Neutrophil Extracellular Traps Associate with Clinical Stages in Breast Cancer

Recently, neutrophil extracellular traps (NETs), three-dimensional structures formed of neutrophil enzymes such as neutrophil elastase (NE) and nuclear components (DNA), have been associated with progression in different types of cancer. However, data remain scarce in breast cancer. Thus, the aim of this study was to associate NETs with clinical stages of breast cancer. A prospective analysis was performed in 45 plasma samples of female patients with newly diagnosed breast cancer. NE-DNA complexes were evaluated by ELISA. Optical density was dichotomized at the median for comparisons (low and high levels of NE-DNA). The most frequent clinical stage was localized (n = 28, 62%) followed by regional (n = 13, 29%) and distant (n = 4, 9%). Higher levels of NE-DNA complexes were observed in regional and distant stages compared to localized disease (68% vs 32%, p = 0.034). No differences were observed when comparing other clinical characteristics between both groups. We demonstrated that the levels of NETs increase in proportion to the stage of the disease, observing higher levels of NE-DNA complexes in regional and metastatic disease, which coincides with the proposed mechanism by which cancer progression and metastasis might result from the formation of NETs.