Immunosuppressive acidic protein serum levels in breast cancer patients in a reference to CA 15-3 levels.

Immunosuppressive acidic protein (IAP) has been described as a tumor marker in a number of malignant diseases. To evaluate the clinical importance of IAP in breast cancer patients, IAP serum level was determined in 75 breast cancer patients, using single radial immunodiffusion. Serum samples were also tested for CA 15-3. Cut off value for IAP was determined according to IAP serum level in 50 patients with benign, non inflammatory, diseases, and was set as 725 microgram/ml. Mean IAP serum level (623 mcg/ml) and positivity rate (20%) in 24 breast cancer patients with active disease were similar to those in 51 breast cancer patients with no evidence of disease (590 mcg/ml and 18%). The mean CA 15-3 serum level and positivity rate were significantly higher in patients with active disease (200 units/ml, 67%), compared to patients with no evidence of disease (18.3 units/ml, 6%). In our experience IAP was not found to be an effective tumor marker in breast cancer.