Delayed hypersensitivity reactions in patients with breast cancer.

Fifty six patients with metastatic cancer of the breast (stage IV) were treated with Cyclophosphamide, 5-Fluorouracil and Cyclophosphamide + 5-Fluorouracil. Tests for delayed hypersensitivity to homologous tumor antigen before treatment were positive in 83.9% and negative in 16.1%. Response to DNCB was positive before treatment in 51.8% and negative in 48.2%. Following chemotherapy the skin reaction, to homologous tumor antigen remained positive, only in 12.6% and negative in 87.4%. The reaction of DNCB remained positive after treatment only in 17.8%. In the remaining 82.2% suppression of the reaction occurred. These data show that chemotherapy may suppress, to a certain excent, immune responses. It is established that among patients who have shown a positive reaction to homologous tumor antigen 55.3% of all cases have displayed objective response to the treatment, and among these with negative skin reactions objective responses were observed in 22.22% of all cases. In patients with positive DNCB reactions objective responses were observed in 79.3% and among the negative ones--in 37.4%.