Serum immunoglobulin levels in patients with breast cancer.

Serum immunoglobulin levels IgA, IgG, and IgM have been estimated in 92 patients with breast cancer and 50 control patients, 40 of whom had benign disease of the breast. In patients with breast cancer, IgA was significantly raised at all stages and IgG was significantly reduced, but the two abnormalities were not necessarily concomitant. These findings may suggest a disturbance in the secretory immune system, and immunologic defect even when the cancer is localized to the breast.