Pulmonary atypical carcinoid (AC) is an extremely rare neuroendocrine tumor. The neurotrophic tropomyosin receptor kinase (NTRK) fusions are reported in only 0.5% of nonsmall cell lung cancer, and are more rare in AC with only one previously reported case. Currently, there is little established evidence on the optimal therapeutic strategies and prognosis for advanced cases. We present a female patient with metastatic AC after complete resection. Due to low expression of somatostatin receptor in this case, somatostatin analogs and peptide receptor radionuclide therapy were not available. After pursuing other alternative treatments, including chemotherapy (ie, carboplatin, etoposide, capecitabine, temozolomide, and paclitaxel), everolimus, and atezolizumab, she returned with significant progression, including innumerable subcutaneous nodules, left pleura metastasis, multiple bone metastases, and brain metastases. New biopsy analysis revealed an ETV6-NTRK2 fusion. She was immediately administered the first-generation tropomyosin receptor kinase inhibitor entrectinib at a dose of 600 mg q.d. A subsequent month of treatment resulted in a complete response in all of the metastatic lung lesions. To date, she has maintained sustained benefit for at least 1 year from initiation of entrectinib. Here, we present the first case of a female patient with metastatic AC harboring the ETV6-NTRK2 fusion, and successfully treated with entrectinib, providing evidence for the application of entrectinib in patients with NTRK-positive AC, and underscoring the critical role of molecular profiling for such cases.

中文翻译：

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恩曲替尼成功治疗转移性肺非典型类癌患者的 ETV6-NTRK2 融合：病例报告及文献综述

肺非典型类癌（AC）是一种极其罕见的神经内分泌肿瘤。据报道，神经营养性原肌球蛋白受体激酶 (NTRK) 融合仅在 0.5% 的非小细胞肺癌中出现，在 AC 中更为罕见，之前仅报道过一例。目前，关于晚期病例的最佳治疗策略和预后的证据很少。我们介绍了一名完全切除后患有转移性 AC 的女性患者。由于该病例生长抑素受体表达低，无法使用生长抑素类似物和肽受体放射性核素治疗。在寻求其他替代治疗后，包括化疗（即卡铂、依托泊苷、卡培他滨、替莫唑胺和紫杉醇）、依维莫司和阿特朱单抗，她的病情恢复了显着进展，包括无数皮下结节、左侧胸膜转移、多发性骨转移和脑转移。新的活检分析显示 ETV6-NTRK2 融合。她立即​​接受了第一代原肌球蛋白受体激酶抑制剂恩曲替尼（entrectinib）治疗，剂量为每日 600 毫克。随后一个月的治疗使所有转移性肺部病灶完全缓解。迄今为止，从开始使用 entrectinib 起，她已经保持了至少 1 年的持续获益。在这里，我们介绍了首例携带 ETV6-NTRK2 融合的转移性 AC 女性患者，并成功接受 entrectinib 治疗，为 entrectinib 在 NTRK 阳性 AC 患者中的应用提供了证据，并强调了分子谱分析的关键作用对于此类情况。