Reproductive characteristics, menopausal status, race and ethnicity, and risk of breast cancer subtypes defined by ER, PR and HER2 status: the Breast Cancer Etiology in Minorities study.

BACKGROUND: Associations between reproductive factors and risk of breast cancer differ by subtype defined by joint estrogen receptor (ER), progesterone receptor (PR), and HER2 expression status. Racial and ethnic differences in the incidence of breast cancer subtypes suggest etiologic heterogeneity, yet data are limited because most studies have included non-Hispanic White women only. METHODS: We analyzed harmonized data for 2,794 breast cancer cases and 4,579 controls, of whom 90% self-identified as African American, Asian American or Hispanic. Questionnaire data were pooled from three population-based studies conducted in California and data on tumor characteristics were obtained from the California Cancer Registry. The study sample included 1,530 luminal A (ER-positive and/or PR-positive, HER2-negative), 442 luminal B (ER-positive and/or PR-positive, HER2-positive), 578 triple-negative (TN; ER-negative, PR-negative, HER2-negative), and 244 HER2-enriched (ER-negative, PR-negative, HER2-positive) cases. We used multivariable unconditional logistic regression models to estimate subtype-specific ORs and 95% confidence intervals associated with parity, breast-feeding, and other reproductive characteristics by menopausal status and race and ethnicity. RESULTS: Subtype-specific associations with reproductive factors revealed some notable differences by menopausal status and race and ethnicity. Specifically, higher parity without breast-feeding was associated with higher risk of luminal A and TN subtypes among premenopausal African American women. In contrast, among Asian American and Hispanic women, regardless of menopausal status, higher parity with a breast-feeding history was associated with lower risk of luminal A subtype. Among premenopausal women only, luminal A subtype was associated with older age at first full-term pregnancy (FTP), longer interval between menarche and first FTP, and shorter interval since last FTP, with similar OR estimates across the three racial and ethnic groups. CONCLUSIONS: Subtype-specific associations with reproductive factors overall and by menopausal status, and race and ethnicity, showed some differences, underscoring that understanding etiologic heterogeneity in racially and ethnically diverse study samples is essential. Breast-feeding is likely the only reproductive factor that is potentially modifiable. Targeted efforts to promote and facilitate breast-feeding could help mitigate the adverse effects of higher parity among premenopausal African American women.

Cumulative menstrual months and breast cancer risk by hormone receptor status and ethnicity: The Breast Cancer Etiology in Minorities Study.

Reproductive and hormonal factors may influence breast cancer risk via endogenous estrogen exposure. Cumulative menstrual months (CMM) can be used as a surrogate measure of this exposure. Using harmonized data from four population-based breast cancer studies (7284 cases and 7242 controls), we examined ethnicity-specific associations between CMM and breast cancer risk using logistic regression, adjusting for menopausal status and other risk factors. Higher CMM was associated with increased breast cancer risk in non-Hispanic Whites, Hispanics and Asian Americans regardless of menopausal status (all FDR adjusted P trends = .0004), but not in African Americans. In premenopausal African Americans, there was a suggestive trend of lower risk with higher CMM. Stratification by body mass index (BMI) among premenopausal African American women showed a nonsignificant positive association with CMM in nonobese (BMI <30 kg/m2 ) women and a significant inverse association in obese women (OR per 50 CMM = 0.56, 95% CI 0.37-0.87, Ptrend  = .03). Risk patterns were similar for hormone receptor positive (HR+; ER+ or PR+) breast cancer; a positive association was found in all premenopausal and postmenopausal ethnic groups except in African Americans. HR- (ER- and PR-) breast cancer was not associated with CMM in all groups combined, except for a suggestive positive association among premenopausal Asian Americans (OR per 50 CMM = 1.33, P = .07). In summary, these results add to the accumulating evidence that established reproductive and hormonal factors impact breast cancer risk differently in African American women compared to other ethnic groups, and also differently for HR- breast cancer than HR+ breast cancer.

Menstrual and reproductive characteristics and breast cancer risk by hormone receptor status and ethnicity: The Breast Cancer Etiology in Minorities study.

