Complement-dependent serum cytotoxicity of cancer patients studied by 51Cr release assay on human cancer lines

The conditions for a 51Cr release assay on cell lines derived from human solid tumors were determined by using a rabbit antihuman antiserum with human AB serum as source of complement. By this assay 38 sera collected before and after surgery from 19 breast cancer patients and 28 sera from 12 melanoma patients and 16 healthy donors were tested on 3 lines derived from breast cancer tissue and 1 line derived from normal breast tissue. Ten of the breast cancer patients had lymph node metastases and 9 did not. Positive reactions were obtained from 4 breast cancer patients, all with lymph node metastases, and from 1 healthy donor. In a second experiment, 58 coded sera belonging to 4 different groups of cancer and non-cancer individuals were assayed on a colonic cancer line (HT-29), and 33 and 20 of them were also treated on a melanoma line (MeWo) and on a breast cancer line (MaCa 13), respectively. Positive responses were few, and were more frequently observed among transfused than non-transfused patients.