Invasive mucinous adenocarcinoma harbored MET exon 14 skipping mutation: case report
Atsushi Washioka1, Hiroaki Akamatsu1, Takeya Sugimoto1
1Internal Medicine III, Wakayama Medical University, Wakayama, Japan.
Background:
Lung mucinous adenocarcinoma has various genetic alterations, but there are no reported cases with MET exon 14 skipping mutations. Multiplex genetic testing is commonly assessed in non-small cell lung cancer (NSCLC) and treatment usually comprises molecular targeted drugs. However, the efficacy of molecular targeted drugs in lung mucinous adenocarcinoma is not reported. Here, we report on the clinical features of tepotinib in invasive mucinous adenocarcinoma (IMA) harboring MET exon 14 skipping mutation.
Case Description:
A 68-year-old Japanese woman was diagnosed with IMA that harbored MET exon 14 skipping mutation. Initial treatment targeting community-acquired pneumonia or cryptogenic organizing pneumonia was ineffective. Blood carcinoembryonic antigen had increased, and positron emission tomography showed uptake of 18F-fluorodeoxyglucose on the infiltration. A second trans-bronchial lung biopsy allowed diagnosis of IMA that harbored MET exon 14 skipping mutation. Tepotinib 500 mg once daily was initiated as the patient's first-line treatment and she showed a durable response with mild adverse events during treatment.
Conclusions:
Molecular targeted drugs (tepotinib) showed similar efficacy for IMA harboring MET exon 14 skipping mutation to their use for NSCLC. This case suggests the benefit of aggressive multiplex genetic testing in patients with IMA and subsequent treatment with molecular targeted drugs.
Insights
This case study shows tepotinib is effective for invasive mucinous adenocarcinoma (IMA) with MET exon 14 skipping mutations. Aggressive genetic testing is recommended for IMA patients to guide targeted therapy.
Area of Science:
- Oncology
- Genetics
- Pharmacology
Background:
- Invasive mucinous adenocarcinoma (IMA) is a subtype of non-small cell lung cancer (NSCLC) with diverse genetic alterations.
- MET exon 14 skipping mutations are uncommon in IMA, with limited data on targeted therapy efficacy.
- Multiplex genetic testing is standard for NSCLC, guiding treatment with molecular targeted drugs.
Observation:
- A 68-year-old woman with IMA was found to have a MET exon 14 skipping mutation.
- Initial treatments for pneumonia were ineffective; elevated CEA and FDG-PET indicated malignancy.
- A second biopsy confirmed IMA with the MET exon 14 skipping mutation.
Findings:
- Tepotinib, a MET inhibitor, was administered as first-line treatment at 500 mg daily.
- The patient achieved a durable response with manageable adverse events.
- The efficacy of tepotinib in IMA with MET exon 14 skipping mutation mirrored its efficacy in NSCLC.
Implications:
- This case highlights the potential benefit of MET-targeted therapy in IMA.
- It underscores the importance of comprehensive genetic profiling in IMA patients.
- Early identification of MET exon 14 skipping mutations can guide effective treatment strategies for IMA.