We pooled multiethnic data from four population-based studies and examined associations of menstrual and reproductive characteristics with breast cancer (BC) risk by tumor hormone receptor (HR) status [defined by estrogen receptor (ER) and progesterone receptor (PR)]. We estimated odds ratios and 95% confidence intervals using multivariable logistic regression, stratified by age (<50, ≥50 years) and ethnicity, for 5,186 HR+ (ER+ or PR+) cases, 1,365 HR- (ER- and PR-) cases and 7,480 controls. For HR+ BC, later menarche and earlier menopause were associated with lower risk in non-Hispanic whites (NHWs) and Hispanics, and higher parity and longer breast-feeding were associated with lower risk in Hispanics and Asian Americans, and suggestively in NHWs. Positive associations with later first full-term pregnancy (FTP), longer interval between menarche and first FTP and shorter time since last FTP were limited to younger Hispanics and Asian Americans. Except for nulliparity, reproductive characteristics were not associated with risk in African Americans. For HR- BC, lower risk was associated with later menarche, except in African Americans and older Asian Americans and with longer breast-feeding in Hispanics and Asian Americans only. In younger African Americans, HR- BC risk associated with higher parity (≥3 vs. 1 FTP) was increased fourfold in women who never breast-fed, but not in those with a breast-feeding history, suggesting that breast-feeding may mitigate the adverse effect of higher parity in younger African American women. Further work needs to evaluate why menstrual and reproductive risk factors vary in importance according to age and ethnicity.

A Pooled Analysis of Breastfeeding and Breast Cancer Risk by Hormone Receptor Status in Parous Hispanic Women.

BACKGROUND: Data on breastfeeding and breast cancer risk are sparse and inconsistent for Hispanic women. METHODS: Pooling data for nearly 6,000 parous Hispanic women from four population-based studies conducted between 1995 and 2007 in the United States and Mexico, we examined the association of breastfeeding with risk of breast cancer overall and subtypes defined by estrogen receptor (ER) and progesterone receptor (PR) status, and the joint effects of breastfeeding, parity, and age at first birth. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression. RESULTS: Among parous Hispanic women, older age at first birth was associated with increased breast cancer risk, whereas parity was associated with reduced risk. These associations were found for hormone receptor positive (HR+) breast cancer only and limited to premenopausal women. Age at first birth and parity were not associated with risk of ER- and PR- breast cancer. Increasing duration of breastfeeding was associated with decreasing breast cancer risk (≥25 vs. 0 months: OR = 0.73; 95% CI = 0.60, 0.89; Ptrend = 0.03), with no heterogeneity by menopausal status or subtype. At each parity level, breastfeeding further reduced HR+ breast cancer risk. Additionally, breastfeeding attenuated the increase in risk of HR+ breast cancer associated with older age at first birth. CONCLUSIONS: Our findings suggest that breastfeeding is associated with reduced risk of both HR+ and ER- and PR- breast cancer among Hispanic women, as reported for other populations, and may attenuate the increased risk in women with a first pregnancy at older ages.

Reproductive history, breast-feeding and risk of triple negative breast cancer: The Breast Cancer Etiology in Minorities (BEM) study.

Few risk factors have been identified for triple negative breast cancer (TNBC) which lacks expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). This more aggressive subtype disproportionately affects some racial/ethnic minorities and is associated with lower survival. We pooled data from three population-based studies (558 TNBC and 5,111 controls) and examined associations of TNBC risk with reproductive history and breast-feeding. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using multivariable logistic regression. For younger women, aged <50 years, TNBC risk was increased two-fold for parous women who never breast-fed compared to nulliparous women (OR = 2.02, 95% CI = 1.12-3.63). For younger parous women, longer duration of lifetime breast-feeding was associated with a borderline reduced risk (≥24 vs. 0 months: OR = 0.52, 95% CI = 0.26-1.04, Ptrend = 0.06). Considering the joint effect of parity and breast-feeding, risk was increased two-fold for women with ≥3 full-term pregnancies (FTPs) and no or short-term (<12 months) breast-feeding compared to women with 1-2 FTPs and breast-feeding ≥12 months (OR = 2.56, 95% CI = 1.22-5.35). None of these associations were observed among older women (≥50 years). Differences in reproductive patterns possibly contribute to the ethnic differences in TNBC incidence. Among controls aged <50 years, the prevalence of no or short-term breast-feeding and ≥3 FTPs was highest for Hispanics (22%), followed by African Americans (18%), Asian Americans (15%) and non-Hispanic whites (6%). Breast-feeding is a modifiable behavioral factor that may lower TNBC risk and mitigate the effect of FTPs in women under age 50 years.

