Detection of Breast Cancer Using the Monoclonal Antibody 3E-1.2

The monoclonal antibody 3E-1.2 was produced by immunizing mice with fresh tissue from a primary breast carcinoma (CaB). The antibody is of the IgM class, reacts with formalin fixed tissues and by immunoperoxidase testing, all breast cancers were found to be 3E-1.2+, but normal breast tissue was either weakly positive or totally non-reactive; as were most other normal tissues, the exceptions being some cell types in lung, kidney, endometrium and urinary bladder. The antibody has the strongest reactions with breast cancer. The antibody has been used for two major purposes described herein, a) the localization of breast cancer in draining axillary lymph nodes. This was performed by injecting radiolabelled monoclonal antibody into the interdigital space of the hand and scanning axillae 16 to 24 hours later. Using this technique lymph nodes containing tumor deposits can be detected when the nodes did not contain a palpable mass. b) A serum test has been developed which detects circulating antigens in the blood and can readily distinguish between normal subjects (n >2000) and those with breast cancer (n > 100); in normal subjects the serum levels are 105 ± 53 (I.S.D.) wherein those with breast cancer the levels are > 267 in 90%. The patients with CaB with a normal serum level (10%) were found to be in remission or undergoing chemotherapy.