagnosed cancer type in the world: about 2.3 million women were diagnosed with breast cancer in 2020, exceeding the number of new cases of lung cancer for the first time. Breast cancer caused about 685 000 deaths in 2020; it was the most common cause of cancer death in women and the fifth most common cause of cancer death overall.