Expression of CK19 in invasive breast carcinomas of special histological types: implications for the use of one-step nucleic acid amplification. Issue 6 (22nd March 2011)

• Record Type: Journal Article
• Authors: Alvarenga, César A; Paravidino, Paula I; Alvarenga, Marcelo; Dufloth, Rozany; Gomes, Madalena; Zeferino, Luiz C; Schmitt, Fernando
• Is Part Of: Journal of clinical pathology. Volume 64:Issue 6(2011)
• Page Start: 493
• Page End: 497
• Publication Date: 2011-03-22
• Subjects: CK 19 -- breast cancer -- histological special types -- OSNA -- immunocytochemistry -- histopathology; Pathology -- Periodicals; Pathology, Molecular -- Periodicals; 616.0705
• DOI: 10.1136/jcp.2011.089862
• Languages: English
• ISSNs: 0021-9746

Abstract

Abstract : Background: The sentinel lymph node (SLN) is the first lymph node to receive the lymphatic drainage of a primary tumour; based on the knowledge that CK19 is positive in more than 95% of breast carcinomas, a molecular method for intraoperative diagnosis of SLN metastases (the one-step nucleic acid amplification (OSNA) assay) was developed. Aims: To evaluate CK19 immunoreactivity in a series of special histological types of breast carcinoma in order to verify whether the OSNA assay can be used in all breast cancer cases independently of the histological type. Methods: 116 samples of invasive breast carcinomas of special type were investigated for CK19 immunoreactivity in tissue microarrays (TMA); negative cases were evaluated in the entire tissue tumour tissue. Results: Of the 116 cases, 88.9% were positive CK19. Micropapillary and apocrine carcinomas were all positive for CK19 in TMAs. The tubular (93%), mucinous (86%), medullary typical and atypical (84%), mixed carcinomas (83%) increased the rate of positivity for this marker to 100% after repeating the immunostain in whole tissue of negative TMA cases, because the expression of those cases was focal. Conclusion: Most breast cancer cases were positive for CK19, independent of the histological type; therefore the OSNA assay can be used in all breast cancer cases with a potential low rate of false negative for CK19 detection of micrometastasis. There is an important variation between the positivity assessed on TMAs and the entire tissue; these findings can be clinically relevant because in some cases CK19 is evaluated on core-needle biopsy prior to surgery.