DNA analysis of ductal carcinoma in situ of the breast. A comparison with histologic features.

In 56 cases of ductal carcinoma in situ (DCIS) of the breast, DNA was analyzed by flow cytometry. The results were compared with standard nuclear grading, the degree of necrosis, and tumor size. Twenty-three cases (41%) showed aneuploidy. The degree of nuclear atypia was correlated significantly with aneuploidy. Tumors with low-grade, intermediate-grade, and high-grade nuclear features were aneuploid in 24%, 41%, and 69% of cases, respectively. The degree of necrosis also correlated with nuclear grade but did not correlate with ploidy status. The combined features of nuclear atypia with necrosis did not predict aneuploidy as well as nuclear grade alone. Tumor size did not correlate with ploidy. These findings indicated that nuclear grade was the best histologic predictor of aneuploidy in DCIS. The potential value of this information in treating DCIS is discussed.