ESMO 2018: Uncommon EGFR Mutations in Lung Adenocarcinoma
Posted: Wednesday, November 7, 2018
At the European Society for Medical Oncology (ESMO) 2018 Congress, Aurélien Brindel, MD, of the Groupement Hospitalier Est in Bron, France, shared his team’s analysis of a large database of sequenced EGFR results and corresponding patient outcomes (Abstract LBA60). They found that patients with lung adenocarcinoma and uncommon EGFR mutations had a poorer response to tyrosine kinase inhibitor (TKI) treatment than did patients with similar mutations receiving a first-line TKI. However, these patients with uncommon mutations had longer median overall survival with first-line chemotherapy than did those treated with first-line TKI therapy.
This analysis comprised EGFR-mutant tumors excluding L858R, exon 19 deletions, T790M, and exon 20 insertions. Sequencing yielded 857 EGFR somatic mutations, of which 95 (11%) were deemed to be uncommon EGFR mutations. The majority of uncommon mutations included 47 exon 18 mutations (50%), which included E709X (15%) and G719X (35%) alterations.
The investigators determined that in patients receiving chemotherapy, the median overall survival was 27.7 months, compared with 16.9 months in those receiving TKIs. The investigators further correlated overall survival with the type of mutation and found that exon 18 and exon 20 were associated with a better prognosis, whereas L861Q was linked to a poorer prognosis.
“Uncommon somatic mutations need to be further investigated, as their clinical and therapeutic significance remains unknown,” Dr. Brindel and colleagues concluded.
