Etiology Of Breast Cancer Research Articles

Cohort profile: a nationwide study in Dutch CHEK2 c.1100delC families using the infrastructure of the HEreditary Breast and Ovarian cancer study Netherlands – Hebon-CHEK2

PurposeCHEK2 c.1100delC is associated with an increased breast cancer risk in women. While this variant is prevalent in the Netherlands (1% in the general population), knowledge of aetiology and prognosis...

The Social Reality of Meaning Making: The Dichotomy in the Illness Narratives of Women With Breast Cancer and Biomedical Practitioners in Nigeria.

Despite the increasing burden of breast cancer in the developing world, there is a misunderstanding of the complex and multifaceted relationship between culture and cancer, particularly breast cancer. Hence, a dichotomy of illness narratives exists due to differential meaning making concerning breast cancer. While clinicians always recommend biomedical treatment, women with breast cancer often seek alternative treatment pathways. To explore the experiences of women with breast cancer and clinicians in Nigeria on the dichotomy in the illness narratives. This qualitative study used in-depth interviews and focus group discussion to explore the experiences of 22 women with breast cancer and 7 clinicians in Nigeria on the dichotomy in the illness narratives using grounded theory method analysis. This study revealed that many women living with breast cancer (WLBC) hold health beliefs that are contradictory to the biomedical norm. They mostly sought treatment based on the perceived aetiology of breast cancer. The treatment pathway follows faith and traditional healing as alternatives or sometimes in combination with biomedicine. WLBC reported a constant fear of biomedical treatment, perceived to be harmful to women's sexuality, fertility and body image. Hence, after perceived treatment failure from alternative care, biomedical care becomes the last resort, usually at an advanced stage of breast cancer, often responsible for poor prognosis. There is a dichotomy of illness construction between sufferers and health practitioners. To guide women with breast cancer on the path of care, modern care practitioners should consider some cultural norms and practices without compromising professional ethos.

Circulating Estrogen Metabolites and Risk of Breast Cancer among Postmenopausal Women in the Nurses' Health Study.

Estradiol and estrone are well-established risk factors for postmenopausal breast cancer (BC). Experimental evidence suggests that specific estrogen metabolites, produced via irreversible hydroxylation of estrone and estradiol at the 2- or 16-position may independently influence carcinogenesis. We performed a nested case-control study of BC (328 BC cases; 639 controls) among postmenopausal women within the Nurses' Health Study (NHS)to examine the role of estrogens and estrogen metabolites (jointly referred to as EM). Plasma concentrations of each EM (unconjugated+conjugated forms) were measured by liquid chromatography-tandem mass spectrometry. Multivariable conditional logistic regression, adjusting for BC risk factors, estimated relative risks (RR) and 95% confidence intervals (CI) of BC across quintiles of individual EM, EM pathways, and pathway ratios. Associations by estrogen/progesterone receptor (ER/PR) status were analyzed by unconditional logistic regression. Estradiol and estrone were strongly associated with increased BC risk [estradiol: RRQ5v.Q1 (95% CI)=2.64 (1.64-4.26), estrone: 2.78 (1.74-4.45); both p-trends<0.001]. The 2-hydroxylation pathway was strongly associated with risk [RRQ5v.Q1=3.09 (1.81-5.27), p-trend<0.001], and remained so after adjusting for unconjugated estradiol [RRQ5v.Q1=2.23 (1.25-3.96), p-trend=0.01]. While the 16-hydroxylation pathway was modestly associated with risk [RRQ5v.Q1=1.62 (1.03-2.54), p-trend=0.01], the association was attenuated after unconjugated estradiol adjustment [RRQ5v.Q1=1.24 (0.77-1.99), p-trend=0.19]. Similar positive associations with the 2-pathway and 16-pathway were observed for ER+/PR+ and ER-/PR- tumors. In this cohort of postmenopausal women, 2-hydroxylation of estrone and estradiol was associated with increased BC risk, independent of unconjugated estradiol. These results highlight the need to revisit the role of estrogen metabolism in BC etiology and prevention.

Rare Germline Variants in DNA Repair Genes Detected in BRCA-Negative Finnish Patients with Early-Onset Breast Cancer.

