FEATURES OF EXPRESSION OF THE KI-67PROLIFERATION MARKER AS A FIXATIONQUALITY INDICATOR IN BREAST CANCER

Abstract

Objective: to study the opportunity of using the localization features of the Ki-67 proliferation marker in tumor samples with delayed fixation as an indicator of poor-quality fixation in breast cancer. Material and methods . The material of the study was 9 tumors diagnosed with breast cancer removed during surgery which were divided into 3 parts. One piece was for control, in the two other pieces fixations were delayed for 6 and 12 hours. The standard immunohistochemical study of HER2, ER, PR and Ki-67 with DAKO reagents (Denmark) was carried out. Result. Ki-67 appeared in the stroma in the form of small granules and artificial fissures were present in the invasive component of the tumor in the 6-hour delayed fixation. In the 12-hour delayed fixation, these changes were more pronounced. A decrease in the degree of HER2 expression was observed in all the cases of the delayed fixation. Changes in the quantitative indices (%) of ER and PR expression were less unambiguous. Conclusion. The presence of Ki-67 in the mammary tumor stroma can be a sign of poor-quality fixation in the testing of the material received for the immunohistochemical examination. Poor-quality fixation distorts the results of the immunohistochemical study of the surgical material.