Transferrin receptor (TrfR) expression in breast carcinoma and its possible relationship to prognosis. An immunohistochemical study.

TrfR, a primitive membrane protein was demonstrated by immunohistochemistry in 87.6% of 105 cases of breast carcinoma, predominantly on the cell surface and in a strong and rather uniform pattern. Sporadic staining in a patchy fashion was observed. No difference between individual tumour types was seen, neither in cytomorphological staining pattern nor in staining intensity. Exceptionally, mucoid carcinomas showed weaker intensity for receptor expression. Because of the heterogenous expression of TrfR within most of the tumours the extent of staining reaction was determined by semiquantitative grading (low, moderate, high). These results were compared with grade of anaplasia, tumour staging and nodal status of the axilla. The extent of immunoreactivity revealed significant correlation with grade of anaplasia, whereas no correlation was found with staging and status of axillary lymph nodes. Tumours with higher degree of malignancy (GII-GIII) showed a higher extent of staining. The presence of TrfR in a high degree of expression thus implies some prognostic value. Its quantitative determination can provide kinetic data on the neoplasm.