Mammary fetal gland: Identification of new oncofetal antigens by monoclonal antibodies B72.3, MM1.80 and 4.36

Aims and background: The B72.3, MM1.80 and 4.63 monoclonal antibodies direc ted against tumor-associated antigens react in human breast also with metap lastic, preneoplastic and metastatic cells, whereas they do not react with normal adult mammary tissue. The aim of our study was to point out the expr ession of these antigens during mammary gland development, since tumor-asso ciated antigens are known to represent antigens of differentiation. Study design: Fifty female fetal breasts between 20 and 40 weeks of gestati onal age were studied. Results: Mammary tissue was identified only in 15 cases. B72.3, MM1.80 and 4.36 monoclonal antibodies reacted with epithelial antigens and maintained the same location and intensity in the various gestational ages. Immunoreac tivity was weak, cytoplasmic and widespread for the 4.36 monoclonal antibod y, intense and cytoplasmatic in a large number of cells for the B72.3 monoc lonal antibody, and intense and luminal for the MM1.80 monoclonal antibody. Conclusions: Such data further support the hypothesis that the normal proce ss of development and differentiation can occur during tumor progression pr ocesses. Identification of these new oncofetal markers could offer a new pe rspective able to recognize the different phases of neoplastic progression and could be useful for prevention.