Epidemiology of basal-like breast cancer

Prevalence of breast and ovarian cancer subtypes in Hispanic populations from Puerto Rico

Background

Previous epidemiological studies aimed at describing characteristics of breast (BC) and ovarian cancer (OC) patients tend to examine Hispanic populations using a mix of individuals that come from ethnically different Hispanic backgrounds. Since most USA cancer statistics do not include cancer data from Puerto Rico (PR), there is a lack of historical and descriptive data analysis for Hispanic women in the island that suffer from these diseases. Therefore, the aim of our study is to provide a comprehensive clinicopathological characterization of BC and OC cases in PR.

Methods

Our study consisted of a longitudinal retrospective review of archived pathology reports at Southern Pathology Services (SPS), which mostly serves southwestern PR, from years 2000–2015. After filtering SPS records with pre-established criteria, tumor samples from 3451 BC and 170 OC cases were used for descriptive statistics and analysis using R program.

Results

In our cohort, the mean age of diagnosis for BC was 60.5 years and 60.3 years for OC. Available data for subtype characterization from BC cases, exhibited an expected subtype distribution that remained stable over time (Luminal A = 68.8%, Luminal B = 9.7%, HER-2 = 6.1% and Triple negative = 15.4%). Additionally, tumor grades distribution varied within different BC subtypes in which the majority of Luminal A tumors were G2 and most Triple negative tumors were G3. For OC cases, available subtype and tumor grade information identified serous histology in 64.71% of all cases and G3 as being the most prevalent tumor grade. Pathology reports revealed that 39.42% of all OC cases were described as late stage, while 50.5% as early stage (by pathological staging).

Conclusion

Our data suggests that OC and BC subtypes distribution in Hispanic populations from PR are in-line with national averages. In a significant number of BC cases, subtype could not be determined due to study limitations, health insurance coverage, or other reasons described here and may constitute a health disparity. Altogether, and despite these gaps, this study represents one of the most complete reviews of BC and OC in PR and provides an opportunity to further study this population separate from other US Hispanic populations.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-5077-z) contains supplementary material, which is available to authorized users.

Identification of differentially expressed genes and typical fusion genes associated with three subtypes of breast cancer

BACKGROUND

This study aimed to identify the differentially expressed genes (DEGs) and the typical fusion genes in different types of breast cancers using RNA-seq.

METHODS

GSE52643 was downloaded from Gene Expression Omnibus, which included 1 normal sample (MCF10A) and 7 breast cancer samples (BT-474, BT-20, MCF7, MDA-MB-231, MDA-MB-468, T47D, and ZR-75-1). The transcript abundance and the DEGs screening were performed by Cufflinks. The functional and pathway enrichment was analyzed by Gostats. SnowShoes-FTD was applied to identify the fusion genes.

RESULTS

We screened 430, 445, 397, 417, 369, 557, and 375 DEGs in BT-474, BT-20, MCF7, DA-MB-231, MDA-MB-468, T47D, and ZR-75-1, respectively, compared with MCF10A. DEGs in each comparison group (such as CD40 and CDH1) were significantly enriched in the functions of cell adhesion and extracellular matrix organization and pathways of CAMs and ECM receptor interaction. UCP2 was a common DEG in the 7 comparison groups. SFRP1 and MMP7 were significantly enriched in wnt/-catenin signaling pathway in MDA-MB-231. FAS was significantly enriched in autoimmune thyroid disease pathway in BT-474. Besides, we screened 96 fusion genes, such as ESR1-C6orf97 in ZR-75-1, COBRA1-C9orf167 in BT-20, and VAPB-IKZF3 and ACACA-STAC2 in BT-474.

CONCLUSIONS

The DEGs such as SFRP1, MMP7, CDH1, FAS, and UCP2 might be the potential biomarkers in breast cancer. Furthermore, some pivotal fusion genes like ESR1-C6orf97 with COBRA1-C9orf167 and VAPB-IKZF3 with ACACA-STAC2 were found in Luminal A and Luminal B breast cancer, respectively.

Breast Cancer Outcomes in a Racially and Ethnically Diverse Cohort of Insured Women

Background

It is unknown how subsequent breast cancer outcomes vary by biologic subtype and race/ethnicity in a diverse cohort of breast cancer survivors.

Methods

We conducted a prospective cohort study of 6,154 insured breast cancer survivors (AJCC TNM stages 0-IV) diagnosed between 1996-2007 and followed them through 1/1/2010 for subsequent breast cancer events (recurrence, contralateral breast cancer, metastasis, mortality). We compared subsequent breast cancer rates by race/ethnicity groups and biologic subtype (luminal A, luminal B, HER2-enriched, and triple negative). We calculated hazard ratios (HRs) with 95% CIs using multivariable Cox proportional hazards models, adjusted for sociodemographics, cancer treatments, and tumor characteristics.

Results

The cohort was diverse: 62.4% non-Hispanic White, 13.2% Hispanic, 14.9% African American, and 9.5% Asian. We identified 1,456 subsequent breast cancer events over 22,830 person-years. Although certain Asian women had higher crude subsequent breast cancer rates compared with Whites, within each biologic subtype category, these disparities disappeared in the multivariable analyses. After accounting for race/ethnicity, compared with women with luminal A tumors (reference), women with luminal B (adjusted HR=3.65, 95% CI: 3.08-4.32), HER2-enriched (adjusted HR=2.81, 95% CI: 2.25-3.51) and triple negative (adjusted HR=1.25, 95% CI: 1.01-1.54) tumors had statistically increased risks of subsequent breast cancer. Factors that were statistically significantly associated with increased risk included higher stage, larger tumor size, positive lymph nodes, and no adjuvant endocrine or chemotherapy (all P<.025).

Discussion

Our data suggest that disparities in subsequent breast cancer outcomes were more strongly associated with tumor characteristics and non-use of adjuvant treatments than race/ethnicity.

Breast Cancer Tissue Markers, Genomic Profiling, and Other Prognostic Factors: A Primer for Radiologists

An understanding of prognostic factors in breast cancer is imperative for guiding patient care. Increased tumor size and more advanced nodal status are established independent prognostic factors of poor outcomes and are incorporated into the American Joint Committee on Cancer (AJCC) TNM (primary tumor, regional lymph node, distant metastasis) staging system. However, other factors including imaging findings, histologic evaluation results, and molecular findings can have a direct effect on a patient's prognosis, including risk of recurrence and relative survival. Several microarray panels for gene profiling of tumors are approved by the U.S. Food and Drug Administration and endorsed by the American Society of Clinical Oncology. This article highlights prognostic factors currently in use for individualizing and guiding breast cancer therapy and is divided into four sections. The first section addresses patient considerations, in which modifiable and nonmodifiable prognostic factors including age, race and ethnicity, and lifestyle factors are discussed. The second part is focused on imaging considerations such as multicentric and/or multifocal disease, an extensive intraductal component, and skin or chest wall involvement and their effect on treatment and prognosis. The third section is about histopathologic findings such as the grade and presence of lymphovascular invasion. Last, tumor biomarkers and tumor biology are discussed, namely hormone receptors, proliferative markers, and categorization of tumors into four recognized molecular subtypes including luminal A, luminal B, human epidermal growth factor receptor 2-enriched, and triple-negative tumors. By understanding the clinical effect of these prognostic factors, radiologists, along with a multidisciplinary team, can use these tools to achieve individualized patient care and to improve patient outcomes. ^©RSNA, 2018.

Stable Isotope-Resolved Metabolomic Differences between Hormone-Responsive and Triple-Negative Breast Cancer Cell Lines

Purpose

To conduct an exploratory study to identify mechanisms that differentiate Luminal A (BT474 and MCF-7) and triple-negative (MDA-MB-231 and MDA-MB-468) breast cancer (BCa) cell lines to potentially provide novel therapeutic targets based on differences in energy utilization.

Methods

Cells were cultured in media containing either [U-¹³C]-glucose or [U-¹³C]-glutamine for 48 hours. Conditioned media and cellular extracts were analyzed by ¹H and ¹³C NMR spectroscopy.

Results

MCF-7 cells consumed the most glucose, producing the most lactate, demonstrating the greatest Warburg effect-associated energy utilization. BT474 cells had the highest tricarboxylic acid cycle (TCA) activity. The majority of energy utilization patterns in MCF-7 cells were more similar to MDA-MB-468 cells, while the patterns for BT474 cells were more similar to MDA-MB-231 cells. Compared to the Luminal A cell lines, TNBC cell lines consumed more glutamine and less glucose. BT474 and MDA-MB-468 cells produced high amounts of ¹³C-glycine from media [U-¹³C]-glucose which was integrated into glutathione, indicating de novo synthesis.

Conclusions

Stable isotopic resolved metabolomics using ¹³C substrates provided mechanistic information about energy utilization that was difficult to interpret using ¹H data alone. Overall, cell lines that have different hormone receptor status have different energy utilization requirements, even if they are classified by the same clinical BCa subtype; and these differences offer clues about optimizing treatment strategies.