Associations between ALDH1A1 polymorphisms, alcohol consumption, and mortality among Hispanic and non-Hispanic white women diagnosed with breast cancer: the Breast Cancer Health Disparities Study.

PURPOSE: ALDH1A1, one of the main isotopes of aldehyde dehydrogenase-1 is involved in the differentiation and protection of normal hematopoietic stem cells and functions in alcohol sensitivity and dependence. We evaluated the associations between ALDH1A1 polymorphisms, alcohol consumption, and mortality among Hispanic and non-Hispanic white (NHW) breast cancer (BC) cases from the Breast Cancer Health Disparities Study. METHODS: Nine SNPs in ALDH1A1 were evaluated in 920 Hispanic and 1372 NHW women diagnosed with incident invasive BC. Adjusted Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Models were stratified by Native American (NA) ancestry and alcohol consumption. RESULTS: A total of 443 deaths occurred over a median follow-up time of 11 years. After adjusting all results for multiple comparisons, rs7027604 was significantly associated with all-cause mortality (HRAA = 1.40; 95% CI 1.13-1.73, P adj = 0.018). The rs1424482 CC genotype (HRCC = 1.69; 95% CI 1.20-2.37, P adj = 0.027) and the rs7027604 AA genotype (HRAA = 1.65; 95% CI 1.21-2.26, P adj = 0.018) were positively associated with non-BC mortality. Among long-term light drinkers, rs1888202 was associated with decreased all-cause mortality (HRCG/GG = 0.36; 95% CI 0.20-0.64), while associations were not significant among non-drinkers or moderate/heavy drinkers (P interation = 0.218). The increased risk of all-cause mortality associated with rs63319 was limited to women with low NA ancestry (HRAA = 1.53; 95% CI 1.19-1.97). CONCLUSIONS: Multiple SNPs in ALDH1A1 were associated with increased risk of mortality after BC. Future BC studies examining the relationship between ALDH1A1 and mortality should consider the modifying effects of alcohol consumption and NA ancestry.

Pre-diagnostic breastfeeding, adiposity, and mortality among parous Hispanic and non-Hispanic white women with invasive breast cancer: the Breast Cancer Health Disparities Study.

BACKGROUND: U.S. Hispanic women have high rates of parity, breastfeeding, and obesity. It is unclear whether these reproductive factors are associated with breast cancer (BC) mortality. We examined the associations between breastfeeding, parity, adiposity and BC-specific and overall mortality in Hispanic and non-Hispanic white (NHW) BC cases. METHODS: The study population included 2921 parous women (1477 Hispanics, 1444 NHWs) from the Breast Cancer Health Disparities Study with invasive BC diagnosed between 1995 and 2004. Information on reproductive history and lifestyle factors was collected by in-person interview. Overall and stratified Cox proportional hazard regression models by ethnicity, parity, and body mass index (BMI) at age 30 years were used to calculate hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: After a median follow-up time of 11.2 years, a total of 679 deaths occurred. Pre-diagnostic breastfeeding was associated with a 16% reduction in mortality (HR 0.84; 95% 0.72-0.99) irrespective of ethnicity. Parity significantly modified the association between breastfeeding duration and mortality (p interaction = 0.05), with longer breastfeeding duration associated with lower risk among women who had ≤2 births (p trend = 0.02). Breastfeeding duration was associated with reduced risk of both BC-specific and overall mortality among women with BMI <25 kg/m2, while positive associations were observed among women with BMI ≥25 kg/m2 (p interactions <0.01). CONCLUSION: Pre-diagnostic breastfeeding was inversely associated with risk of mortality after BC, particularly in women of low parity or normal BMI. These results provide another reason to encourage breastfeeding and weight management among young women.

Ethnic differences in the relationships between diabetes, early age adiposity and mortality among breast cancer survivors: the Breast Cancer Health Disparities Study.

