Ribonucleic Acid In Situ Hybridization Is a More Sensitive Method Than Immunohistochemistry in Detection of Thyroid Transcription Factor 1 and Napsin A Expression in Lung Adenocarcinomas

Abstract

Context.-TTF-1 and napsin A immunomarkers have a crucial role in differentiating lung adenocarcinoma from lung squamous cell carcinoma and in identifying a primary lung adenocarcinoma when working on a tumor of unknown origin.Objectives.-To investigate the diagnostic sensitivity of ribonucleic acid in situ hybridization (RNAscope) in the detection of expression of these biomarkers in lung adenocarcinomas and to compare RNAscope to immunohistochemical techniques.Design.-Both RNAscope and the immunohistochemical assays for TTF-1 and napsin A were performed on tissue microarray sections containing 80 lung adenocarcinomas and 80 lung squamous cell carcinomas. The RNAscope assay for both TTF-1 and napsin A was also performed on 220 adenocarcinomas from various organs.Results. Conclusions.-Preliminary data suggest that RNAscope is superior to immunohistochemistry in detecting TTF-1 and napsin A expression in primary lung adenocarcinomas. Therefore, performing an RNAscope assay may be considered for both TTF-1 À and napsin A À cases with a clinical suspicion of lung adenocarcinoma. The TTF-1 results should be interpreted with caution because a small percentage of squamous cell carcinomas can be focally positive by either assay.

Age and Gender Associations of Virus Positivity in Merkel Cell Carcinoma Characterized Using a Novel RNA In Situ Hybridization Assay

“…Advances in RNA in situ hybridization (ISH) have revolutionized the ability to assess RNA expression in multiple specimen types, including formalin-fixed paraffin-embedded (FFPE) tissues (18,19). RNAscope technology provides single-molecule sensitivity and resolution, enabling quantification of specific RNA molecules at the single cell level (20).…”

Analytic Validation of RNA In Situ Hybridization (RISH) for AR and AR-V7 Expression in Human Prostate Cancer

“…The recent emergence of highly sensitive RNA in situ hybridization (RISH) methodologies for use in formalin fixed paraffin embedded (FFPE) tissues has revolutionized our ability to examine RNA expression in tissues (32). The novel RISH assays provide a higher level of target sensitivity and specificity when compared with many immunostaining protocols (33). The increased specificity is achieved by requiring two separate oligonucleotides (Z-pairs) to hybridize near each other in order to generate a signal, and the increased sensitivity is achieved by having a series of these Z-pairs bind to the target as well has having a branched DNA amplification step prior to enzymatic amplification (32).…”

Comparison of RNAscope and immunohistochemistry for evaluation of the UPK2 status in urothelial carcinoma tissues

“…Our results in this study showed that the difference in the detection of UPK2 in UC between RNAscope (68.0%) and IHC (62.6%) was not significant and that there was a moderate positive correlation between RNAscope and IHC ( P < 0.001, R = 0.441) for the detection of UP II. However, RNAscope can improve TTF1 sensitivity by 10.0% and Napsin A sensitivity by 12.5% compared with those of IHC in lung adenocarcinomas [ 16 ]. In addition, compared with IHC, RNAscope improved both the specificity and sensitivity for GPC3 and GS by 20–30% in hepatocellular carcinoma [ 17 ].…”

“…RNAscope is a more sensitive method than IHC for detecting thyroid transcription factor 1 (TTF-1) and Napsin A expression in primary lung adenocarcinomas. RNAscope may be considered for patients with clinically suspected lung adenocarcinoma but who are TTF-1- and Napsin A-negative as detected by IHC[ 16 ]. RNAscope improves Glypican3 (GPC3) and glutamine synthetase (GS) specificity and sensitivity by 20-30% in hepatocellular carcinoma.…”