ABSTRACT
Evaluation of human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) is subject to interobserver variation and lack of reproducibility. Digital image analysis (DIA) has been shown to improve the consistency and accuracy of the evaluation and its use is encouraged in current testing guidelines. We studied whether digital image analysis using a free software application (ImmunoMembrane) can assist in interpreting HER2 IHC in equivocal 2+ cases. We also compared digital photomicrographs with whole-slide images (WSI) as material for ImmunoMembrane DIA. We stained 750 surgical resection specimens of invasive breast cancers immunohistochemically for HER2 and analysed staining with ImmunoMembrane. The ImmunoMembrane DIA scores were compared with the originally responsible pathologists' visual scores, a researcher's visual scores and in situ hybridisation (ISH) results. The originally responsible pathologists reported 9.1 % positive 3+ IHC scores, for the researcher this was 8.4 % and for ImmunoMembrane 9.5 %. Equivocal 2+ scores were 34 % for the pathologists, 43.7 % for the researcher and 10.1 % for ImmunoMembrane. Negative 0/1+ scores were 57.6 % for the pathologists, 46.8 % for the researcher and 80.8 % for ImmunoMembrane. There were six false positive cases, which were classified as 3+ by ImmunoMembrane and negative by ISH. Six cases were false negative defined as 0/1+ by IHC and positive by ISH. ImmunoMembrane DIA using digital photomicrographs and WSI showed almost perfect agreement. In conclusion, digital image analysis by ImmunoMembrane can help to resolve a majority of equivocal 2+ cases in HER2 IHC, which reduces the need for ISH testing.
Subject(s)
Biomarkers, Tumor/analysis , Breast Neoplasms/pathology , Image Processing, Computer-Assisted , Receptor, ErbB-2/metabolism , Breast Neoplasms/chemistry , Breast Neoplasms/metabolism , Female , Humans , Image Processing, Computer-Assisted/methods , Immunohistochemistry/methods , In Situ Hybridization, Fluorescence/methods , Observer Variation , Receptor, ErbB-2/chemistry , Reproducibility of Results , Software , Tissue Array Analysis/methodsABSTRACT
BACKGROUND: S100P is a Ca2+ binding protein overexpressed in a variety of cancers, and thus, has been considered a potential tumor biomarker. Very little has been studied about its normal expression and functions. METHODS: We examined S100P expression in normal human tissues by quantitative reverse transcription polymerase chain reaction and immunohistochemistry. S100P protein expression was also studied in a series of tumors, consisting of 74 ovarian, 11 pancreatic, 56 gastric, 57 colorectal, 89 breast and 193 prostate carcinomas using a novel anti-S100P monoclonal antibody. RESULTS: Among the normal tissues, the highest S100P mRNA levels were observed in the placenta and esophagus. Moderate signals were also detected in the stomach, duodenum, large intestine, prostate and leukocytes. At the protein level, the highest reactions for S100P were seen in the placenta and stomach. Immunostaining of tumor specimens showed that S100P protein is expressed in all the tumor categories included in the study, being most prevalent in gastric tumors. CONCLUSION: Based on our observations, S100P is widely expressed in both normal and malignant tissues. The high expression in some tumors suggests that it may represent a potential target molecule for future diagnostic and therapeutic applications.
ABSTRACT
PURPOSE: Histopathological diagnosis of small focus carcinomas in prostatic needle biopsies is often assisted by IHC. To make a definitive diagnosis the pathologist must compare IHC findings with hematoxylin and eosin stained tissue morphology. We introduce what is to our knowledge a new application of virtual microscopy, in which hematoxylin and eosin, and IHC stains done sequentially on the same microscope slide can be simultaneously displayed and compared on a computer screen. MATERIALS AND METHODS: A total of 30 hematoxylin and eosin stained prostatic needle biopsies were scanned with a computer controlled microscope. The slides were destained and then immunostained with a cocktail of AMACR and p63 antibodies, which labels the nuclei of nonmalignant basal cells (p63) and the cytoplasm of neoplastic glandular cells suspicious for malignancy (AMACR). The slides were then scanned again and the pairs of virtual slides were aligned for synchronized viewing. RESULTS: The presented technique was found helpful when suspicious lesions were small and when examining the immunoprofile of specimens was warranted, in addition to examining hematoxylin and eosin stained tissue morphology. The usefulness of our approach based on virtual microscopy can be evaluated on the website , which also serves as an educational tool for self-learning the correlation between hematoxylin and eosin stained tissue morphology, and AMACR/p63 IHC in prostate biopsies. CONCLUSIONS: The technology for simultaneously viewing sequentially hematoxylin and eosin and IHC stained prostate biopsies can be readily used for educational purposes, as exemplified by our website, and along with the availability of rapid virtual slide scanners it can also be used for clinical diagnostics.
