Expression of CD44-v6-containing isoform on breast tissue adjacent to silicone breast implants

Although a variety of studies exists, the silicone controversy is still going on. In the present study we investigated the expression of the activation markers CD44-v6, intracellular adhesion molecule 1 (ICAM-1), and HLA class II molecules on breast epithelia adjacent to a silicone gel-filled breast implants (SGBI). Using an indirect immunoperoxidase procedure 12 tissue samples from implant recipients were investigated and 6 tissue samples from patients with slight breast hyperplasia were used as controls. Expression of CD44-v6 was found on ductal epithelia in all specimens from implant recipients, HLA-DR was expressed in all specimens, HLA-DQ in 3 of 10, and ICAM-1 in 8 of 12. In contrast, neither CD44-v6 nor HLA-DQ nor ICAM-1 were expressed on ductal epithelia from patients with slight breast hyperplasia, and HLA-DR was only weakly expressed in 2 of 6 patients. These data show that CD44-v6 can be expressed by benign cells under certain conditions, which may indicate an abnormal state of activation in breast tissue adjacent to an SGBI.