The contribution of type 2 diabetes and obesity on mortality in breast cancer (BC) patients has not been well studied among Hispanic women, in whom these exposures are highly prevalent. In a multi-center population-based study, we examined the associations between diabetes, multiple obesity measures, and mortality in 1180 Hispanic and 1298 non-Hispanic white (NHW) women who were diagnosed with incident invasive BC from the San Francisco Bay Area, New Mexico, Utah, Colorado, and Arizona. Adjusted hazard ratios (HR) and 95 % confidence intervals (CI) were calculated using Cox proportional hazards regression models. The median follow-up time from BC diagnosis to death was 10.8 years. In ethnic-stratified results, the association for BC-specific mortality among Hispanics was significantly increased (HR 1.85 95 % CI 1.11, 3.09), but the ethnic interaction was not statistically significant. In contrast, obesity at age 30 increased BC-specific mortality risk in NHW women (HR 2.33 95 % CI 1.36, 3.97) but not Hispanics (p-interaction = 0.045). Although there were no ethnic differences for all-cause mortality, diabetes, obesity at age 30, and post-diagnostic waist-hip ratio were significantly associated with all-cause mortality in all women. This study provides evidence that diabetes and adiposity, both modifiable, are prognostic factors among Hispanic and NHW BC patients.

Uncovering the liver's role in immunity through RNA co-expression networks.

Gene co-expression analysis has proven to be a powerful tool for ascertaining the organization of gene products into networks that are important for organ function. An organ, such as the liver, engages in a multitude of functions important for the survival of humans, rats, and other animals; these liver functions include energy metabolism, metabolism of xenobiotics, immune system function, and hormonal homeostasis. With the availability of organ-specific transcriptomes, we can now examine the role of RNA transcripts (both protein-coding and non-coding) in these functions. A systems genetic approach for identifying and characterizing liver gene networks within a recombinant inbred panel of rats was used to identify genetically regulated transcriptional networks (modules). For these modules, biological consensus was found between functional enrichment analysis and publicly available phenotypic quantitative trait loci (QTL). In particular, the biological function of two liver modules could be linked to immune response. The eigengene QTLs for these co-expression modules were located at genomic regions coincident with highly significant phenotypic QTLs; these phenotypes were related to rheumatoid arthritis, food preference, and basal corticosterone levels in rats. Our analysis illustrates that genetically and biologically driven RNA-based networks, such as the ones identified as part of this research, provide insight into the genetic influences on organ functions. These networks can pinpoint phenotypes that manifest through the interaction of many organs/tissues and can identify unannotated or under-annotated RNA transcripts that play a role in these phenotypes.

Red meat, poultry, and fish intake and breast cancer risk among Hispanic and Non-Hispanic white women: The Breast Cancer Health Disparities Study.

PURPOSE: There is suggestive but limited evidence for a relationship between meat intake and breast cancer (BC) risk. Few studies included Hispanic women. We investigated the association between meats and fish intake and BC risk among Hispanic and NHW women. METHODS: The study included NHW (1,982 cases and 2,218 controls) and the US Hispanics (1,777 cases and 2,218 controls) from two population-based case-control studies. Analyses considered menopausal status and percent Native American ancestry. We estimated pooled ORs combining harmonized data from both studies, and study- and race-/ethnicity-specific ORs that were combined using fixed or random effects models, depending on heterogeneity levels. RESULTS: When comparing highest versus lowest tertile of intake, among NHW we observed an association between tuna intake and BC risk (pooled OR 1.25; 95 % CI 1.05-1.50; trend p = 0.006). Among Hispanics, we observed an association between BC risk and processed meat intake (pooled OR 1.42; 95% CI 1.18-1.71; trend p < 0.001), and between white meat (OR 0.80; 95% CI 0.67-0.95; trend p = 0.01) and BC risk, driven by poultry. All these findings were supported by meta-analysis using fixed or random effect models and were restricted to estrogen receptor-positive tumors. Processed meats and poultry were not associated with BC risk among NHW women; red meat and fish were not associated with BC risk in either race/ethnic groups. CONCLUSIONS: Our results suggest the presence of ethnic differences in associations between meat and BC risk that may contribute to BC disparities.

Associations between ALOX, COX, and CRP polymorphisms and breast cancer among Hispanic and non-Hispanic white women: The breast cancer health disparities study.

