Objectives: Formalin-fixed, paraffin-embedded unstained archived diagnostic tissue sections are frequently exchanged between clinical laboratories for immunohistochemical staining. The manner in which such sections are prepared represents a type of preanalytical variable that must be taken into account given the growing importance of immunohistochemical assays, especially predictive and prognostic tests, in personalized medicine.
Methods: Recommendations were derived from review of the literature and expert consensus of the Canadian Association of Pathologists-Association canadienne des pathologists National Standards Committee for High Complexity Testing/Immunohistochemistry.
This review is designed to highlight several key challenges in the diagnosis of human epidermal growth factor receptor 2 (her2)-positive breast cancer currently faced by pathologists in Canada: Pre-analysis issues affecting the accuracy of her2 testing in non-excision sample types: core-needle biopsies, effusion samples, fine-needle aspirates, and bone metastasesher2 testing of core-needle biopsies compared with surgical specimensCriteria for retesting her2 status upon disease recurrenceLiterature searches for each topic were carried out using the medline, Embase, International Pharmaceutical Abstracts, and biosis databases. In addition, the congress databases of the American Society of Clinical Oncology (2005-2011) and the San Antonio Breast Cancer Symposium (2007-2011) were searched for relevant abstracts.All authors are expert breast pathologists with extensive experience of her2 testing, and several participated in the development of Canadian her2 testing guidelines.
View Article and Find Full Text PDFBackground: Immunohistological assessment of Ki 67 expression is less expensive than Oncotype Dx, which is currently used to identify patients with lymph node-negative breast cancer, who will benefit from adjuvant chemotherapy.
Methods: The relationship of immunohistologically measured Ki 67 to Oncotype DX recurrence score (RS) was examined in 53 cases of T1-2 N0 M0 (oestrogen receptor-positive, HER2/neu negative) breast cancer.
Results: There was a strong linear correlation between Ki 67 value and the Oncotype Dx RS.
Canadian Immunohistochemistry Quality Control (CIQC) operates an academic proficiency testing (PT) program using a traditional expert panel-based qualitative assessment system. The image analysis approach is increasingly considered for use in PT to follow demand for precision in immunohistochemical test calibration. CIQC introduces and explores the usefulness of a novel image analysis-based tool, the laboratory score/reference method score ratio (LSRSR) for PT.
View Article and Find Full Text PDFAims: Pan-cytokeratin (pan-CK) and low molecular weight cytokeratin (LMWCK) tests are the most common immunohistochemistry (IHC) tests used to support evidence of epithelial differentiation. Canadian Immunohistochemistry Quality Control (CIQC), a new provider of proficiency testing for Canadian clinical IHC laboratories, has evaluated the performance of Canadian IHC laboratories in two proficiency testing challenges for both pan-CK and LMWCK.
Methods: CIQC has designed a 70-sample tissue microarray (TMA) for challenge 1 and a 30-sample TMA for challenge 2.