Outcomes for Patients with Non-metastatic Triple-negative Breast Cancer in New Zealand

AIMS

Triple-negative breast cancer (TNBC) has inferior outcomes to other subtypes of breast cancer. We studied the demographics and baseline breast cancer characteristics of patients in New Zealand with TNBC and assessed survival outcomes and prognostic/predictive factors.

MATERIALS AND METHODS

We searched the New Zealand breast cancer registry database and identified patients with TNBC without distant metastatic disease. We retrieved demographic, tumour characteristic and treatment information. Locoregional recurrence-free survival, breast cancer-specific survival (BSS), metastasis-free survival (MRFS) and overall survival were determined. Predefined univariate and multivariate analyses were carried out investigating the association of survival outcomes with treatment and tumour characteristics.

RESULTS

In total, 1390 patients were identified, with a median follow-up of 3.5 years. The median age was 55 years. Thirty-eight per cent were node positive and 79% were grade III. Mastectomy was carried out in 53%, adjuvant radiation delivered in 66% and chemotherapy in 69%. The significant predictive factors for overall survival, BSS and MRFS were radiotherapy, chemotherapy and neoadjuvant chemotherapy. The significant prognostic indicators were lymphovascular invasion, nodal status and tumour size. On Kaplan-Meier analysis, the 5 year overall survival was 72%. The median time to death for those who died was 3.55 years with 92% of deaths within 5 years. Seventy-four per cent of patients had distant metastasis as a first recurrence and isolated local recurrences occurred in only 4.5%. Metastatic disease occurred in lung (55.9%) and was in multiple sites in 51%.

CONCLUSION

We report a large population-based series of TBNC without distant metastatic disease at diagnosis highlighting the unique behavioural characteristics of TNBC. Traditional therapies are positively associated with survival outcomes, and yet, particularly in the setting of recurrent disease, prognosis remains poor. Increased research into more effective systemic agents and the most effective timing of delivery of these may result in improved outcomes.

Prognostic Value of Lymphangiogenesis Determinants in Luminal and Non-luminal Breast Carcinomas

Background:

Breast carcinomas (BCs) are sub-classified according to the molecular characteristics into luminal and non-luminal subtypes that clinically show different biological behavior, treatment and prognosis. BCs spread primarily through lymphatic vessels using cascade processes of lymphagiogenesis in which VEGF-C plays an important role during lymph node metastasis. Prognostic value of VEGF-C in luminal and non-luminal BC is still unclear and has not been studied thoroughly to clarify and define prognosis and therapeutic monitoring.

Aim:

To define the prognostic value of lymphangiogenesis on survival rates of luminal and non-luminal subtypes BC.

Materials and Methods:

This study applied prospective cohort design, using 130 patients of invasive duct carcinoma of the breast, stage I-IIIA, from Sardjito General Hospital, Indonesia and subsequent longitudinal follow-up. Immunohistochemical staining was carried out using anti-ER, -PR, -Her-2, VEGF-C, VEGFR-3 and D2-40 antibodies. The related clinicopathologic characteristics of BC patients and lymphangiogenesis determinants, including VEGF-C expression, were statistically analyzed.

Results:

In non-luminal BC subtypes, VEGF-C expression (HR=0.04; 95% CI=0.01-0.41), lymph node metastasis (HR=0.14; 95% CI=0.04-0.55) and stage (HR=0.30; 95% CI= 0.02-0.76) were determined as independent prognostic factors on survival rates. However, the lymphangiogenesis determinants were not associated with the survival rates of luminal BC subtypes.

Conclusion:

This study suggested that lymphangiogenesis affects survival rates of non-Luminal subtype rather than the luminal subtypes of BC.

Epidemiology of Moderate Alcohol Consumption and Breast Cancer: Association or Causation?

Epidemiological studies have been used to show associations between modifiable lifestyle habits and the incidence of breast cancer. Among such factors, a history of alcohol use has been reported in multiple studies and meta-analyses over the past decades. However, associative epidemiological studies that were interpreted as evidence that even moderate alcohol consumption increases breast cancer incidence have been controversial. In this review, we consider the literature on the relationship between moderate or heavy alcohol use, both in possible biological mechanisms and in variations in susceptibility due to genetic or epigenetic factors. We argue that there is a need to incorporate additional approaches to move beyond the associations that are reported in traditional epidemiological analyses and incorporate information on molecular pathologic signatures as a requirement to posit causal inferences. In particular, we point to the efforts of the transdisciplinary field of molecular pathological epidemiology (MPE) to evaluate possible causal relationships, if any, of alcohol consumption and breast cancer. A wider application of the principles of MPE to this field would constitute a giant step that could enhance our understanding of breast cancer and multiple modifiable risk factors, a step that would be particularly suited to the era of "personalized medicine".

Breast cancer risk factors, survival and recurrence, and tumor molecular subtype: analysis of 3012 women from an indigenous Asian population

BACKGROUND

Limited evidence, mostly from studies in Western populations, suggests that the prognostic effects of lifestyle-related risk factors may be molecular subtype-dependent. Here, we examined whether pre-diagnostic lifestyle-related risk factors for breast cancer are associated with clinical outcomes by molecular subtype among patients from an understudied Asian population.

METHODS

In this population-based case series, we evaluated breast cancer risk factors in relation to 10-year all-cause mortality (ACM) and 5-year recurrence by molecular subtype among 3012 women with invasive breast cancer in Sarawak, Malaysia. A total of 579 deaths and 314 recurrence events occurred during a median follow-up period of ~ 24 months. Subtypes (luminal A-like, luminal B-like, HER2-enriched, triple-negative) were defined using immunohistochemical markers for hormone receptors and human epidermal growth factor receptor 2 (HER2) in conjunction with histologic grade. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between risk factors and ACM/recurrence were estimated in subtype-specific Cox regression models.

RESULTS

We observed heterogeneity in the relationships between parity/breastfeeding, age at first full-term pregnancy (FFP), family history, body mass index (BMI), and tumor subtype (p value < 0.05). Among luminal A-like patients only, older age at menarche [HR (95% CI) _{≥15 vs ≤ 12 years} = 2.28 (1.05, 4.95)] and being underweight [HR_{BMI < 18.5kg/m}²_{vs. 18.5-24.9kg/m}² = 3.46 (1.21, 9.89)] or overweight [HR_25-29.9kg/m²_{vs. 18.5-24.9kg/m}²₌ 3.14 (1.04, 9.50)] were associated with adverse prognosis, while parity/breastfeeding [HR_{breastfeeding vs nulliparity} = 0.48 (0.27, 0.85)] and older age at FFP [HR _{> 30 vs < 21 years} = 0.20 (0.04, 0.90)] were associated with good prognosis. For these women, the addition of age at menarche, parity/breastfeeding, and BMI, provided significantly better fit to a prognostic model containing standard clinicopathological factors alone [LRχ² (8df) = 21.78; p value = 0.005]. Overall, the results were similar in relation to recurrence.

CONCLUSIONS

Our finding that breastfeeding and BMI were associated with prognosis only among women with luminal A-like breast cancer is consistent with those from previously published data in Western populations. Further prospective studies will be needed to clarify the role of lifestyle modification, especially changes in BMI, in improving clinical outcomes for women with luminal A-like breast cancer.

Breast cancer subtype and survival among Indigenous American women in Peru

Latina women in the U.S. have relatively low breast cancer incidence compared to Non-Latina White (NLW) or African American women but are more likely to be diagnosed with the more aggressive “triple negative” breast cancer (TNBC). Latinos in the U.S. are a heterogeneous group originating from different countries with different cultural and ancestral backgrounds. Little is known about the distribution of tumor subtypes in Latin American regions. Clinical records of 303 female Peruvian patients, from the Peruvian National Cancer Institute, were analyzed. Participants were diagnosed with invasive breast cancer between 2010 and 2015 and were identified as residing in either the Selva or Sierra region. We used Fisher’s exact test for proportions and multivariable Cox Proportional Hazards Models to compare overall survival between regions. Women from the Selva region were more likely to be diagnosed with TNBC than women from the Sierra region (31% vs. 14%, p = 0.01). In the unadjusted Cox model, the hazard of mortality was 1.7 times higher in women from the Selva than the Sierra (p = 0.025); this survival difference appeared to be largely explained by differences in the prevalence of TNBC. Our results suggest that the distribution of breast cancer subtypes differs between highly Indigenous American women from two regions of Peru. Disentangling the factors that contribute to this difference will add valuable information to better target prevention and treatment efforts in Peru and improve our understanding of TNBC among all women. This study demonstrates the need for larger datasets of Latin American patients to address differences between Latino subpopulations and optimize targeted prevention and treatment.

Comparison of Receptor-Defined Breast Cancer Subtypes Between German and Sudanese Women: A Facility-Based Cohort Study

PURPOSE

The objective of this study was to compare tumor characteristics, biomarkers, and surrogate subtypes of breast cancer between Sudanese and German women.

