Inter-laboratory comparison of Ki-67 proliferating index detected by visual assessment and automated digital image analysis.

Background: Proliferation rate is a major determinant of the biologic behavior of the tumor and provides information that can be used to guide treatment decisions.

Methods: This ring study included 27 pathologists from 14 Institutions, in order to assess inter-observer concordance between pathologists in Croatia. We analyzed Ki-67 proliferative index on ten randomly selected breast cancer samples comparing consistency between visual assessment using light microscopy compared to digital image analyses results from one central laboratory as a referral value.

[CLINICAL RECOMMENDATIONS FOR DIAGNOSIS, TREATMENT AND MONITORING OF PATIENTS WITH ESOPHAGEAL AND ESOPHAGOGASTRIC JUNCTION CANCERS].

Esophageal and esophagogastric junction cancers comprise histologically and biologically different malignant tumors in which the progress in the understanding of the disease has not been followed by the improvement in the survival. Diagnosis is set by tumor biopsy during endoscopy. Multimodal approaches containing surgery, radiotherapy and chemotherapy are frequently applied in the treatment of locoregionally advanced disease.

INTERLABORATORY CONCORDANCE IN HER-2 POSITIVE BREAST CANCER.

Accurate assessment of HER-2 status is essential for identifying patients who will benefit from HER-2 targeted therapy. The aim of the present study was to show results on the concordance between local and central laboratory testing results in HER-2 positive breast cancer patients. In cases with discordant findings, the immunohistochemical (IHC) and/or in situ hybridization (FISH/SISH) analysis was performed in central laboratories.

Expression of genes responsible for the repair of mispaired bases of the DNA (MLH1) in invasive ductal breast carcinoma.

Breast cancer is a heterogeneous group of diseases determined and distinguished by cellular type, gene expression and clinical signs and symptoms. Identification of histological and biological markers is of great value in predicting the progression of tumor growth and anticipating the expected response to various treatment options. Due to a high degree of cell proliferation in breast tumors and high genetic instability of these tumors, as a consequence of defective DNA repair mechanisms, chemotherapy as a treatment option often renders very successful results.

Role of Ki-67 as a prognostic factor in gastrointestinal stromal tumors.

Aim: To investigate primarily the prognostic value of Ki-67, as well as other parameters, in gastrointestinal stromal tumors (GISTs).

Methods: Ki-67, c-KIT, platelet-derived growth factor receptor-alpha (PDGFRα), smooth muscle actin (SMA), CD34, S100 were stained for immunohistochemistry which was performed on formalin-fixed, paraffin-embeded sections on representative block from each case. Proliferation index counted by Ki-67 antibody was calculated as a number of positive nuclear reaction over 100 cells.