Lee et al. Breast Cancer Research 2014, 16:R64 http://breast-cancer-research.com/content/16/3/R64

RESEARCH ARTICLE

Open Access

Breast cancer risk assessment using genetic variants and risk factors in a Singapore Chinese population Charmaine Pei Ling Lee1,2†, Astrid Irwanto2,3†, Agus Salim4, Jian-min Yuan5, Jianjun Liu2,3, Woon Puay Koh6,2 and Mikael Hartman2,7,8*

Abstract Introduction: Genetic variants for breast cancer risk identified in genome-wide association studies (GWAS) in Western populations require further testing in Asian populations. A risk assessment model incorporating both validated genetic variants and established risk factors may improve its performance in risk prediction of Asian women. Methods: A nested case-control study of female breast cancer (411 cases and 1,212 controls) within the Singapore Chinese Health Study was conducted to investigate the effects of 51 genetic variants identified in previous GWAS on breast cancer risk. The independent effect of these genetic variants was assessed by creating a summed genetic risk score (GRS) after adjustment for body mass index and the Gail model risk factors for breast cancer. Results: The GRS was an independent predictor of breast cancer risk in Chinese women. The multivariate-adjusted odds ratios (95% confidence intervals) of breast cancer for the second, third, and fourth quartiles of the GRS were 1.26 (0.90 to 1.76), 1.47 (1.06 to 2.04) and 1.75 (1.27 to 2.41) respectively (P for trend