HETEROGENEITY OF DUCTAL CARCINOMA IN-SITU OF THE BREAST

Ductal carcinoma in situ (DCIS) now accounts for 20-30% of all newly d iagnosed breast cancers in centers which use mammographic surveillance as a standard part of the examination. The majority of these DCIS les ions, at least in the United States, are of very limited size, with me an estimated extents of 8-20 mm, based on pathological examination. A small fraction of these are incidental microscopic features of the bio psy; the majority are detected on the basis of mammographic microcalci fications. These mammographically detected DCIS lesions are biological ly heterogeneous, and this is reflected by their histology. Moreover, a number of recent independent studies have shown that the clinical ou tcome of patients, particularly those treated by breast conservation, is related to the presence of reproducible and identifiable histologic features, and possibly to certain immunohistochemically demonstrable gene markers as well. Regardless of the type of therapy, local recurre nce in the breast is the most common and often the only site of failur e after breast conservation therapy for DCIS. Although individual stud ies show some variation in the proportion of invasive to non-invasive recurrence, equal numbers of invasive and non-invasive recurrences are most commonly noted. (C) 1993 Wiley-Liss, Inc.