Breast cancer is the most common malignancy, with a mean age of onset of approximately 60 years. Only a minority of breast cancer patients present with an early onset at or before 40 years of age. An exceptionally young age at diagnosis hints at a possible genetic etiology. Currently, known pathogenic genetic variants only partially explain the disease burden of younger patients. Thus, new knowledge is warranted regarding additional risk variants. In this study, we analyzed DNA repair genes to identify additional variants to shed light on the etiology of early-onset breast cancer. Germline whole-exome sequencing was conducted in a cohort of 63 patients diagnosed with breast cancer at or before 40 years of age (median 33, mean 33.02, range 23-40 years) with no known pathogenic variants in BRCA genes. After filtering, all detected rare variants were sorted by pathogenicity prediction scores (CADD score and REVEL) to identify the most damaging genetic changes. The remaining variants were then validated by comparison to a validation cohort of 121 breast cancer patients with no preselected age at cancer diagnosis (mean 51.4 years, range 28-80 years). Analysis of novel exonic variants was based on protein structure modeling. Five novel, deleterious variants in the genes WRN, RNF8, TOP3A, ERCC2, and TREX2 were found in addition to a splice acceptor variant in RNF4 and two frameshift variants in EXO1 and POLE genes, respectively. There were also multiple previously reported putative risk variants in other DNA repair genes. Taken together, whole-exome sequencing yielded 72 deleterious variants, including 8 novel variants that may play a pivotal role in the development of early-onset breast cancer. Although more studies are warranted, we demonstrate that young breast cancer patients tend to carry multiple deleterious variants in one or more DNA repair genes.

Serum and urinary cadmium and zinc profiles in breast cancer patients and their association with estrogen and HER-2 receptors, and redox status

BackgroundCadmium, a metal implicated in environmental toxicity, is linked to tumor growth and cancer. On the other hand, zinc plays an essential function in oxidative stress and can counteract cadmium toxicity and carcinogenicity. This research aims to evaluate the urine and serum values of cadmium and zinc in breast cancer (BC) patients and their association with estrogen (ER) and HER-2 receptors, and redox status. MethodsForty BC patients and thirty healthy subjects participated in this study. Cadmium and zinc levels were measured in serum and urine samples by atomic absorption spectrophotometer. Redox status markers were determined by colorimetric methods. ResultsThe amount of cadmium in the BC patients was substantially greater than in the healthy subjects. Zinc levels were significantly lower in patients with BC compared to controls. Breast cancer patients with ER-positive tumors had significantly higher urinary cadmium concentrations (U-Cd) compared to patients with ER-negative tumors. There was no significant difference between the parameters of redox status and the value of cadmium and zinc between patients with BC in the HER-2 subgroup. Malondialdehyde levels in the serum were substantially greater in BC patients than in healthy subjects. Total thiol level and catalase and superoxide dismutase activity in serum were considerably lower in BC patients than in healthy subjects. ConclusionsThe etiology of BC may be due to a disturbance in redox status and levels of elements. Increasing U-Cd and lowering zinc levels in the serum could be the risk factors for BC.

Polycystic ovary syndrome and risk of breast cancer in premenopausal and postmenopausal women: a nationwide population-based cohort study.

Although some reproductive and metabolic characteristics of polycystic ovary syndrome (PCOS) are known risk factors for breast cancer, the evidence regarding a potential association between PCOS and breast cancer is scarce. In this population-based cohort study including all 1,719,452 women born in Denmark between 1940 and 1993, we investigated the association between PCOS and breast cancer. PCOS diagnoses, cancer diagnoses, covariates, migrations, and vital status were all obtained from national population and health registers. Hazard ratios (HR) and 95% confidence intervals (CI) for breast cancer overall and for histological subtypes separately were calculated based on adjusted cox proportional hazards models. During a median follow-up of 26years, 63,078 women were diagnosed with breast cancer. We found an increased risk of breast cancer overall among women with PCOS compared with women without PCOS (HR: 1.21, 95% CI 1.02-1.44). In analyses stratified for menopausal status, the increased risk was restricted to postmenopausal women (HR: 1.63, 95% CI 1.23-2.15). The results for ductal and lobular histological subtypes analyses separately resembled those observed for breast cancer overall. This is the first study to report an increased risk of breast cancer among women with a history of PCOS. The increased risk was seemingly confined to postmenopausal women. Our results therefore contribute to an increased knowledge of the etiology of breast cancer, but our findings should be further confirmed in other large cohort studies with an appropriately long follow-up period.

Breast cancer treatment with coenzyme Q10 (CoQ10)

