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

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 Cl = 0.93 - 1 p = 0.001 and fAUC = 0.724 Cl = 0.59 - 0.85 , p = 0.004 respectively. Conclusions: The con- centration of cfDNA and the combination of ofDNA and nDNA are useful biomarkers for diagnosing patients with BC.