2292P - Prevalence of druggable EGFR genomic alterations in solid tumours other than lung cancer

Background

An increasing number of rare oncogene-driven solid cancers have been detected through comprehensive genomic profiling testing. EGFR genomic alterations are the most frequent oncogenic driver alterations in non-small cell lung cancer, and EGFR-tyrosine kinase inhibitors (TKIs) are effective in this population. However, the frequency of EGFR genomic alterations and clinical outcomes of EGFR-TKIs are not well understood in other types of solid tumours.

Methods

Clinical and genomic data retrieved from the Center for Cancer Genomics and Advanced Therapeutics database, the national datacentre for cancer genomic medicine in Japan (Kohno T, et al. Cancer Discov. 2022;12(11):2509-2515.), were collected and analysed (n = 18,124, March 2022-February 2023). This study aimed to investigate the prevalence of druggable EGFR genomic alterations in patients with solid tumours other than lung cancer. Druggable EGFR genomic alterations were defined based on OncoKB™ Therapeutic Level of Evidence V2 (≥Level 3B) that could confer sensitivity to EGFR-TKIs.

Results

Among 17,155 patients with solid tumours other than lung cancer, druggable EGFR genomic alterations were identified in 37 patients (0.22%). The median age was 61 years (range, 10-78 years). The most frequent cancer type was central nervous system/brain (n = 10), followed by head and neck (n = 5), bowel (n = 4), biliary tract (n = 3), and breast (n = 3). The druggable EGFR genomic alterations were observed with EGFR exon 20 in-frame insertions (n = 11), EGFR kinase domain duplication (n = 10), EGFR exon 19 in-frame deletions (n = 4), EGFR L858R (n = 3), EGFR S768I (n = 3), EGFR G719D (n = 3), EGFR L861Q (n = 1), EGFR T790M (n = 1), and EGFR G719A (n = 1). Clinical data regarding treatment using EGFR-TKIs were not recorded in this database.

Conclusions

Druggable EGFR genomic alterations in solid tumours other than lung cancer were observed in 0.22% of this nationwide large cohort. Further clinical investigation is needed to understand the clinical relevance of EGFR-TKIs in patients with solid tumours harbouring druggable EGFR genomic alterations not limited to non-small cell lung cancer patients.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.