METHODS

Tumor characteristics and immunohistochemistry markers (estrogen receptor [ER], progesterone receptor [PR], and human epidermal growth factor receptor 2 [HER2]) were collected from the routine assessment of consecutive patients with invasive breast cancer diagnosed from 2010 to 2015 (Gezira University Pathology Laboratory, Gezira, Sudan) and from 1999 to 2013 (Breast Centre, Martin-Luther-University, Halle, Germany).

RESULTS

A total of 2,492 patients (German [n = 1,932] and Sudanese [n = 560]) were included. Age at diagnosis ranged from 20 to 94 years. Sudanese women were, on average, 10 years younger than German women, with a mean (± standard deviation) age of 48.8 (13.5) and 58.6 (12.4) years, respectively. The Sudanese women had a higher grade, larger tumor, and more lymph node positivity compared with German women. ER-, PR-, and HER2-negative proportions were 55%, 61.8%, and 71.3%, respectively, for Sudanese women versus 22.7%, 32.3%, and 82.5%, respectively, for German women. The triple-negative subtype was more prevalent in Sudanese women (34.5%) than in German women (14.2%). The strongest factor associated with ER-negative disease was grade III (odds ratio, 19.6; 95% CI 11.6 to 33.4; P < .001). Sudanese patients were at higher risk for ER-negative breast cancer, with an odds ratio of 2.01 ( P = .001; adjusted for age, size, nodal status, histologic type, and grade). Stratified by grade, the influence of origin was observed in grade I and grade II tumors, but not in grade III tumors.

CONCLUSION

Sudanese women had more aggressive tumor characteristics and unfavorable prognostic biomarkers. After adjustment, Sudanese origin was still associated with hormone receptor-negative disease, especially in grade I and II tumors. These findings suggest differences in tumor biology among these ethnic groups.

Relationships between Reproductive Risk Factors for Breast Cancer and Tumor Molecular Subtypes

Background: Due to wide clinical differences in the various pathological types of breast cancer and also close associations between disease prognosis and molecular subtypes, relationships of the latter with traditional risk factors have been suggested. Hence, the present study aimed to assess any associations. Methods: This bi-center cross-sectional study was performed on 800 consecutive women with known breast cancer referred to two Comprehensive Cancer Centers in Tehran between 2006 and 2016. Baseline information related to reproductive risk profiles as well as pathological tumor diagnosis and molecular subtypes determined using immunohistochemical analysis by immune-staining for ER, PR, and HER2 molecules were collected by reviewing hospital records. Results: Of 800 samples included for immunohistochemical analysis, 314 (39.3%) were diagnosed as of Luminal A subtype, 107 (13.4%) as Luminal B subtype, 153 (19.1%) as HER-2 over-expressing, and 226 (28.3%) as triple negative. Among all reproductive risk factors initially assessed, young age was associated with HER-2 over-expression, greater tumor size and a history of abortion with the luminal B subtype, lower age at pregnancy with the luminal A subtype, and lower gravidity and a shorter duration of breastfeeding with the triple negative subtype. Conclusion: Each molecular subtype of breast cancer in our population may be associated with specific reproductive risk factors.

TP53 protein levels, RNA-based pathway assessment, and race among invasive breast cancer cases

Mutations in tumor suppressor TP53 have been inconsistently linked to breast cancer risk factors and survival. Immunohistochemistry (IHC) staining, a primary clinical means of TP53 mutation determination, only detects mutations that facilitate protein accumulation (e.g., missense mutations). RNA-based pathway methods capture functional status and may aid in understanding the role of TP53 function in racial disparities of breast cancer. TP53 status was assessed among invasive breast cancer cases from the Carolina Breast Cancer Study (CBCS) (2008–2013) using IHC and an established RNA-based TP53 signature (CBCS and The Cancer Genome Atlas (TCGA)). Frequency of TP53 status (IHC, RNA-based) was estimated in association with tumor characteristics, PAM50 intrinsic subtype, age, and race using relative frequency differences (RFDs) and 95% confidence intervals (95% CI) as the measure of association. Approximately 60% of basal-like tumors were TP53 protein positive (IHC), while nearly 100% were TP53 mutant-like (RNA). Luminal A tumors had low frequency of TP53 positivity (IHC: 7.9%) and mutant-like status (RNA: 1.7%). Mutant-like TP53 (RNA) was strongly associated with age ≤50 years, high tumor grade, advanced stage of disease, large tumor size, and basal-like and HER2 intrinsic subtypes. Black race was strongly associated with TP53 mutant-like status (RNA) (RFD: 24.8%, 95% CI: 20.5, 29.0) even after adjusting for age, grade, stage (RFD: 11.3%; 95% CI: 7.6, 15.0). Associations were attenuated and non-significant when measured by IHC. IHC-based TP53 status is an insensitive measurement of TP53 functional status. RNA-based methods suggest a role for TP53 in tumor prognostic features and racial disparities.

RNA-based assays offer a more sensitive and clinically informative measure of mutations in the tumor suppressor TP53 among women with invasive breast cancer than do immunohistochemistry techniques that can only detect altered proteins. Using tumor samples from more than 1000 women enrolled in the Carolina Breast Cancer Study (CBCS), Melissa Troester from the University of North Carolina at Chapel Hill, USA, and coworkers assessed the functional status of TP53 via both classical immunohistochemistry methods and an RNA-based test of expression levels among 52 TP53-dependent genes. The results of the RNA analysis were strongly associated with younger age-of-onset, higher grade tumors, more advanced stage disease, larger tumor size, aggressive cancer subtypes and race—with more black women harboring TP53 mutant-like tumors than white women. By comparison, these associations were weaker or non-significant when using immunohistochemistry-based tests.

Adipocytes induce distinct gene expression profiles in mammary tumor cells and enhance inflammatory signaling in invasive breast cancer cells

Obesity is a known risk factor for breast cancer. Since obesity rates are constantly rising worldwide, understanding the molecular details of the interaction between adipose tissue and breast tumors becomes an urgent task. To investigate potential molecular changes in breast cancer cells induced by co-existing adipocytes, we used a co-culture system of different breast cancer cell lines (MCF-7 and T47D: ER+/PR+/HER2- and MDA-MB-231: ER-/PR-/HER2-) and murine 3T3-L1 adipocytes. Here, we report that co-culture with adipocytes revealed distinct changes in global gene expression pattern in the different breast cancer cell lines. Our microarray data revealed that in both ER+ cell lines, top upregulated genes showed significant enrichment for hormone receptor target genes. In triple-negative MDA-MB-231 cells, co-culture with adipocytes led to the induction of pro-inflammatory genes, mainly involving genes of the Nf-κB signaling pathway. Moreover, co-cultured MDA-MB-231 cells showed increased secretion of the pro-inflammatory interleukins IL-6 and IL-8. Using a specific NF-κB inhibitor, these effects were significantly decreased. Finally, migratory capacities were significantly increased in triple-negative breast cancer cells upon co-culture with adipocytes, indicating an enhanced aggressive cell phenotype. Together, our studies illustrate that factors secreted by adipocytes have a significant impact on the molecular biology of breast cancer cells.

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.

Advances in the systemic treatment of triple-negative breast cancer

Triple-negative breast cancer constitutes a heterogeneous group of malignancies that are often aggressive and associated with a poor prognosis. Molecular characterization, while not a standard of care, can further subtype triple-negative breast cancer and provide insight into prognostication and behaviour. Optimal chemotherapy regimens have yet to be established; however, there have been advances in the systemic treatment of triple-negative breast cancer in the neoadjuvant, adjuvant, and metastatic settings. In this review, we discuss evidence for the potential benefit of neoadjuvant platinum-based chemotherapy, adjuvant combination chemotherapy with weekly paclitaxel, and BRCA mutation-directed therapy in the metastatic setting. The role for adjuvant capecitabine in patients who do not achieve a pathologic complete response with neoadjuvant chemotherapy is reviewed. Future directions and data concerning novel targeted agents are reviewed, including the most recent data on parp [poly (adp-ribose) polymerase] inhibitors, antiandrogen agents, and immunotherapy.

