Retrospective analysis of the clinicopathologic profile of ALK-positive patients in the south of Spain.

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e19105 Background: The anaplastic lymphoma kinase (ALK) fusion gene is a key oncogenic driver in a subset of patients with advanced non small cell lung cancer (NSCLC). ALK rearragement is detected in 2-7% of NSCLC patients. Fluorescence in situ hybridization (FISH) is the recommended method of detection. The clinical features of lung cancer that harbors ALK include light- or never-smokers, younger age, adenocarcinomas with acinar pattern or signet ring adenocarcinoma, and a lack of EGFR or KRASmutations. Crizotinib has shown an important benefit in terms of overall response rate (ORR) and progression free survival (PFS) in the 2nd/3rd line setting. Treatment related adverse events include gastrointestinal and visual disorders. Methods: Retrospective analysis of the clinico-pathological profile of ALK NSCLC patients between May 2011 and December 2012 in our region. Results: 10 cases (6,7%) were identified from 150 screened patients with adenocarcinoma histology and EGFR wild-type status. 7 (70%) patients were women. Median age at diagnosis was 62 years old (36-77). 9 (90%) patients were light-or-never smokers. All tumors were adenocarcinomas with EGFR wild-type status: Acinar growth pattern was detected in 4 cases (40%); 4 (40%) patients showed mucous cells and previous described signet-ring cells were detected in the last 2 (20%) cases. Only 5 (50%) patients received crizotinib therapy: 2 patients were treated during 1st line with partial response, 1 patient on 2nd line with stable disease and 2 patients received treatment in 3rdline with partial response. Only one patient required a dose reduction due to a grade 3 nausea and mucositis. Conclusions: Most of the patients with ALK rearragements in our serie have clinical and pathological characteristics to previously described. More women and older population were showed. In stead of the small sample size, pathological pattern based on acinar growth and mucous or signet-ring cells in adenocarcinomas with no EGFR mutation should guide the ALK screening. ORR and toxicity profile confirmed Crizotinib benefit as soon as ALK status was detected.