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 ... -  《-》

Assessment of cytology based molecular analysis to guide targeted therapy in advanced non-small-cell lung cancer.

Li W ，Zhang Z ，Guo L ，Qiu T ，Ling Y ，Cao J ，Guo H ，Zhao H ，Li L ，Ying J ... -  《Oncotarget》

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 ... -  《-》

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 ... -  《-》

The use of stained cytologic direct smears for ALK gene rearrangement analysis of lung adenocarcinoma.

Rearrangements involving the anaplastic lymphoma kinase (ALK) gene are present in approximately 5% of lung adenocarcinomas. Crizotinib is approved for the treatment of lung adenocarcinomas harboring ALK rearrangements. Patients with advanced stage lung cancer are not candidates for surgical resection of their primary tumors. For these patients, cytologic specimens often represent the only diagnostic tissue available. Cell blocks (CBs) are routinely used for molecular studies; however, insufficient CB cellularity can impede the performance of these assays. Thirty-two cytology cases of lung adenocarcinomas were analyzed by fluorescence in situ hybridization (FISH) for ALK rearrangements. Diff-Quik-stained smears were examined to identify tumor cell-enriched areas that were marked using a diamond-tipped scribe. Paired ALK rearrangement FISH was performed using smears and CBs in each case. An ALK rearrangement was detected on direct smears and CB sections in 5 (16%) and 4 (13%), respectively, of the 32 cases studied. Concordant FISH results for smears and CBs were observed in 31 (97%) of 32 cases. In the 1 discordant case, an ALK rearrangement was detected on the direct smear but not in the CB. Reverse transcriptase-polymerase chain reaction analysis of this CB revealed the presence of an EML4-ALK rearrangement, thereby confirming a false-negative FISH result in the CB. Stained cytologic direct smears can be effectively used for ALK rearrangement analysis by FISH. This approach represents a useful safeguard when insufficient CB cellularity is encountered and could prevent delays in treatment in this era of precision medicine.

Betz BL ，Dixon CA ，Weigelin HC ，Knoepp SM ，Roh MH ... -  《-》