In vivo modulation of natural killer cell activity by tamoxifen in patients with bilateral primary breast cancer

Open Access
Publisher Website
Google Scholar
Abstract
Natural killer (NK) cell activity, the autologous mixed lymphocyte reaction (AMLR) and proportions of T cell subpopulations (CD3+/CD4+ and CD3+/CD8+) and NK cells (CD16+) were studied in 21 patients with bilateral primary breast cancer (BBC), 10 patients with single-breast cancer (SBC) and 20 healthy controls. All patients studied had no evidence of disease and had been off radiotherapy and/or chemotherapy for at least 1 year. Ten patients with BBC were also treated with tamoxifen. Patients with SBC had NK cell activity, AMLR responses and T cell subpopulations that were comparable to those of normal controls. In patients with BBC, a significant (PP+ T cell proportions (30±15% versus 49±13%) and absolute numbers (472±82/mm3 versus 953±131/mm3) were found. However, the proliferative response of BBC patients' T lymphocytes in AMLR was in the range of the normal controls. Lymphocytes derived from 10 BBC patients treated with tamoxifen exhibited NK cell activity that was comparable to that of normal controls and patients with SBC, and was significantly (P+ T cells and in AMLR proliferative responses, which decreased compared to levels in normal controls. Taken together, these results indicate that long-term tamoxifen treatment modulates immune responses in BBC patients.