Increased IL-17 and IL-6 Transcripts in Peripheral Blood Mononuclear Cells: Implication for a Robust Proinflammatory Response in Early Stages of Breast Cancer

Several recent studies demonstrated that transforming growth factor beta (TGF-β), by stimulating T regulatory cells, and interleukins 6 and 17 (IL-6, IL-17), by inducing inflammatory reactions, may be critical factors in cancer pathogenesis. We used quantitative real-time polymerase chain reaction assays to quantify the expression of IL-17, IL-6 and TGF-β mRNA in peripheral blood mononuclear cells and lymphocytes from draining lymph nodes of 60 women with breast cancer. The results were compared according to the patients’ clinical or pathological status. Higher amounts of IL-17 and IL-6 mRNA, but not TGF-β transcripts, were found in patients compared to controls. There were no significant differences between patients with negative or positive nodes or with different histological grades or stages of disease. Most women in this analysis had stage I or II disease. We thus conclude that IL-17, a prominent proinflammatory cytokine, may play an important role in recruiting and infiltrating antitumor immune responses in early stages of breast cancer.