1 FGFR2 Genetic Polymorphisms Modify the Association of Oral Contraceptive Use with the Risk of Breast Cancer in Chinese Women 徐 望 红 复旦大学公共卫生学院流行病学教研室 上海市肿瘤研究所流行病室

研 究 背 景研 究 背 景 Breast cancer – most common cancer in women – a hormone-related malignancy – a complex and multi-factorial disease – a result of interplays between different exposures and host susceptibility

Oral contraceptives (OC) – exogenous hormones – classified as group 1 carcinogens Schneider HP, et al. Climacteric. 2005;8: Cogliano V, et al. Lancet Oncol. 2005;6: – consistent positive association with breast cancer risk in western populations Kahlenborn C, et al. Mayo Clin Proc. 2006;81(10): Collaborative Group on Hormonal Factors in Breast Cancer. Lancet. 1996;347: – null association in Asian populations Kawai M, et al.Cancer Causes Control. 2010;21(1): Dorjgochoo T, et al. Int J Cancer. 2009;124(10): Ursin G, et al. Am J Epidemiol. 1999;150(6): Huang CS, et al. Br J Cancer. 1999;80(11): Yuan JM, et al. Cancer Res. 1988;48(7):

FGFR2 gene – well recognized breast cancer susceptibility gene – multiple SNPs in association with breast cancer risk across ethnic groups – a sex hormone-dependent role of FGFR2 gene in breast cancer

FGFR2 genetic polymorphisms may modify the association between OC use and breast cancer risk in Chinese women 研 究 假 设研 究 假 设

材 料 与 方 法材 料 与 方 法 A two-stage population-based case-control study SBCS-I ( ) 1459 of 1602 newly-diagnosed breast cancer cases at age of 1724 eligible controls 1193 (82%) cases and 1310 (84%) controls donated a blood sample SBCS-II ( ) 1989 incident cases (83.7%) aged 25 to 70 years old 1989 population controls (70.4%) 969 (48.7%) cases and 975 (49.0%) controls provided a blood sample

Epidemiological data Demographic characteristics Menstrual and reproductive history OCs use and postmenopausal HRT Prior disease history Physical activity Tobacco and alcohol use Diet Weight history Family history of cancer Measured body weight, height, and circumferences of the waist and hips

Genotyping data From a GWAS scan covering about 120 kb of the FGFR2 gene plus 10 kb region of its 5' upstream and 5 kb region of its 3' downstream Genotyping conducted using Affymetrix Genome-Wide Human SNP array 6.0 following Affymetrix’s protocol 42 SNPs genotyped 19 had minor allele frequency of > 0.05 Imputation conducted using the program MACH 93 imputed SNPs 26 SNPs had minor allele frequency of > 0.05 and average imputation quality score of > 0.90.

结 果 Characteristics Stage I StudyStage II Study Cases (n=1104) Controls (n=1109) P value Cases (n=969 ) Controls (n=975) P value Age (yrs), mean ± SD47.6 ± ± ± Education, % Elementary school or below Middle school High school College or above Breast cancer in 1 st degree relatives, % Ever had breast fibroadenoma, %9.54.6< Age at menarche (yrs.), mean ± SD14.5 ± ± ± ± Ever had a live birth, % Number of live births, mean ± SD1.5 ± ± ± ± Age at first live birth (yrs), mean ± SD26.8 ± ± ± ± Post-menopausal, % Age at menopause (yrs.), mean ± SD48.1 ± ± ± ± Oral contraceptive use, % Duration of OC use, mean ± SD8.6 ± ± ± ± HRT use among postmenopausal women, % Physical active in past 10 years, % < BMI (kg/m 2 ), mean ± SD23.6 ± ± ± ± 3.3< a From χ 2 test (categorical variables) or t test (continuous variables). Table 1. Comparison of demographic characteristics between breast cancer cases and controls, the Shanghai Breast Cancer Study

Sex hormones useCases/ControlsAdjusted OR (95%CI) Oral contraceptives use Never1654/ Ever419/ ( ) Type of OC used Never1654/ Progesterone plus estrogen328/ ( ) Progesterone only42/520.86( ) Estrogen only24/300.80( ) Others25/201.30( ) Duration of OC use Never1654/ <18 months208/ ( ) ≥ 18 months211/ ( ) P for trend=0.48 HRT use (postmenopausal women only) Never753/ Ever48/411.14( ) Table 2. Association of sex hormones use and breast cancer risk among Chinese women, the Shanghai Breast Cancer Study OR: adjusted for age, educational levels, age at menarche, menopausal status, breast cancer in 1st-degree relatives, number of live births and body mass index.

Figure 1. Age-adjusted ORs and 95%CI for breast cancer with FGFR2 genetic polymorphisms by OC use, the Shanghai Breast Cancer Study OR per allele: adjusted for age, educational levels, age at menarche, menopausal status, breast cancer in 1st- degree relatives, number of live births and body mass index

OC use No. of MA OC use No. of MA rs rs rs rs Figure 2. Breast cancer odds ratios estimates for OC use according to the number of minor alleles of FGFR2 SNPs, the Shanghai Breast Cancer Study

Hap1: in the order of rs , rs , rs , rs755793, rs , rs , rs , rs and rs Hap2: in the order of rs and rs Hap3: in the order of rs , rs , rs , rs755793, rs , rs , rs , rs , rs , rs , rs and rs OR: adjusted for age, educational levels, age at menarche, menopausal status, breast cancer in 1st-degree relatives, number of live births and body mass index. a additionally adjusted for oral contraceptive use. Table 3. Haplotype analysis of FGFR2 with the risk of breast cancer under dominant model, the Shanghai Breast Cancer Study

讨 论 First study reporting the modifying effect of FGFR2 in the OCs- breast cancer association – effect of OC use in breast cancer depends on the genotypes of FGFR2 at rs755793, rs , and rs – dose-response relationship between duration of OC use and cancer risk among women carrying at least one minor allele at rs755793, rs and rs or those having two minor alleles at rs – unclear function of the loci and poorly understood mechanism underlying the results

Strengths – population-based study design – large sample size – high participation rate – homogeneous ethnic background – extensive coverage of the FGFR2 gene

Limitations  possibility of chance  very few users of OCs containing estrogen or progesterone only  no enough statistical power to evaluate the interaction between HRT use and FGFR2

Significance test our hypothesis provide a possible explain for the null OC-breast cancer association in Chinese women support the hormone-dependent nature of FGFR2 gene important implications in personalized prevention of breast cancer

致 谢 美国 Vanderbilt 大学上海市肿瘤研究所 高玉堂 项永兵 Wei Zheng Xiao-ou Shu Jirong Long Qiuyin Cai Qi Dai 上海市疾病预防控制中心 卢伟 郑莹 顾凯 鲍萍萍 复旦大学公共卫生学院 赵根明 This research was supported by NSFC