Published online Feb 26, 2021. doi: 10.12998/wjcc.v9.i6.1329
Peer-review started: September 8, 2020
First decision: November 20, 2020
Revised: December 3, 2020
Accepted: December 22, 2020
Article in press: December 22, 2020
Published online: February 26, 2021
The most common EGFR mutations are in-frame deletions in exon 19 and point mutations in exon 21. Cases with classical EGFR mutations show a good response to EGFR tyrosine kinase inhibitors (TKIs), the standard first-line treatment. With the development of next generation sequencing, some uncommon genomic mutations have been detected. However, the effect of TKIs on such uncommon EGFR mutations remains unclear.
Here, we report a case of rare EGFR co-mutation in non-small cell lung cancer and the efficacy of afatinib on this EGFR co-mutation. A 64-year-old woman was diagnosed with thoracolumbar and bilateral local rib bone metastases, bilateral pulmonary nodules, and pericardial and left pleural effusion. The pathological diagnosis was lung adenocarcinoma. To seek potential therapeutic regimens, rare co-mutation comprising rare EGFR G724S/R776H mutations and amplification were identified. The patient experienced a significant clinical response with a progression-free survival of 17 mo.
A case of non-small cell lung cancer with rare EGFR G724S/R776H mutations and EGFR amplification responds well to TKI treatment.
Core Tip: EGFR represents the first identified targetable oncogenic driver discovered in non-small cell lung cancer (NSCLC). The most common EGFR mutations are in-frame deletions in exon 19 and point mutations in exon 21. However, rare mutations were found in nearly 10%-15% of EGFR-positive NSCLC and NSCLC with rare co-mutations had significantly different responses to EGFR tyrosine kinase inhibitor. Herein, we describe a rare case of rare EGFR G724S/R776H mutations and amplification in a NSCLC responding to afatinib.