Usefulness of circulating free DNA for monitoring epidermal growth factor receptor mutations in advanced non-small cell lung cancer patients: a case report.

Genomic analysis of circulating tumor DNA (ctDNA) released from cancer cells into the bloodstream has been proposed as a useful method to capture dynamic changes during the course of the disease. In particular, the ability to monitor epidermal growth factor receptor (EGFR) mutation status in cell-free circulating DNA (cfDNA) isolated from advanced non-small cell lung cancer (NSCLC) patients EGFR can help to the correct management of the disease and overcome the challenges associated with tumor heterogeneity and insufficient biopsied material to perform key molecular diagnosis. Here, we report a case of long term monitorization of EGFR mutation status in cfDNA from peripheral blood in an NSCLC patient in, with excellent correlation with clinical evolution.

cfDNA analysis from blood in melanoma.

Testing of tumor tissue remains the recommended method for detecting the presence of somatic mutations in human malignancies. V600E is the most frequent somatic point mutation in metastatic melanoma, providing a unique molecular marker for this malignancy. In addition, tumors carrying this mutation are primary candidates for BRAF-targeted therapy. Although metastatic melanoma patients usually have sufficient tumor tissue available for genetic analyses, the detection of V600E in blood can have prognostic and predictive value. In addition, patients are rarely re-biopsied and genetic testing in blood can be useful for monitoring response to therapy. Cell-free DNA (cfDNA) and cell-free RNA (cfRNA), RNA associated to platelets and circulating tumor cells (CTCs) are some of the materials that can be derived from the blood of cancer patients. cfDNA can be easily purified from serum and plasma and contains DNA fragments of tumor origin. For this reason, it is the most widely used material for the detection of somatic mutations in blood. Several methodologies have been used to determine V600E status in the cfDNA of metastatic melanoma and some studies have demonstrated that the identification and follow-up of V600E in cfDNA can have prognostic and predictive value.