The variation of breast parenchymal patterns with age.

The Wolfe classification of mammographic parenchymal patterns has been applied to 9036 women attending a Breast Cancer Screening Unit. Overall, two thirds fell into high risk categories (P2 and DY). The incidence of DY decreases with age, while the low risk categories (N1 and P1) increase with age. P2 remains constant over most of the age range. The implications of these findings are discussed and comparison is made with other series.