Small-scale variants and large deletions in BRCA1/2 genes in Slovak high-grade serous ovarian cancer.

The role of PARP inhibitors is to prevent the polymerase from repairing the single-strand break that occurred due to tumor growth and thus induce cell apoptosis when the homologous recombination deficiency (HRD) system is disabled. The eliminated system can be monitored especially in patients with serous ovarian epithelial tumors. Current studies still show the highest progression-free survival (PFS) in the examined groups with BRCA mutant status, even though they are also effective in the case of a disrupted HRD system, apart from BRCA genes. The study cohort consists of women diagnosed with high-grade serous ovarian cancer (HGSOC), after at least two lines of chemotherapy and after relapse of the disease, as determined by ESMO standards and guidelines. The commercially available tool SOPHIA DDM™ (SophiaGenetics, Switzerland) was used to classify the variants after sequencing. The most common variants (pathogenic or likely pathogenic) were in BRCA1 c.1067 A>G (rs1799950) and c.5266dupC (rs80357906) and in BRCA2 c.9976 A>T (rs11571833). Large deletions were detected in one and three cases in the BRCA1 and BRCA2 genes, respectively. A mutation in the BRCA1/2 genes was confirmed in 50% of the examined patients. In the study, we focused on the identification of mutated BRCA genes by a commercially available Sophia DDM™ system to identify a pathogenic or probable pathogenic variant in a cohort of patients with HGSOC in the Slovak population, which could result in better management and stratification of the individual.

High-grade serous ovarian carcinoma and detection of inactivated BRCA genes from biopsy material of Slovak patients.

Ovarian cancer is the leading cause of mortality among all gynecological cancers in developed countries and its most common and most lethal type is the high-grade serous ovarian carcinoma (HGSC). At the molecular level, nearly half of all HGSCs exhibit ineffective homologous DNA recombination and disruption of DNA damage/repair pathway inactivation caused often by BRCA1 and BRCA2 gene mutation. Recently, the detection of BRCA1/2 mutations became important for personalized treatment of HGSC patients with the PARP-inhibitors in the defined clinical setting of relapse after positive adjuvant platinum-based chemotherapeutic response. Based on the selection of patients by regional oncologists, we attempted to verify the possibilities of BRCA1/2 mutation testing on archival formalin-fixed paraffin-embedded (FFPE) biopsy material from regional hospitals. In the study we used: a/ FFPE tumor resections of 97 patients sent to our laboratory, originally stored in archives of regional departments for a period of 1-3 years and retrieved on the principle to contain a maximum of non-necrotic tumor tissue, b/ next-generation sequencing (NGS) assay covering all known mutations in the BRCA1/2 genes on MiSeq (Illumina® platform), and c/ Sophia DDM® bioinformatics platform. After processing of FFPE samples, 5 cases were excluded due to the insufficient genomic DNA quantity. Bioinformatics results of NGS analyses of 92 patients' samples indicated 17.39% pathogenic mutations and 32.61% potentially pathogenic mutations in genes BRCA1/2. Overall, 50% pathogenic and potentially pathogenic mutations were detected in the patient's cohort. The relatively high incidence of BRCA1/2 mutations in our series may be influenced by various indicators including the selection of patients based on adjuvant therapy response as well as regional or population heterogeneity in their frequency. Based on the interdisciplinary cooperation, the use of archival biopsy material processed primarily and stored for a longer period in different laboratories without uniformly defined pre-analytical conditions allows identifying the HGSC patients who might better respond to the PARP-inhibition therapy.

Clinicopathological analysis of programmed death-ligand 1 testing in tumor cells of 325 patients with non-small cell lung cancer: Its predictive and potential prognostic value.

INTRODUCTION: Recent studies on check-point inhibitor therapy, which seems to improve the prognosis of patients with advanced non-small cell lung carcinoma increase the importance of immunohistochemical analyses of the programmed-death receptor and of its ligand, PD-L1 protein. MATERIAL AND METHODS: In our study we present results of PD-L1 immunohistochemical tumor cell expression in a series of 325 lung carcinoma patients biopsies, using the clone 22C3 (and DAKO Link 48 immunostainer). Evaluation of the expression using tissue proportion scoring system allowed to distinguish negative cases (either 0 % or < 1 % of positive tumor cells) versus positive cases in the categories 1-9 %, 10-49 % and ≥ 50 % of positive tumor cells. RESULTS: In association to histopathologic parameters we observed similar rates of positive expression in patients with adenocarcinoma types (47,8 % of all the cases) as well as with squamous cell carcinomas (44,4 %). Within these histological categories, the rates of positivity were similar also in patients with small versus large (resectional) biopsies. In the biopsies of patients with adenocarcinoma we identified differences in the PD-L1 protein expression associated with its histological subtype. In the cases with predominant lepidic pattern the PD-L1 positivity was present in 18,8 %, with predominant acinar or papillary pattern in 40,8 % and in cases with predominant solid or micropapillary component in 74,1 % of the cases resp. Keratinizing squamous cell carcinomas were positive in 38,5 % and non-keratinizing in 53,8 % of all the cases. The hiqhest incidence of an extensive posivity was observed in sarcomatoid carcinoma type. DISCUSSION AND CONCLUSION: Immunohistochemically verified PD-L1 protein expression represents a broadly accepted predictive biomarker for immunotherapy of NSCLC patients. The indicated differences of the expression among various NSCLC types and subtypes require to be verified in larger cohorts of patients in relation with clinical parameters to demonstrate whether it could be plausible to use the PD-L1 expression in a role of a negative prognostic parameter.