Plasma Nucleosome Levels in Node-Negative Breast Cancer Patients

BACKGROUND: A nucleosome is a primary repeating unit of organized DNA in chromatin, and cell death may lead to increased levels of circulating nucleosomes inplasma (PNLs) in various circumstances such as inflammation, pulmonary embolism, autoimmune disease and cancer. MATERIALS AND METHODS: We investigated PNLs in 96 patients with stage 0-III breast cancer (node-negative, n =57; node-positive, n=39), and in 111 women without any evidence of disease as healthy controls. PNLs were detected using the Cell Death Detection ELISAplus kit (Boehringer Mannheim, Japan). RESULTS: The PNLs in normal controls were 0.010 +/- 0.012 units (mean +/- SD), while PNLs were significantly higher in both node-negative breast cancer (0.153 +/- 0.242) and node-positive breast cancer patients (0.116 +/- 0.172) (p <0.01). When PNLs were classified as high (>0.10) and low(