Single Nucleotide Polymorphisms In FGFR2 Research Articles

Abstract P5-06-30: Identification of novel single nucleotide polymorphisms located in MAP3K1 and ABCB1 genes as markers for poor overall survival in early-stage hormone receptor-positive breast cancer using next-generation sequencing

Abstract Background: We previously revealed that single nucleotide polymorphisms (SNPs) of CYP19A1, MAP3K1 rs889312, and ABCB1 rs2032582 were associated with overall survival (OS) in early-stage hormone receptor (HR)-positive breast cancer patients. Previous studies also showed that FGFR2 rs1219468 and TOX3 rs8051542 influenced OS in early-stage breast cancer patients. In this study, we assessed whether undiscovered SNPs of CYP19A1, MAP3K1, ABCB1, FGFR2, and TOX3 are associated with clinical outcome of patients with early-stage HR-positive breast cancer. Patients and Methods: We used next-generation sequencing (NGS) methods to explore unidentified SNPs of CYP19A1, MAP3K1, ABCB1, FGFR2, and TOX3 in 80 patients who had HR+, T1 to T2, and N0 to N1 breast cancer and had matched clinicopathological features and clinical outcomes (experimental cohort). The mapping selected SNPs identified from NGS were located in different chromosomes, such as chromosome 5 (MAP3K), 7 (ABCB1), 10 (FGFR2), 15 (CYP19A1), and 16 (TOX3), were analyzed. The multivariate-adjusted hazard ratio (aHR) of OS associated with the individual genotypes of the experimental cohort was assessed after adjusting for age, tumor size, tumor grade, HER2 status, menopausal status, and chemotherapy using Cox regression analyses. We further correlated identified significant novel SNPs with disease-free survival (DFS) and OS in 195 patients with HR-positive, T1-T2, and N0-1 breast cancer (validation cohort) using stepwise selection multiple Cox model analyses. Results: Through target region re-sequencing, we identified 69 novel SNPs, including 18 CYP19A1 SNPs, 16 MAP3K SNPs, 18 ABCB1 SNPs, 12 FGFR2 SNPs, and 5 TOX3 SNPs in the experimental cohort (n = 80). After multivariate-adjusted analyzing, FGFR2 rs2981460(C/C) (p = 0.0115), and MAP3K1 rs3822625 (A/A) (p = 0.0475), rs702689 (G/G) (p = 0.0312), rs832567 (C/C) (p = 0.0312), and rs9687226 (C/C) (p = 0.0475), and ABCB1 rs2032582 (T/T+T/C) (p = 0.0061) were significantly associated with the poorer OS of the experimental cohort. In a validated cohort (n =195) (Table 1), we found that MAP3K1 rs702689 (G/G) was significantly associated with poorer DFS (aHR = 2.3; 95% confidence interval [CI] = 1.1 to 5.1; p = 0.03) and OS (aHR = 4.9; 95% CI = 1.3 to 18.7; p = 0.02). In addition, MAP3K1 rs832567 (C/C) was significantly associated with poorer DFS (aHR = 2.5; 95% CI = 1.1 to 5.5; p = 0.02) and OS (aHR = 5.4; 95% CI = 1.4 to 21.6; p = 0.02). In premenopausal women of validation cohort (n = 108), ABCB1 rs2032582 (T/T+T/C) was significantly associated with a poor OS (aHR = 62.3; 95% CI = 2.0 to 1911.7; p = 0.02). Conclusions: Our results indicate that 3 novel SNPs, MAP3K1 rs702689, MAP3K1 rs832567, and ABCB1 rs2032582, may affect the prognosis of early-stage HR-positive breast cancer. Further validation of these SNPs in a large series of patients with early-stage HR-positive breast cancer who received adjuvant endocrine therapy alone is warranted. Table 1. The Associations of Hormone Receptor-Positive Breast Cancer Patients with Various Genotypes in multiple Cox model (validation cohort)Disease-free survivalOverall survivalGenotypeaHR (95%CI)PaHR (95%CI)PTotal (n = 195)FGFR2_ rs2981460 (C/C vs.C/T+T/T)0.4 (0.1-1.8)0.220.6 (0.1-5.4)0.68MAP3K1_ rs3822625 (A/A vs. G/A+GG)2.0 (0.7-5.3)0.192.7 (0.6-12.9)0.20MAP3K1_ rs702689 (G/G vs. A/A+A/G)2.3 (1.1-5.1)0.034.9 (1.3-18.7)0.02MAP3K1_rs832567 (C/C vs. A/A+A/C)2.5 (1.1-5.5)0.025.4 (1.4-21.6)0.02MAP3K1_rs9687226 (C/C vs. T/T+T/C)2.0 (0.7-5.3)0.192.7 (0.6-12.9)0.20Premenopausal (n=108)ABCB1_rs2032582 (T/T+T/C vs. C/C)2.0 (0.8-5.0)0.1562.3 (2.0-1911.7)0.02aHR: adjusted by age, estrogen receptor and progesterone receptor status, number of lymph nodes, menopausal status, adjuvant chemotherapy, lymphovascular invasion, and tumor size. Citation Format: Sung-Hsin Kuo, Shi-Yi Yang, Po-Han Lin, Chen-Hsin Chen, Hsin-Chou Yang, Chih-Yuan Hsu, Chiun-Sheng Huang. Identification of novel single nucleotide polymorphisms located in MAP3K1 and ABCB1 genes as markers for poor overall survival in early-stage hormone receptor-positive breast cancer using next-generation sequencing [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-06-30.

