Objective: To explore the expression of anaplastic lymphoma kinase (ALK) protein in pleural effusion cells from patients with lung adenocarcinoma and to investigate the relationship between ALK status and the clinicopathological features, and the response to crizotinib.
Methods: Eighty-five cases were reviewed from Sept. 2013-Nov. 2014 at Beijing Chest Hospital. There were 42 males and 43 females, with a median age of 58 (30-87). ALK rearrangements were screened by using immunohistochemistry on Benchmark XT auto-stainer.
Results: The frequency of ALK positive reactivity was 15.3% among the 85 patients. The incidence of ALK expression was more frequent in patients <60 years as compared with patients ≥ 60 years of age (26.1%, 2.6%, χ² =9.015, P=0.002). Among the ALK-positive patients, 8 were males and 5 were females (19.1%, 11.6%, χ² =0.903, P=0.259). There were 8 never-smokers and 5 smokers harboring ALK rearrangement (17.0%, 13.5%, χ²=0.379, P=0.827). Among patients with ALK rearrangement, 6 received EGFR detection, and 5 showed no EGFR mutation, and 1 showed 19del EGFR mutation. Among the 13 ALK-positive patients, 4 received crizotinib therapy, and all showed partial response.
Conclusion: Patients with lung adenocarcinoma with ALK rearrangement were significantly younger than those with ALK wild-type, and ALK rearrangement was rarely concur with EGFR mutation. Screening ALK fusion protein expression in patients with lung adenocarcinoma by paraffin-embedded sediments of pleural effusion was useful in guide of crizotinib therapy.