PAM50 and Risk of Recurrence Scores for Interval Breast Cancers

Breast cancers detected after a negative breast screening examination and prior to the next screening are referred to as interval cancers. These cancers generally have poor clinical characteristics compared with screen-detected cancers, but associations between interval cancer and genomic cancer characteristics are not well understood. Mammographically screened women diagnosed with primary invasive breast cancer from 1993 to 2013 (n = 370) were identified by linking the Carolina Breast Cancer Study and the Carolina Mammography Registry. Among women with a registry-identified screening mammogram 0 to 24 months before diagnosis, cancers were classified as screen-detected (N = 165) or interval-detected (N = 205). Using logistic regression, we examined the association of mode of detection with cancer characteristics (clinical, IHC, and genomic), overall, and in analyses stratified on mammographic density and race. Interval cancer was associated with large tumors [>2 cm; OR, 2.3; 95% confidence interval (CI), 1.5-3.7], positive nodal status (OR, 1.8; 95% CI, 1.1-2.8), and triple-negative subtype (OR, 2.5; 95% CI, 1.1-5.5). Interval cancers were more likely to have non-Luminal A subtype (OR, 2.9; 95% CI, 1.5-5.7), whereas screen-detected cancers tended to be more indolent (96% had low risk of recurrence genomic scores; 71% were PAM50 Luminal A). When stratifying by mammographic density and race, associations between interval detection and poor prognostic features were similar by race and density status. Strong associations between interval cancers and poor-prognosis genomic features (non-Luminal A subtype and high risk of recurrence score) suggest that aggressive tumor biology is an important contributor to interval cancer rates. Cancer Prev Res; 11(6); 327-36. ©2018 AACR.

The Association between Molecular Subtypes of Breast Cancer with Histological Grade and Lymph Node Metastases in Indonesian Woman

Objective: Breast carcinoma is a heterogeneous disease which is rich in diversity. Molecular subtypes of breast cancer, histological grade and lymph node metastases are strong prognostic and predictive factors. In Indonesia, only a limited number of studies have investigated the correlation between molecular subtypes with histological grade and lymph node metastases. Methods: We analyzed 247 invasive breast carcinoma cases from the Anatomic Pathology Installation of Dr. Sardjito General Hospital Yogyakarta between 2012-2015. The slides were stained for estrogen receptors (ER), progesterone receptors (PR), HER2, Ki-67 and CK5/6 for classification into breast cancer subtypes (BCS). Histological grade using the Nottingham system and lymph node status were obtained from anatomic pathology records. The association between histological grade and lymph node status with BCS was examined with Chi-square tests. Results: The immunohistochemical features of 247 cases of women with invasive breast carcinoma were examined. There were 102 (41.3%) patients with Luminal A, 34 (13.8%) patients with Luminal B, 48 (19.4%) patients with HER2-positive, and 63 (25.5%) patients with triple negative breast cancer (TNBC). There were 148 (59.9%) patients with negative lymph node status and 99 (40.1%) with positive status. Among 63 TNBC cases, 37 (58.7%) patients were positive for CK5/6 staining (basal-like). Statistically, there were significant differences between histological grade and subtypes (p=0.013). However, no significant differences were found for lymph node metastases (p=0.540). Conclusion: Among subtypes, Luminal A has the highest frequency, followed by TNBC, HER2-positive and Luminal B. Histological grade was associated with molecular subtypes of breast carcinoma in Yogyakarta. Grade I was associated with Luminal A, while Grade III was associated with Luminal B, HER2 and TNBC subtypes.

Biopsychosocial Challenges and Needs of Young African American Women with Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer known to have poorer prognoses and lower survival rates compared with other types of breast cancer. In addition, TNBC is overrepresented in premenopausal African American women. Using grounded theory as the qualitative methodological approach, the present article elucidates unique biopsychosocial challenges and needs of young African American women with TNBC. A study group of six women with TNBC and a comparison group of six women with estrogen receptor-positive breast cancer were interviewed longitudinally over three time points throughout the cancer treatment trajectory. Major themes that were unique to the study group of women with TNBC include (a) longer, more aggressive treatment trajectories; (b) more difficult struggles with feminine identity; (c) the presence of fertility and parenting issues; (d) higher burdens of care; (e) barriers to separation and individuation as a maturation milestone; and (f) feeling out of place compared with peers. These themes provide a foundation to inform how social workers care for this underserved group of women.

Update on the Treatment of Early-Stage Triple-Negative Breast Cancer

OPINION STATEMENT

Triple-negative breast cancer (TNBC) accounts for 15% of all breast cancers and is associated with poor long-term outcomes compared to other breast cancer subtypes. Currently, chemotherapy remains the main modality of treatment for early-stage TNBC, as there is no approved targeted therapy for this subtype. The biologic heterogeneity of TNBC has hindered the development and evaluation of novel agents, but recent advancements in subclassifying TNBC have paved the way for further investigation of more effective systemic therapies, including cytotoxic and targeted agents. TNBC is enriched for germline BRCA mutation and for somatic deficiencies in homologous recombination DNA repair, the so-called "BRCAness" phenotype. Together, germline BRCA mutations and BRCAness are promising biomarkers of susceptibility to DNA-damaging therapy. Various investigational approaches are consequently being investigated in early-stage TNBC, including immune checkpoint inhibitors, platinum compounds, PI3K pathway inhibitors, and androgen receptor inhibitors. Due to the biological diversity found within TNBC, patient selection based on molecular biomarkers could aid the design of early-phase clinical trials, ultimately accelerating the clinical application of effective new agents. TNBC is an aggressive breast cancer subtype, for which multiple targeted approaches will likely be required for patient outcomes to be substantially improved.

Associations of parity-related reproductive histories with ER± and HER2± receptor-specific breast cancer aetiology

Background

Associations of reproductive history with breast cancer risk differ by oestrogen receptor (ER±) status and possibly by the joint expression of ER and the human epidermal growth factor receptor-2 (ER±/HER2±). However, large sample sizes are needed to establish ER-specific risks by HER2± expression.

Methods

We linked a cancer registry covering nearly 95% of the primary breast cancer diagnoses in Denmark with a research parity database to assess associations for parity, number of live births and age at first live birth (AFLB) with receptor-specific risk. Relative risks (RRs) for associations were estimated with Poisson regression models.

Results

With nearly 31 million women-years of follow-up, 45 786 Danish women aged 20-84 years developed invasive breast cancer during 1992-2011. ER± expression was available for the entire study period and HER2± after 2006. Of the breast cancers with known ER expression, 79% were ER+. Most breast cancers with known ER and HER2 were HER2- (90% of ER+ cancers and 65% of ER- cancers). RRs differed by ER± expression for all reproductive variables ( p -homogeneity < 0.001). Associations were stronger for ER+ than ER- cancers and for those diagnosed before age 50. Parity and early [not later] AFLB showed a protective association with ER+/HER2- and risk association with ER-/HER2- cancers.

Conclusion

Associations of reproductive history with breast cancer risk varied among Danish women by ER± and ER±/HER2± expression and age-at-diagnosis, consistent with receptor-specific and age-related etiological heterogeneity. Further stratification by HER2 status demonstrated dual (or opposite) effects for ER+/HER2- and ER-/HER2- cancers.

Metformin Targets Glucose Metabolism in Triple Negative Breast Cancer

Metformin is the most widely administered anti-diabetic agent worldwide. In patients receiving metformin for metabolic syndrome or diabetes, it reduces the incidence and improves the survival of breast cancer (BC) patients. We have previously shown that metformin is particularly potent against triple negative breast cancer (TNBC), with a reduction of proliferation, oncogenicity and motility, inhibition of pro-oncogenic signaling pathways and induction of apoptosis. These BCs are well recognized to be highly dependent on glucose/glucosamine (metabolized through anaerobic glycolysis) and lipids, which are metabolized for the production of energy and cellular building blocks to sustain a high rate of proliferation. We have previously demonstrated that metformin inhibits lipid metabolism, specifically targeting fatty acid synthase (FASN), cholesterol biosynthesis and GM1 lipid rafts in TNBC. We also reported that glucose promotes phenotypic aggression and reduces metformin efficacy. We now show that metformin inhibits several key enzymes requisite to glucose metabolism in TNBC, providing additional insight into why metformin is especially toxic to this subtype of BC. Our data suggests that the use of metformin to target key metabolic defects in lipid and carbohydrate metabolism in cancer may be broadly applicable, especially against highly aggressive malignant cells.

The prognostic value of node status in different breast cancer subtypes

Nodal metastases and breast cancer subtypes (BCS) are both well-recognized prognostic indicators. However, the association between nodal metastases and BCS, and the prognostic value of nodal metastases in different BCS are still remains unclear. Our aim was to investigate the association between nodal metastases and BCS, and the prognostic value of nodal metastases in the different BCS.

We found that the breast cancer subtype was closely associated with the pN stage. pN stage and breast cancer subtype were significantly associated with disease-free survival. The subgroup analysis showed that the patients in higher pN stage had a poor outcome than patients in lower pN stage in each breast cancer subtype. Furthermore, when the analysis was stratified by breast cancer subtype, we found that even in the same pN stage (pN0-pN2), there was significant survival difference among patients in different BCS, and Luminal A breast cancer patients had the best survival outcome. However, there were no significant survival difference between Luminal A patients and other breast cancer subtype when patients in pN3 stage. Thus, our study suggested that both lymph node status and molecular subtype played important roles in the outcome of breast cancer patients and they cannot replace each other.

