[Characteristics of PIK3CA gene mutations in Her2-low breast cancer].

Background: Mutations in the gene, encoding the catalytic subunit of the PI3K class IA p110α, is a common mechanism of activating of PI3K/AKT/mTOR pathway in breast cancer (BC). The detection of these mutations in patients with hormone-positive Her2-negative BC is of important clinical value, since they are the predictor of the sensitivity of the tumor to the PI3K inhibitor - alpelisib. According to the status of the Her2/neu expression, all patients with hormone-positive Her2-negative BC can be divided into two groups - with low expression of Her2/neu (IHC 1+; 2+, ISH-) and with a complete lack of expression of this protein (IHC 0).

Agreement between PDL1 immunohistochemistry assays and polymerase chain reaction in non-small cell lung cancer: CLOVER comparison study.

The goal of the CLOVER study was to perform a pairwise comparison of four tests based on the same patient population with non-small cell lung cancer (NSCLC): three validated PDL1 immunohistochemistry (IHC) assays (Ventana SP142, Ventana SP263, Dako 22C3) and one PCR test. Four hundred seventy-three NSCLC samples were obtained from a biobank and were stained using PDL1 IHC assays. Four trained pathologists independently evaluated the percentage of tumor cells (TC) and immune cells (IC) that stained positive at any intensity.

[HER2/neu gene amplification as a mechanism of clonal heterogeneity in breast cancer].

Objective: To estimate the heterogeneity of HER2/neu gene amplification in HER2/neu-positive breast cancer (BC).

Material And Methods: Fluorescence in situ hybridization (FISH) assay was used to estimate HER2/neu gene amplification and HER2/CEP17 ratios in BC samples with an immunohistochemical evaluation of HER2/neu2+ expression. The results were interpreted according to the 2018 ASCO/CAP guidelines.

RUSSCO-RSP comparative study of immunohistochemistry diagnostic assays for PD-L1 expression in urothelial bladder cancer.

In this collaborative study by the Russian Society of Clinical Oncology and the Russian Society of Pathology, we assessed the concordance among three validated, commercially available PD-L1 immunohistochemistry assays for patients with urothelial cancer. Tumors from 100 urothelial cancer patients were stained with the antibody clones 22C3 (Agilent), SP142 (Ventana Medical Systems), and SP263 (Ventana Medical Systems), which are used in clinical trials of second-line therapy with checkpoint inhibitors. Four trained pathologists independently evaluated the percentages of tumor cells (TC) and tumor-infiltrating immune cells (IC) that were stained at any intensity by each of the antibodies.

[Morphological evidence of the ischemic nature of the prostatic fibrosis in the classical chronic pelvic pain syndrome / IIIB chronic prostatitis].

Aim: To examine the structure of the prostate tissue in patients with III B chronic prostatitis (CP) and chronic pelvic pain syndrome (CPPS).

Materials And Methods: The study analyzed transrectal fine-needle biopsy specimens of 10 patients with the verified diagnosis of chronic pelvic pain syndrome/category III B chronic prostatitis (CPPS/IIIB CP) according to the National Institutes of Health classification. Tissues were examined using light and electron microscopy, and immunohistochemical study of the expression of CD31, CD34, NSE and S-100 markers.