Project description:A significant proportion of breast cancer patients develop multiple synchronous unilateral breast tumors, also referred to as multifocal tumors, which represent a diagnostic and therapeutic challenge. Multifocality has been associated with a possible adverse patient outcome, propensity for axillary nodal involvement, and increased risk of local recurrence following breast conserving surgery when compared to unifocal tumors. Previous studies indicate that most lesions from multifocal tumors are concordant with regard to the currently used pathological parameters (histological subtype and grade, hormonal receptors and HER2 status). However, to our knowledge, no study has yet provided a detailed molecular analysis of multifocal breast cancer. Here, we aimed to better define the incidence of multifocal breast cancer using a systematic analysis of pathology reports of primary breast cancers and to compare different foci from 5 multifocal breast cancers in a global analysis using genomic, transcriptomic and epigenomic data. We demonstrate that multifocality is a frequent finding since it concerns 22% (945/4340) of breast cancer patients with primary ductal breast cancer. We find that different lesions from multifocal breast cancer can differ at the (epi)genomic and transcriptomic level even when the foci present similar histology, grading, hormonal and HER2 status despite having a common genetic background. Since the number of (epi)genetic alterations with potential clinical utility is rapidly growing due to increasing numbers of targeted therapies, these findings suggest that it might be necessary to interrogate the different lesions of multifocal breast cancers for adequate treatment management of these tumors. The biological characterization of multifocal breast cancer here is focused on 5 cancers for which the foci did not differ in terms of histological grade, hormonal receptors and HER2 status. The characterization of multifocal tumors involved the identification of somatic rearrangements in 2 foci from each patient via low-coverage whole genome sequencing. Putative rearrangements were amplified by polymerase chain reaction (PCR) and capillary sequenced in tumor and matching blood-derived germline DNA to validate the somatic rearrangements. For all patients, the presence of a number of validated rearrangements was assessed in different paraffin blocks of tumor-adjacent histologically normal tissue by nested PCR. We also performed transcriptomic and epigenomic profiling in 4 and 5 patients respectively using the HG-U133 Plus 2.0 Chips and Infinium Methylation 450K arrays (RNA was not available for patient E).
Project description:Hereditary endocrine neoplasias, including phaeochromocytoma/paraganglioma (PPGL) and medullary thyroid cancer (MTC), are caused by autosomal dominant mutations in a multitude of familial cancer genes. A common feature of these diseases is the presentation of multiple primary tumours or multifocal disease representing independent tumour clones that have arisen from the same initiating genetic lesion but have undergone independent clonal evolution. Such tumours provide a unique opportunity to discover common co-operative changes required for tumorigenesis while controlling for the genetic background of the individual. We performed an in-depth genomic analysis of synchronous and metachronous tumours from five patients harbouring germline mutations in the genes SDHB, RET and MAX. Using whole exome sequencing and high-density SNP-arrays we analyzed between two and four primary tumours from each patient. Furthermore, we applied multi-regional sampling to assess intra-tumoral heterogeneity and clonal evolution in two cases involving PPGL and MTC, respectively. Heterogeneous patterns of genomic change existed between synchronous or metachronous tumours with evidence of branching evolution. We observed striking examples of evolutionary convergence involving the same rare somatic copy-number events in synchronous primary PPGL. Convergent events also occurred during clonal evolution of metastatic MTC. These observations suggest that genetic or epigenetic changes acquired early within precursor cells, or pre-existing within the genetic background of the individual, create contingencies that determine the evolutionary trajectory of the tumour.
Project description:Multiple synchronous and metachronous lung tumors are frequently encountered in patients with lung cancer. For treatment purposes it is important to determine, whether or not tumors are clonally related. In other words, whether multiple tumors in a patient are either metastases or multiple primaries. Previous reports show considerable discordance between histopathological and molecular comparison of tumor pairs. The purpose of this study is to compare genome-wide copy number analysis to the classical histological and clinicopathological routine for clonality analysis in a prospective cohort of patients with synchronous or metachronous tumors, of which at least one site occurred in the thorax.
Project description:We evaluated the profile of miRNA and snoRNA expression in 5 synchronous CRC and matched normal colorectal tissues using the Affymetrix GeneChip miRNA 1.0 array. A total of 24 miRNA differential expressed transcripts which represent 27 mature miRNAs, including an oncogenic miR-17-92a and oncosuppressive miR-143-145 cluster, and a global up-regulation of snoRNAs were revealed in cancer tissues compared with matched normal tissues. Global miRNA expression could distinguish synchronous cancer from normal mucosa. Our findings represent the first comprehensive miRNA and snoRNA expression signatures for synchronous CRC, which increase the understanding of the molecular basis of synchronous CRC, and firstly implicate that dysregulation of snoRNAs and miRNA clusters may present therapeutic targets for synchronous CRC.
Project description:MMTV-NeuNT transgenic mouse model harbors an activated form of Neu (NeuNT). Mice develop stochastically multifocal mammary adenocarcinomas that metastasize to the lung (Muller et al., 1988). MMTV-NeuNT mouse model exhibits both intravascular and parenchymal metastasis which provides a good tool to comprehensively study breast cancer metastasis. In this study, we investigated the role of TNC in tumor progression using the MMTV-NeuNT mouse model. (3 MMTV-NeuNT TNC WT v/s 3 MMTV-NeuNT TNC KO). Breast tumor tissue were collected 3 months after first tumor palpation.
Project description:Multifocal synchronous or metachronous central nervous system (CNS) and extra-CNS malignant rhabdoid tumors (MRTs) are rare and deadly cancers. To further understand these cancers, we performed genome-wide DNA methylation and CNA analysis in 27 tumors (16 of which were paired samples). 26 samples were newly generated and one sample was from a previously published cohort of MRTs. We compared our results with the previously published reference group of 150 atypical teratoid rhabdoid tumors. We showed that that CNS and extra-CNS MRTs for the most part clustered in distinct methylation groups and had heterogeneous molecular characteristics.
Project description:We analysed a cohort of breast papillary lesions cases with (n=4) or without (n=7) co-existed cancer for genome-wide copy number and loss of heterozygosity using Affymetrix OncoScan® MIP arrays. Cases included pure papilloma (withoout cancer) (n=7), papilloma cases synchronous with cancer (n=4). We have analysed copy number calling from these samples including carcinoma components of synchronous cases in order to understand the precursor relationship as well any biomarker for progression from papillary lesions to carcinoma.
Project description:Comparison of genomic rearrangements and DNA methylation
patterns between different foci of multiple synchronous
(multifocal and multicentric) invasive breast cancers