Which age group is most commonly affected by breast cancer?

The most commonly affected age group by breast cancer is women aged 55 and older. This is primarily due to the fact that breast cancer risk increases with age, with the majority of diagnoses occurring in women who are postmenopausal. Studies have shown that breast cancer is more prevalent in older women because they tend to have longer exposure to estrogen, which is linked to the development of certain types of breast cancer. Additionally, genetic factors and cell proliferation changes over time contribute to the increased likelihood of developing the disease in this age group.

In contrast, while breast cancer can occur in younger women, those aged 30 and younger are at a significantly lower risk. Women aged 40-50 represent a transitional group where risk begins to increase, but it is the 55 and older demographic where the incidence rates sharply rise. Furthermore, while men can also develop breast cancer, it is considerably less common than in women, making the male demographic, regardless of age, less relevant when considering the most commonly affected group for breast cancer.