Rapidly fatal advanced EGFR-mutated lung cancers and the need for rapid tumor genotyping in clinical practice.

Use of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is associated with dramatic, durable, and tolerable responses and side effect profiles when applied for palliation of advanced EGFR-mutated non-small-cell lung cancers (NSCLCs). Expert guidelines recommend that EGFR mutation testing results should be available within 10 working days of receipt of tumor specimen by the testing laboratory; in circumstances where the tumor specimen needs to be sent to an external laboratory for testing, the sample should be sent within 3 working days of receiving the request for testing. We report here 2 cases, out of 109 EGFR-mutated (exon 19 deletion or L858R) NSCLCs seen at our institution, experiencing rapid clinical deterioration and death within the window of time prescribed by consensus testing guidelines. We hypothesize that a faster turn-around time may have changed the clinical outcome. Improving rapid turnaround times for tumor genotyping may afford more optimal palliation vis-à-vis early initiation of oral targeted therapy in patients with advanced EGFR-mutated NSCLC.