Pregnancy-associated breast cancer: the risky status quo and new concepts of predictive medicine

The paper is motivated by severe concerns regarding currently applied care of the pregnancy-associated breast cancer (PABC) characterised by particularly poor outcomes of the disease. Psychological and ethical aspects play a crucial role in PABC: the highest priority not to damage the foetus significantly complicates any treatment generally, and it is quite usual that patients disclaim undergoing any breast cancer treatment during pregnancy. Although, due to global demographic trends, PABC is far from appearing rarely now, severe societal and economic consequences of the disease are still neglected by currently applied reactive medical approach. These actualities require creating new strategies which should be better adapted to the needs of the society at large by advancing the PABC care based on predictive diagnostic approaches specifically in premenopausal women, innovative screening programmes focused on young female populations, targeted prevention in high-risk groups, and optimised treatment concepts. The article summarises the facts and provides recommendations to advance the field-related research and medical services specifically dedicated to the PABC care.

Progestin-only and combined oral contraceptives and receptor-defined premenopausal breast cancer risk: The Norwegian Women and Cancer Study

Receptor-defined subtypes of breast cancer represent distinct cancer types and have differences in risk factors. Whether the two main hormonal forms of oral contraceptives (OCs); i.e. progestin-only (POC) and combined oral contraceptives (COC), are differentially associated with these subtypes are not well known. The aim of our study was to assess the effect of POC and COC use on hormone receptor-defined breast cancer risk in premenopausal women in a prospective population-based cohort - The Norwegian Women and Cancer Study (NOWAC). Information on OC use was collected from 74,862 premenopausal women at baseline. Updated information was applied when follow-up information became available. Multiple imputation was performed to handle missing data, and multivariable Cox regression models were used to calculate hazard ratios (HR) for breast cancer. 1,245 incident invasive breast cancer cases occurred. POC use ≥5 years was associated with ER+ (HR = 1.59, 95% CI 1.09- 2.32, p_trend  = 0.03) and ER+/PR+ cancer (HR = 1.63, 95% CI 1.07-2.48, p_trend  = 0.05), and was not associated with ER- (p_{heterogeneity}  = 0.36) or ER-/PR- (p_{heterogeneity}  = 0.49) cancer. COC use was associated with ER- and ER-/PR- cancer, but did not increase risk of ER+ and ER+/PR+ cancer. Current COC use gave different estimates for ER/PR-defined subtypes (p_{heterogeneity}  = 0.04). This is the first study to show significant associations between POC use and hormone receptor-positive breast cancer. The lack of power to distinguish effects of POC use on subtype development calls for the need of larger studies to confirm our finding.

Frequency of breast cancer subtypes among African American women in the AMBER consortium

Background

Breast cancer subtype can be classified using standard clinical markers (estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2)), supplemented with additional markers. However, automated biomarker scoring and classification schemes have not been standardized. The aim of this study was to optimize tumor classification using automated methods in order to describe subtype frequency in the African American Breast Cancer Epidemiology and Risk (AMBER) consortium.

Methods

Using immunohistochemistry (IHC), we quantified the expression of ER, PR, HER2, the proliferation marker Ki67, and two basal-like biomarkers, epidermal growth factor receptor (EGFR) and cytokeratin (CK)5/6, in 1381 invasive breast tumors from African American women. RNA-based (prediction analysis of microarray 50 (PAM50)) subtype, available for 574 (42%) cases, was used to optimize classification. Subtype frequency was calculated, and associations between subtype and tumor characteristics were estimated using logistic regression.

Results

Relative to ER, PR and HER2 from medical records, central IHC staining and the addition of Ki67 or combined tumor grade improved accuracy for classifying PAM50-based luminal subtypes. Few triple negative cases (< 2%) lacked EGFR and CK5/6 expression, thereby providing little improvement in accuracy for identifying basal-like tumors. Relative to luminal A subtype, all other subtypes had higher combined grade and were larger, and ER-/HER2+ tumors were more often lymph node positive and late stage tumors. The frequency of basal-like tumors was 31%, exceeded only slightly by luminal A tumors (37%).

Conclusions

Our findings indicate that automated IHC-based classification produces tumor subtype frequencies approximating those from PAM50-based classification and highlight high frequency of basal-like and low frequency of luminal A breast cancer in a large study of African American women.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-0939-5) contains supplementary material, which is available to authorized users.

MicroRNA-10b expression in breast cancer and its clinical association

MicroRNAs (miRNAs) are short non-coding RNA molecules that play a significant role in many types of cancers including breast cancer. In the current study, we evaluated the expression levels of microR-10b (miR-10b) in 115 breast cancer patients from Sichuan Cancer Center. Real time reverse transcription-PCR was used to assess miR-10b expression. Clinical data including disease stage, survival status, age, ER/PR/HER2 status, molecular subtypes, tumor size, lymph node status and Ki-67 expression levels were correlated with miR-10b expression levels. Our data showed that the miR-10b expression is correlated with disease stage, living status and tumor sizes. We also found that miR-10b expression levels are higher in the lymph node positive group and the Ki-67 higher scoring group (score > 20). No statistically significant differences were observed based on age or molecular sub-type grouping. In conclusion, miR-10b may be a biomarker for breast cancer and is a potential treatment target.

Linking Race, Cancer Outcomes, and Tissue Repair

The burden of cancer in the United States is unevenly spread across its different populations, with stark differences in both disease prevalence and outcome on the basis of race and ethnicity. Although a large portion of these differences can be explained by a variety of sociobehavioral and socioeconomic factors, even after these exposures are taken into consideration, considerable disparities persist. In this review, we explore a conceptual framework of biological theories and unifying concepts, based on an evolutionary perspective, that may help better define common guiding principles for exploration of underlying causes of cancer health disparities. The ultimate goal of this conceptual perspective is to outline approaches that may aid in establishing integrated pathway and processes analyses to provide useful insights to guide the development of future interventions. These interventions will improve outcome, increase prevention, and ultimately eliminate all disparities.

The protective effect of longer duration of breastfeeding against pregnancy-associated triple negative breast cancer

Parity associated breast cancer (PABC) often diagnosed within the 2-5 years after a full term pregnancy. PABC is usually present with more advanced, poorly differentiated, high-grade cancers that show shorter time to progression and often of the triple negative breast cancer (TNBC) subtype. Data from around the world show that pregnancy-associated TNBC is independently associated with poor survival, underscoring the impact of the pregnant breast microenvironment on the biology and consequently the prognosis of these tumors. Although it is not yet clear, a link between pregnancy-associated TNBCs and lack or shorter duration of breastfeeding (not pregnancy per se) has been proposed. Here, we present epidemiological and experimental evidence for the protective effect of longer duration of lactation against pregnancy-associated TNBCs, and propose a putative molecular mechanism for this protective effect and its effect in eliminating any potential TNBC precursors from the breast by the end of the natural breast involution.

Functional and prognostic significance of long non-coding RNA MALAT1 as a metastasis driver in ER negative lymph node negative breast cancer

MALAT1 (metastasis associated lung adenocarcinoma transcript1) is a conserved long non-coding RNA, known to regulate gene expression by modulating transcription and post-transcriptional pre-mRNA processing of a large number of genes. MALAT1 expression is deregulated in various tumors, including breast cancer. However, the significance of such abnormal expression is yet to be fully understood. In this study, we demonstrate that regulation of aggressive breast cancer cell traits by MALAT1 is not predicted solely based on an elevated expression level but is context specific. By performing loss- and gain-of-function studies, both under in vitro and in vivo conditions, we demonstrate that MALAT1 facilitates cell proliferation, tumor progression and metastasis of triple-negative breast cancer (TNBC) cells despite having a comparatively lower expression level than ER or HER2-positive breast cancer cells. Furthermore, MALAT1 regulates the expression of several cancer metastasis-related genes, but displays molecular subtype specific correlations with such genes. Assessment of the prognostic significance of MALAT1 in human breast cancer (n=1992) revealed elevated MALAT1 expression was associated with decreased disease-specific survival in ER negative, lymph node negative patients of the HER2 and TNBC molecular subtypes. Multivariable analysis confirmed MALAT1 to have independent prognostic significance in the TNBC lymph node negative patient subset (HR=2.64, 95%CI 1.35 − 5.16, p=0.005). We propose that the functional significance of MALAT1 as a metastasis driver and its potential use as a prognostic marker is most promising for those patients diagnosed with ER negative, lymph node negative breast cancer who might otherwise mistakenly be stratified to have low recurrence risk.

Interplay Between Genetic and Epigenetic Changes in Breast Cancer Subtypes

Breast cancer is the most common cancer among women and represents one of the top five leading causes of cancer-related mortality. Inherited and acquired genetic mutations as well as epigenetic aberrations are known to be important contributors to the development and progression of breast cancer. Recent developments in high-throughput technologies have increased our understanding of the molecular changes in breast cancer, leading to the identification of distinctive genetic and epigenetic modifications in different breast cancer molecular subtypes. These genetic and epigenetic changes in luminal A, luminal B, ERBB2/HER2-enriched, basal-like, and normal-like breast cancer subtypes are discussed in this chapter. Furthermore, recent epigenome studies provided more information about further stratification of breast cancer subtypes, with essential role in the appropriate diagnosis and treatment of breast cancer. Thus, the inclusion of both genetic and epigenetic information in breast cancer clinical care could provide critical scientific base for precision medicine in breast cancer.

