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( </=0.10), no correlation was found between high PNLs and clinicopathological factors such as tumor size, menopausal status, estrogen receptor status, histological type and lymphatic or venous spread in node-negative breast cancer. The relapse-free survival of patients with high PNLs tended to be better than those with low PNLs in both node-negative and node-positive breast cancer.
CONCLUSION: Increased PNLs were found in breast cancer patients, and PNLs seem promising as a new prognostic factor for both node-negative and node-positive breast cancer.