Circulating free DNA holds clues to cancer diagnosis and risk of relapse

Posted by pt91 at Feb 03, 2012 02:52 PM |
Research led by University of Leicester focuses on breast cancer

Issued on 2 February 2012

Dr Jacqueline Shaw, of the Department of Cancer Studies and Molecular Medicine at the University of Leicester, and colleagues at Imperial College have published the genomic analysis of circulating free DNA (cfDNA) in the blood of breast cancer patients in Genome Research.

The journal ( publishes online and in print today a special issue entitled, "Cancer Genomics," highlighting insights gained from cutting-edge genomic and epigenomic analyses of cancer.

Despite recent advances that have improved breast cancer survival rates, means of monitoring residual disease and the risk for relapse with metastatic cancer have remained elusive. Circulating free DNA (cfDNA), present in the blood at low levels in healthy individuals but elevated in patients suffering from different cancers, has been suggested as a means of cancer diagnosis.  Because elevated cfDNA can also occur in benign disease, its utility in the clinic has been limited and thus there has been no reliable method using blood to diagnose breast cancer or to monitor patients following treatment.

However, cfDNA might still be a key to efficient and reliable diagnosis of breast cancer and effective monitoring of potential for relapse.  Shaw and colleagues recognized that a genomic analysis of cfDNA could shed light on the genetic signatures of disease progression.

Utilizing genotyping technology that identifies single nucleotide variations and copy number variations in cfDNA and the DNA of primary tumours, the research group was able to distinguish between healthy individuals and patients with breast cancer.  “In the future this could lead to new tests for the detection of breast cancer and for monitoring patients on therapy. ” said Dr. Shaw, lead author of the report.

The research team's analysis of patients on follow-up after treatment showed that even 12 years after diagnosis some breast cancer patients still had cfDNA with genetic signatures of their primary cancer, despite no clinical evidence of disease reoccurrence, suggesting dormancy of the cancer or minimal residual disease.  Therefore further monitoring of cfDNA could potentially hep to predict relapse. "CfDNA analysis can determine whether a patient has evidence of dormancy or not, and intriguingly, may help to predict the onset of relapse.  This should enable clinicians to target therapy earlier, at a time when disease is potentially curable." Shaw noted.

The study is part of an established collaboration between Dr Shaw’s group at Leicester and Professor RC Coombes’ team at Imperial College and was supported by grants from Cancer Research UK (BIDD) the Cancer Research UK/Department of Health Experimental Cancer Medicine Centres (at the University of Leicester and Imperial College) and the BRC (Imperial College).


Shaw et al., Genomic analysis of circulating cell free DNA infers breast cancer dormancy. Genome Res. doi:10.1101/gr.123497.111

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