Challenge of NSCLC diagnosis after progression

The majority of patients with epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer(NSCLC) respond to first-line EGFR tyrosine kinase inhibitors (TKIs), but nearly all inevitably acquire resistance and develop disease progression. Conventional practice would be to switch treatments to second-line therapy. TKIs are generally followed by second- or third-line salvage chemotherapy until treatment failure, after which no standard treatment options are available, resulting in a poor prognosis and a high risk of death. In over 60% of patients that have progressed on first- and second-generation TKIs, the mechanism of resistance is an acquired T790M mutation.Recommended approach to detect T790M mutation is to do a tisue rebiopsy on paient with progressive disease after first or second line EGFR TKI. A valid alternative to tissue rebiopsy is represented by liquid biopsy, which has been validated, represents a surrogate source of DNA and is a new strategy for tumour genotyping, mainly at the time of progression for EGFR-mutated patients.