Expression of anaplastic lymphoma kinase fusion gene in patients with lung sarcomatoid carcinoma and treatment analysis

Abstract

Objective: To investigate the expression status of anaplastic lymphoma kinase (ALK) fusion gene in lung sarcomatoid carcinoma (LSC) and the role of ALK inhibitors for treatment. Methods: Total of 84 cases of LSC confirmed by histopathology were detected for ALK fusion gene from January 2011 to December 2014 in the Cancer Hospital of Chinese Academy of Medical Science&Peking Union Medical College and Shandong Zibo Wanjie Cancer Hospital. All patients were primarily treated by the multi-disciplinary mode in combination with chemotherapy or targeted therapy based on surgery. Postoperative adjuvant chemotherapy was given on platinum based two-drug combination regimen. In ALK fusion gene (+ ) patients with recurrence or metastasis, crizotinib target therapy was prefered. Chi-square test was applied for the comparison of 1, 3, 5-year survival rates between the two groups. Results: Eighty-two cases completed the follow-up. ALK fusion gene was found in 9(10.7%) patients. After application of crizotinib, 1 case was evaluated as complete remission, 6 cases as partial response, 2 cases as stable disease; the 1, 3, 5-year survival rate was 100% (9/9), 100% (9/9) and 88.9% (8/9) for the patients with ALK fusion gene, and it was 65.8% (48/73), 15.1% (11/73) and 6.8% (5/73) respectively for patients without ALK fusion gene. There was significant difference in the survival rate between the two groups (χ(2)=1.56, 1.56, 0.83, all P<0.05). Conclusion: ALK fusion gene maybe expressed in LSC patients. Compared with conventional chemotherapy, crizotinib can significantly prolong the survival time of patients with ALK fusion gene.