IMMUNOPHENOTYPE OF INTRADUCTAL CARCINOMA

Objective,-Mammography and breast-conserving therapy have focused atte ntion on the classification of intraductal carcinoma (IDC) and emphasi zed the prognostic importance of comedo versus noncomedo variants. We used histochemical markers to define the immunophenotype of 43 IDCs wi th respect to comedo versus noncomedo status and patterns of angiogene sis. Results.-Reactions in comedo carcinomas were significantly negati ve for estrogen receptor and progesterone receptor, and positive for p 53 and HER-2/neu more often than the noncomedo variant. All seven IDCs associated with Paget's disease showed positive reactions for HER-2/n eu. Basement membrane immunoreactivity for type IV collagen and lamini n was discontinuous in most examples of IDC regardless of type, with a trend toward more intense staining in comedo than in noncomedo carcin omas. Periductal angiogenesis was not significantly related to the typ e of IDC but was more pronounced with comedo carcinomas. Conclusions,T hese observations indicate that there are immunophenotypic correlates to the current structural classification of IDC. The immunophenotype o f IDC is helpful in subclassifying an IDC and could prove useful as a prognostic indicator for local control in patients treated by breast-c onserving therapy.