RESUMEN
Inflammatory myofibroblastic tumor (IMT) is a rare tumor originating from mesenchymal tissue. Epithelioid inflammatory myofibroblastic sarcoma (EIMS) represents a rare and particularly aggressive variant, associated with a worse prognosis. Almost all EIMS cases exhibits activating anaplastic lymphoma kinase (ALK) gene rearrangements, which suggests that EIMS patients may potentially benefit from treatment with ALK tyrosine kinase inhibitors (TKIs). We presented a case involving a 34-year-old woman who was diagnosed with mediastinal EIMS and had a rare echinoderm microtubule-associated protein-like 4 (EML4) -ALK fusion. Following 15 months of neoadjuvant lorlatinib treatment, the patient underwent a complete surgical resection, resulting in a pathological complete response. Given the heightened risk of postoperative recurrence associated with EIMS, the patient's treatment plan included ongoing adjuvant therapy with lorlatinib. As of the present moment, the patient has achieved an overall survival of over 2 years with no observed tumor recurrence. Consequently, the case offers valuable clinical evidence supporting the potential benefits of neoadjuvant lorlatinib treatment for ALK-positive locally mediastinal EIMS patients, with a demonstrated tolerable safety profile.
RESUMEN
Background: Patients with v-raf murine sarcoma viral oncogene homolog B1 (BRAF)V600E-mutant non-small cell lung cancer (NSCLC) benefit from treatment with a combination of BRAF and mitogen-activated protein kinase (MEK) inhibitors, but resistance and disease progression develop in most patients. Pre-clinical studies and case studies of melanoma indicate that acquired resistance to BRAF inhibition may be reversible. However, studies on the effects of dabrafenib-trametinib (D/T) re-challenge for relapse in NSCLC are limited. Case Description: A 58-year-old Chinese woman with a history of smoking and hypertension was diagnosed with stage IV B lung adenocarcinoma with metastasis. The targeted next-generation sequencing (NGS) of the patient's lung tumor biopsy tissues revealed the presence of a BRAF V600E mutation with an allele frequency (AF) of 30.54%. The patient was treated with cytotoxic chemotherapy (the 1st line), D/T targeted therapy (the 2nd line), and immune checkpoint inhibitor monotherapy (pembrolizumab, the 3rd line), all of which achieved a partial response (PR) that lasted for a total of 8 months. The 2nd NGS analysis of the lung tissue specimens revealed the presence of a BRAF V600E mutation (AF =18.41%) without mutations, which was potentially involved in the resistance to BRAF/MEK inhibition. At the 4th line, she subsequently re-challenged D/T, and achieved a 4th PR, lasting for 5 months. The 3rd NGS analysis revealed the retention of the BRAF V600E mutation (AF =0.39%). Her treatment was switched to pembrolizumab (the 5th line), and the disease remained stable for another 6 months as of the last follow-up in November 2021. She didn't experience any adverse events throughout the treatment. Conclusions: Our findings suggest that the re-challenge of D/T and immune checkpoint blockage therapies offer another therapeutic option for NSCLC patients with the BRAF V600E-mutant who have received extensive prior treatments. In addition, our advanced NSCLC patient with the BRAF V600E-mutant also derived long-term clinical benefits from initial chemotherapy, molecular-targeted therapy, and immunotherapy.