A CRITICAL-APPRAISAL OF 6 MODERN CLASSIFICATIONS OF DUCTAL CARCINOMA IN-SITU OF THE BREAST (DCIS) - CORRELATION WITH GRADE OF ASSOCIATED INVASIVE-CARCINOMA

The in-situ component of 180 cases of screen detected infiltrating duc t carcinoma of the breast was classified according to six published cl assifications for ductal carcinoma in situ based on architecture, necr osis and cytology. All cases were assessed independently by two experi enced observers to assess inter-observer variation, The differentiatio n of ductal carcinoma in situ as assessed by all the classification sy stems correlated with the grade of the associated invasive carcinoma ( chi-squared between 50 and 107: P < 0.0001), Disagreements were common est in the assessment of architecture and least common in the assessme nt of necrosis. For cytonuclear grade most disagreements (62.2%) invol ved the distinction between low and intermediate as against 33.9% disa greements for intermediate vs, high, Nuclear grade alone and necrosis alone were correlated with the gl-ade of invasive carcinoma associated with the ductal carcinoma in situ and the Nottingham prognostic index of the patient, The Van Nuys classification of ductal carcinoma in si tu is commended because it has a low inter-observer disagreement, is s ignificantly correlated with the grade of the infiltrating carcinoma, uses simple well-defined criteria with no requirement for percentage e stimations), is applicable to small numbers of ducts and, most importa ntly, appears to correlate with disease-free survival.