A novel genotyping test for non-small cell lung carcinoma
Chemotherapy is the standard treatment regimen for non-small cell lung carcinoma (NSCLC) patients but it has limited efficacy. Newer drugs that inhibit the function of the epidermal growth factor receptor (EGFR) improved outcome in patients with mutations in the Egfr gene. Clearly, Egfr mutation analysis should be routinely performed before treatment decisions. Existing molecular methodologies are expensive and time-consuming, and can only utilise certain types of samples. Scientists on the EU-funded LUNGCARD (Point-of-care blood device for fast and reliable prediction of drug response in non- small-cell lung carcinoma patients from blood samples) project set out to develop a point-of-care device that can address these bottlenecks. The generated microfluidic chip combined easy patient blood sample collection with DNA genotyping in one single step. The use of human blood also overcame limitations associated with the availability or poor condition of tumour biopsy samples. The LUNGCARD device was designed to detect Egfr somatic mutations in exons 19 and 21 that together comprise 90 % of Egfr mutations. DNA extraction and Egfr gene amplification were performed after magnetic separation of circulating lung cancer cells in the blood. Genetic analysis entailed the hybridisation of gold silver nanoprobes to the target DNA and mutations were detected by micro capillary electrophoresis. The estimated time for the assay was two hours with an overall cost of the ready-to-use chips below 50 euros. Taken together, the LUNGCARD system provides a cheaper, rapid and reliable assay for detecting a subpopulation of NSCLC patients with Egfr mutations. These device features should facilitate the implementation of genetic screening for lung cancer patients at the point-of-care and personalise their therapeutic regimen.
