title: Applications of tissue microarray technology in immunohistochemistry: a study on c-kit expression in small cell lung cancer.
abstract: Tissue microarray technology allows the immediate evaluation of molecular profiles of numerous different tissues, with savings of money and time. It was created for rapid, large-scale molecular studies, and the main concern regarding its possible broad acceptance is that the analysis of tissue microarrays instead of whole tissue sections may lead to false negative or positive results because of tissue heterogeneity. In the present study, we analyzed in 54 small cell lung cancers, by immunohistochemistry, the expression of the antigen c-kit, which seems to be important in these neoplasms' tumorigenesis, and compared the staining obtained on whole sections with that of the corresponding tissue microarrays. Although c-kit expression of the whole sections agreed with that of the corresponding biopsies in many cases, the correlation between whole sections and all the companion nonlost single cores or their mean value turned out to be highly significant only if the 36 double negatives (ie, both whole sections and companion tissue microarrays negative) were included (P <0.0001). In fact, if only cases positive to at least 1 of the tests (i.e. whole sections or corresponding tissue microarrays positive) were considered, the correlation was not significant (P=0.055). Tissue microarrays showed a good specificity (94.2% for all single cores and 92.3% for their mean value) but a rather poor sensitivity (respectively, 69.4% and 71.4%). Moreover, a high percentage (13.4%) of cores was lost, and this loss was not random. To sum up, in our experience, tissue microarray technology cannot be a substitute for whole sections in clinical diagnosis of individual cases.
authors.affiliation: Department of Surgery, Division of Surgical Pathology, University of Pisa, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Donati
authors.forename: Pinuccia
authors.initials: P
authors.lastname: Faviana
authors.forename: Matteo
authors.initials: M
authors.lastname: Dell'omodarme
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Prati
authors.forename: Tiziano
authors.initials: T
authors.lastname: Camacci
authors.forename: Katia
authors.initials: K
authors.lastname: De Ieso
authors.forename: Riccardo
authors.initials: R
authors.lastname: Giannini
authors.forename: Marco
authors.initials: M
authors.lastname: Lucchi
authors.forename: Alfredo
authors.initials: A
authors.lastname: Mussi
authors.forename: Raffaele
authors.initials: R
authors.lastname: Pingitore
authors.forename: Fulvio
authors.initials: F
authors.lastname: Basolo
authors.forename: Gabriella
authors.initials: G
authors.lastname: Fontanini
mesh_terms: D000328:Adult; D000368:Aged; D018288:Carcinoma, Small Cell / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics* / Q000378:metabolism; D015203:Reproducibility of Results
chemical_list: D004273:DNA, Neoplasm; D019009:Proto-Oncogene Proteins c-kit