Intraosseous Spindle Cell/Epithelioid Rhabdomyosarcoma with TFCP2 Rearrangement: A Recent Recognized Subtype with Partial Response to Alectinib.

Rhabdomyosarcoma affects mainly pediatric patients and is currently classified into four categories: embryonal, alveolar, pleomorphic, and spindle cell/sclerosing. Recently, a molecular group of spindle cell/sclerosing rhabdomyosarcoma demonstrated new fusion transcripts involving FET-family genes with TFCP2. In this report, we describe a rare case of spindle cell/sclerosing rhabdomyosarcoma in a 19-year-old woman, presenting as a destructive lesion involving the condyle of mandible. Next generation sequencing was performed, revealing a FUS::TFCP2 fusion and deletion of ALK gene. Alectinib therapy was initiated, which resulted in a favorable response for 4 months. However, the patient died due progression of the tumor. To make an accurate diagnosis and ensure appropriate patient management, it is necessary to be aware of this variant and use proper immunohistochemical stains when facing malignant mesenchymal bone lesions, expanding its differential diagnosis.

Successful treatment with alectinib after crizotinib-induced hepatitis in ALK-rearranged advanced lung cancer patient: a case report.

BACKGROUND: Besides the clinical benefit of crizotinib in ALK-rearranged metastatic non-small cell lung cancer (NSCLC), concerns about its hepatotoxicity have arisen. It is not clear whether this is a drug class side effect or if the use of other selective ALKs inhibitors is safe after this serious adverse event. While evidence from clinical trials is scarce, reports of treatment after crizotinib-induces hepatitis may add to clinical decision. CASE PRESENTATION: Herein, we report a case of acute hepatitis induced by crizotinib in a 32-years-old female diagnosed with metastatic NSCLC, harboring the ALK-rearrangement. After 60 days of crizotinib therapy, the patient presented with acute hepatitis, diagnosed after investigation of non-specific symptoms, such as nausea and fatigue. Serum aspartate aminotransferase and alanine aminotransferase levels had increased from baseline to 3010 IU/L and 9145 IU/L, respectively. Total bilirubin increased up to 7.91 mg/dL, but she did not develop liver failure. After crizotinib discontinuation, a gradual hepatic function recovery occurred. Unfortunately, during the period without specific oncology treatment, her disease showed an unequivocal progression. Therefore, she started on alectinib with great response, and no liver function alteration recurred. CONCLUSIONS: This case suggests that alectinib, even belonging to the same drug class, could be used as an alternative agent when crizotinib is the etiology of liver damage, but more robust evidence has awaited.

Treating patients with ALK-rearranged non-small-cell lung cancer: mechanisms of resistance and strategies to overcome it.

Anaplastic lymphoma kinase (ALK) rearrangement is detected in 3-7% of patients with non-small-cell lung cancer. Crizotinib is an ALK inhibitor, which was approved in 2011 for the treatment of ALK-positive lung cancer. Despite the initial enthusiasm, most of the patients develop resistance within the first year of treatment. The main mechanisms are secondary mutations and bypass track activation. Moreover, crizotinib has low penetration into the central nervous system. The need to overcome these limitations has led to the development of second-generation inhibitors that have better effectiveness against crizotinib-resistant mutations and brain metastases. Ceritinib and alectinib are the only approved drugs of this group. Many ongoing trials try to define the most appropriate agent for the treatment of ALK-positive lung cancer depending on the responsible mechanism. This review focuses on the current data regarding the potential mechanisms of resistance to ALK inhibitors and the strategies to overcome it.