Association of FGFR2 and PI3KCA genetic variants with the risk of breast cancer in a Chinese population.

PurposeGenome-wide association studies have found plenty of single nucleotide polymorphisms (SNPs) which are associated with breast cancer risk. SNPs in FGFR2 are mostly identified. However, the association between PI3KCA SNP and breast cancer risk remains largely unknown. The aim of this study was to investigate the significance of FGFR2 and PI3KCA genetic variants in breast cancer and their association with prognosis.MethodsWe performed genotyping of 328 breast cancer patients and 389 healthy controls. Then, we evaluated the associations of FGFR2 rs1219648 and PI3KCA rs6443624 with the susceptibility and clinicopathological features of breast cancer. Kaplan-Meier curve with log-rank test was performed to determine the prognostic values of FGFR2 rs1219648 and PI3KCA rs6443624.ResultsThe results indicated that genotype frequencies of rs1219648 and rs6443624 were significantly different between breast cancer patients and healthy controls. Furthermore, PI3KCA rs6443624 A carriers and FGFR2 rs1219648 G carriers more frequently had advanced stages and shorter survival times.ConclusionThe SNPs of FGFR2 rs1219648 and PI3KCA rs6443624 may contribute to the identification of breast cancer patients at risk of more aggressive disease and may be potential prognostic factors in breast cancer in a Chinese population.

