alpha-1-Antitrypsin phenotypes among breast cancer patients in the Basque population

One of the main functions of alpha 1-antitrypsin (A1AT) is to inhibit the activity of most proteases. It has been suggested that a deficiency in this protein may favor invasion by cancer cells--consequently, individuals with A1AT-deficient alleles (null, S and Z) may be at greater risk of tumoral invasion due to their lower capacity of response to proteolytic enzymes. This work examines the frequencies of A1AT phenotypes in breast cancer (BC) patients. A sample of patients classified as having infiltrative ductal carcinoma was chosen to be studied as it is a highly invasive tumor, and a sample of patients with BC and a familial history of cancer has also been studied. An increase in the frequency of A1AT-deficient phenotypes was not observed in any of the three groups. One possible explanation could be the immunosuppressive activity of A1AT.