Analysis of circulating cell-free nuclear and mitochondrial DNA in plasma of Mexican patients with breast cancer.

Abstract

Background: The usefulness of circulating free DNA (cfDNA), nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) as potential biomarkers in cancer remains controversial.

Objective: To determine the concentration of cfDNA and plasma nDNA and mtDNA levels in breast cancer (BC) patients.

Material and methods: This study included a total of 86 women (69 patients with BC and 17 women as a control group). The cfDNA was determined using fluorometry, and the levels of mtDNA and nDNA were quantified using real-time polymerase chain reaction (qPCR).

Results: The concentration of cfDNA was higher in patients with BC compared to the control group (p = 0.001). A higher concentration of cfDNA was also associated with patients over 50 years old (p = 0.001). The level of nDNA was higher in patients with CM compared to the control group (p = 0.004). Levels of mtDNA did not show significant differences (p > 0.005). The concentration of cfDNA and nDNA showed significant discriminatory power (AUC = 0.968, CI = 0.93-1.00, p = 0.001; and AUC = 0.724, CI = 0.59-0.85, p = 0.004, respectively.

Conclusions: The concentration of cfDNA and the combination of cfDNA and nDNA are useful biomarkers for diagnosing patients with BC.