Candidate Gene Analyses of Skeletal Variation in Malocclusion

This study evaluated associations between craniofacial candidate genes and skeletal variation in patients with malocclusion. Lateral cephalometric radiographs of 269 untreated adults with skeletal classes I, II, and III malocclusion were digitized with 14 landmarks. Two-dimensional coordinates were analyzed using Procrustes fit and principal component (PC) analysis to generate continuous malocclusion phenotypes. Skeletal class classifications (I, II, or III) were used as a categorical phenotype. Individuals were genotyped for 198 single-nucleotide polymorphisms (SNPs) in 71 craniofacial genes and loci. Phenotype-genotype associations were tested via multivariate linear regression for continuous phenotypes and multinomial logistic regression for skeletal malocclusion class. PC analysis resulted in 4 principal components (PCs) explaining 69% of the total skeletal facial variation. PC1 explained 32.7% of the variation and depicted vertical discrepancies ranging from skeletal deep to open bites. PC1 was associated with a SNP near PAX5 (P = 0.01). PC2 explained 21.7% and captured horizontal maxillomandibular discrepancies. PC2 was associated with SNPs upstream of SNAI3 (P = 0.0002) and MYO1H (P = 0.006). PC3 explained 8.2% and captured variation in ramus height, body length, and anterior cranial base orientation. PC3 was associated with TWIST1 (P = 0.000076). Finally, PC4 explained 6.6% and detected variation in condylar inclination as well as symphysis projection. PC4 was associated with PAX7 (P = 0.007). Furthermore, skeletal class II risk increased relative to class I with the minor alleles of SNPs in FGFR2 (odds ratio [OR] = 2.1, P = 0.004) and declined with SNPs in EDN1 (OR = 0.5, P = 0.007). Conversely, skeletal class III risk increased versus class I with SNPs in FGFR2 (OR 2.2, P = 0.005) and COL1A1 (OR = 2.1, P = 0.008) and declined with SNPs in TBX5 (OR = 0.5, P = 0.014). PAX5, SNAI3, MYO1H, TWIST1, and PAX7 are associated with craniofacial skeletal variation among patients with malocclusion, while FGFR2, EDN1, TBX5, and COL1A1 are associated with type of skeletal malocclusion.

Rationale for targeting fibroblast growth factor receptor signaling in breast cancer.

Fibroblast growth factor receptor (FGFR) signaling is involved in multiple biological processes, including cell proliferation, survival, differentiation, migration, and apoptosis during embryonic development and adult tissue homeostasis. Given its role in the activation of critical signaling pathways, aberrant FGFR signaling has been implicated in multiple cancer types. A comprehensive search of PubMed and congress abstracts was conducted to identify reports on FGFR pathway components in breast cancer. In breast cancers, FGFR1 and FGFR4 gene amplification and single nucleotide polymorphisms in FGFR2 and FGFR4 have been detected. Commonly, these FGFR aberrations and gene amplifications lead to increased FGFR signaling and have been linked with poor prognosis and resistance to breast cancer treatments. Here, we review the role of FGFR signaling and the impact of FGFR genetic amplifications/aberrations on breast tumors. In addition, we summarize the most recent preclinical and clinical data on FGFR-targeted therapies in breast cancer. Finally, we highlight the ongoing clinical trials of the FGFR-targeted agents dovitinib, AZD4547, lucitanib, BGJ398, and JNJ-42756493, which are selected for patients with FGFR pathway-amplified breast cancer. Aberrant FGFR pathway amplification may drive some breast cancers. Inhibition of FGFR signaling is being explored in the clinic, and data from these trials may refine our ability to select patients who would best respond to these treatments.

Abstract LB-294: Growth factor genes, interaction with hormone therapy use and breast cancer risk in the California Teachers Study