Coenzyme Q10 (CoQ10) was identified in the late 1950s, and its potential role in cancer therapy appeared in the early 1960s when decreasing CoQ10 levels were found in some cancer patients. Breast cancer is a serious global health issue, and novel treatments are being developed. Its treatment is being investigated. CoQ10 has shown immune-boosting effects in clinical studies, encouraging researchers to look into its possible influence on breast cancer. Several research have looked at the link between CoQ10 and breast Coenzyme Q10 (CoQ10) was identified in the late 1950s, and its potential role in cancer therapy appeared in the early 1960s when decreasing CoQ10 levels were found in some cancer patients. Breast cancer is a serious global health issue, and novel treatments are being developed. Its treatment is being investigated. CoQ10 has shown immune-boosting effects in clinical studies, encouraging researchers to look into its possible influence on breast cancer. Several research have looked at the link between CoQ10 and breast cancer, focusing on its biological effects such as cytochrome c release and subsequent radical production. CoQ10 supplementation is commonly used by cancer patients to alleviate a perceived CoQ10 deficit associated with treatment-related toxicity. Notably, evidence shows that CoQ10 may be connected to lower tocopherol levels increasing the risk of breast cancer. However, bigger sample sizes, longer follow-up periods, and a better knowledge of the physiological role of circulating CoQ10 are required for a thorough assessment of CoQ10's possible role in breast cancer etiology. Antibacterial medications, therapy-induced adverse effects, and oxidative stress all have an impact on chemotherapy-related problems. Although CoQ10 has shown potential as an alternative breast cancer treatment, it is crucial to highlight that existing standard therapies, such as chemotherapy, radiation therapy, and hormone therapy, are not without their limitations. and targeted therapies are all options. Remain the cornerstone of breast cancer care. Always seek the most current and trustworthy information about breast cancer therapy from medical specialists.

International survey on invasive lobular breast cancer identifies priority research questions

There is growing awareness of the unique etiology, biology, and clinical presentation of invasive lobular breast cancer (ILC), but additional research is needed to ensure translation of findings into management and treatment guidelines. We conducted a survey with input from breast cancer physicians, laboratory-based researchers, and patients to analyze the current understanding of ILC, and identify consensus research questions. 1774 participants from 66 countries respondents self-identified as clinicians (N = 413), researchers (N = 376), and breast cancer patients and advocates (N = 1120), with some belonging to more than one category. The majority of physicians reported being very/extremely (41%) to moderately (42%) confident in describing the differences between ILC and invasive breast cancer of no special type (NST). Knowledge of histology was seen as important (73%) and as affecting treatment decisions (51%), and most agreed that refining treatment guidelines would be valuable (76%). 85% of clinicians have never powered a clinical trial to allow subset analysis for histological subtypes, but the majority would consider it, and would participate in an ILC clinical trials consortium. The majority of laboratory researchers, reported being and very/extremely (48%) to moderately (29%) confident in describing differences between ILC and NST. They reported that ILCs are inadequately presented in large genomic data sets, and that ILC models are insufficient. The majority have adequate access to tissue or blood from patients with ILC. The majority of patients and advocates (52%) thought that their health care providers did not sufficiently explain the unique features of ILC. They identified improvement of ILC screening/early detection, and identification of better imaging tools as top research priorities. In contrast, both researchers and clinicians identified understanding of endocrine resistance and identifying novel drugs that can be tested in clinical trials as top research priority. In summary, we have gathered information from an international community of physicians, researchers, and patients/advocates that we expect will lay the foundation for a community-informed collaborative research agenda, with the goal of improving management and personalizing treatment for patients with ILC.

Correlation between fasting blood glucose level and risk of breast cancer in women: a single-center, prospective cohort study.

We prospectively analyzed the correlation between fasting plasma glucose (FPG) and the risk of breast cancer in women; explored the independent risk factors for breast cancer in women, and compared the effect of FPG level on the risk of young and non-young breast cancer. Our study provides new evidence and ideas for research into breast cancer etiology in China, improves the accuracy of secondary prevention of breast cancer, and provides options for the clinical diagnosis and treatment of breast cancer patients with diabetes. Three cohorts of women participating in the first health examination of the Kailuan Group in 2006, 2008 and 2010 were assembled to conduct a descriptive analysis of the baseline data on FPG. The cumulative incidence of breast cancer in different groups over 13 years was calculated using the Kaplan-Meier method and groups were compared using the log-rank test. A Cox proportional hazards regression model was used to analyze the association between FPG level and the risk of breast cancer. The cumulative incidence of breast cancer increased in people with FPG higher than 5.29 mmol/L, but there was no significant difference in the effect of different levels of FPG on the risk of young breast cancer in the population. Different degrees of fasting glucose can affect the risk of non-young breast cancer in the population. The results of this study suggest that the risk of breast cancer can be reversed by early intervention to control levels of FPG. Regular monitoring of FPG may reduce the misdiagnosis rate of breast cancer in the population.

Ti4+ functionalized zirconium metal-organic frameworks with polymer brushes for specific identification of phosphopeptides in human serum and skimmed milk.

