Clinicopathological study of centrally necrotizing carcinoma of the breast.

Background: Centrally necrotizing carcinoma of the breast (CNC) represents a newly-identified subset of breast cancer. The clinical and pathological characteristics of this breast cancer subtype are not yet completely understood. Methods: We assessed the clinicopathological characteristics of 73 cases of CNC and 30 control cases of high-grade infiltrating ductal carcinoma (IDC) with focal necrosis based on light microscopy and immunohistochemical staining for estrogen receptor, progesterone receptor, Cerb-B2/HER2, Ki-67, epidermal growth factor receptor, cytokeratin 5/6, smooth muscle actin, S-100 protein, p63 and CD10. Results: All the tumors showed extensive central necrotic or acellular zones with different degrees of fibrotic or hyaline material surrounded by ring-like or ribbon-like residual tumour tissue which were usually high-grade IDCs. The central necrotic zone accounted for at least 30% of the cross-sectional area of the tumor. Thirty-six cases (49.3%) showed a component of ductal carcinoma in situ. The tumorous stroma around the central necrotic zone was accompanied by myxoid matrix formation in 28 cases (40%). Lymphocytic infiltration was present in 53 cases (72.6%). Granulomatous reactions were detected at the periphery of the tumors in 49 cases (67.1%). Immunohistochemistry showed greater expression of basal-like markers (72.2%, 52 cases) than myoepithelial markers (60.6%, 43 cases), both of which were significantly higher than in controls (26.7%, 8 cases) (P < 0.001). According to molecular typing, most CNCs were basal-like subtype (37 cases, 50.7%). Follow-up data were available for 28 patients. Disease progression occurred in 11 patients. The combined rate of recurrence, distant metastasis or death was significantly higher in CNC patients compared with controls (P < 0.05). Conclusions: CNC was associated with distinctive clinicopathologic features mostly characterized as basal-like type. Its high proliferative activity, highly-aggressive biological behavior, and high rates of recurrence and metastasis, suggest that CNC should be classified as a new type of breast carcinoma. [ABSTRACT FROM AUTHOR]