A prospective comparison study on EGFR mutations by direct sequencing and ARMS in completely resected Chinese non-small cell lung cancer with adenocarcinoma histology (ICAN).

Abstract

1547 Background: ICAN study investigated EGFR mutation (M) status, clinical outcomes and recurrent risk factors in Chinese lung adenocarcinoma (ADC) patients (pts) after complete resection. Here we report analysis results for the overall EGFR M rate and the consistency between two EGFR M detecting methods, ARMS and PCR+direct sequencing (Seq). Methods: Pts were aged ≥18 years, with histological diagnosed lung ADC, and received surgical complete resection. Tumor sample EGFR M status (primary endpoint; positive [M+]) was determined according to clinical routine practice by whatever methods, including ARMS, Seq, liquid chip and mutant-enriched PCR. For the pts whose tissue was adequate after EGFR M testing by single method of either ARMS or Seq, the other method was applied. Results: Of 571 pts from 26 sites, 315 (55.2%) pts were EGFR M+. 420 pts’ tissues were tested by both ARMS and Seq. EGFR M+ rates were 58.1% and 54.5% respectively without statistical significance (p=0.0548). The total consistent rate (both M status and M types) between two methods was 76.7%. The following Table showed individual EGFR M types by two methods. Conclusions: The overall EGFR M+ rate in operable Chinese ADC was 55.2%. For resection samples, two common methods, ARMS and Seq, didn’t show statistical significance on EGFR M+ rate. Regarding EGFR M types, Seq found some rare mutations which ARMS kit could not detect, while ARMS seemed more sensitive for exon 20 and 21 mutations, especially for S768I and L861Q. Clinical trial information: NCT01106781. [Table: see text]