In the present study, click chemistry and Schiff base reactions were simultaneously applied to prepare polymer brush (PEG)-functionalized MOF materials (UiO-66-NH2) and immobilized with Ti4+ (MOF-Brush-THBA-Ti4+) for phosphopeptide analysis. The material has a detection limit of 0.5 fmol, a selectivity of 2000:1, and a loading capacity of 133 mg/g for phosphopeptides. It also demonstrated great repeatability (10 cycles) and recovery rate (96.7 ± 1.4%). During the analysis of bio-samples, 4 specific phosphopeptides were identified in endogenous breast cancer serum, while 11 phosphopeptides were identified in skimmed milk. Moreover, 47 phosphopeptides correlated with 29 phosphorylated proteins were selectively identified from normal control serum, and 66 phosphopeptides correlated with 26 phosphorylated proteins were identified from breast cancer serum. Further analysis of gene ontology (GO) revealed that the detected phosphorylated proteins associated with breast cancer included positive regulation of receptor-mediated endocytosis, proteolysis, extracellular exosome, heparin binding, and chaperone binding. These findings suggest that these associated pathways might contribute to the etiology of breast cancer. Overall, this application exhibits enormous potential in the identification of phosphorylated peptides within bio-samples.

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

BackgroundAssociations 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.MethodsWe 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.ResultsSubtype-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.ConclusionsSubtype-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.

Impact of residence on the association between benzo[a]pyrene-DNA adduct levels and CYP1B1 gene polymorphisms in breast cancer patients

Globally, breast cancer is the primary cause of cancer-related death, and rising incidence rates are anticipated. Im¬proving illness prevention and treatment strategies requires a better understanding of the interactions occurring be¬tween genetic variables, environmental exposures, and disease pathogenesis. This study investigated the impact of residence on the association between benzo[a]pyrene-DNA adduct levels and CYP1B1 gene polymorphisms in breast cancer patients. In brief, 58 female breast cancer patients in Babylon, Iraq were recruited as subjects of this cross-sectional study. We gathered clinical information (including residency, age, age at diagnosis, and haematological markers), and by using molecular and biochemical methods, the CYP1B1 polymorphisms and the benzo[a]pyrene-DNA adduct levels were assessed. Among the different types of breast cancer, there was no apparent association between the residence and CYP1B1 polymorphisms. However, the amounts of benzo[a]pyrene-DNA adduct varied according to where a patient lived, with urban residents showing higher concentrations than rural residents. Benzo[a]pyrene-DNA adduct levels were shown to be correlated with specific polymorphisms in the CYP1B1 gene. Our study highlights the intricate connections between environmental exposures, genetic variables, and place of res¬idency in the aetiology of breast cancer. Variations in quantities of benzo[a]pyrene-DNA adducts imply possible func¬tions for environmental carcinogens, although no substantial correlation was found between genetic polymorphisms and the place of residence.

Abstract PO2-28-04: Pregnancy-associated relapse of triple-negative breast cancer

Abstract Introduction: Pregnancy Triple-negative breast cancer(TNMC) is the absence of ER PR and HER2 receptor expression. It constitutes about 15-20% of all breast cancers and is known to be the aggressive form with a high relapse rate (1). Interestingly, it usually affects women aged &amp;lt; 40 and has a low survival rate in African-American females. This case is a typical presentation of a 38-year-old young woman with PMH of T2NO right triple-negative breast cancer diagnosed in 2017 s/p right mastectomy with sentinel LN biopsy, received immunotherapy and chemotherapy, has been cancer-free for two years, and developed metastatic cancer during her pregnancy. In this case, we understand the diagnostic and therapeutic challenges of TNBC during pregnancy. Case: A 38-year-old African American woman, G0, T2NO triple negative invasive ductal carcinoma, underwent a right breast mastectomy and sentinel LN biopsy. She received treatment with (Anti-PD-L1 Antibody) concomitant with weekly paclitaxel and Doxorubicin/Cyclophosphamide (AC) chemotherapy. However, she had a residual 4cm tumor for which she was treated with adjuvant therapy with capecitabine for six months. A repeat Mammogram in 2019 showed no evidence of malignancy. In 2021, the patient was G2P2L1, admitted to the hospital after having a seizure. CT reported cystic/necrotic left parietal lesion mass effect with 8mm right-sided midline shift with metastasis to lungs and abdominal wall. She underwent L parietal craniectomy with resection of the tumor. At 32 weeks of gestation , chemotherapy with carboplatin and paclitaxel was given after her C-section and Gamma knife radiosurgery for metastatic lesions. She developed super refractory seizures, was induced into a coma with therapeutically anesthetic agents, and passed eventually. Discussion: Little literature exists on pregnancy-associated relapse of triple-negative breast cancer and its deterioration. Our patient was in remission for two years and was diagnosed with metastatic cancer during her second pregnancy. John et al., (2018) discussed an interesting association between breastfeeding, parity, and occurrence of TNBC, that there is a two-fold increased risk of developing TNBC with high parity(3 full-term pregnancies) and short-term breastfeeding (&amp;lt; 12 months) (2). Studies have also shown that cancers during or postpartum pregnancy are aggressive with more tumor burden and metastasize to the lungs, liver, and brain, which is consistent with our patient. (3) Conclusion: Pregnancy-associated breast cancer is diagnostically and therapeutically challenging during or in the postpartum period and with a high propensity of the triple-negative type. It requires a multidisciplinary team approach, awareness in the African American population, clinical suspicion of breast mass during pregnancy warrants imaging, and prolonged breastfeeding postpartum. Diagnosis is usually delayed due to pregnancy, and more research is needed on the diagnostic modalities during pregnancy for early treatment initiation. References Almansour NM. Triple-Negative Breast Cancer: A Brief Review About Epidemiology, Risk Factors, Signaling Pathways, Treatment and Role of Artificial Intelligence. Front Mol Biosci. 2022 Jan 25;9:836417. doi: 10.3389/fmolb.2022.836417. PMID: 35145999; PMCID: PMC8824427. John EM, Hines LM, Phipps AI, et al. Reproductive history, breast-feeding and risk of triple-negative breast cancer: The Breast Cancer Etiology in Minorities (BEM) study. International Journal of Cancer. 2018;142(11):2273. doi:10.1002/ijc.31258 Amant F, Deckers S, Van Calsteren K, Loibl S, Halaska M, Brepoels L, et al. Breast cancer in pregnancy: recommendations of an international consensus meeting. Eur J Cancer (2010) 46(18):3158–68. 10.1016/j.ejca.2010.09.010 Citation Format: Vaidarshi Abbagoni. Pregnancy-associated relapse of triple-negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-28-04.