Abstract Background: Growth factor and angiogenesis pathway genes are important candidate genes in breast carcinogenesis. Breast cell proliferation is modified by exogenous hormone therapy (HT) use, particularly estrogen plus progestin therapy (EPT). Estrogen-dependent cell proliferation requires activation of growth factor pathways, such as IGF-1, and potential interactions between a few FGFR2 single nucleotide polymorphisms (SNPs) and EPT have been reported. Further, angiogenesis genes such as VEGF and EGR3 were shown to be induced by steroid hormones. Therefore, we investigated SNPs in growth factor and angiogenesis genes and their interaction with HT in relation to breast cancer risk. Methods: We analyzed data from a breast cancer case-control study nested within the California Teachers Study. We genotyped 202 tagging SNPs in 12 growth factor and angiogenesis genes in 2746 non-Hispanic white women: 1351 cases and 1395 controls. We used conditional logistic regression models to estimate odds ratios (ORs) per minor allele and 95% confidence intervals (CI), and we repeated the analyses separately by HT use at cohort enrollment. P values were corrected for multiple testing using the Bonferroni method (Padj). Results: The most significant associations were observed for rs6899540 in VEGFA and 3 other VEGFA SNPs that are not in linkage disequilibrium with rs6899540. After Bonferroni correction within this gene, only rs6899540, located 4kb distal of the 3’end of the gene, remained statistically significant: OR per C allele=1.27 (95% CI=1.10-1.47), P=0.001, Padj=0.020. Additional SNPs nominally associated with breast cancer risk included rs2072454 in EGFR, rs4970503 in RPS6KA1, and rs9580185 in FGF9. Analyses among postmenopausal EPT users identified nominal associations with 5 VEGFR3 SNPs including rs6889643 and rs2290983 (ORs per risk allele ranging from 1.28 to 1.46; P-values range 0.008-0.015). Although none of these associations were statistically significant after Bonferroni correction, P values for interaction with EPT use (vs. never-HT use) were 0.03 for both rs6889643 and rs2290983. Among ET users, rs308441 in FGF2 was significantly associated with breast cancer risk (OR=1.69, Padj=0.019). Conclusions: Our results suggest that SNPs in growth factor and VEGF pathways may be associated with breast cancer risk, and these associations may be modified by ET or EPT use. Of particular interest are potential gene-HT interactions for SNPs in VEGFA, a key player in angiogenesis, and FGF2, a gene involved in VEGF signaling. Our results provide a strong rationale for further exploring these pathways and potential gene-environment interactions in pooled analyses. Citation Format: Eunjung Lee, Fredrick Schumacher, Susan L. Neuhausen, Hoda Anton Culver, Argyrios Ziogas, David Van Den Berg, Leslie Bernstein, Giske Ursin. Growth factor genes, interaction with hormone therapy use and breast cancer risk in the California Teachers Study. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-294. doi:10.1158/1538-7445.AM2014-LB-294

Breast Cancer Subtypes and Previously Established Genetic Risk Factors: A Bayesian Approach

Gene expression analyses indicate that breast cancer is a heterogeneous disease with at least five immunohistologic subtypes. Despite growing evidence that these subtypes are etiologically and prognostically distinct, few studies have investigated whether they have divergent genetic risk factors. To help fill in this gap in our understanding, we examined associations between breast cancer subtypes and previously established susceptibility loci among white and African-American women in the Carolina Breast Cancer Study. We used Bayesian polytomous logistic regression to estimate ORs and 95% posterior intervals for the association between each of 78 single nucleotide polymorphisms (SNP) and five breast cancer subtypes. Subtypes were defined using five immunohistochemical markers: estrogen receptors (ER), progesterone receptors (PR), human epidermal growth factor receptors 1 and 2 (HER1/2), and cytokeratin (CK) 5/6. Several SNPs in TNRC9/TOX3 were associated with luminal A (ER/PR+, HER2-) or basal-like breast cancer (ER-, PR-, HER2-, HER1, or CK 5/6+), and one SNP (rs3104746) was associated with both. SNPs in FGFR2 were associated with luminal A, luminal B (ER/PR+, HER2+), or HER2+/ER- disease, but none were associated with basal-like disease. We also observed subtype differences in the effects of SNPs in 2q35, 4p, TLR1, MAP3K1, ESR1, CDKN2A/B, ANKRD16, and ZM1Z1. We found evidence that genetic risk factors for breast cancer vary by subtype and further clarified the role of several key susceptibility genes. .

Identification of a Breast Cancer Susceptibility Locus at 4q31.22 Using a Genome-Wide Association Study Paradigm

