Why does mammography sensitivity increase with age?

Mammography sensitivity increases with age primarily due to decreased breast density. In younger women, breast tissue tends to be denser, comprising more glandular and fibrous tissue, which can obscure the detection of tumors on mammograms. As women age, particularly after menopause, breast tissue is replaced by more fatty tissue, making the mammogram images clearer and allowing for better visualization of tumors. This change in breast composition enhances the ability of mammography to accurately identify potential cancers, resulting in higher sensitivity in older populations.

In contrast, other factors listed, such as hormone levels, improvements in imaging technology, or the incidence of breast cancer, do not directly relate to the fundamental changes in breast tissue density that contribute to the increased sensitivity of mammograms with age. Hormone levels affect breast tissue but do not account for the increased clarity of the mammographic images that comes with decreased density. Similarly, while advances in technology may improve imaging, the age-related changes in breast tissue composition remain a key factor in sensitivity. Lastly, while older age correlates with a higher incidence of breast cancer, the increase in sensitivity is primarily attributed to the physical properties of the breast tissue rather than the mere presence of more cases of the disease.