Molecular portrait of breast cancer in China reveals comprehensive transcriptomic likeness to Caucasian breast cancer and low prevalence of luminal A subtype.

Xiaoyan Huang,Matteo Dugo,Sylvie Ménard,Jiong Wu,Zhimin Shao,Rosaria Orlandi,Jingyan Xue,Elda Tagliabue,Maurizio Callari,Maria Grazia Daidone,Silvia Veneroni,Maria Luisa Carcangiu,Marco Sandri,Barbara Valeri,Rui Bi,Loris De Cecco

doi:10.1002/cam4.442

Abstract

The recent dramatic increase in breast cancer incidence across China with progressive urbanization and economic development has signaled the urgent need for molecular and clinical detailing of breast cancer in the Chinese population. Our analyses of a unique transethnic collection of breast cancer frozen specimens from Shanghai Fudan Cancer Center (Chinese Han) profiled simultaneously with an analogous Caucasian Italian series revealed consistent transcriptomic data lacking in batch effects. The prevalence of Luminal A subtype was significantly lower in Chinese series, impacting the overall prevalence of estrogen receptor (ER)-positive disease in a large cohort of Chinese/Caucasian patients. Unsupervised and supervised comparison of gene and microRNA (miRNA) profiles of Chinese and Caucasian samples revealed extensive similarity in the comprehensive taxonomy of transcriptional elements regulating breast cancer biology. Partition of gene expression data using gene lists relevant to breast cancer as “intrinsic” and “extracellular matrix” genes identified Chinese and Caucasian subgroups with equivalent global gene and miRNA profiles. These findings indicate that in the Chinese and Caucasian groups, breast neoplasia and the surrounding stromal characteristics undergo the same differentiation and molecular processes. Transcriptional similarity across transethnic cohorts may simplify translational medicine approaches and clinical management of breast cancer patients worldwide.

Highlights

Breast cancer is a leading cause of morbidity and mortality among female cancer patients worldwide
The prevalence of Luminal A subtype was significantly lower in Chinese series, impacting the overall prevalence of estrogen receptor (ER)-positive disease in a large cohort of Chinese/Caucasian patients
There is abundant epidemiological evidence that race/ethnicity is associated with disparities in cancer incidence and mortality [6], and some studies have shown that such differences are affected by social–economic conditions leading to inequality in access to effective medical care or exposure to risk factors [6, 7], it is still unclear whether race/ethnic variability in cancer reflects differences in cancer biology

Summary

Introduction

Breast cancer is a leading cause of morbidity and mortality among female cancer patients worldwide. Heterogeneity and complexity of breast cancer have been extensively detailed by large genomic and transcriptomic studies [4, 5] that must be translated into a personalized management of the disease based on genetic and molecular traits of each breast tumor, and accounting for social and environmental conditions of each patient. Fan et al [9] highlighted how socioeconomic development, accelerated urbanization, higher lifetime expectancy, and the aging of the Shanghai population have greatly contributed to the rapid change in risk factors and the increase in breast cancer incidence and mortality Since this increase is likely to continue in the decades across all of China [8], there is an urgent need for molecular and clinical detailing of breast cancer in this population. Chinese and Caucasian comprehensive transcriptomic data were examined for patterns of similarity and dissimilarities using unsupervised and supervised analysis, and breast cancer molecular taxonomy was explored and compared in both Chinese and Caucasian gene profiles

Materials and Methods

Results

81 Taiwan GSE48390

Discussion