Mammographic density is a well-documented independent risk factor for breast cancer. Measurements of density come in various forms, ranging from qualitative descriptions to quantitative assessments or a combination of both. The different means of examining density lead to variations in density–risk relationship. Currently there is no consensus on which method is preferable. The interrelation of mammographic density with other risk factors is crucial to density–risk assessments, since each of these risk factors can influence density on its own. Mammographic density can be modified through hormonal and chemical means, which can have important implications on mammographic sensitivity, accuracy in cancer diagnosis and cancer prevention.
