High frequency and allele‐specific differences of BRCA1 founder mutations in breast cancer and ovarian cancer patients from Belarus

Bogdanova NV, Antonenkova NN, Rogov YI, Karstens JH, Hillemanns P, Dörk T. High frequency and allele‐specific differences of BRCA1 founder mutations in breast cancer and ovarian cancer patients from Belarus. Breast cancer and ovarian cancer are common malignancies in Belarus accounting for about 3500 and 800 new cases per year, respectively. For breast cancer, the rates and age of onset appear to vary significantly in regions differentially affected by the Chernobyl accident. We assessed the frequency and distribution of three BRCA1 founder mutations 5382insC, 4153delA and Cys61Gly in two hospital‐based series of 1945 unselected breast cancer patients and of 201 unselected ovarian cancer patients from Belarus as well as in 1019 healthy control females from the same population. Any of these mutations were identified in 4.4% of the breast cancer patients, 26.4% of the ovarian cancer patients and 0.5% of the controls. In the breast cancer patients, BRCA1 mutations were strongly associated with earlier age at diagnosis, with oestrogen receptor (ER) negative tumours and with a first‐degree family history of breast cancer, although only 35% of the identified BRCA1 mutation carriers had such a family history. There were no marked differences in the regional distribution of BRCA1 mutations, so that the significant differences in age at diagnosis and family history of breast cancer patients from areas afflicted by the Chernobyl accident could not be explained by BRCA1. We next observed a higher impact and a shifted mutational spectrum of BRCA1 in the series of Byelorussian ovarian cancer patients where the three founder mutations accounted for 26.4% (53/201). While the Cys61Gly mutation appeared underrepresented in ovarian cancer as compared with breast cancer cases from the same population (p = 0.01), the 4153delA mutation made a higher contribution to ovarian cancer than to breast cancer (p < 0.01). BRCA1 mutations were significantly enriched among ovarian cancer cases with a first‐degree family history of breast or ovarian cancer, whereas the median age at ovarian cancer diagnosis was not different between mutation carriers and non‐carriers. Taken together, these results identify three BRCA1 founder mutations as key components of inherited breast and ovarian cancer susceptibility in Belarus and might have implications for cancer prevention, treatment and genetic counselling in this population.     

Fluorescence in situ hybridisation (FISH) accelerates identification of Gram-positive cocci in positive blood cultures

Sepsis is a life-threatening disease with a high mortality rate. Rapid identification of blood culture isolates plays a crucial role in adequate antimicrobial therapy in sepsis patients. To accelerate microbiological diagnosis, a comprehensive panel of oligonucleotide probes for fluorescence in situ hybridisation (FISH) targeting Gram-positive cocci was compiled and evaluated on 428 positive blood culture specimens. By combining genus-specific and species-specific probes, the assay allowed discrimination of staphylococci, streptococci and enterococci as well as differentiation of therapy-relevant pathogens such as Staphylococcus aureus and Enterococcus faecium/durans. Furthermore, the newly designed FISH probes STREP2, ENCO and GRANU targeted Streptococcus pneumoniae/mitis, Enterococcus spp. (except E. faecalis) and Granulicatella adiacens group, respectively. The FISH assay achieved an overall sensitivity of 98.65% and a specificity of 99.0% and therefore allowed rapid and reliable molecular identification of Gram-positive cocci in blood culture specimens.     

Predicting carotid restenosis by comparison of plaque MCP-1 mRNA expression and serum levels

As cardiovascular pathology grows in numbers, research into the discovery of new chemokine biomarkers should not be neglected, as they seem to be paramount in atherosclerosis prevention and its early detection. Chemokines attract and activate leukocytes and are well recognized in the environment of inflammatory response. MCP-1 is a valuable chemokine whose potential to become a new crucial atherosclerosis marker is surely worth investigating. Since quantities of MCP-1 found in lesions are as low as immeasurable, we propose the use of an immunohistochemical method for the quantification of MCP-1 levels in atherosclerotic lesions. Additionally, serum levels of MCP-1 can be measured by commercially available immunoassays. Proposed MCP-1 concentration increase may explain the acceleration in lesion’s atherosclerosis progression as chemokine activation occurs once they bind to specific ligands. If proven, this hypothesis would indicate the need for further studies in order to objectively link the increased MCP-1 expression with carotid restenosis.     

Subtyping of intraductal papillary mucinous neoplasms – pitfalls of MUC1 immunohistochemistry

Intraductal papillary mucinous neoplasms (IPMNs) are precursor lesions of pancreatic ductal adenocarcinoma (PDAC). Current edition of WHO Classification of Tumors of the Digestive System recognizes four different subtypes (gastric, intestinal, pancreatobiliary, and oncocytic) and recommends analysis of mucin expression (MUC1, MUC2, MUC5AC, MUC6) as well as evaluation of architectural and cell differentiation patterns for correct classification. However, there is no consensus on MUC1 expression of IPMN‐lesions in the literature. Current recommendations are based on studies where antibodies against the core MUC1 protein or sialylated MUC1 (tumor associated MUC1), not the fully glycosylated MUC1 were used. We have recently reported that MUC1 is strongly expressed in both gastric and intestinal types IPMN specimens from the cystic wall, obtained by endoscopic ultrasound guided microbiopsy procedure. We have used a commercial MUC1 antibody, validated and recommended for diagnostic use, which recognizes fully glycosylated MUC1. Based on the above, we propose a revision of the WHO Classification, specifying that antibodies against tumor associated MUC1 should be used for IPMN subtyping.