ALK fusion gene positive lung cancer and 3 cases treated with an inhibitor for ALK kinase activity

摘要

Background: Anaplastic lymphoma kinase (ALK) fusion gene-positive lung cancer accounts for 4-5% of non-small cell lung carcinoma. A clinical trial of the specific inhibitor of ALK fusion-type tyrosine kinase is currently under way. Methods: ALK fusion gene products were analyzed immunohistochemically with the materials obtained by surgery or by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). The echinoderm microtubule-associated protein-like 4(EML4)-ALK or kinesin family member 5B (KIF5B)-ALK translocation was confirmed by the reverse transcription polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH). After eligibility criteria were met and informed consent was obtained, 3 patients were enrolled for the Pfizer Study of Crizotinib (PF02341066), Clinical Trial A8081001, conducted at Seoul National University. Results: Out of 404 cases, there were 14 of EML4-ALK non-small cell carcinoma (NSCLC) and one KIF5B-ALK NSCLC case (8 men, 7 women; mean age, 61.9 years, range 48-82). Except for 2 light smokers, all patients were non-smokers. All cases were of adenocarcinoma with papillary or acinar subtypes. Three were of stage IA, 5 of stage IIIA, 1 of stage IIIB and 6 of stage IV. Ten patients underwent thoracotomy, 3 received chemotherapy and 2 only best supportive care (BSC). One BSC and 2 chemotherapy cases were enrolled for the clinical trial. Patients with advanced stages who received chemotherapy or best supportive care were younger (54.0 ± 6.3) than those who were surgically treated (65.8 ± 10.1) (p< 0.05).The powerful effect of ALK inhibitor on EML4-ALK NSCLC was observed. Soon after its administration, almost all the multiple bone and lymph node metastases quickly disappeared. Nausea, diarrhea and the persistence of a light image were the main side effects, but they diminished within a few months. Conclusion: ALK-fusion gene was found in 3.7% (15/404) NSCLC cases and advanced disease with this fusion gene was correlated with younger generation. The ALK inhibitor presented in this study is effective in EML4-ALK NSCLC cases. A further study will be necessary to evaluate the clinical effectiveness of this drug.