A Living Biobank of Breast Cancer Organoids Captures Disease Heterogeneity.

Breast cancer (BC) comprises multiple distinct subtypes that differ genetically, pathologically, and clinically. Here, we describe a robust protocol for long-term culturing of human mammary epithelial organoids. Using this protocol, >100 primary and metastatic BC organoid lines were generated, broadly recapitulating the diversity of the disease. BC organoid morphologies typically matched the histopathology, hormone receptor status, and HER2 status of the original tumor. DNA copy number variations as well as sequence changes were consistent within tumor-organoid pairs and largely retained even after extended passaging. BC organoids furthermore populated all major gene-expression-based classification groups and allowed in vitro drug screens that were consistent with in vivo xeno-transplantations and patient response. This study describes a representative collection of well-characterized BC organoids available for cancer research and drug development, as well as a strategy to assess in vitro drug response in a personalized fashion.

BRCA promoter methylation in sporadic versus BRCA germline mutation-related breast cancers.

BACKGROUND: In breast cancer, BRCA promoter hypermethylation and BRCA germline mutations are said to occur together rarely, but this property has not yet been translated into a clinical test. Our aim in this study was to investigate the diagnostic value of BRCA1/2 methylation in distinguishing breast carcinomas of BRCA1 and BRCA2 germline mutation carriers from sporadic breast carcinomas using a recently developed BRCA methylation assay based on methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA). METHODS: MS-MLPAs were performed to assess BRCA1 and BRCA2 methylation in breast carcinoma tissues from 39 BRCA1 and 33 BRCA2 germline mutation carriers, 80 patients with sporadic breast cancer, and normal breast tissues from 5 BRCA1 and 4 BRCA2 mutation carriers and 5 nonmutation carriers. RESULTS: Methylation frequencies varied considerably between CpG sites across the BRCA1 and BRCA2 promoters. Some CpG sites were methylated more frequently in BRCA1/2-related than in sporadic carcinomas, whereas other CpG sites were methylated more frequently in sporadic carcinomas, with large variances in sensitivity and specificity as a consequence. CONCLUSIONS: The diagnostic value of BRCA promoter methylation analysis in distinguishing BRCA1/2-related from sporadic breast carcinomas seems to be considerably dependent on the targeted CpG sites. These findings are important for adequate use of BRCA methylation analysis as a prescreening tool for BRCA germline genetic testing or to identify BRCAness patients who may benefit from targeted therapies such as poly(adenosine diphosphate-ribose) polymerase inhibitors.

The microRNA Lifecycle in Health and Cancer.

MicroRNAs (miRNAs) are small non-coding RNAs of ~22 nucleotides that regulate gene expression at the post-transcriptional level. They can bind to around 60% of all protein-coding genes with an average of 200 targets per miRNA, indicating their important function within physiological and pathological cellular processes. miRNAs can be quickly produced in high amounts through canonical and non-canonical pathways that involve a multitude of steps and proteins. In cancer, miRNA biogenesis, availability and regulation of target expression can be altered to promote tumour progression. This can be due to genetic causes, such as single nucleotide polymorphisms, epigenetic changes, differences in host gene expression, or chromosomal remodelling. Alternatively, post-transcriptional changes in miRNA stability, and defective or absent components and mediators of the miRNA-induced silencing complex can lead to altered miRNA function. This review provides an overview of the current knowledge on the lifecycle of miRNAs in health and cancer. Understanding miRNA function and regulation is fundamental prior to potential future application of miRNAs as cancer biomarkers.

Interventional Ductoscopy as an Alternative for Major Duct Excision or Microdochectomy in Women Suffering Pathologic Nipple Discharge: A Single-center Experience.

INTRODUCTION: Pathologic nipple discharge (PND) is, after palpable lumps and pain, the most common breast-related reason for referral to the breast surgeon and is associated with breast cancer. However, with negative mammography and ultrasound, the chance of PND being caused by malignancy is between 5% and 8%. Nevertheless, most patients with PND still undergo surgery in order to rule out malignancy. Ductoscopy is a minimally invasive endoscopic technique that enables direct intraductal visualization. The aim of this study was to evaluate (interventional) ductoscopy as an alternative to surgery in patients with negative conventional imaging. MATERIALS AND METHODS: All patients with PND referred between 2010 and 2017 to our hospital for ductoscopy were retrospectively analyzed. Ductoscopy procedures were performed under local anesthesia in the outpatient clinic. The follow-up period was at least 3 months, and the primary outcome was the number of prevented surgical procedures. Furthermore, we evaluated possible complications after ductoscopy (infection and pain). RESULTS: A total of 215 consecutive patients undergoing ductoscopy were analyzed. In 151 (70.2%) patients, ductoscopy was successful. In 102 procedures, an underlying cause for PND was visualized, of which 34 patients could be histologically proven and 82 patients treated. Sixty of the 215 patients were eventually operated, 8 owing to suspicious findings during ductoscopy, 42 owing to persistent PND, and 10 because of recurrent PND. In 7 patients, a malignancy was found (5 of them classified as suspicious at dusctoscopy). No serious side effects were seen. CONCLUSION: Ductoscopy can be safely used as an alternative for surgery in the workup for PND.

A systematic review on the frequency of BRCA promoter methylation in breast and ovarian carcinomas of BRCA germline mutation carriers: Mutually exclusive, or not?

BACKGROUND: A considerable number of breast and ovarian carcinomas are due to underlying BRCA gene aberrations. Of these, BRCA germline mutations and BRCA promoter methylation are thought to be mutually exclusive, which could be exploited in clinical practice. However, this paradigm has not been studied extensively and systematically. OBJECTIVE: To systematically investigate to what extent BRCA promoter methylation has been reported in breast and ovarian carcinomas of BRCA germline mutation carriers. METHODS: A comprehensive search on BRCA promoter methylation was performed in PubMed and Embase databases. Two authors independently selected studies, assessed study quality and extracted data according to PRISMA and QUADAS-2 guidelines. RESULTS: 21 articles met the inclusion criteria. BRCA1 methylation was found in at least 10/276 (3,6%) breast and 2/174 (1,1%) ovarian carcinomas of BRCA germline mutation carriers, and BRCA2 methylation was found in at least 7/131 (5.3%) breast and 0/51 (0.0%) ovarian carcinomas of BRCA germline mutation carriers. Methylation frequencies varied between individual CpG sites. The selected studies showed important differences in methodology and performed in general a limited methylation and incomplete mutation analysis. CONCLUSIONS: BRCA methylation is rare in breast and ovarian carcinomas of BRCA germline mutation carriers, although the frequency of BRCA promoter methylation may be underestimated. This could have major implications for clinical practice, including referral for genetic testing and BRCAness analysis for treatment decision-making.