Is there an advantage of monitoring via exosome-based detection of EGFR mutations during treatment in non-small cell lung cancer patients?

Abstract

We know that detection of EGFR mutations is very important for individual therapy. Nowadays FFPE samples are commonly using to detect the EGFR mutation status. But it has a few handicaps such as, tumor heterogeneity and non-repeatable, it is need to examine mutation statues of EGFR after each treatment regimen for individually treatment of NSCLC patients. Therefore, there is still need to develop non-invasive and useable over and over again approach for monitoring EGFR mutation statues and other genes for individual therapy. So, we aim to examine whether exosomes are good target for detection of EGFR mutation status or not. Pyrosequencing was used to detect, EGFR mutation in FFPE and exosome samples in some NSCLC patients. For the patients given different chemotherapy regime (n=28), PFS was evaluated before and after treatment. In patients who were EGFR positive before treatment, the median PFS for EGFR mutation-positive patients after treatment was 101.7 weeks (95% CI: 0.09-3.21), while for patients who were negative after treatment, the median PFS was 42.43 weeks (95% CI: 0.31- 10.52). Likewise, in patients who were EGFR negative before treatment and EGFR mutation negative after treatment, the PFS was median 52 weeks (95% CI: 0.17-2.84), while in patients who were positive after treatment, the median PFS was 27.57 weeks (95% CI: 0.35-5.58). We show that exosomes are good tools for monitoring EGFR mutation status and exosomes can be use as semi-invasive method for isolation of tumor DNAs for detection of mutation statues for individually treatment of NSCLC patients.