Background
The recent approval of targeted therapies for mesenchymal epithelial transition exon 14 skipping mutations (METex14) has increased the treatments available for advanced lung squamous cell carcinoma (SCC). It is estimated that around 2% of SCC patients will harbour METex14. RNA testing is preferred for its sensitivity detecting the genomic aberrations which cause METex14. We aimed to identify patients with lung SCC harbouring METex14 who may benefit from targeted therapy.
Methods
We conducted a retrospective review of 336 patients discussed at Western Health lung multidisciplinary team meetings (MDM) between April 2022 and April 2023. Data extracted from electronic medical records included patient demographics, cancer stage and histological subtype, prior molecular testing, and available tissue. Lung SCC patients who were alive as of May 2023 had tumour samples screened for METex14 via RNA testing.
Results
Thirty-seven alive lung SCC patients were identified, the median age was 71 years and 51% were male. Six (16%) had locally advanced disease and thirteen (35%) had metastatic disease. Prior molecular testing had been completed for two patients; however, neither had been tested for METex14. Thirty-three patients (89%) had appropriate tumour samples for RNA testing to detect METex14, comprising of 61% small biopsy samples, 21% resection samples and 15% cytology samples. A METex14 result could not be obtained for one sample likely due to poor quality or low yield of RNA. No patients harboured METex14.
Conclusions
Real world prevalence of METex14 in lung SCC patients is low. However, sufficient tumour samples are available for testing in the majority of patients. Routine molecular testing should be considered for patients with lung SCC given the limited number of actionable targets and reimbursed therapies available.