Chronic inflammation is suggested to be associated with specific cancer sites, including breast cancer. Recent research has focused on the roles of genes involved in the leukotriene/lipoxygenase and prostaglandin/cyclooxygenase pathways in breast cancer etiology. We hypothesized that genes in ALOX/COX pathways and CRP polymorphisms would be associated with breast cancer risk and mortality in our sample of Hispanic/Native American (NA) (1430 cases, 1599 controls) and non-Hispanic white (NHW) (2093 cases, 2610 controls) women. A total of 104 Ancestral Informative Markers was used to distinguish European and NA ancestry. The adaptive rank truncated product (ARTP) method was used to determine the significance of associations for each gene and the inflammation pathway with breast cancer risk and by NA ancestry. Overall, the pathway was associated with breast cancer risk (PARTP = 0.01). Two-way interactions with NA ancestry (P(adj) < 0.05) were observed for ALOX12 (rs2292350, rs2271316) and PTGS1 (rs10306194). We observed increases in breast cancer risk in stratified analyses by tertiles of polyunsaturated fat intake for ALOX12 polymorphisms; the largest increase in risk was among women in the highest tertile with ALOX12 rs9904779CC (Odds Ratio (OR), 1.49; 95% Confidence Interval (CI) 1.14-1.94, P(adj) = 0.01). In a sub-analysis stratified by NSAIDs use, two-way interactions with NSAIDs use were found for ALOX12 rs9904779 (P(adj) = 0.02), rs434473 (P(adj ) = 0.02), and rs1126667 (P(adj) = 0.01); ORs for ALOX12 polymorphisms ranged from 1.55 to 1.64 among regular users. Associations were not observed with breast cancer mortality. These findings could support advances in the discovery of new pathways related to inflammation for breast cancer treatment.

Genetic variants in interleukin genes are associated with breast cancer risk and survival in a genetically admixed population: the Breast Cancer Health Disparities Study.

Interleukins (ILs) are key regulators of immune response. Genetic variation in IL genes may influence breast cancer risk and mortality given their role in cell growth, angiogenesis and regulation of inflammatory process. We examined 16 IL genes with breast cancer risk and mortality in an admixed population of Hispanic/Native American (NA) (2111 cases and 2597 controls) and non-Hispanic white (NHW) (1481 cases and 1585 controls) women. Adaptive Rank Truncated Product (ARTP) analysis was conducted to determine gene significance and lasso (least absolute shrinkage and selection operator) was used to identify potential gene by gene and gene by lifestyle interactions. The pathway was statistically significant for breast cancer risk overall (P ARTP = 0.0006), for women with low NA ancestry (P(ARTP) = 0.01), for premenopausal women (P(ARTP) = 0.02), for estrogen receptor (ER)+/progesterone receptor (PR)+ tumors (P(ARTP) = 0.03) and ER-/PR- tumors (P(ARTP) = 0.02). Eight of the 16 genes evaluated were associated with breast cancer risk (IL1A, IL1B, IL1RN, IL2, IL2RA, IL4, IL6 and IL10); four genes were associated with breast cancer risk among women with low NA ancestry (IL1B, IL6, IL6R and IL10), two were associated with breast cancer risk among women with high NA ancestry (IL2 and IL2RA) and four genes were associated with premenopausal breast cancer risk (IL1A, IL1B, IL2 and IL3). IL4, IL6R, IL8 and IL17A were associated with breast cancer-specific mortality. We confirmed associations with several functional polymorphisms previously associated with breast cancer risk and provide support that their combined effect influences the carcinogenic process.

Genetic variation in the JAK/STAT/SOCS signaling pathway influences breast cancer-specific mortality through interaction with cigarette smoking and use of aspirin/NSAIDs: the Breast Cancer Health Disparities Study.

The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway is involved in immune function and cell growth; genetic variation in this pathway could influence breast cancer risk. We examined 12 genes in the JAK/STAT/SOCS signaling pathway with breast cancer risk and mortality in an admixed population of Hispanic (2,111 cases, 2,597 controls) and non-Hispanic white (1,481 cases, 1,585 controls) women. Associations were assessed by Indigenous American (IA) ancestry. After adjustment for multiple comparisons, JAK1 (three of ten SNPs) and JAK2 (4 of 11 SNPs) interacted with body mass index (BMI) among pre-menopausal women, while STAT3 (four of five SNPs) interacted significantly with BMI among post-menopausal women to alter breast cancer risk. STAT6 rs3024979 and TYK2 rs280519 altered breast cancer-specific mortality among all women. Associations with breast cancer-specific mortality differed by IA ancestry; SOCS1 rs193779, STAT3 rs1026916, and STAT4 rs11685878 associations were limited to women with low IA ancestry, and associations with JAK1 rs2780890, rs2254002, and rs310245 and STAT1 rs11887698 were observed among women with high IA ancestry. JAK2 (5 of 11 SNPs), SOCS2 (one of three SNPs), and STAT4 (2 of 20 SNPs) interacted with cigarette smoking status to alter breast cancer-specific mortality. SOCS2 (one of three SNPs) and all STAT3, STAT5A, and STAT5B SNPs significantly interacted with use of aspirin/NSAIDs to alter breast cancer-specific mortality. Genetic variation in the JAK/STAT/SOCS pathway was associated with breast cancer-specific mortality. The proportion of SNPs within a gene that significantly interacted with lifestyle factors lends support for the observed associations.

