Clinical characteristics associated with ALK rearrangements in never-smokers with pulmonary adenocarcinoma.

Anaplastic lymphoma kinase (ALK) rearrangement is a validated predictive marker to define patients with non-small cell lung cancer (NSCLC) who can benefit from selective ALK inhibitors. Therefore, accurate assessment of its prevalence and clinical characteristics is increasingly important in the treatment of NSCLC. Also, this ALK rearrangement was previously reported to be more common in patients with no smoking history or those with adenocarcinoma. Never-smokers with completely resected pulmonary adenocarcinoma were screened for ALK rearrangements using Nanostring's gene expression platform. Clinicopathologic data, such as information about epidermal growth factor receptor (EGFR) and KRAS mutation status were retrospectively reviewed. Of 231 tumors screened, 20 (9%) had an ALK rearrangement and all were confirmed to be positive with immunohistochemical and fluorescent in situ hybridization analysis. Of the tumors with available data on the EGFR/KRAS mutation status, EGFR and KRAS mutation rates were 64% (69/108) and 5% (5/102), respectively. Amongst the tumors that were free of EGFR and KRAS mutations, the proportion of ALK rearrangements reached up to 33%. At the time of data cut-off, total of 68 tumors were recurred. Although the recurrence rate was similar between the ALK-positive and negative groups (30% vs. 29%), there was a tendency for ALK-positive tumors to recur more frequently in the pleural space (15% vs. 5%). The five-year disease-free survival (61%) and overall survival rates (79%) in the ALK-positive group were similar to those in the ALK-negative group (51% and 83%, respectively). Even after excluding two patients treated with crizotinib after disease recurrence, overall survival was similar between the two groups. In an NSCLC subpopulation based on smoking history, histology, and EGFR and KRAS mutation status, the prevalence of ALK rearrangements is considerably high. However, ALK rearrangement status itself has no prognostic relevance in patients with completely resected NSCLC.

Sun JM ，Lira M ，Pandya K ，Choi YL ，Ahn JS ，Mao M ，Han J ，Park K ，Ahn MJ ，Kim J ... -  《-》

Clinical and prognostic implications of ALK and ROS1 rearrangements in never-smokers with surgically resected lung adenocarcinoma.

The aim of this study is to evaluate the prevalence and prognostic significance of anaplastic lymphoma kinase (ALK) and c-ros oncogene 1 (ROS1) rearrangement in never-smokers with surgically resected lung adenocarcinoma. We retrospectively analyzed 162 consecutive never-smokers who underwent curative resection for stage IB to IIIA lung adenocarcinoma at a single institution. We concurrently analyzed mutations in the epidermal growth factor receptor (EGFR) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) genes, and investigated ALK rearrangements by fluorescence in situ hybridization assay. ROS1 rearrangement was also determined in all triple (EGFR/KRAS/ALK)-negative tumors. Of 162 never smokers with lung adenocarcinoma, 14 (8.6%) and 5 (3.1%) had ALK and ROS1 rearrangements, respectively. Nineteen of the 74 (25.7%) EGFR and KRAS mutation-negative patients were fusion-positive (ALK or ROS1 fusion). Fusion-positive patients tended to have shorter median disease-free survival (DFS) than fusion-negative patients (28.0 vs. 33.9 months; p=0.128). In multivariate analysis, fusion-positive patients had significantly poorer DFS than fusion-negative patients after adjustment for age, sex, T stage, N stage, and adjuvant chemotherapy use (p=0.022; hazard ratio, 2.11; 95% confidence interval, 1.19-4.30). The first recurrence sites were not significantly different between fusion-positive and fusion-negative patients in this study. This study shows significantly poorer DFS of ALK or ROS1 fusion-positive lung adenocarcinoma in never-smokers after curative surgery.

Kim MH ，Shim HS ，Kang DR ，Jung JY ，Lee CY ，Kim DJ ，Lee JG ，Bae MK ，Kim HR ，Lim SM ，Kim EY ，Park JS ，Chung KY ，Kim HJ ，Kim JH ，Cho BC ... -  《-》

Distinct clinical features and outcomes in never-smokers with nonsmall cell lung cancer who harbor EGFR or KRAS mutations or ALK rearrangement.

The objectives of this study were to determine the proportions of major oncogenic alterations and to examine survival in genotype-specific subsets of never-smokers with nonsmall cell lung cancer (NSCLC). The authors concurrently analyzed mutations in the epidermal growth factor receptor (EGFR) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) genes and investigated anaplastic lymphoma kinase (ALK) gene rearrangements in samples from 229 never-smokers with NSCLC. ALK rearrangements were identified by fluorescent in situ hybridization and were confirmed by immunohistochemistry. Mutations in EGFR (exons 18 to 21) and KRAS (codons 12 and 13) were determined by direct sequencing. Of 229 tumors, the frequency of EGFR mutations, ALK rearrangements, KRAS mutations, and no mutations (wild type [WT]) in any of the 3 genes (WT/WT/WT) was 48%, 8.3%, 3.5%, and 40.2%, respectively. All genetic alterations were mutually exclusive. The median progression-free survival after treatment with EGFR tyrosine kinase inhibitors (TKIs) was 12.8 months, 6.3 months, 2.1 months, and 1.6 months in patients with EGFR mutations, the WT/WT/WT genotype, KRAS mutations, and ALK rearrangements, respectively. In a Cox regression model, the adjusted hazard ratio for the risk of disease progression after treatment with EGFR TKIs was 0.59 (95% confidence interval [CI], 0.40-0.87; P = .008) for patients with EGFR mutations, 4.58 (95% CI, 2.07-10.15; P < .001) for patients with ALK rearrangements, and 4.23 (95% CI, 1.65-10.8; P = .003) for patients with KRAS mutations. Overall survival also differed significantly among genotypes. To the authors' knowledge, this was the largest comprehensive and concurrent analysis to date of 3 major oncogenic alterations in a cohort of East Asian never-smokers with NSCLC. Because survival outcomes differed among genotypes, and drugs that target specific alterations currently are available, genetic profiling to identify genotype-specific subsets can lead to successful treatment with appropriate kinase inhibitors.