Reproductive risk factor associations with lobular and ductal carcinoma in the Carolina Breast Cancer Study

BACKGROUND

Invasive lobular breast tumors display unique reproductive risk factor profiles. Lobular tumors are predominantly Luminal A subtype, and it is unclear whether reported risk factor associations are independent of molecular subtype.

METHODS

Polytomous logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs) for the associations between risk factors and histologic subtype [ductal (n = 2,856), lobular (n = 326), and mixed ductal-lobular (n = 473)] in the Carolina Breast Cancer Study (1993-2013). Three-marker immunohistochemical clinical subtypes were defined as Luminal A (ER+ or PR+/HER2-), Luminal B (ER+ or PR+/HER2+), Triple Negative (ER-/PR-/HER2-), and HER2+ (ER-/PR-/HER2+).

RESULTS

In case-case analyses compared to ductal, lobular tumors were significantly associated with lactation duration > 12 months [OR 1.86, 95% CI (1.33-2.60)], age at first birth ≥ 26 years [OR: 1.35, 95% CI: (1.03-1.78)], and current oral contraceptive use [OR: 1.86, 95% CI: (1.08-3.20)]. Differences in risk factor associations between ductal and lobular tumors persisted after restricting to Luminal A subtype.

CONCLUSIONS

Lobular tumors were associated with older age at first birth, increased lactation duration, and current oral contraceptive use. Etiologic heterogeneity by histology persisted after restricting to Luminal A subtype, suggesting both tumor histology and intrinsic subtype play integral parts in breast cancer risk.

De novo metastasis in breast cancer: occurrence and overall survival stratified by molecular subtype

Breast cancer molecular subtypes, categorized jointly by hormone receptors (HR) and human epidermal growth factor-2 (HER2), are utilized to guide systemic therapy. We hypothesized distinct patterns of de novo metastasis and overall survival by molecular subtype using a retrospective cohort of 399,772 women in the National Cancer Database diagnosed with first primary invasive breast cancer between 2010 and 2014, of whom 13,924 were diagnosed with de novo metastasis from 2010 to 2013 and had follow up data. The relationship of molecular subtype with patient and tumor characteristics, including site of de novo metastasis, were examined using Chi-squared tests. Kaplan-Meier and Cox proportional hazards analyses were used to examine overall survival by molecular subtype. Bone was the most frequent de novo metastatic site for all molecular subtypes. Compared to HR+/HER2-, patients with HR-/HER2+ experienced 4.5, 3.0, and 6.0 times the de novo brain, lung, and liver metastasis respectively. In survival analyses of women diagnosed with de novo metastasis, the mortality risk relative to HR+/HER2- was twice as high for triple-negative (hazard ratio = 2.02, 95% CI 1.89-2.16) and modestly lower for HR+/HER2+ (hazard ratio = 0.83, 95% CI 0.78-0.88). The median survival difference between metastatic patients with and without chemotherapy was 28.6 months in HR+/HER2+ and 28.2 months in HR-/HER2+, but only 10.9 months in triple-negative and 5.2 months in HR+/HER2-. In conclusion, despite unfavorable patterns of de novo metastasis, HER2+ breast cancers had relatively better survival in recent years, probably due to treatment differences. Utilizing molecular subtype and site of de novo metastasis may predict prognosis and guide treatment.

Tumor-Suppressor Inactivation of GDF11 Occurs by Precursor Sequestration in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an aggressive and heterogeneous carcinoma in which various tumor-suppressor genes are lost by mutation, deletion, or silencing. Here we report a tumor-suppressive mode of action for growth-differentiation factor 11 (GDF11) and an unusual mechanism of its inactivation in TNBC. GDF11 promotes an epithelial, anti-invasive phenotype in 3D triple-negative cultures and intraductal xenografts by sustaining expression of E-cadherin and inhibitor of differentiation 2 (ID2). Surprisingly, clinical TNBCs retain the GDF11 locus and expression of the protein itself. GDF11 bioactivity is instead lost because of deficiencies in its convertase, proprotein convertase subtilisin/kexin type 5 (PCSK5), causing inactive GDF11 precursor to accumulate intracellularly. PCSK5 reconstitution mobilizes the latent TNBC reservoir of GDF11 in vitro and suppresses triple-negative mammary cancer metastasis to the lung of syngeneic hosts. Intracellular GDF11 retention adds to the concept of tumor-suppressor inactivation and reveals a cell-biological vulnerability for TNBCs lacking therapeutically actionable mutations.

Immunotherapy in triple-negative breast cancer

Breast cancer can be classified based on the expression or lack of expression of protein receptors including estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth receptor 2 (Her2). The basal molecular subtype is mostly made up of breast cancers that do not express ER/PR or Her2, triple-negative breast cancers (TNBC) (Bertucci et al. in Int J Cancer 123(1):236, 2008). TNBC tends to be more aggressive as there are no approved targeted treatments and the only treatment option currently is cytotoxic chemotherapy. Recent data show that some chemotherapies, specifically anthracyclines, not only have cytotoxic effects but also use the immune system by activating CD8+ T cell responses to kill cancer cells (Stagg et al. in Ther Adv Med Oncol 5(3):169-181, 2013), and thus, tumor-infiltrating lymphocytes respond well to chemotherapy. Currently, systemic immunotherapy which utilizes the patient's own immune system directly to eradicate and target neoplastic cells is being explored as treatment for TNBC as this type of breast cancer has been shown to be immunogenic (Yu et al. in Int J Environ Res Public Health 14:68, 2017). According to the Cancer Genome Atlas, TNBC has higher PD-L1 mRNA expression (Mittendorf et al. Cancer Immunol Res 2(4):361-370, 2014). Higher rates of CD8+ T cell infiltration were also found in TNBC according to a study by Liu et al. (Breast Cancer Res 14:R48, 2012). In TNBC patients, Pembrolizumab, a monoclonal antibody that targets programmed cell death protein 1 (PD-1), and Atezolizumab, a monoclonal antibody that targets its ligand, have been investigated to assess dose tolerability and side effects. Further studies involving vaccines, immunotherapy that targets cytotoxic T lymphocyte-associated protein-4 and PD-L1, are currently being investigated for treatment of TNBC. This review outlines the systemic immunotherapies that are currently being investigated for patients with TNBC.

Responding to a Community's Concern: A Comparison of Breast Cancer Characteristics and Initial Treatment in Three Selected North Carolina Counties

BACKGROUND A 2007 national report identified North Carolina's Edgecombe County as having among the highest breast cancer incidence and mortality rates nationally, motivating the initiation of a task force and other local efforts to address the problem. The goal of this study is to examine county breast cancer characteristics before and after the report, including whether geographic variation may mask racial disparities in this majority African American community.METHOD With guidance from community partners, breast cancer cases from 2000 to 2012 in Edgecombe, Nash, and Orange Counties (N = 2,641) were obtained from the North Carolina Central Cancer Registry. Bivariate and trend analyses of tumor and treatment characteristics were examined by county and race.RESULTS Women in Edgecombe and Nash Counties were diagnosed with more advanced stage, higher grade tumors. African Americans in Edgecombe and Nash Counties were diagnosed with advanced disease more often than African Americans in Orange County. Average time-to-treatment was well within guideline recommendations. Incidence and mortality rates appear to have declined, with variation in measures of racial differences over time.LIMITATIONS Changes in coding standards across the observation period required reliance on coarse measures that may partially mute useful findings.CONCLUSIONS Racial disparities remain a concern in North Carolina; however, they appear to be less profound than in the 2007 national report. The portentous statistics in the report represent an all-time high, after which some, but not all, measures reflect positive change amidst ongoing local efforts to improve breast cancer knowledge and care.

Immunohistochemistry defined subtypes of breast cancer in 678 Sudanese and Eritrean women; hospitals based case series

BACKGROUND

Breast cancer is the most common malignancy accounting for 25% of all cancers in females. In Africa, breast cancer prevalence and mortality are steadily increasing. Knowledge of hormone receptors and human epidermal growth factor receptor-2 (HER-2) expressions are vital for breast cancer management plans and decision making. There is wide regional variation in the proportion of these biomarkers, especially in African countries. Hormone receptors positivity in indigenous African and African American women is considered to be low and triple negative breast cancer is a dominant phenotype. There is paucity of data regarding hormone receptors (ER and PR) and HER2 expressions in North-eastern Africa (Eritrea and Sudan). The purpose of this study was to evaluate the expression of ER, PR and HER2 in Eritrean and Sudanese case series and correlate these biomarkers with the clinicopathological profile.

