DUCTAL CARCINOMA IN-SITU OF THE BREAST - HISTOLOGIC CATEGORIZATION AND ITS RELATIONSHIP TO PLOIDY AND IMMUNOHISTOCHEMICAL EXPRESSION OF HORMONE RECEPTORS, P53, AND C-ERBB-2 PROTEIN

Background. Ductal carcinoma in situ (DCIS) of the breast has been dia gnosed increasingly since the advent of mammography. However, the natu ral history of these lesions remains uncertain. Ductal carcinoma in si tu of the breast does not represent a single entity but a heterogeneou s group with histologic and clinical differences. The histologic subty pe of DCIS seems to have an influence on its biologic behavior, but th ere are few studies correlating subtype with biologic markers. Methods . The authors studied a consecutive series of 40 cases of DCIS and aft er its histologic categorization verified its relationship with ploidy using image analysis and analyzing estrogen receptor (ER), progestero ne receptor (PR), p53 and c-erbB-2 expression using immunohistochemist ry. Results. The three groups proposed according to the grade of malig nancy were correlated significantly with some of the additional parame ters studied, including aneuploidy and c-erB-2 expression. Aneuploidy was detected in 77.5% of cases of DCIS mainly in high and intermediate grade subtypes (100% and 80% vs. 35.7% in low grade) whereas immunore activity for c-erbB-2 was detected in 45% of cases of DCIS mainly in t he high grade group. Expression of ER and PR were observed frequently in this study (63.9% and 65.7% respectively), but without correlation with the histologic subtype of DCIS, although we found a somewhat sign ificant association between high grade DCIS and lack of ER. p53 protei n expression was detected in 36.8% of these cases, but no relationship between this expression and histologic subtype or grading of DCIS was found. Conclusions. These results provide further evidence for the mo rphologic and biologic heterogeneity of DCIS. Besides histologic class ification and nuclear grading, some biologic markers such as aneuploid y and c-erbB-2 expression constitute additional criteria of high grade of malignancy.