Associations between CYP19A1 polymorphisms, Native American ancestry, and breast cancer risk and mortality: the Breast Cancer Health Disparities Study.

The cytochrome p450 family 19 gene (CYP19A1) encodes for aromatase, which catalyzes the final step in estrogen biosynthesis and conversion of androgens to estrogens. Genetic variation in CYP19A1 is linked to higher circulating estrogen levels and increased aromatase expression. Using data from the Breast Cancer Health Disparities Study, a consortium of three population-based case-control studies in the United States (n = 3,030 non-Hispanic Whites; n = 2,893 Hispanic/Native Americans (H/NA) and Mexico (n = 1,810), we examined influence of 25 CYP19A1 tagging single-nucleotide polymorphisms (SNPs) on breast cancer risk and mortality, considering NA ancestry. Odds ratios (ORs) and 95 % confidence intervals (CIs) and hazard ratios estimated breast cancer risk and mortality. After multiple comparison adjustment, none of the SNPs were significantly associated with breast cancer risk or mortality. Two SNPs remained significantly associated with increased breast cancer risk in women of moderate to high NA ancestry (≥29 %): rs700518, ORGG 1.36, 95 % CI 1.11-1.67 and rs11856927, ORGG 1.35, 95 % CI 1.05-1.72. A significant interaction was observed for rs2470144 and menopausal status (p adj = 0.03); risk was increased in postmenopausal (ORAA 1.22, 95 % CI 1.05-1.14), but not premenopausal (ORAA 0.78, 95 % CI 0.64-0.95) women. The absence of an overall association with CYP19A1 and breast cancer risk is similar to previous literature. However, this analysis provides support that variation in CYP19A1 may influence breast cancer risk differently in women with moderate to high NA ancestry. Additional research is warranted to investigate the how variation in an estrogen-regulating gene contributes to racial/ethnic disparities in breast cancer.

Telomere length, telomere-related genes, and breast cancer risk: the breast cancer health disparities study.

Telomeres are involved in maintaining genomic stability. Previous studies have linked both telomere length (TL) and telomere-related genes with cancer. We evaluated associations between telomere-related genes, TL, and breast cancer risk in an admixed population of US non-Hispanic white (1,481 cases, 1,586 controls) and U.S. Hispanic and Mexican women (2,111 cases, 2,597 controls) from the Breast Cancer Health Disparities Study. TL was assessed in 1,500 women based on their genetic ancestry. TL-related genes assessed were MEN1, MRE11A, RECQL5, TEP1, TERC, TERF2, TERT, TNKS, and TNKS2. Longer TL was associated with increased breast cancer risk [odds ratio (OR) 1.87, 95% confidence interval (CI) 1.38, 2.55], with the highest risk (OR 3.11, 95% CI 1.74, 5.67 p interaction 0.02) among women with high Indigenous American ancestry. Several TL-related single nucleotide polymorphisms had modest association with breast cancer risk overall, including TEP1 rs93886 (OR 0.82, 95% CI 0.70,0.95); TERF2 rs3785074 (OR 1.13, 95% CI 1.03,1.24); TERT rs4246742 (OR 0.85, 95% CI 0.77,0.93); TERT rs10069690 (OR 1.13, 95% CI 1.03,1.24); TERT rs2242652 (OR 1.51, 95% CI 1.11,2.04); and TNKS rs6990300 (OR 0.89, 95% CI 0.81,0.97). Several differences in association were detected by hormone receptor status of tumors. Most notable were associations with TERT rs2736118 (ORadj 6.18, 95% CI 2.90, 13.19) with estrogen receptor negative/progesterone receptor positive (ER-/PR+) tumors and TERT rs2735940 (ORadj 0.73, 95% CI 0.59, 0.91) with ER-/PR- tumors. These data provide support for an association between TL and TL-related genes and risk of breast cancer. The association may be modified by hormone receptor status and genetic ancestry.

