Circulating Cell Free DNA as Blood Based Biomarker in Breast Cancer
The prevalence of circulating cell free DNA (cfDNA) in the peripheral blood of healthy persons and patients with several different diseases is well known since decades. Especially in cancer patients high amounts of cfDNA can be found because of the higher cellular turnover in cancer cells. CfDNA integrity reflects the ratio of longer to shorter DNA fragments and therefore represents the relation between non-apoptotic and apoptotic cell death. For calculation of cfDNA and cfDNA integrity
... A integrity different non-specific repetitive DNA sequences have been used. In patients with breast cancer, several studies demonstrated the ability of cf DNA and cfDNA-integrity to discriminate between healthy persons and patients with breast cancer. However it remains still unclear if the use of non-tumour-specific cf DNA can be helpful in breast cancer diagnostic and monitoring of therapy. Next generation sequencing for somatic tumour specific mutations like PI3K or TP53 gene mutations in circulating cf DNA has successfully demonstrated to be accurate and feasible in patients with breast cancer. Tracking tumour-specific cf DNA may become a valuable tool for monitoring therapy and residual disease in breast cancer patients.