Genomic alterations of primary tumor and blood in invasive ductal carcinoma of breast

Ja Seong Bae,Jeong Soo Kim,Seung Ho Baik,Jin Soo Choi,Byung Joo Song,Young Lim,Sang Seol Jung,Woo Chan Park

doi:10.1186/1477-7819-8-32

Ja Seong Bae, Jeong Soo Kim + Show 6 more

Open Access

https://doi.org/10.1186/1477-7819-8-32

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Abstract

BackgroundGenomic alterations are important events in the origin and progression of various cancers, with DNA copy number changes associated with progression and treatment response in cancer. Array CGH is potentially useful in the identification of genomic alterations from primary tumor and blood in breast cancer patients. The aim of our study was to compare differences of DNA copy number changes in blood and tumor tissue in breast cancer.MethodsDNA copy number changes in blood were compared to those in tumor tissue using array-comparative genomic hybridization in samples obtained from 30 breast cancer patients. The relative degree of chromosomal changes was analyzed using log2 ratios and data was validated by real-time polymerase chain reaction.ResultsForty-six regions of gains present in more than 30% of the tissues and 70 regions of gains present in more than 30% of blood were identified. The most frequently gained region was chromosome 8q24. In total, agreement of DNA copy numbers between primary tumor and blood was minimal (Kappa = 0.138, p < 0.001).ConclusionAlthough there was only a slight agreement of DNA copy number alterations between the primary tumor and the blood samples, the blood cell copy number variation may have some clinical significance as compared to the primary tumor in IDC breast cancer patients.

Highlights

Genomic alterations are important events in the origin and progression of various cancers, with DNA copy number changes associated with progression and treatment response in cancer
The MYC oncogene in the 8q24 region is associated with a worsened prognosis or more aggressive clinical features [25]
We identified 46 regions of gain present in more than 30% of the primary tumor samples and 70 regions of gain present in more than 30% of blood samples

Summary

Introduction

Genomic alterations are important events in the origin and progression of various cancers, with DNA copy number changes associated with progression and treatment response in cancer. Array CGH is potentially useful in the identification of genomic alterations from primary tumor and blood in breast cancer patients. The aim of our study was to compare differences of DNA copy number changes in blood and tumor tissue in breast cancer. Breast cancer is the most frequently occurring malignancy in Korean women [1]. Histological and molecular heterogeneity of breast cancer, even in the same stage, hampers the use of standardized treatment. With the aim of individualizing therapy and to refine predictive prognosis, studies have sought to identify biomolecular markers and candidate genes [2,3,4,5,6]. It is crucial to elucidate the mechanisms involved in breast cancer carcinogenesis at the genetic and molecular levels

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