Abstract PO4-08-06: Causal Relationships and Familial Aggregation of Mammogram Risk Scores: Insights from Breast Cancer in Twins and Families

Abstract Background: Mammogram risk scores based on texture and density, determined by brightness thresholds, are associated with breast cancer risk differently and could reveal distinct information about breast cancer risk. This study aimed to investigate the causal relationships between these intercorrelated risk scores and the familial aggregation of a texture-based mammogram measure, shedding light on the relevance to breast cancer aetiology. Methods: We analysed data from the Australian Mammographic Density Twins and Sisters Study, including 3195 breast-cancer-free women from 1519 families. The dataset comprised 527 pairs of monozygotic (MZ) twins, 271 pairs of dizygotic (DZ) twins, and 1599 sisters. The average age at mammography for sister pairs ranged from 40 to 70 years. Mammogram risk scores based on texture (named Cirrus) and three density-defined areas (light, bright, and brightest) that were spatially independent were generated. The Inference about Causation from Examination of Familial Confounding (ICE FALCON) method was employed for causal inference. Familial aggregation and the variance of Cirrus were assessed as a function of age using a multivariate normal model for pedigree analysis. The classic twin model was employed but allowing for varying shared environmental effects among different sister pairs. The single-nucleotide polymorphism (SNP)-based heritability was estimated using genetic variants from both closely and distantly related individuals. Model fits were compared using likelihood ratio tests and the Akaike Information Criterion. Results: Causal analysis using ICE FALCON revealed significant positive causal effects, with Cirrus, light areas, and bright areas influencing the brightest areas (accounting for 34%, 55%, and 85% of the associations, respectively). Similarly, light areas and bright areas demonstrated causal effects on Cirrus (accounting for 37% and 28% of the associations, respectively). No age-related differences in familial correlations or Cirrus variance were found for women aged 40 to 70 years. Familial correlations were estimated at 0.51 (0.03) for MZ pairs and 0.16 (0.03) for combined DZ and non-twin sister pairs, with no significant difference between DZ and non-twin sister pairs (P=0.3). Additive genetic effects accounted for up to 32% (5%) of the variance, consistent with SNP-based heritability estimates of 36% (12%). MZ-specific environmental effects contributed to at least 20% (3%), while shared environmental effects for DZ and non-twin sibling pairs accounted for less than 40% of that for MZ pairs. Conclusion: In a mammogram, the lighter (less dense) areas causally influence the brightest (highly dense) areas, including through textural features. These causal relationships provide insights into the relative importance of different mammogram features in breast cancer aetiology. For example, the brightest areas are more aetiologically important for screen-detected breast cancer, while the light areas are more aetiologically important for interval breast cancer. Additionally, specific textural features capture aetiologically independent breast cancer risk information from dense areas. We also confirm the partial heritability of Cirrus, the texture-based mammogram measure, substantially influenced by environmental factors (familial and non-familial). As well as genetic factors, Cirrus could be determined by factors operating at times of life when MZ pairs share their environments to a greater extent than do DZ and non-twin sisters, starting in utero and prior to adulthood, and remaining constant thereafter. These insights from twin and family data enhance our understanding of mammogram risk scores and their implications for breast cancer risk assessment. Citation Format: Zhoufeng Ye, Shuai Li, Gill Dite, Tuong Nguyen, Robert MacInnis, John Hopper. Causal Relationships and Familial Aggregation of Mammogram Risk Scores: Insights from Breast Cancer in Twins and Families [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-08-06.

