Up-regulation of a tumor-associated antigen (tag-72) by interferon-alpha and interferon-gamma in patients with cutaneous breast-cancer recurrences.

: Up-regulation of a tumor-associated antigen (TAA) TAG-72 was investigated immunohistochemically in skin recurrences of 10 breast cancer patients treated with intralesional injections of natural interferons (nIFNs) alpha and gamma. Up-regulation was assessed by comparing the immunoreactivity of pre-IFN and post-IFN specimens stained with monoclonal antibodies (MoAbs) B72.3 and CC49 at near end-point dilutions. Varying degrees of enhanced immunoreactivity were detected in IFN-injected and non-IFN-injected lesions except in 1 patient with high constitutive expression of TAG-72 and another patient not expressing TAG-72. Thus, IFN-mediated up-regulation of TAG-72 can occur in patients whose breast cancer cells express this TAA, independently of the initial levels of antigenic expression.