The laboratory test aims to significantly improve on current methods, one of which is a tumour biopsy. This method is normally used, as it is the only way to detect the low levels of specific mutations shed from the tumour into the blood against the high background of normal DNA.
However, the major disadvantage of this procedure is the high degree of invasiveness when obtaining a sample from patients with lung cancer.
Clinical research using DxS' Epidermal Growth Factor Receptor (EGFR) Mutation Test kit has resulted in the National Cancer Centre in Tokyo reliably measure mutations in serum and use this as a predictor of response to Gefitinib (Iressa).
The DxS EGFR Mutation Test Kit is a molecular assay combining ARMS (allele specific PCR) and Scorpionsô, a fluorescent signalling system.
In addition to heralding the introduction of blood-based mutation detection, the paper also concluded that patients who were EGFR mutation positive appeared to have better outcomes with Gefitinib treatment in terms of progression-free survival, overall survival and response, than those patients who were EGFR mutation-negative.
"The DxS test kit detected mutations that were missed by direct sequencing techniques," said corresponding author Kazuto Nishio.
"We anticipate that the detection of EGFR mutations in serum DNA using the Scorpions ARMS assay will be useful as a feasible approach for predicting tumour response to gefitinib."
DxS has already developed assays for the 26 next most common EGFR mutations, which predict both drug response and also drug resistance (T790M). Further oncology mutation kits are in development.
Scorpions is a homogeneous or closed-tube platform for PCR analysis. It is ideal for all diagnostic applications which require rapid and reliable PCR detection such as viral load testing, RNA profiling, pharmacogenomics and environmental analysis.