Mammographic patterns as indicators of risk of breast cancer. A cross-sectional population study.

As part of a breast cancer screening project, radiographic patterns were classified according to Wolfe as N1, P1, P2, or DY. P2 and DY were found to be more common in young women and were seen more frequently in women with breast cancer in all age groups, especially 45-49 years (odds ratio = 3.1; p = 0.19). 66% of the women in this age were classified as having P2 or DY breasts. The authors conclude that in women 45-49 years old, P2 and DY patterns are associated with a moderately increased risk of breast cancer; however, selective follow-up of women found to have P2 or DY at initial screening is not feasible, as no more than 50-60% of all cancers in this age group are associated with the P2 and DY patterns.