More than 40 single nucleotide polymorphisms (SNPs) for breast cancer susceptibility were identified by genome-wide association studies (GWASs). However, additional SNPs likely contribute to breast cancer susceptibility and overall genetic risk, prompting this investigation for additional variants. Six putative breast cancer susceptibility SNPs identified in a two-stage GWAS that we reported earlier were replicated in a follow-up stage 3 study using an independent set of breast cancer cases and controls from Canada, with an overall cumulative sample size of 7,219 subjects across all three stages. The study design also encompassed the 11 variants from GWASs previously reported by various consortia between the years 2007–2009 to (i) enable comparisons of effect sizes, and (ii) identify putative prognostic variants across studies. All SNP associations reported with breast cancer were also adjusted for body mass index (BMI). We report a strong association with 4q31.22-rs1429142 (combined per allele odds ratio and 95% confidence interval = 1.28 [1.17–1.41] and P combined = 1.5×10−7), when adjusted for BMI. Ten of the 11 breast cancer susceptibility loci reported by consortia also showed associations in our predominantly Caucasian study population, and the associations were independent of BMI; four FGFR2 SNPs and TNRC9-rs3803662 were among the most notable associations. Since the original report by Garcia-Closas et al. 2008, this is the second study to confirm the association of 8q24.21-rs13281615 with breast cancer outcomes.

Gene variants in the angiogenesis pathway and prostate cancer

Although the causes of prostate cancer are still unknown, numerous studies support the role of genetic factors in the development and progression of this disease. Single nucleotide polymorphisms (SNPs) in key angiogenesis genes have been studied in prostate cancer. In this review, we provide an overview of the current knowledge of the role of genetic variants in the angiogenesis pathway in prostate cancer risk and progression. Of the 17 prostate cancer genome-wide association studies (GWAS) conducted to date, only one identified disease-associated SNPs in a region of an angiogenesis pathway gene. An association was observed between aggressive disease and three intergenic SNPs (rs11199874, rs10749408 and rs10788165) in a region on chromosome 10q26 that encompasses FGFR2. The majority (27/32, 84.4%) of primary candidate gene studies reviewed had a small (n < 800, 20/32, 62.5%) to medium sample size (n = 800-2000, 7/32, 21.9%), whereas only five (15.6%) had a large sample size (n ≥ 2000). Results from the large studies revealed associations with risk and aggressive disease for SNPs in NOS2A, NOS3 and MMP-2 and risk for HIF1-α. Meta-analyses have so far been conducted on FGFR2, TGF-β, TNF-α, HIF1-α and IL10 and the results reveal an association with risk for SNPs in FGFR2 and TGF-β and aggressive disease for SNPs in IL-10. Thus, existing evidence from GWAS and large candidate gene studies indicates that SNPs from a limited number of angiogenesis pathway genes are associated with prostate cancer risk and progression.

Interactions Between Genetic Variants and Breast Cancer Risk Factors in the Breast and Prostate Cancer Cohort Consortium

Recently, several genome-wide association studies have identified various genetic susceptibility loci for breast cancer. Relatively little is known about the possible interactions between these loci and the established risk factors for breast cancer. To assess interactions between single-nucleotide polymorphisms (SNPs) and established risk factors, we prospectively collected DNA samples and questionnaire data from 8576 breast cancer case subjects and 11 892 control subjects nested within the National Cancer Institute's Breast and Prostate Cancer Cohort Consortium (BPC3). We genotyped 17 germline SNPs (FGFR2-rs2981582, FGFR2-rs3750817, TNRC9-rs3803662, 2q35-rs13387042, MAP3K1-rs889312, 8q24-rs13281615, CASP8-rs1045485, LSP1-rs3817198, COL1A1-rs2075555, COX11-rs6504950, RNF146-rs2180341, 6q25-rs2046210, SLC4A7-rs4973768, NOTCH2-rs11249433, 5p12-rs4415084, 5p12-rs10941679, RAD51L1-rs999737), and odds ratios were estimated by logistic regression to confirm previously reported associations with breast cancer risk. We performed likelihood ratio test to assess interactions between 17 SNPs and nine established risk factors (age at menarche, parity, age at menopause, use of hormone replacement therapy, family history, height, body mass index, smoking status, and alcohol consumption), and a correction for multiple testing of 153 tests (adjusted P value threshold = .05/153 = 3 × 10(-4)) was done. Case-case comparisons were performed for possible differential associations of polymorphisms by subgroups of tumor stage, estrogen and progesterone receptor status, and age at diagnosis. All statistical tests were two-sided. We confirmed the association of 14 SNPs with breast cancer risk (P(trend) = 2.57 × 10(-3) -3.96 × 10(-19)). Three SNPs (LSP1-rs3817198, COL1A1-rs2075555, and RNF146-rs2180341) did not show association with breast cancer risk. After accounting for multiple testing, no statistically significant interactions were detected between the 17 SNPs and the nine risk factors. We also confirmed that SNPs in FGFR2 and TNRC9 were associated with greater risk of estrogen receptor-positive than estrogen receptor-negative breast cancer (P(heterogeneity) = .0016 for FGFR2-rs2981582 and P(heterogeneity) = .0053 for TNRC9-rs3803662). SNP 5p12-rs10941679 was statistically significantly associated with greater risk of progesterone receptor-positive than progesterone receptor-negative breast cancer (P(heterogeneity) = .0028). This study does not support the hypothesis that known common breast cancer susceptibility loci strongly modify the associations between established risk factors and breast cancer.

