Large, central acellular zones indicating myoepithelial tumor differentiation in high-grade invasive ductal carcinomas as markers of predisposition to lung and brain metastases

High-grade invasive ductal carcinomas (IDCs) of the breast with large, cent ral acellular zones on their cut surfaces are usually associated with the m yoepithelial immunophenotype of carcinoma cells, which includes the express ion of S-100 protein, alpha-smooth muscle actin, and keratin 14. To clarify the clinical significance of these features of IDCs, the authors compared the incidence of the myoepithelial immunophenotype immunohistochemically pa tient prognosis, and metastatic sites of the tumor between 20 high-grade ID Cs with large, central acellular zones and 40 control high-grade IDCs witho ut these zones. The myoepithelial immunophenotype was detected in 16 IDCs ( 80%) with large, central acellular zones but in only seven IDCs (18%) witho ut. The risk ratio of metastasis, especially in the brain and lung, and dea th from cancer were significantly higher (p = 0.0096 and p = 0.030) for the 20 IDCs with large, central acellular zones than for those without by Cox' s univariate analysis. Using Cox's multivariate analysis, large, central ac ellular zones in IDCs were an indicator of high risk of brain and lung meta stases and of death by cancer independent of nodal status and tumor size. E xamination of large, central acellular zones and myoepithelial immunophenot ype in high-grade IDCs appears helpful in predicting patient prognosis and preferential metastatic sites of the tumors.