Genetic ancestry modifies the association between genetic risk variants and breast cancer risk among Hispanic and non-Hispanic white women.

Hispanic women in the USA have lower breast cancer incidence than non-Hispanic white (NHW) women. Genetic factors may contribute to this difference. Breast cancer genome-wide association studies (GWAS) conducted in women of European or Asian descent have identified multiple risk variants. We tested the association between 10 previously reported single nucleotide polymorphisms (SNPs) and risk of breast cancer in a sample of 4697 Hispanic and 3077 NHW women recruited as part of three population-based case-control studies of breast cancer. We used stratified logistic regression analyses to compare the associations with different genetic variants in NHWs and Hispanics classified by their proportion of Indigenous American (IA) ancestry. Five of 10 SNPs were statistically significantly associated with breast cancer risk. Three of the five significant variants (rs17157903-RELN, rs7696175-TLR1 and rs13387042-2q35) were associated with risk among Hispanics but not in NHWs. The odds ratio (OR) for the heterozygous at 2q35 was 0.75 [95% confidence interval (CI) = 0.50-1.15] for low IA ancestry and 1.38 (95% CI = 1.04-1.82) for high IA ancestry (P interaction 0.02). The ORs for association at RELN were 0.87 (95% CI = 0.59-1.29) and 1.69 (95% CI = 1.04-2.73), respectively (P interaction 0.03). At the TLR1 locus, the ORs for women homozygous for the rare allele were 0.74 (95% CI = 0.42-1.31) and 1.73 (95% CI = 1.19-2.52) (P interaction 0.03). Our results suggest that the proportion of IA ancestry modifies the magnitude and direction of the association of 3 of the 10 previously reported variants. Genetic ancestry should be considered when assessing risk in women of mixed descent and in studies designed to discover causal mutations.

Genetic variation in bone morphogenetic proteins and breast cancer risk in hispanic and non-hispanic white women: The breast cancer health disparities study.

Bone morphogenetic proteins (BMP) are thought to be important in breast cancer promotion and progression. We evaluated genetic variation in BMP-related genes and breast cancer risk among Hispanic (2,111 cases, 2,597 controls) and non-Hispanic White (NHW) (1,481 cases, 1,586 controls) women who participated in the 4-Corner's Breast Cancer Study, the Mexico Breast Cancer Study and the San Francisco Bay Area Breast Cancer Study. BMP genes and their receptors evaluated include ACVR1, AVCR2A, ACVR2B, ACVRL1, BMP1, BMP2, BMP4, BMP6, BMP7, BMPR1A, BMPR1B, BMPR2, MSTN and GDF10. Additionally, 104 ancestral informative markers were assessed to discriminate between European and native American ancestry. The importance of estrogen on BMP-related associations was suggested through unique associations by menopausal status and estrogen (ER) and progesterone (PR) receptor status of tumors. After adjustment for multiple comparisons ACVR1 (8 SNPs) was modestly associated with ER+PR+ tumors [odds ratios (ORs) between 1.18 and 1.39 padj < 0.05]. ACVR1 (3 SNPs) and BMP4 (3 SNPs) were associated with ER+PR- tumors (ORs 0.59-2.07; padj < 0.05). BMPR2 was associated with ER-PR+ tumors (OR 4.20; 95% CI 1.62, 10.91; padj < 0.05) as was GDF10 (2 SNPs; ORs 3.62 and 3.85; padj < 0.05). After adjustment for multiple comparisons several SNPs remained associated with ER-PR- tumors (padj < 0.05) including ACVR1 BMP4 and GDF10 (ORs between 0.53 and 2.12). Differences in association also were observed by percentage of native ancestry and menopausal status. Results support the hypothesis that genetic variation in BMPs is associated with breast cancer in this admixed population.

Associations between genetic variants in the TGF-ß signaling pathway and breast cancer risk among Hispanic and non-Hispanic white women.

