Gains and losses of HLA class II (DR) and CD4 in atypical hyperplasia, carcinoma in situ and infiltrating ductal carcinoma of the breast.

Aim: Breast cancer is a frequent cause of death among women with gynaecologic malignancies despite the introduction of combination chemotherapy. There is therefore a need for new therapeutic strategies for patients with breast cancer, such as cellular immunotherapy. In this immunohistochemical study we analyzed the epithelial expression of major histocompatibility complex (MHC) class II (HLA-DR) on atypical and malignant primary mammary epithelial cells, as well as the magnitude of the stromal T lymphocytes (T4 subset) at the tumor site.