Autoantibodies to breast and other cancers are commonly present in cancer 
patients. A method to rapidly produce these anti-cancer autoantibodies in the 
lab would be valuable for understanding immune events and to generate candidate 
reagents for therapy and diagnostics. The purpose of this report is to evaluate 
sentinel nodes (SNs) of breast cancer patients as a source of anti-cancer 
antibodies. Radiotracer lymphatic mapping in 29 patients with breast cancer 
confirmed the identity of the SNs which provided source cells for this study. 
Flow cytometry demonstrated ~28% of the MNCs were B cells and ~44% of the B 
cells were class switched memory B cells. EBV-induced proliferation of B cells 
yielded tumor binding antibodies from 3 wells per 1000 but cultures were too 
unstable for detailed evaluations. Hybridomas generated by electrofusion 
produced IgG (48%), IgM (34%) and IgA (18%) antibody isotypes which were 
screened for binding to a panel of breast cancer cells of the major molecular 
subtypes. Tumor lysate binding was observed in 28% of the hybridoma clones and 
10% of these bound whole tumor cells with unique binding patterns. More detailed 
evaluation of selected clones showed binding to the patient's own tumor. SNs are 
removed from more than 100,000 breast cancer patients in the US per year. 
Samples from these lymph nodes represent a substantial opportunity to generate 
anticancer antibodies.