Leukocyte migration inhibition among breast cancer patients in response to various oncogenic viruses

The direct leukocyte migration inhibition (LMI) test was done with leukocytes from healthy women and from patients with primary operable breast cancer, benign breast disease, or head and neck cancer. Purified preparations of murine mammary tumor virus (MuMTV), Mason-Pfizer monkey virus (MPMV), and murine leukemia virus (MuLV) were used. For each virus, the lowest 10th percentile of the LMI responses of controls was used to discriminate positive from negative responses. Leukocytes from 46 of 94 (49%) breast cancer patients responded to MuMTV, which was significantly different from each of the other test groups: Positive reactions were observed in only 9 of 67 (13%) healthy persons, 2 of 32 (6%) patients with benign breast tumors, and 2 of 20 (10%) patients with head and neck cancer. Although leukocytes from 29% of the breast cancer patients responded to MPMV, this response did not significantly differ from that observed in healthy women (14%), in patients with benign disease (20%), or in patients with head and neck cancer (20%). The leukocytes from the breast cancer patients were not reactive to MuLV. LMI tests to both MuMTV and extracts of MCF-7 cultured breast cancer cells were done in 36 breast cancer patients and 40 healthy women simultaneously. Of the breast cancer patients, 75% responded to MuMTV and/or MCF-7 antigen as compared to 18% of the controls (P less than 0.005). These data suggest that leukocytes from breast cancer patients are presensitized to MuMTV and antigen(s) present in MCF-7 breast cancer cell line, but not to MPMV or MuLV.