Variation in the FGFR2 Gene and the Effect of a Low-Fat Dietary Pattern on Invasive Breast Cancer

The Women's Health Initiative dietary modification (DM) trial provided suggestive evidence of a benefit of a low-fat dietary pattern on breast cancer risk, with stronger evidence among women whose baseline diet was high in fat. Single nucleotide polymorphisms (SNP) in the FGFR2 gene relate strongly to breast cancer risk and could influence intervention effects. All 48,835 trial participants were postmenopausal and ages 50 to 79 years at enrollment (1993-1998). We interrogated eight SNPs in intron 2 of the FGFR2 gene for 1,676 women who developed breast cancer during trial follow-up (1993-2005). Case-only analyses were used to estimate odds ratios for the DM intervention in relation to SNP genotype. Odds ratios for the DM intervention did not vary significantly with the genotype for any of the eight FGFR2 SNPs (P > or = 0.18). However, odds ratios varied (P < 0.05) with the genotype of six of these SNPs, among women having baseline percent of energy from fat in the upper quartile (> or =36.8%). This variation is most evident for SNP rs3750817, with odds ratios for the DM intervention at 0, 1, and 2 minor SNP alleles of 1.06 [95% confidence intervals (95% CI), 0.80-1.41], 0.53 (95% CI, 0.38-0.74), and 0.62 (95% CI, 0.33-1.15). The nominal significance level for this interaction is P = 0.005, and P = 0.03 following multiple testing adjustment, with most evidence deriving from hormone receptor-positive tumors. Invasive breast cancer odds ratios for a low-fat dietary pattern, among women whose usual diets are high in fat, seem to vary with SNP rs3750817 in the FGFR2 gene.

Fibroblast Growth Factors in Development and Cancer: Insights from the Mammary and Prostate Glands

The fibroblast growth factor (FGF) family is comprised of 22 ligands that bind and activate several FGF receptor (FGFR) isoforms. Critical roles for FGFs and FGFRs have been well-established during embryonic development. For example, the FGF10/FGFR2IIIb axis has been linked to embryonic development of both the mammary and prostate glands, which are the subject of this review. Furthermore, recent studies using novel mouse models have suggested that this pathway also participates in postnatal development in the mammary and prostate glands. These studies have provided novel insights into the mechanisms by which FGFs and FGFRs promote ductal outgrowth and branching morphogenesis. In addition to the established roles of FGFs in development, aberrant activation of the FGF pathway has been linked to tumor progression in both breast and prostate cancer. Recent studies have linked FGFR1 expression and single nucleotide polymorphisms in FGFR2 to breast cancer. Furthermore, novel pre-clinical models have demonstrated the ability of FGFRs to promote numerous aspects of breast and prostate cancer. Understanding the roles of FGFs in development will provide insights into the mechanisms by which deregulation of the FGF pathway leads to tumorigenesis, ultimately leading to the development of novel therapeutic strategies designed to target this pathway in cancer patients.

