Distribution of ferritin, transferrin and lactoferrin in breast carcinoma tissue.

An immunoperoxidase staining technique was used for detecting three major iron binding proteins (ferritin, transferrin and lactoferrin) in 40 breast carcinoma cases and six benign breast proliferative lesions. Ferritin staining was detected mainly in connectival stroma and in histiocytes surrounding neoplastic cells. Few and faint ferritin positivities were also detected in neoplastic cells of 20 carcinoma cases. Transferrin was found inconsistently in myoepithelial cells surrounding normal ductules, or around neoplastic ducts of ductal in situ carcinoma. In eight carcinoma cases, transferrin staining was also positive in neoplastic cells. Lactoferrin was detected only in normal breast epithelial cells and in benign breast proliferative lesions. These immunohistochemical findings may suggest that raised serum ferritin concentrations in breast carcinoma patients might be attributed to stromal reaction rather than to tumour synthesis. Transferrin staining of neoplastic cells in these carcinoma cases appears to be very intriguing, particularly since transferrin is considered an obligate requirement for growing cells, and transferrin receptors have been demonstrated only in dividing cells. On the basis of the immunohistochemical data, lactoferrin might be used as a pointer to benign lesions.