Stage dependence of NK cell activity and its modulation by interleukin 2 in patients with breast cancer.

NK cell activity was evaluated in breast cancer patients with different clinical stages of disease prior to surgery. In 58 patients with Stages I-III of breast cancer the peripheral blood NK cell activity was significantly reduced as compared to controls, and NK activity of 11 patients with Stage IV and metastases was significantly reduced as compared to both controls and patients with locoregional disease. In vitro treatment of peripheral blood lymphocytes (PBL) in medium with 10% fetal bovine serum (FBS) alone significantly increased NK cell activity in patients with Stages I-III and Stage IV of disease, although the level of NK cell activity of patients with Stage IV remained below that for less advanced disease. In vitro treatment of PBL of some Stages I-III patients (n = 41) with interleukin 2 (IL 2) gave a significant, dose-dependent enhancement of their NK cell activity so that it was significantly higher than basic NK activity of healthy controls. The results showed decrease of NK cell activity in breast cancer patients especially in advanced disease and enhancement with IL 2 indicating the possibility of immunotherapy in this neoplasm.