Abstract PO1-15-04: Young Black Women With Triple-Negative Breast Cancer Molecular Subtypes: Population-Specific Patterns and Batch Effect Considerations

Abstract Introduction: While triple-negative breast cancer (TNBC) molecular subtypes have been associated with biological differences and clinical outcomes, studies have overwhelmingly been conducted in populations of European or Asian ancestry. Data collected across diverse populations is required to better leverage clinical directions from translational studies in TNBC. Through females recruited through the Black Women: Etiology and Survival of Triple-Negative Breast Cancers (BEST) study, we sought to characterize subtypes and explore associations. Methods: Our study included Black women diagnosed with early-stage (I-III) invasive TNBC at &amp;lt; = age 50 from 2005 to 2016, with recruitment from Florida and Tennessee state cancer registries. Germline DNA, tumor RNA, clinical outcomes, and risk factor data were collected. TNBC status in the BEST study was based on immunohistochemistry from pathology reports, cancer registry data, and self-reported data. Analyses on banked tumor samples, extracted at multiple time points, were conducted through PAM50 (Nanostring) and whole-transcriptome RNA-seq. TNBC subtype was assessed using TNBCtype-4 (Lehmann et al. 2016). Sources of batch effect were evaluated using PCA and corrected via limma. Genetic ancestry based on OncoArray or MEGA genotyping data was inferred using 1000Genomes continental reference samples. Immune cell characterization was performed via CIBERSORT and ESTIMATE. Statistical significance in comparing differences across subtypes was assessed via Chi-square test. Kaplan-Meier estimates and log-rank test were used for survival analysis. Results: RNA-seq from 114 self-reported Black females with TNBC was analyzed. TNBC subtype distribution in the BEST study cohort included 31.6% basal-like 1 (BL1), 28.9% basal-like 2 (BL2), 16.7% luminal androgen receptor (LAR), and 21.9% mesenchymal (M). While results were largely consistent with prior studies in patients of European or East Asian ancestry, a higher percentage of BL2 subtype was observed (28.9% vs. 21.0%, p=0.053). Based on PAM50 subtyping, 100% of tumors with BL1 and M were basal, whereas 68.8% of LAR and 86.7% of BL2 subtypes were basal. Tumors without subtype decreased from 9.8% to 1.1% after batch correcting for location at which RNA was extracted (Moffitt vs. Vanderbilt) and time between RNA banking and sequencing. All TNBC subtypes in this population demonstrated monocyte/activated dendritic cell predominance, with no significant subtype-specific associations with immune cell patterns. A lower relative proportion of M subtype was found in tumors from BRCA1/2 carriers, but this was not statistically significant due to the small number of carriers (8% vs. 18%; p=0.22). With a median follow-up time of 9 years, there was no significant difference in 10-year overall survival by TNBC subtype (p=0.18). However, patients with M subtype appeared to have worse survival relative to other subtypes combined (p=0.036). Conclusion: Our study is among the largest to date that interrogates TNBC subtypes and associated molecular/clinical data in self-reported Black females with invasive breast cancer. Our findings suggest that established TNBC subtyping can be applied in patients of African ancestry. Furthermore, data to correct for lab-based confounders remains critical; in this study, it enabled us to use many samples that could not be subtyped initially. Several population-specific patterns were observed, including no difference in 10-year overall survival across TNBC subtypes (consistent with prior data), but worse initial outcomes in M subtype; a preliminary association between BRCA1/2 carriers and non-M subtypes (in contrast to prior data); and no significant difference in immune cell distributions (in contrast to prior data mainly from patients of European ancestry). Studies of associations between TNBC subtypes, additional clinical data, and treatment data (type and response rates) are ongoing. Citation Format: Padma Rajagopal, Sonya Reid, Run Fan, Lindsay Venton, Anne Weidner, Mya Roberson, Susan Vadaparampil, Xuefeng Wang, Sean Yoder, Marilin Rosa, Jibril Hirbo, Jennifer Whisenant, Jennifer Pietenpol, Fei Ye, Tuya Pal, Brian Lehmann. Young Black Women With Triple-Negative Breast Cancer Molecular Subtypes: Population-Specific Patterns and Batch Effect Considerations [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-15-04.