The TGF-ß signaling pathway has a significant role in breast cancer initiation and promotion by regulating various cellular processes. We evaluated whether genetic variation in eight genes (TGF-ß1, TGF-ß2, TGF-ßR1, TGF-ßR2, TGF-ßR3, RUNX1, RUNX2, and RUNX3) is associated with breast cancer risk in women from the Breast Cancer Health Disparities Study. A total of 3,524 cases (1,431 non-Hispanic whites (NHW); 2,093 Hispanics/Native Americans(NA)) and 4,209 population-based controls (1,599 NHWs; 2,610 Hispanics/NAs) were included in analyses. Genotypes for 47 single nucleotide polymorphisms (SNPs) were determined. Additionally, 104 ancestral informative markers estimated proportion of NA ancestry. Associations with breast cancer risk overall, by menopausal status, NA ancestry, and estrogen receptor (ER)/progesterone receptor tumor phenotype were evaluated. After adjustment for multiple comparisons, two SNPs were significantly associated with breast cancer risk: RUNX3 (rs906296 ORCG/GG = 1.15 95 % CI 1.04-1.26) and TGF-ß1 (rs4803455 ORCA/AA = 0.89 95 % CI 0.81-0.98). RUNX3 (rs906296) and TGF-ßR2 (rs3773644) were associated with risk in pre-menopausal women (p adj = 0.002 and 0.02, respectively) and in those with intermediate to high NA ancestry (p adj = 0.04 and 0.01, respectively). Self-reported race was strongly correlated with NA ancestry (r = 0.86). There was a significant interaction between NA ancestry and RUNX1 (rs7279383, p adj = 0.04). Four RUNX SNPs were associated with increased risk of ER- tumors. Results provide evidence that genetic variation in TGF-ß and RUNX genes are associated with breast cancer risk. This is the first report of significant associations between genetic variants in TGF-ß and RUNX genes and breast cancer risk among women of NA ancestry.

Long-term weight gain among Hispanic and non-Hispanic White women with and without breast cancer.

Weight gain following breast cancer diagnosis is common, but limited data exists on whether this gain is in excess of that gained during normal aging. This study investigated weight patterns among women with and without breast cancer to determine the effects of the breast cancer experience on weight change. Using the SHINE 4-Corners Breast Cancer Study, 305 women with breast cancer and 345 women without were followed prospectively. Weight change of ≥5% was defined as the difference between the self-reported weight measurements obtained at breast cancer diagnosis (or referent date for women without breast cancer) and about 6 yr later. Multiple logistic regression analyses were used. Within this cohort, 60% of women were overweight or obese and 37% of women gained weight. No significant greater weight gain was observed between women with vs. without breast cancer [adjusted odds ratio (ORadj) = 1.15, 95% CI 0.79-1.68] or between Hispanic vs. non-Hispanic White women (ORadj = 1.09, 95% CI 0.72-1.66) after adjustment. Weight gain was associated with being younger and having a lower body mass index. Among breast cancer survivors, cancer treatment factors were not associated with weight gain. These results suggest that weight management approaches are needed, especially those targeted to at-risk populations such as breast cancer survivors.

Changes in Breast Cancer Risk and Risk Factor Profiles among U.S.-Born and Immigrant Asian American Women Residing in the San Francisco Bay Area.

BACKGROUND: Breast cancer incidence rates in women of Asian descent have been increasing in the United States and Asia. METHODS: In a case-control study of Asian American women from the San Francisco Bay Area, we assessed associations with birthplace and migration-related characteristics and compared risk factors between Asian American and non-Hispanic White women by birthplace and birth cohort. RESULTS: Birthplace and migration-related characteristics were associated with breast cancer risk only among women in the younger birth cohort (1951-1984) that comprised 355 cases diagnosed at age ≤55 years and 276 sister and population controls. Breast cancer risk was marginally increased among foreign-born women [OR = 1.40; 95% confidence interval (CI), 0.97-2.03] and two-fold among foreign-born Chinese women (OR = 2.16; 95% CI, 1.21-3.88). Two-fold increased risks were associated with migration at age ≥40 years and longer U.S. residence (≥30 years or ≥75% of life). The education level was high among both cases and controls. Differences in the prevalence of risk factors by birthplace and birth cohort suggest temporal changes in reproductive and lifestyle-related factors. The prevalence in risk factors was similar between foreign-born and U.S.-born women in the younger birth cohort, and did not fully explain the observed associations with birthplace and other migration characteristics. CONCLUSIONS: In contrast to studies from earlier decades, younger foreign-born Asian American women had a higher risk of breast cancer than U.S.-born Asian American women. IMPACT: It is important and urgent to understand what factors drive the increasing burden of breast cancer in women of Asian descent and implement effective prevention programs.