METHOD

Clinicopathologic data of patients were collected from clinical records. Immunohistochemistry biomarkers (ER, PR, and HER2) were assessed in consecutive female patients who had been diagnosed with invasive breast cancer from 2011 to 2015 in Gezira University Pathology Laboratory, the Sudan and National Health laboratory, Asmara, Eritrea.

RESULTS

There were 678 cases involved in this study. The mean age was 48.8 years with ±0.53 standard error of the mean. Two-thirds of the case were ≤50 years. Invasive ductal carcinoma, no special type was the most dominant histologic type (86%) in both study groups. The majority of cases (70%) had tumour stage pT2 and pT3 and about 50% had lymph node involvement. Less than 5% of the cases had well-differentiated tumours. The ER, PR and HER2 positive rates were 45%, 32%, and 29%, respectively. The proportion of luminal-A like, luminal-B like, HER2 enriched and TNBC were 37%, 13%, 16% and 34%, respectively. Fisher extract analysis showed age (p = .015), tumour size (p = .041), and histologic grade (p = .000) were significantly associated with intrinsic subtypes. Furthermore, Logistic regression analysis stratified by origin, age, tumour size, lymph-node metastasis and grade indicated that younger women age (≤50 years) and grade III tumours were more likely to be diagnosed with ER negative breast cancer.

CONCLUSION

Most of Sudanese and Eritrean women were diagnosed at younger age and with unfavourable prognostic clinicopathologic prognostic markers. TNBC is more frequent in this cohort study; patients with grade III tumours and young age are more likely to be hormone receptors negative. Therefore, routine determination of hormone receptors is warranted for appropriate targeted therapy.

Black-White Disparities in Breast Cancer Subtype: The Intersection of Socially Patterned Stress and Genetic Expression

Hormone receptor negative (HR-) breast cancer subtypes are etiologically distinct from the more common, less aggressive, and more treatable form of estrogen receptor positive (ER+) breast cancer. Numerous population-based studies have found that, in the United States, Black women are 2 to 3 times more likely to develop HR- breast cancer than White women. Much of the existing research on racial disparities in breast cancer subtype has focused on identifying predisposing genetic factors associated with African ancestry. This approach fails to acknowledge that racial stratification shapes a wide range of environmental and social exposures over the life course. Human stress genomics considers the role of individual stress perceptions on gene expression. Yet, the role of structurally rooted biopsychosocial processes that may be activated by the social patterning of stressors in an historically unequal society, whether perceived by individual black women or not, could also impact cellular physiology and gene expression patterns relevant to HR- breast cancer etiology. Using the weathering hypothesis as our conceptual framework, we develop a structural perspective for examining racial disparities in breast cancer subtypes, integrating important findings from the stress biology, breast cancer epidemiology, and health disparities literatures. After integrating key findings from these largely independent literatures, we develop a theoretically and empirically guided framework for assessing potential multilevel factors relevant to the development of HR- breast cancer disproportionately among Black women in the US. We hypothesize that a dynamic interplay among socially patterned psychosocial stressors, physiological & behavioral responses, and genomic pathways contribute to the increased risk of HR- breast cancer among Black women. This work provides a basis for exploring potential alternative pathways linking the lived experience of race to the risk of HR- breast cancer, and suggests new avenues for research and public health action.

DNA Repair Mechanism Gene, XRCC1A ( Arg194Trp) but not XRCC3 ( Thr241Met) Polymorphism Increased the Risk of Breast Cancer in Premenopausal Females: A Case-Control Study in Northeastern Region of India

X-ray repair cross complementary group gene is one of the most studied candidate gene involved in different types of cancers. Studies have shown that X-ray repair cross complementary genes are significantly associated with increased risk of breast cancer in females. Moreover, studies have revealed that X-ray repair cross complementary gene polymorphism significantly varies between and within different ethnic groups globally. The present case–control study was aimed to investigate the association of X-ray repair cross complementary 1A (Arg194Trp) and X-ray repair cross complementary 3 (Thr241Met) polymorphism with the risk of breast cancer in females from northeastern region of India. The present case–control study includes histopathologically confirmed and newly diagnosed 464 cases with breast cancer and 534 apparently healthy neighborhood community controls. Information on sociodemographic factors and putative risk factors were collected from each study participant by conducting face-to-face interviews. Genotyping of X-ray repair cross complementary 1A (Arg194Trp) and X-ray repair cross complementary 3 (Thr241Met) was carried out by polymerase chain reaction-restriction fragment length polymorphism. For statistical analysis, both univariate and multivariate logistic regression analyses were performed. We also performed stratified analysis to find out the association of X-ray repair cross complementary genes with the risk of breast cancer stratified based on menstrual status. This study revealed that tryptophan allele (R/W-W/W genotype) in X-ray repair cross complementary 1A (Arg194Trp) gene significantly increased the risk of breast cancer (adjusted odds ratio = 1.44, 95% confidence interval = 1.06-1.97, P < .05 for R/W-W/W genotype). Moreover, it was found that tryptophan allele (W/W genotype) at codon 194 of X-ray repair cross complementary 1A (Arg194Trp) gene significantly increased the risk of breast cancer in premenopausal females (crude odds ratio = 1.66, 95% confidence interval = 1.11-2.46, P < .05 for R/W-W/W genotype). The present study did not reveal any significant association of X-ray repair cross complementary 3 (Thr241Met) polymorphism with the risk of breast cancer. The present study has explored that X-ray repair cross complementary 1A (Arg194Trp) gene polymorphism is significantly associated with the increased risk of breast cancer in premenopausal females from northeastern region of India which may be beneficial for prognostic purposes.

Body mass index, age at breast cancer diagnosis, and breast cancer subtype: a cross-sectional study

PURPOSE

Evidence suggests that premenopausal obesity decreases and postmenopausal obesity increases breast cancer risk. Because it is not well known whether this is subtype dependent, we studied the association between body mass index (BMI) and age at breast cancer diagnosis, or the probability of being diagnosed with a specific breast cancer phenotype, by menopausal status.

METHODS

All patients with non-metastatic operable breast cancer from the University Hospital Leuven diagnosed between January 1, 2000 and December 31, 2013 were included (n = 7020) in this cross-sectional study. Linear models and logistic regression were used for statistical analysis. Allowing correction for age-related BMI-increase, we used the age-adjusted BMI score which equals the difference between a patient's BMI score and the population-average BMI score corresponding to the patient's age category.

RESULTS

The quadratic relationship between the age-adjusted BMI and age at breast cancer diagnosis (p = 0.0207) interacted with menopausal status (p < 0.0001); increased age at breast cancer diagnosis was observed with above-average BMI scores in postmenopausal women, and with below-average BMI scores in premenopausal women. BMI was linearly related to the probabilities of Luminal B and HER2-like breast cancer phenotypes, but only in postmenopausal women. The relative changes in probabilities between both these subtypes mirrored each other.

CONCLUSION

BMI associates differently before and after menopause with age at breast cancer diagnosis and with the probability that breast cancer belongs to a certain phenotype. The opposite effect of increasing BMI on relative frequencies of Luminal B and HER2-like breast cancers suggests a common origin.

Prediagnostic Smoking Is Associated with Binary and Quantitative Measures of ER Protein and ESR1 mRNA Expression in Breast Tumors

Background: Smoking is a possible risk factor for breast cancer and has been linked to increased risk of estrogen receptor-positive (ER⁺) disease in some epidemiologic studies. It is unknown whether smoking has quantitative effects on ER expression.Methods: We examined relationships between smoking and ER expression from tumors of 1,888 women diagnosed with invasive breast cancer from a population-based study in North Carolina. ER expression was characterized using binary (±) and continuous measures for ER protein, ESR1 mRNA, and a multigene luminal score (LS) that serves as a measure of estrogen signaling in breast tumors. We used logistic and linear regression models to estimate temporal and dose-dependent associations between smoking and ER measures.Results: The odds of ER⁺, ESR1⁺, and LS⁺ tumors among current smokers (at the time of diagnosis), those who smoked 20 or more years, and those who smoked within 5 years of diagnosis were nearly double those of nonsmokers. Quantitative levels of ESR1 were highest among current smokers compared with never smokers overall [mean (log₂) = 9.2 vs. 8.7, P < 0.05] and among ER⁺ cases; however, we did not observe associations between smoking measures and continuous ER protein expression.Conclusions: In relationship to breast cancer diagnosis, recent smoking was associated with higher odds of the ER⁺, ESR1⁺, and LS⁺ subtype. Current smoking was associated with elevated ESR1 mRNA levels and an elevated LS, but not with altered ER protein.Impact: A multigene LS and single-gene ESR1 mRNA may capture tumor changes associated with smoking. Cancer Epidemiol Biomarkers Prev; 27(1); 67-74. ©2017 AACR.

