Issues with the targeted therapy of non‑small cell lung cancer with thyroid metastases: A case report

Lung cancer is a common malignancy that has usually already metastasized at the time of diagnosis; however, thyroid metastases are extremely rare. Echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (ALK) fusion has been observed in 3-7% of cases of lung adenocarcinoma. ALK inhibitor therapy has been shown to exert a positive effect on disease progression. The present study describes the case of a patient with ALK-positive non-small cell lung carcinoma and thyroid metastases who exhibited a minimal response to ALK inhibitor therapy in the primary lesion, but had a complete pathological response in the thyroid, as confirmed by a thyroid biopsy. The present case report undermines the need for further evidence from genomic testing following this different tumor course in thyroid tissue.