p53, ErbB2, and TAG-72 expression in the spectrum of ductal carcinoma in situ of the breast classified by the Van Nuys system

Context.-The Van Nuys (VN) classification system for ductal carcinoma in si tu (DCIS) of the breast is a simplified morphology-based system that uses t he presence of nuclear pleomorphism and comedo-type necrosis to stratify DC IS lesions into 3 prognostic groups. Objective.-To determine if there is an underlying biological basis that cor relates with the morphologic aspects of the VN classification system. Design.-We evaluated the expression of markers implicated In the developmen t of breast cancer (p53, ErbB2, and TAG-72) in DCIS classified with the VN system. Forty-five cases of pure DCIS were classified as 8 cases of VN1, 7 cases of VN2, and 30 cases of VN3. p53, ErbB2, and TAG-72 antigen expressio n was measured by immunohistologic means In each of the cases. Results.-Nuclear accumulation of p53 was only observed in VN3 (30%). ErbB2 overexpression was found only in VN2 (14%) and VN3 (43%). TAG-72 expression was observed in all categories of lesions but was more frequent in VN2 (71 %) and VN3 (70%) compared with VN1 (25%). It appears that overexpression of ErbB2 and p53 are features associated with the high-grade lesions. Conclusion.-The simplified VN classification system for DCIS has a clear un derlying biological basis as evidenced by differential expression of tumor- associated antigens in each of the 3 morphologic categories. These differen ces may contribute to the differential clinical behavior of the separate gr oups.