engleski

ER, PR and HER-2 antigen expression in a sample of 48 medullary breast cancers

The medullary breast carcinoma (typical, MBC, and atypical, AMBC) is rare (<2%) and peculiar form of breast invasive carcinomas. Despite its features of aggressiveness, it is usually associated with good survival. Recent publications of breast cancer classifications based on gene expression profile analyses indicate that medullary breast cancinomas may be considered part of the basal- like carcinoma spectrum made up of the ER negative, PR negative and HER-2 negative cells ('triple-negative phenotype'). On the other hand, there are also data showing that a proportion of MBC and AMBC is ER, PR and/or HER-2 positive. Therefore, we have decided to immunohistochemically analyze (IHC) ER, PR and HER-2 expression in our archival paraffin embedded MBC and AMBC samples from 48 patients. These samples were derived from patients operated on at our two hospitals between 1999 and 2005. Typical MBC was found in 39 patients and AMBC in 9 patients. The patients ranged in age from 32 to 84 years (median 55). Modified radical mastectomy with axillary dissection was performed on 30/48 (63%) patients while breast segmentomy with axillary dissection was performed on 18/48 (37%) patients. The median tumor size was 2.5 cm (range 0.8 - 5.0 cm). Metastases in axillary lymph nodes were observed in 15/48 (31%) patients. ER positivity was present in 3/48 patients (6%), PR positivity in 8/48 patients (17%) and positive HER-2 reaction was present in 14/48 patients (29%). Eleven out of 39 patients with typical MBC and 3 out of 9 patients with AMBC were HER-2 antigen positive and there was no statistical difference between these two groups. Positive HER- 2 antigen expression in the analyzed sample was not found to be associated with the MBC or AMBC histological tumor type, tumor size, axillary lymph node metastases, ER and PR status nor with patient survival. Adjuvant therapy was applied in all but 2 patients. The mean follow-up time of patients was 42.2 months (range from 3 to 113 months) and over 90% of patients were alive. In conclusion, the data from our study seem to be generally comparable with the relatively scarce published data on clinicopathological parameters of MBC and AMBC. Moreover, since some of the analyzed tumors are IHC found to be HER-2 positive some patients with MBC and AMBC may be also candidates for herceptin treatment.

breast cancer ; medullary breast cancer

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