Project description:Background The dramatic increase in incidence of ductal carcinoma in situ (DCIS) associated with mammographic screening for breast cancer has given emphasis to the challenges of managing this important clinical entity. Unlike invasive breast cancer, there is no established histopathologic grading system for DCIS, nor are there biological markers of prognosis to guide clinical management. The aim of this study is to use molecular profiling to identify robust and clinically applicable indicators of DCIS malignant potential. Methods Areas of intraduct carcinoma, atypical ductal hyperplasia and benign epithelium were isolated from 46 well-characterised invasive breast cancers by laser capture microdissection. Microarray based gene expression profiling was used to identify genes differentially expressed between DCIS associated with grade 1 and grade 3 invasive carcinoma (‘grade associated genes’). The expression profile of these genes was then determined in all samples and used to define ‘molecular grade’ categories. The genomic basis of gene expression derived categories was examined by array-based comparative genomic hybridisation (CGH). Results DCIS samples could be divided into two subgroups, designated low and high molecular grade (MG) on the basis of expression at 173 grade associated oligonucleotide probes. The low MG subgroup included 21 DCIS samples of low (n=10) and intermediate (n=11) nuclear grade as well as all samples of ADH (n=4) and benign epithelium (n=7). The high MG subgroup included 27 DCIS samples of intermediate (n=7) and high (n=19) nuclear grade. Array CGH revealed distinct differences in the character and degree of genomic aberration associated with MG and the clinical significance of MG was verified by a strong correlation with survival in two independent invasive breast cancer gene expression datasets (n=295 and n=186). MG categories were strongly associated with histopathologic and biomarker features of DCIS. Using a classification tree model, DCIS MG could be accurately predicted in 44/46 (95.7%) of samples using a combination of nuclear grade and Ki67 score. Conclusions Molecular profiling indicates a binary grading scheme for DCIS that is both biologically relevant and clinically informative. The low and high MG DCIS classification could be recapitulated by a novel combination of routinely accessible features. This practical approach has potential to immediately improve clinical evaluation and management of DCIS. Keywords: Paired gene expression and CGH

Project description:Background The dramatic increase in incidence of ductal carcinoma in situ (DCIS) associated with mammographic screening for breast cancer has given emphasis to the challenges of managing this important clinical entity. Unlike invasive breast cancer, there is no established histopathologic grading system for DCIS, nor are there biological markers of prognosis to guide clinical management. The aim of this study is to use molecular profiling to identify robust and clinically applicable indicators of DCIS malignant potential. Methods Areas of intraduct carcinoma, atypical ductal hyperplasia and benign epithelium were isolated from 46 well-characterised invasive breast cancers by laser capture microdissection. Microarray based gene expression profiling was used to identify genes differentially expressed between DCIS associated with grade 1 and grade 3 invasive carcinoma (‘grade associated genes’). The expression profile of these genes was then determined in all samples and used to define ‘molecular grade’ categories. The genomic basis of gene expression derived categories was examined by array-based comparative genomic hybridisation (CGH). Results DCIS samples could be divided into two subgroups, designated low and high molecular grade (MG) on the basis of expression at 173 grade associated oligonucleotide probes. The low MG subgroup included 21 DCIS samples of low (n=10) and intermediate (n=11) nuclear grade as well as all samples of ADH (n=4) and benign epithelium (n=7). The high MG subgroup included 27 DCIS samples of intermediate (n=7) and high (n=19) nuclear grade. Array CGH revealed distinct differences in the character and degree of genomic aberration associated with MG and the clinical significance of MG was verified by a strong correlation with survival in two independent invasive breast cancer gene expression datasets (n=295 and n=186). MG categories were strongly associated with histopathologic and biomarker features of DCIS. Using a classification tree model, DCIS MG could be accurately predicted in 44/46 (95.7%) of samples using a combination of nuclear grade and Ki67 score. Conclusions Molecular profiling indicates a binary grading scheme for DCIS that is both biologically relevant and clinically informative. The low and high MG DCIS classification could be recapitulated by a novel combination of routinely accessible features. This practical approach has potential to immediately improve clinical evaluation and management of DCIS. Keywords: Paired gene expression and CGH Paired CGH and Gene Expression on DCIS of the breast

Project description:Classifying intracystic papillary carcinoma under invasive or in situ ductal carcinoma is still a matter of debate. The purpose of this study was to explore the genomic relationship of this tumor to its concurrent invasive ductal carcinoma and ductal carcinoma in situ using array comparative genomic hybridization. Intracystic papillary carcinoma cases were classified into three categories: pure, with concurrent ductal carcinoma in situ or with concurrent invasive ductal carcinoma. Each component was dissected using laser capture microdissection. DNA was extracted and array comparative genomic hybridization was performed. The test of difference in copy number changes among the three tumors was carried out using CGHMultiArray. Intracystic papillary carcinoma clustered with four of five concurrent ductal carcinoma in situ cases and with two of two invasive ductal carcinoma cases. Intracystic papillary carcinoma showed the highest proportions of genome copy number aberration, followed by ductal carcinoma in situ, and then by invasive ductal carcinoma (P=0.06). Comparing intracystic papillary carcinoma with invasive ductal carcinoma vs without invasive ductal carcinoma, the former had 11q22.1-23.3 loss (P=0.031) and chr5 gain (P=0.085), and was enriched with matrix metalloproteinase genes. Comparing intracystic papillary carcinoma with ductal carcinoma in situ vs without ductal carcinoma in situ, the former had gain in 5q35.3 (P=0.041), 8q24.3 (P=0.041) and 21q13.2 to 21q13.31 (P=0.011). Comparing intracystic papillary carcinoma with ductal carcinoma in situ, the latter acquired a group of genes involved in cell adhesion and motility, whereas intracystic papillary carcinoma differentially expressed genes that are involved in papillary carcinomas of other organs (thyroid and kidney). We conclude that the overall molecular change in intracystic papillary carcinoma is closer to ductal carcinoma in situ than to invasive ductal carcinoma, which may explain the indolent behavior of this tumor. We offer herein a proposal of intracystic papillary carcinoma pathogenesis through its relation to invasive ductal carcinoma and ductal carcinoma in situ.

Dataset Information

Gene Expression and Comparative Genomic Hybridization of Ductal Carcinoma In Situ of the Breast

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets