Human milk fat globule antigen III D 5, steroid receptors and histopathologic parameters in breast cancer.

Immunohistochemical reactivity of mammary carcinomas with the monoclonal human milk fat globule (HMFG) antibody III D 5, and the estrogen receptor (ER) and progesterone receptor (PR) status were compared with the histopathology of primary breast cancer. The reactivity with III D 5 has earlier been shown to be associated with the estrogen receptor status of tumours and with a favourable prognosis. The reactivity of tumours with III D 5, as well as the presence of ER and PR correlated significantly with the histological features of differentiation; histological grade, nuclear grade, tumour necrosis and lymphoid infiltration. Reactivity with III D 5 correlated with all these parameters, while the presence of ER did not correlate with the nuclear grade and that of PR correlated only with the nuclear grade and the lymphoid infiltration of tumours. Reactivity of III D 5 may thus have prognostic and therapeutic implications in the management of breast cancer.