Abstract PO5-09-03: Multi-tissue transcriptome-wide association studies identified genes for intrinsic subtypes of breast cancer

Abstract Background: Though several genome-wide association studies (GWAS) of breast cancer (BC) have identified common variants which differ between intrinsic subtypes, the genes through which these variants act through to impact BC risk have not been fully established. Furthermore, transcriptome-wide association studies (TWAS) have thus far been primarily employed to identify genes associated with overall BC risk, while overlooking how the influence of common variation on gene expression may contribute to subtype-specific differences. Methods: In this study, we performed two complementary multi-tissue TWASs for each of the following BC intrinsic subtypes: Luminal A-like, Luminal B-like, Luminal B/HER2-negative-like, HER2-enriched-like, Triple Negative BC. These two approaches included 1) an expression-based approach that collated TWAS signals from expression quantitative trait loci (eQTLs) across multiple tissues using the Aggregated Cauchy Association Test (ACAT) and 2) a splicing-based approach that utilized two applications of ACAT to collate splicing QTLs (sQTLs) for a given gene in a tissue and then across tissues. To perform these two TWASs, we utilized e/sQTL models trained in 11 tissues from the Genotype-Tissue Expression Project including breast, ovary, uterus, vagina, EBV-transformed lymphocytes, whole blood, spleen, liver, subcutaneous adipose, visceral adipose, and cell-cultured fibroblasts. GWAS summary statistics were previously generated from 133,384 BC cases and 113,789 controls who were participants in the Breast Cancer Association Consortium (BCAC). We further performed our TWAS while conditioning e/sQTL effect sizes on nearby GWAS index SNPs. Additionally, we utilized gene-based fine-mapping of eQTLs and sQTL to identify candidate causal genes for each intrinsic subtype. Results: Overall, we identified 164 genes in 69 loci that were associated with Luminal A-like, 19 genes in 9 loci with Luminal B-like, 18 genes in 11 loci with Luminal B/HER2-negative-like, 10 genes in 7 loci with HER2-enriched-like, and 29 genes in 12 loci with TNBC. Among these genes, 17 genes had not been reported in previous TWAS of BC, and 140 genes, 1 gene, 2 genes, 2 genes, and 16 genes were uniquely associated with each of the intrinsic subtypes, respectively. Additionally, we identified one gene associated with Luminal A-like and one gene with Luminal B-like BC that were each in a locus located at least 1.4 Mb from published GWAS hits. Furthermore, we identified 106, 11, 10, 5, and 21 candidate causal genes for each of the intrinsic subtypes, respectively, that had a posterior inclusion probability of 0.9 in at least one e/sQTL. Conclusion: In summary, our multi-tissue TWAS corroborated previous GWAS loci for overall BC risk and intrinsic subtypes, while underscoring how common variation impacts BC etiology by modulating the expression and splicing of genes in multiple tissue types. Citation Format: James Li, Julian McClellan, Haoyu Zhang, Guimin Gao, Dezheng Huo. Multi-tissue transcriptome-wide association studies identified genes for intrinsic subtypes of breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-09-03.

Association between trace element contents in normal human breast and age investigated using inductively coupled plasma mass spectrometry

The etiology of breast cancer remains largely unclear; however, it is well known that the incidence of this disease increases with age. In the presented work, for the first time, the age-related changes of Al, As, B, Ba, Bi, Cd, Ce, Cr, Cu, La, Li, Mg, Mn, Nb, Ni, Pb, Rb, Sb, Sn, Sr, Ti, W, and Zn content in the mammary gland of women aged 16-60 years was investigated. For this purpose, a method based on inductively coupled plasma mass spectrometry (ICP-MS) was employed, which makes it possible to determine the mass fractions of these trace elements in microsamples (mass from 10 mg) of breast tissue. With the help of this method, the material obtained during the autopsy of 38 practically healthy women aged 16-60 years who died suddenly was studied. Trace element mass fractions were determined in two age groups of women: 16-40 and 41-60 years old. Using the parametric Student's t-test and the non-parametric Wilcoxon-Mann-Whitney U-test to compare two age groups, as well as Pearson's correlation coefficients between age and trace elements mass fractions, it was found that the Cu, Mg, Rb, and Zn mass fractions in normal breast tissue decrease with age, while the As mass fraction increase. The phenomenon of the age-related changes of trace elements mass fractions in the normal mammary gland, discovered for the first time, requires further detailed study.

The Canadian Breast Cancer Symposium 2023 Meeting Report.