FGFR2 variants and breast cancer risk: fine-scale mapping using African American studies and analysis of chromatin conformation

Genome-wide association studies have identified FGFR2 as a breast cancer (BC) susceptibility gene in populations of European and Asian descent, but a causative variant has not yet been conclusively identified. We hypothesized that the weaker linkage disequilibrium across this associated region in populations of African ancestry might help refine the set of candidate-causal single nucleotide polymorphisms (SNPs) previously identified by our group. Eight candidate-causal SNPs were evaluated in 1253 African American invasive BC cases and 1245 controls. A significant association with BC risk was found with SNP rs2981578 (unadjusted per-allele odds ratio = 1.20, 95% confidence interval 1.03-1.41, P(trend) = 0.02), with the odds ratio estimate similar to that reported in European and Asian subjects. To extend the fine-mapping, genotype data from the African American studies were analyzed jointly with data from European (n = 7196 cases, 7275 controls) and Asian (n = 3901 cases, 3205 controls) studies. In the combined analysis, SNP rs2981578 was the most strongly associated. Five other SNPs were too strongly correlated to be excluded at a likelihood ratio of < 1/100 relative to rs2981578. Analysis of DNase I hypersensitive sites indicated that only two of these map to highly accessible chromatin, one of which, SNP rs2981578, has previously been implicated in up-regulating FGFR2 expression. Our results demonstrate that the association of SNPs in FGFR2 with BC risk extends to women of African American ethnicity, and illustrate the utility of combining association analysis in datasets of diverse ethnic groups with functional experiments to identify disease susceptibility variants.

The influence of genetic variation in 30 selected genes on the clinical characteristics of early onset breast cancer

IntroductionCommon variants that alter breast cancer risk are being discovered. Here, we determine how these variants influence breast cancer prognosis, risk and tumour characteristics.MethodsWe selected 1,001 women with early onset nonfamilial invasive breast cancer from the Prospective study of Outcomes in Sporadic versus Hereditary breast cancer (POSH) cohort and genotyped 206 single nucleotide polymorphisms (SNPs) across 30 candidate genes. After quality control, 899 cases and 133 SNPs remained. Survival analyses were used to identify SNPs associated with prognosis and determine their interdependency with recognized prognostic factors. To identify SNPs that alter breast cancer risk, association tests were used to compare cases with controls from the Wellcome Trust Case Control Consortium. To search for SNPs affecting tumour biology, cases were stratified into subgroups according to oestrogen receptor (ER) status and grade and tested for association.ResultsWe confirmed previous associations between increased breast cancer risk and SNPs in CASP8, TOX3 (previously known as TNRC9) and ESR1. Analysis of prognosis identified eight SNPs in six genes (MAP3K1, DAPK1, LSP1, MMP7, TOX3 and ESR1) and one region without genes on 8q24 that are associated with survival. For MMP7, TOX3 and MAP3K1 the effects on survival are independent of the main recognized clinical prognostic factors. The SNP in 8q24 is more weakly associated with independent effects on survival. Once grade and pathological nodal status (pN stage) were taken into account, SNPs in ESR1 and LSP1 showed no independent survival difference, whereas the effects of the DAPK1 SNP were removed when correcting for ER status. Interestingly, effects on survival for SNPs in ESR1 were most significant when only ER-positive tumours were examined. Stratifying POSH cases by tumour characteristics identified SNPs in FGFR2 and TOX3 associated with ER-positive disease and SNPs in ATM associated with ER-negative disease.ConclusionsWe have demonstrated that several SNPs are associated with survival. In some cases this appears to be due to an effect on tumour characteristics known to have a bearing on prognosis; in other cases the effect appears to be independent of these prognostic factors. These findings require validatation by further studies in similar patient groups.

