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 ... -  《-》

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 ... -  《-》

Detection of ALK rearrangement by immunohistochemistry in lung adenocarcinoma and the identification of a novel EML4-ALK variant.

To KF ，Tong JH ，Yeung KS ，Lung RW ，Law PP ，Chau SL ，Kang W ，Tong CY ，Chow C ，Chan AW ，Leung LK ，Mok TS ... -  《-》

Cytology specimens offer an effective alternative to formalin-fixed tissue as demonstrated by novel automated detection for ALK break-apart FISH testing and immunohistochemistry in lung adenocarcinoma.

Minimally invasive sampling by cytology or core needle biopsy often provides an initial diagnosis for treatment in patients with lung nodules. From these limited specimens, multiple molecular studies are frequently requested. Current guidelines from the US Food and Drug Administration recommend using formalin-fixed paraffin-embedded tissue sections for the detection of anaplastic lymphoma kinase (ALK) gene rearrangement by fluorescence in situ hybridization (FISH). The authors compared alcohol-fixed and formalin-fixed cytology specimens using a novel automated detection for ALK rearrangements by FISH and immunohistochemistry (IHC). ALK FISH testing was performed on 129 lung adenocarcinomas from 71 cytology cases and 58 biopsy/resection specimens using Papanicolaou staining with integrated cytomorphology. IHC with the ALK D5F3 antibody was performed on cases with residual material (88 of 129 cases). The mean age of the patients was 66 years; there were 62 women and 67 men. ALK gene rearrangement was present in 4% of cytology specimens (3 of 71 specimens) and 7% of surgical specimens (4 of 58 specimens). FISH in 13 cases was technically unsuccessful. Of the 7 FISH-positive cases, only 2 cytology cases (4%) and 2 surgical cases (6%) were found to be positive with the ALK antibody, demonstrating 80% concordance. The one case found to be negative for ALK by IHC demonstrated a variant rearrangement of the ALK 2p23 gene locus by FISH. The results of the current study validate the usefulness of alcohol-fixed and/or formalin-fixed cytology specimens for ALK rearrangement by a novel automated FISH method. IHC using the D5F3 antibody for ALK is specific in this limited cohort. The authors also demonstrated that alcohol-fixed cytology specimens can be used for ALK rearrangement by automated FISH, alone or in conjunction with IHC.

Rosenblum F ，Hutchinson LM ，Garver J ，Woda B ，Cosar E ，Kurian EM ... -  《-》

Anaplastic lymphoma kinase immunoreactivity correlates with ALK gene rearrangement and transcriptional up-regulation in non-small cell lung carcinomas.

Boland JM ，Erdogan S ，Vasmatzis G ，Yang P ，Tillmans LS ，Johnson MR ，Wang X ，Peterson LM ，Halling KC ，Oliveira AM ，Aubry MC ，Yi ES ... -  《-》