On 15-16 June 2023, healthcare professionals and breast cancer patients and advocates from across Canada met in Toronto, Ontario, for the 2023 Canadian Breast Cancer Symposium (CBSC.). The CBSC. is a national, multidisciplinary event that occurs every 2 years with the goal of developing a personalized approach to the management of breast cancer in Canada. Experts provided state-of-the-art information to help optimally manage breast cancer patients, including etiology, prevention, diagnosis, experimental biology, and therapy of breast cancer and premalignant breast disease. The symposium also had the objectives of increasing communication and collaboration among breast cancer healthcare providers nationwide and providing a comprehensive and real-life review of the many facets of breast cancer. The sessions covered the patient voice, the top breast cancer papers from different disciplines in 2022, artificial intelligence in breast cancer, systemic therapy updates, the management of central nervous system metastases, multidisciplinary management of ductal carcinoma in situ, special populations, optimization-based individual prognostic factors, toxicity management of novel therapeutics, survivorship, and updates in surgical oncology. The key takeaways of these sessions have been summarized in this conference report.

Identification of miR-125a and miR-106b signature as a potential diagnostic biomarker in breast cancer tissues

MicroRNAs (miRNAs) have essential roles in the etiology of breast cancer and are regarded as possible markers in this malignancy. In order to find new markers for breast cancer, the current study has measured expression level of four miRNAs, namely miR-125a, miR-106b, miR-96 and miR-92a-3p in the paired breast samples. Expression levels of miR-125a and miR-106b were higher in tumoral tissues compared with control tissues (Expression ratios (95% CI) = 4.01 (1.96–8.19) and 3.9 (1.95–7.81); P values = 0.0005 and 0.0003, respectively). miR-106b and miR-125a differentiated between malignant and non-malignant tissues with AUC values of 0.7 and 0.67, respectively. We detected association between expression of miR-106b and clinical stage (P = 0.03), in a way that its expression was the lowest in the advanced stages. Finally, significant relationships were found between miR-96 and miR-125a in both tumoral and non-tumoral specimens (ρ = 0.76 and 0.69, respectively). This nonparametric measure of rank correlation also showed relationship between miR-106b and miR-96 in both sets of samples (ρ = 0.63 and 0.61, respectively). Cumulatively, the assessed miRNAs, particularly miR-125a and miR-106b are putative targets for further expression and functional assays in breast cancer.

Abstract 3458: DNA methylation-predicted blood protein levels and breast cancer risk

Abstract Background: Blood DNA methylation (DNAm) profiles can be used to predict a variety of human physiologic traits that are associated with breast cancer incidence and plasma concentrations of over 100 proteins, including those involved in inflammation, coagulation, metabolism, and growth. DNAm predictions of circulating proteins, here referred to as “DNAm proteins,” may be useful in providing molecular insights into breast cancer etiology and could be a valuable resource for personalizing breast cancer risk prediction. Methods: The Sister Study is a nationwide, prospective cohort of 50,884 women with a family history of breast cancer designed to identify novel environmental and biological risk factors for breast cancer. Epigenome-wide DNAm data were previously generated using the HumanMethylation450 or MethylationEPIC arrays on baseline blood samples collected from two case-cohort samples, for a combined sample of 4,479 women. This sample included 2,151 (48%) women who were selected because they were diagnosed with breast cancer (1,673 invasive cancer and 478 ductal carcinomas in situ) in the 15 years (mean: 7.9 years) following blood draw. Blood levels of 109 DNAm proteins were estimated from DNAm profiles using the method developed by Gadd et al. (eLife, 2022). Weighted Cox regression models were used to estimate associations between these DNAm proteins and incident breast cancer; associations were considered statistically significant at a False Discovery Rate (q) ≤ 0.10. Results: In age and platform adjusted models, higher breast cancer rates were associated with higher DNAm-predicted blood concentrations of RARRES2, IGFBP4, and CCL21 and lower predicted concentrations of F7, SELL, CXCL9, CD48, and IL19. The strongest associations were observed for RARRES2 (per 1-SD increase, HR: 1.24, 95% CI: 1.10, 1.40, P= 6 × 10−4, q= 0.03) and F7 (per 1-SD increase, HR: 0.82, 95% CI: 0.74, 0.91, P= 3 × 10−4, q= 0.03). Estimates were similar after adjustment for known breast cancer risk factors and excluding those diagnosed within two years of their blood draw. Associations appeared stronger for invasive breast cancer. Conclusions: Using novel DNAm-based estimates of blood proteins, we identified associations between circulating proteins and breast cancer incidence. IGFBP4 and RARRES2 have previously been reported to be higher in newly-diagnosed breast cancer patients. We also identify new potential protein biomarkers related to immune response (CCL21, SELL, CXCL9, CD48, and IL19). Citation Format: Jacob K. Kresovich, Brett Reid, Doratha A. Byrd, Katie M. O'Brien, Zongli Xu, Clarice R. Weinberg, Dale P. Sandler, Jack A. Taylor. DNA methylation-predicted blood protein levels and breast cancer risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3458.