Obesity and Triple-Negative Breast Cancer: Disparities, Controversies, and Biology

Once considered a problem of Western nations, obesity (body mass index ≥30 kg/m²) has rapidly increased since the 1970s to become a major threat to world health. Since 1970, the face of obesity has changed from a disease of affluence and abundance to a disease of poverty. During the last 10 years, studies have mechanistically linked obesity and an obese tumor microenvironment with signaling pathways that predict aggressive breast cancer biology. For example, in the United States, African American women are more likely than non-Hispanic European American women to be obese and to be diagnosed with triple-negative breast cancer (TNBC). In 2008, the Carolina Breast Study found that obesity (increased waist/hip ratio) was linked to an increased incidence of TNBC in premenopausal and postmenopausal African American women. Subsequently, several groups have investigated the potential link between obesity and TNBC in African American women. To date, the data are complex and sometimes contradictory. We review epidemiologic studies that investigated the potential association among obesity, metabolic syndrome, and TNBC in African American women and mechanistic studies that link insulin signaling to the obese breast microenvironment, tissue inflammation, and aggressive TNBC biology.

Obesity and Triple-Negative Breast Cancer: Disparities, Controversies, and Biology

Once considered a problem of Western nations, obesity (body mass index ≥30 kg/m²) has rapidly increased since the 1970s to become a major threat to world health. Since 1970, the face of obesity has changed from a disease of affluence and abundance to a disease of poverty. During the last 10 years, studies have mechanistically linked obesity and an obese tumor microenvironment with signaling pathways that predict aggressive breast cancer biology. For example, in the United States, African American women are more likely than non-Hispanic European American women to be obese and to be diagnosed with triple-negative breast cancer (TNBC). In 2008, the Carolina Breast Study found that obesity (increased waist/hip ratio) was linked to an increased incidence of TNBC in premenopausal and postmenopausal African American women. Subsequently, several groups have investigated the potential link between obesity and TNBC in African American women. To date, the data are complex and sometimes contradictory. We review epidemiologic studies that investigated the potential association among obesity, metabolic syndrome, and TNBC in African American women and mechanistic studies that link insulin signaling to the obese breast microenvironment, tissue inflammation, and aggressive TNBC biology.

Breast Cancer in Latinas: A Focus on Intrinsic Subtypes Distribution

Breast cancer is the most frequent cancer in women worldwide. It is classified into intrinsic subtypes characterized by different molecular profiles and prognosis. The prevalence of the different intrinsic subtypes varies between population groups. IHC surrogates based on the expression of the estrogen receptor, progesterone receptor, and HER2 have been widely used to study the distribution of intrinsic subtypes in non-Hispanic whites and African Americans, but data are limited for Hispanic/Latina women. Similarly, most studies analyzing gene expression profiles only include women of European descent. This review focuses on studies that describe the distribution of breast cancer subtypes in Hispanic/Latina women and highlights the need for more research in this population. Cancer Epidemiol Biomarkers Prev; 27(1); 3-10. ©2017 AACR.

Pubertally Initiated High-Fat Diet Promotes Mammary Tumorigenesis in Obesity-Prone FVB Mice Similarly to Obesity-Resistant BALB/c Mice

Premenopausal breast cancer is associated with increased animal fat consumption among normal-weight but not overweight women. Our previous findings in obesity-resistant BALB/c mice showed that a diet high in saturated animal fat (HFD) promotes mammary tumorigenesis in both DMBA carcinogenesis and Trp53-null transplant models. Having made these observations in BALB/c mice, which have very modest HFD weight gain, we determined the effects of HFD in FVB mice, which gain significant weight on HFD. Three-week-old FVB mice fed a low-fat diet or HFD were subjected to 7,12-dimethylbenz[a]anthracene-induced carcinogenesis. Like BALB/c mice, HFD promoted mammary tumorigenesis. Development of tumors largely occurred prior to mice becoming obese, indicating the role of animal-derived HFD rather than resulting obesity in tumor promotion. Also similar to BALB/c mice, early-occurring adenosquamous mammary tumors were abundant among HFD-fed FVB mice. Tumors from HFD mice also had increased intra-tumor M2 macrophages. Prior to tumor development, HFD accelerated normal mammary gland development and increased mammary M2 macrophages, similarly to BALB/c mice. The promotional effects of puberty-initiated HFD on carcinogen-induced mammary cancer are thus largely weight gain-independent. Like BALB/c mice, HFD promoted adenosquamous tumors, suggesting a role for early age HFD in promoting this subtype of triple negative mammary cancer. M2 macrophage recruitment was common to both mouse strains. We speculate that a similar effect of HFD on immune function may contribute to epidemiological findings of increased breast cancer risk in young, premenopausal, normal-weight women who consume a diet high in saturated animal fat.

Triple-negative breast cancer and its association with obesity

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that lacks expression of the estrogen and progesterone receptor and does not overexpress human epidermal growth factor 2 receptor protein. TNBC is associated with special characteristics, including aggressiveness, poor prognosis and poor response to treatment, and has been attracting increasing attention worldwide. Obesity is a well-documented factor exerting a significant effect on the development of breast cancer, including TNBC. The purpose of the present review was to focus on the association between obesity and TNBC and provide a summary of novel research findings. The aim was to highlight the association between TNBC and obesity and provide an overview of novel outlooks on clinical issues, biological rationale, novel targeted therapies and prognosis, in order to draw attention to the significance of weight management, primary prevention, early diagnosis and treatment of this intractable disease.

Racial Differences in PAM50 Subtypes in the Carolina Breast Cancer Study

Background

African American breast cancer patients have lower frequency of hormone receptor-positive (HR+)/human epidermal growth factor receptor 2 (HER2)-negative disease and higher subtype-specific mortality. Racial differences in molecular subtype within clinically defined subgroups are not well understood.

Methods

Using data and biospecimens from the population-based Carolina Breast Cancer Study (CBCS) Phase 3 (2008-2013), we classified 980 invasive breast cancers using RNA expression-based PAM50 subtype and recurrence (ROR) score that reflects proliferation and tumor size. Molecular subtypes (Luminal A, Luminal B, HER2-enriched, and Basal-like) and ROR scores (high vs low/medium) were compared by race (blacks vs whites) and age (≤50 years vs > 50 years) using chi-square tests and analysis of variance tests.

Results

Black women of all ages had a statistically significantly lower frequency of Luminal A breast cancer (25.4% and 33.6% in blacks vs 42.8% and 52.1% in whites; younger and older, respectively). All other subtype frequencies were higher in black women (case-only odds ratio [OR] = 3.11, 95% confidence interval [CI] = 2.22 to 4.37, for Basal-like; OR = 1.45, 95% CI = 1.02 to 2.06, for Luminal B; OR = 2.04, 95% CI = 1.33 to 3.13, for HER2-enriched). Among clinically HR+/HER2- cases, Luminal A subtype was less common and ROR scores were statistically significantly higher among black women.

Conclusions

Multigene assays highlight racial disparities in tumor subtype distribution that persist even in clinically defined subgroups. Differences in tumor biology (eg, HER2-enriched status) may be targetable to reduce disparities among clinically ER+/HER2- cases.

Biology and Etiology of Young-Onset Breast Cancers among Premenopausal African American Women: Results from the AMBER Consortium

Background: African American (AA) women have higher incidence of aggressive, young-onset (<40 years) breast cancers. Young- and older-onset disease may have distinct tumor biologies and etiologies; however, studies investigating age differences among AA women have been rare and generally underpowered.Methods: We examined tumor characteristics and breast cancer risk factors associated with premenopausal young (<40) vs. older (≥40) AA women's breast cancer in the African American Breast Cancer Epidemiology and Risk Consortium (2,008 cases and 5,144 controls). Unconditional logistic regression models assessed heterogeneity of tumor biology and risk factor associations by age, overall, and by estrogen receptor status.Results: Premenopausal AA women <40 years had higher frequency of poorer-prognosis tumor characteristics compared with older women, including negative estrogen and progesterone receptor status, triple-negative subtype, higher grade, higher stage, and larger tumors. Adiposity (i.e., waist-to-hip ratio) and family history of breast cancer were more strongly associated with young-onset disease [case-control OR = 1.46, 95% confidence interval (CI) = 1.04-2.05; OR = 3.10, 95% CI = 2.08-4.63, respectively] compared with older-onset disease (OR = 1.11, 95% CI = 0.91-1.35; OR = 1.57, 95% CI = 1.26-1.94). Breastfeeding showed a slight inverse risk association among young women (OR = 0.70, 95% CI = 0.43-1.16). Oral contraceptive use was associated with increased risk regardless of age. Considering various cutoff points for young age (<40, <45, <50), age-related heterogeneity was greatest when <40 was used.Conclusions: Among premenopausal AA women, diagnosis before age 40 is associated with more aggressive breast tumor biology and some etiologic differences.Impact: Modifiable risk factors including breastfeeding, adiposity, and oral contraceptive use may be important targets for mitigating harms of young-onset breast cancer. Cancer Epidemiol Biomarkers Prev; 26(12); 1722-9. ©2017 AACR.