Mammographic Parenchymal Patterns

To the Editor.— In response to the article by Tabar and Dean and the editorial by Moskowitz, I wish to report some conflicting results. The mammographic parenchymal pattern has been in use at the Kaiser-Permanente Medical Center in Los Angeles for several years. Much data have been gathered on a large, mixed population of symptomatic and asymptomatic women. The Table explains our results regarding the parenchymal pattern. More than twice as many of the cancers in the prevalent population were found in the high-risk breast groups (P2 and DY pattern groups). Perhaps even more convincing in regards to the validity of mammographic parenchymal pattern as a risk indicator is the result that 80% of our incident cancers occurred in women who had been previously designated high risk, ie, P2 and DY. If we consider the age of the patients with breast cancer in conjunction with the assigned parenchymal pattern, as