The role of B lymphocytes in breast cancer: a review and current status

Abstract

Primary breast carcinomas are often associated with tumour-infiltrating lymphocytes and metastatic carcinoma cells in axillary lymph nodes make intimate contact with lymphocytic cells. The defensive role of these lymphocytes against breast cancer remains controversial despite several decades of investigation. The identification of human tumour antigens recognised by the autologous host has provided convincing evidence for immune recognition of the tumour. Medullary breast carcinoma is characterized by heavy B lymphocyte infiltration, but these tumourinfiltrating lymphocytes clearly fail to eradicate it and apparently also fail to contain its growth, as the prognosis of medullary breast carcinoma may be no better than that of the more common ductal breast carcinoma. On the other hand, the effectiveness of herceptin has demonstrated that antibodies against tumour-associated antigens are potentially potent agents in the treatment of breast cancer. It is therefore possible that neoplastic zones that elicit effective immunological attack might be destroyed before they are clinically significant. The purpose of this article is to review the role of tumour-infiltrating B lymphocytes in breast cancer, the development of monoclonal antibodies from these lymphocytes, and their possible uses in therapy. It is not our intent nor can we discuss all breast cancer antigens and antibodies against them, as the numbers are too large, nor the role of other types of immune cells such as cytotoxic T cells and natural killer cells