Background: A single nucleotide polymorphism located in the 3'-untranslated region of the KRAS oncogene (KRAS variant; rs61764370) disrupts a let-7 miRNA binding and was recently reported to act as a genetic marker for increased risk of developing human cancers. We aimed to investigate an association of the KRAS variant with sporadic and familial breast cancer and breast tumor characteristics. Methods: Genotyping was accomplished in 530 sporadic postmenopausal breast cancer cases, 165 familial breast cancer cases (including N = 29, who test positive for BRCA1/2 mutations) and 270 postmenopausal control women using the flurogenic 5' nuclease assay. Information on hormone replacement therapy (HRT) use and tumor characteristics in sporadic breast cancer cases was ascertained from a postal questionnaire and pathology reports, respectively. Associations between the KRAS genotype and breast cancer or breast tumor characteristics were assessed using chi-square test and logistic regression models. Results: No evidence of association was observed between the KRAS variant and risk of sporadic and familial breast cancer - either among BRCA carriers or non-BRCA carriers. The KRAS variant was statistically significantly more often associated with human epidermal growth factor receptor 2 (HER2) - positive tumors and tumors of higher histopathologic grade. However, both associations were detected only in HRT users. Conclusion: Our data do not support the hypothesis that the KRAS variant rs61764370 is implicated in the aetiology of sporadic or of familial breast cancer. In postmenopausal women using HRT, the KRAS variant might lead to HER2 overexpressed and poorly-differentiated breast tumors, both indicators of a worse prognosis.

Background: The BRCA1 and BRCA2 mutation spectrum and mutation detection rates according to different family histories were investigated in 521 subjects from 322 unrelated Slovenian cancer families with breast and/or ovarian cancer. Methods: The BRCA1 and BRCA2 genes were screened using DGGE, PTT, HRM, MLPA and direct sequencing. Results: Eighteen different mutations were found in BRCA1 and 13 in BRCA2 gene. Mutations in one or other gene were found in 96 unrelated families. The mutation detection rates were the highest in the families with at least one breast and at least one ovarian cancer - 42% for BRCA1 and 8% for BRCA2. The mutation detection rate observed in the families with at least two breast cancers with disease onset before the age of 50 years and no ovarian cancer was 23% for BRCA1 and 13% for BRCA2. The mutation detection rate in the families with at least two breast cancers and only one with the disease onset before the age of 50 years was 11% for BRCA1 and 8% for BRCA2. In the families with at least two breast cancers, all of them with disease onset over the age of 50 years, the detection rate was 5% for BRCA2 and 0% for BRCA1. Conclusion: Among the mutations detected in Slovenian population, 5 mutations in BRCA1 and 4 mutations in BRCA2 have not been described in other populations until now. The most frequent mutations in our population were c.181T > G, c.1687C > T, c.5266dupC and c.844_850dupTCATTAC in BRCA1 gene and c.7806-2A > G, c.5291C > G and c.3978insTGCT in BRCA2 gene (detected in 69% of BRCA1 and BRCA2 positive families).

High-grade serous ovarian cancer is a detrimental disease. Treatment options in patients with a recurrent disease are dependent on BRCA1/2 mutation status since only patients with known BRCA mutation are eligible for treatment with poly(ADP-ribose) polymerase inhibitors (PARPi). The aim of this study was to compare concordance of BRCA mutation analyses from cytological samples (CS) with BRCA mutation analyses from histological formalin fixed paraffin embedded (FFPE) samples. Mutation analysis of BRCA1 and BRCA2 genes was performed in 44 women diagnosed with primary or recurrent high-grade ovarian cancer from three different samples: blood, cytological sample (ascites, pleural effusion and enlarged lymph nodes) and tumor tissue. Results from all three samples were compared. Among 44 patients, there were 15 germline mutations and two somatic mutations. A 100% concordance was found between cytological and histologic samples. There is a 100% concordance in BRCA mutation testing between cytological and histologic samples. BRCA mutation testing from CS could replace testing from FFPE tissue in clinical decision making in ovarian cancer patients. The study was retrospectively registered at ISRCTN registry on 24/11/2015 - ISRCTN42408038 .

Detection of germline and somatic pathogenic/likely pathogenic variants (PV/LPV) in BRCA genes is at the moment a prerequisite for use of PARP inhibitors in different treatment settings of different tumors. The aim of our study was to determine the most appropriate testing workflow in epithelial ovarian cancer (EOC) patients using germline and tumor genotyping of BRCA and other hereditary breast and/or ovarian cancer (HBOC) susceptibility genes. Consecutive patients with advanced non-mucinous EOC, who responded to platinum-based chemotherapy, were included in the study. DNA extracted from blood and FFPE tumor tissue were genotyped using NGS panels TruSightCancer/Hereditary and TruSight Tumor 170. Among 170 EOC patients, 21.8% had BRCA germline or somatic PV/LPV, and additionally 6.4% had PV/LPV in other HBOC genes. Sensitivity of tumor genotyping for detection of germline PV/LPV was 96.2% for BRCA genes and 93.3% for HBOC genes. With germline genotyping-only strategy, 58.8% of HBOC PV/LPV and 68.4% of BRCA PV/LPV were detected. By tumor genotyping-only strategy, 96.1% of HBOC PV/LPV and 97.4% of BRCA PV/LPV were detected. Genotyping of tumor first, followed by germline genotyping seems to be a reasonable approach for detection of PV/LPV in breast and/or ovarian cancer susceptibility genes in non-mucinous EOC patients.

An ideal tumor vaccine should activate both effector and memory immune response against tumor-specific antigens. Beside the CD8+ T cells that play a central role in the generation of a protective immune response and of long-term memory, dendritic cells (DCs) are important for the induction, coordination and regulation of the adaptive immune response. The DCs can conduct all of the elements of the immune orchestra and are therefore a fundamental target and tool for vaccination. The present study was aimed at assessing the ability of tumor vaccine composed of C-class CpG ODNs and irradiated melanoma tumor cells B16F1 followed by two additional injections of CpG ODNs to induce the generation of a functional long-term memory response in experimental tumor model in mice (i.p. B16F1).

The diagnostics of Lynch syndrome (LS) is focused on the detection of DNA mismatch repair (MMR) system deficiency. MMR deficiency can be detected on tumor tissue by microsatellite instability (MSI) using molecular genetic test or by loss of expression of one of the four proteins (MLH1, MSH2, MSH6, and PMS2) involved in the MMR system using immunohistochemistry (IHC) staining. According to the National Comprehensive Cancer Network (NCCN) guidelines, definitive diagnosis of LS requires the identification of the germline pathogenic variant in one of the MMR genes. In the report, we are presenting interesting novel MLH1 in-frame deletion LRG_216t1:c.2236_2247delCTGCCTGATCTA p.(Leu746_Leu749del) associated with LS. The variant appears to be associated with uncommon isolated loss of PMS2 immunohistochemistry protein staining (expression) in tumor tissue instead of MLH1 and PMS2 protein loss, which is commonly seen with pathogenic variants in MLH1. The variant was classified as likely pathogenic, based on segregation analysis and molecular characterization of blood and tumor samples. According to the American College of Medical Genetics (ACMG) guidelines, the following evidence categories of PM1, PM2, PM4, and PP1 moderate have been used for classification of the novel variant. By detecting and classifying the novel MLH1 variant as likely pathogenic, we confirmed the LS in this family.