Kim HR ，Shim HS ，Chung JH ，Lee YJ ，Hong YK ，Rha SY ，Kim SH ，Ha SJ ，Kim SK ，Chung KY ，Soo R ，Kim JH ，Cho BC ... -  《-》

Identification of EGFR mutation, KRAS mutation, and ALK gene rearrangement in cytological specimens of primary and metastatic lung adenocarcinoma.

The identification of molecular alterations has an important therapeutic implication in patients with lung adenocarcinomas. In the current study, the authors evaluated their experience with the identification of epidermal growth factor receptor (EGFR), Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation, and anaplastic lymphoma kinase (ALK) gene rearrangement using cytological specimens of primary and metastatic lung adenocarcinoma. A total of 54 cases of lung adenocarcinomas (11 primary and 43 metastatic tumors) in which molecular tests were performed were retrieved. Molecular tests were performed on the cell block material of 19 effusions and 35 fine-needle aspirates. EGFR mutation was evaluated by polymerase chain reaction sequencing analysis of exons 18, 19, 20, and 21. KRAS mutation was tested using polymerase chain reaction-single-strand conformational polymorphism analysis of codons 12 and 13. ALK gene rearrangement was evaluated by fluorescence in situ hybridization using an ALK break apart probe. Molecular tests were successful in 49 of 54 cases (91%). Evaluation of EGFR mutation, KRAS mutation, and ALK gene rearrangement were performed in 49 cases, 14 cases, and 22 cases, respectively. EGFR mutations were found in 14 of 49 cases (29%), including 5 primary and 9 metastatic tumors. Three metastatic/recurrent adenocarcinomas demonstrated an additional EGFR T790M mutation that was not identified in the original specimens. KRAS mutation was detected in 3 of 14 cases (21%) including 1 primary and 2 metastatic tumors. ALK gene rearrangement was evident in 3 of 22 cases (14%), all of which were metastatic tumors. The results of the current study have demonstrated the feasibility of using cytological specimens for EGFR mutation, KRAS mutation, and ALK gene rearrangement analysis. Repeating molecular testing in metastatic/recurrent lung adenocarcinomas may uncover newly acquired molecular alterations.

Cai G ，Wong R ，Chhieng D ，Levy GH ，Gettinger SN ，Herbst RS ，Puchalski JT ，Homer RJ ，Hui P ... -  《-》

Anaplastic lymphoma kinase gene rearrangements in cytological samples of non-small cell lung cancer: comparison with histological assessment.

Anaplastic lymphoma kinase (ALK) gene rearrangements are detected in approximately 5% of cases of non-small cell lung cancer (NSCLC). Patients who are positive for ALK rearrangements may be successfully treated with the ALK inhibitor crizotinib. Because advanced-stage lung cancers are not suitable for surgical resection, approximately 70% of patients are diagnosed via preoperative specimens. In the current study, the authors evaluated the suitability of stained cytologic direct smears and cell blocks for fluorescence in situ hybridization (FISH) to determine ALK status compared with small biopsies. A total of 493 consecutive patients with NSCLC were analyzed by FISH for ALK gene rearrangements. The analyzed sample comprised 180 cytological samples, 94 direct smears, 86 cell blocks, and 313 preoperative small biopsies. Moreover, in the same series, 426 patients and 369 patients, respectively, were evaluated for epidermal growth factor receptor and KRAS mutations, respectively. Of the total of 493 patients, 18 patients who were positive for a gene rearrangement (4.4%) demonstrated ALK FISH rearrangements, whereas 387 patients (95.6%) were negative. All other cases were classified as inadequate (7.7%) and insufficient (10.1%). A strong statistical association was found between the cytology and the small biopsy with respect to ALK rearrangements (P=.0048). Fifty-three patients (12.4%) demonstrated an epidermal growth factor receptor mutation, whereas 90 patients (24.4%) were found to have KRAS mutations. None of these patients presented with ALK gene rearrangements. ALK gene rearrangements may be easily detected in cytological samples and particularly in direct smears, thereby yielding important improvements in the diagnostic approach to patients with advanced NSCLC. Cytological samples may be useful for ALK analysis when insufficient material is available in cell blocks or small biopsies.

Proietti A ，Alì G ，Pelliccioni S ，Lupi C ，Sensi E ，Boldrini L ，Servadio A ，Chella A ，Ribechini A ，Cappuzzo F ，Miccoli M ，Fontanini G ... -  《-》