FGFR2 Is a Breast Cancer Susceptibility Gene in Jewish and Arab Israeli Populations

Genetic variation in FGFR2 is a newly described risk factor for breast cancer. We estimated the relative risk and contribution of FGFR2 polymorphisms to breast cancer risk in diverse ethnic groups within Jewish and other Middle Eastern populations. We genotyped four FGFR2 single nucleotide polymorphisms (SNP) and tested for association of these SNPs and haplotypes with breast cancer risk in a population-based case-control study of 1,529 women with breast cancer and 1,528 controls. We found significant associations between breast cancer risk and all four studied SNPs in FGFR2 (P trend for all SNPs < 0.0001). In ethnicity-specific analysis, all four SNPs were significantly associated with breast cancer risk in Ashkenazi and Sephardi Jews, with a similar but not significant trend in Arabs. Haplotype analysis identified five common haplotypes (>1%). The previously described AAGT risk haplotype was significantly associated with breast cancer risk in Ashkenazi [odds ratio (OR), 1.25; 95% confidence interval (95% CI), 1.07-1.45; P = 0.0059] and Sephardi Jews (OR, 1.46; 95% CI, 1.17-1.80; P = 0.0006) compared with the reference GGAC haplotype. The AAAC haplotype was significantly associated with breast cancer risk in Sephardi Jews (OR, 1.97; 95% CI, 1.16-3.35; P = 0.0125) but not in Ashkenazi Jews (OR, 0.83; 95% CI, 0.41-1.62; P = 0.5613) or in Arabs (OR, 1.31; 95% CI, 0.80-2.14; P = 0.2881). Genetic variation in FGFR2, identified by rs1219648, may account for a substantial fraction of breast cancer in Arab (12%), Ashkenazi (15%), and Sephardi Jewish (22%) populations. The identification of population-specific risk haplotypes in FGFR2 is likely to help identify causal variants for breast cancer.

Heterogeneity of Breast Cancer Associations with Five Susceptibility Loci by Clinical and Pathological Characteristics

A three-stage genome-wide association study recently identified single nucleotide polymorphisms (SNPs) in five loci (fibroblast growth receptor 2 (FGFR2), trinucleotide repeat containing 9 (TNRC9), mitogen-activated protein kinase 3 K1 (MAP3K1), 8q24, and lymphocyte-specific protein 1 (LSP1)) associated with breast cancer risk. We investigated whether the associations between these SNPs and breast cancer risk varied by clinically important tumor characteristics in up to 23,039 invasive breast cancer cases and 26,273 controls from 20 studies. We also evaluated their influence on overall survival in 13,527 cases from 13 studies. All participants were of European or Asian origin. rs2981582 in FGFR2 was more strongly related to ER-positive (per-allele OR (95%CI) = 1.31 (1.27–1.36)) than ER-negative (1.08 (1.03–1.14)) disease (P for heterogeneity = 10−13). This SNP was also more strongly related to PR-positive, low grade and node positive tumors (P = 10−5, 10−8, 0.013, respectively). The association for rs13281615 in 8q24 was stronger for ER-positive, PR-positive, and low grade tumors (P = 0.001, 0.011 and 10−4, respectively). The differences in the associations between SNPs in FGFR2 and 8q24 and risk by ER and grade remained significant after permutation adjustment for multiple comparisons and after adjustment for other tumor characteristics. Three SNPs (rs2981582, rs3803662, and rs889312) showed weak but significant associations with ER-negative disease, the strongest association being for rs3803662 in TNRC9 (1.14 (1.09–1.21)). rs13281615 in 8q24 was associated with an improvement in survival after diagnosis (per-allele HR = 0.90 (0.83–0.97). The association was attenuated and non-significant after adjusting for known prognostic factors. Our findings show that common genetic variants influence the pathological subtype of breast cancer and provide further support for the hypothesis that ER-positive and ER-negative disease are biologically distinct. Understanding the etiologic heterogeneity of breast cancer may ultimately result in improvements in prevention, early detection, and treatment.