The prevalence of EGFR, KRAS, BRAF and PIK3CA somatic mutations in 861 randomly selected Chinese patients with non-small cell lung cancer (NSCLC) was assayed by the SurPlex®-xTAG70plex platform and analyzed. The results showed that the occurrence rates were 41.0, 8.0, 0.7 and 3.7%, respectively. The mutation rates significantly correlated with gender, histology and smoking history. The EGFR exon 19, 20 and 21 mutations were higher in females compared to males (p< 0.001, exon 19 and 21; p=0.018, exon 20), higher in adenocarcinomas compared to other forms of lung cancers (p< 0.001, exon 19 and 21; p=0.035, exon 20), and higher in non-smokers compared to smokers (p< 0.001, exon 19 and 21; p=0.029, exon 20). Conversely, the KRAS mutations were higher in males compared to females (p=0.004), higher in adenocarcinomas compared to other forms of lung cancers (p< 0.001), and higher in smokers compared to non-smokers (p< 0.001). The PIK3CA mutation rate was lower in adenocarcinomas compared to other forms of lung cancers (p=0.003).

A simple, accurate, sensitive HTP technology was developed and standardized for detecting simultaneously 70 different alleles of EGFR, KRAS, BRAF and PIK3CA gene mutations from FFPE tumor slides.

A novel, qualitative, sensitive, reliable and high throughput liquidchip technology has been developed for detecting KRAS mutations using clinical serum and formalin-fixed and paraffin-embedded samples.

We have developed and standardized a novel technology, mutant-enriched liquidchip (MEL), for clinical detection of EGFR mutations. The MEL integrates a mutant-enriched PCR procedure with liquidchip technology for detections of EGFR exon 19 deletions and L858R mutation on both formalin-fixed and paraffin-embedded (FFPE) slides and plasma samples from patients with non-small cell lung cancer (NSCLC). The detection sensitivity was 0.1% of mutant DNA in the presence of its wild-type DNA. The cross-reaction rate was lower than 5%. To evaluate the MEL platform, the EGFR mutation status of 59 patients with advanced NSCLC treated with EGFRTKIs (Tyrosine Kinase Inhibitors) were tested on their FFPE samples. EGFR exon 19 deletions and L858R were detected in 21 patients (21/59) and 76.2% (16/21) of them had partial response to the EGFR-TKIs, while by sequencing method, only 4 (4/59) mutations were detected. Plasma samples from 627 patients with various stages of NSCLC were examined with the MEL and 22% of EGFR exon 19 deletions and L858R were detected. Furthermore, in patients with advanced disease there are more mutations detected in plasma samples than in patients with less advanced disease. In conclusion, the MEL is a sensitive, stable, and robust technology for detecting EGFR DNA mutations from both FFPE and plasma samples from patients with NSCLC and is now routinely used for clinical diagnosis.

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