Tumor characteristics in African American and white women

Differences in Breast Cancers Among American Indian/Alaska Native and non-Hispanic Whites in the USA

IMPORTANCE

Breast cancer (BC) death rates have not improved for American Indian/Alaska Native (AI/AN) women, whereas, it has significantly decreased for non-Hispanic White (White) women.

OBJECTIVE

Delineate the differences in patient and tumor characteristics among AI/AN and Whites with BC, and its impact on age and stage at diagnosis as well as overall survival (OS).

METHODS

Hospital-based, cohort study using the National Cancer Database to identify female AI/AN and Whites diagnosed with BC between the years 2004 and 2016.

RESULTS

BC in 6866 AI/AN (0.3%) and 1,987,324 Whites (99.7%) were studied. The median age at diagnosis was 58 for AI/AN and 62 for Whites. AI BC patients traveled double the distance for treatment, lived in lower median income zip codes, had a higher percentage of uninsured, higher comorbidities, lower percentage of Stage 0/I, larger tumor size, greater number of positive lymph nodes, higher proportion of triple negative and HER2-positive BC than Whites. All the above comparisons were significant, p<0.001. Association between patient/tumor characteristics with age and stage at diagnosis was not significantly different between AI/AN and Whites. Unadjusted OS was worse for AI/AN as compared to Whites (HR=1.07, 95% CI=1.01-1.14, p=0.023). After adjustment of all covariates, OS was not different (HR=1.038, 95%CI=0.902-1.195, p=0.601).

CONCLUSION

There were significant differences in patient/tumor characteristics among AI/AN and White BC which adversely impacted OS in AI/AN. However, when adjusted for various covariates, the survival was similar, suggesting that the worse survival in AI/AN is mostly the impact of known biological, socio-economic, and environmental determinants of health.

The DNA damage repair landscape in Black women with breast cancer

BACKGROUND

Estrogen receptor positive (ER+) breast cancer is one of the most commonly diagnosed malignancies in women irrespective of their race or ethnicity. While Black women with ER+ breast cancer are 42% more likely to die of their disease than White women, molecular mechanisms underlying this disparate outcome are understudied. Recent studies identify DNA damage repair (DDR) genes as a new class of endocrine therapy resistance driver that contributes to poor survival among ER+ breast cancer patients. Here, we systematically analyze DDR regulation in the tumors and normal breast of Black women and its impact on survival outcome.

METHOD

Mutation and up/downregulation of 104 DDR genes in breast tumor and normal samples from Black patients relative to White counterparts was assessed. For DDR genes that were differently regulated in the tumor samples from Black women in multiple datasets associations with survival outcome were tested.

RESULTS

Overall, Black patient tumors upregulate or downregulate RNA levels of a wide array of single strand break repair (SSBR) genes relative to their white counterparts and uniformly upregulate double strand break repair (DSBR) genes. This DSBR upregulation was also detectable in samples of normal breast tissue from Black women. Eight candidate DDR genes were reproducibly differently regulated in tumors from Black women and associated with poor survival. A unique DDR signature comprised of simultaneous upregulation of homologous recombination gene expression and downregulation of SSBR genes was enriched in Black patients. This signature associated with cell cycle dysregulation (p < 0.001), a hallmark of endocrine therapy resistance, and concordantly, with significantly worse survival outcomes in all datasets analyzed (hazard ratio of 9.5, p < 0.001).

CONCLUSION

These results constitute the first systematic analysis of DDR regulation in Black women and provide strong rationale for refining biomarker profiles to ensure precision medicine for underserved populations.

Association of Life-Course Educational Attainment and Breast Cancer Grade in the MEND Study

Background:

Nigeria reports the highest age-standardized mortality rate for breast cancer (BC) among African countries and disproportionately high rates of high-grade cancer. Histological grade is a strong predictor of mortality, and evidence suggests that educational attainment influences cancer outcomes.

Objective:

We characterize the association between educational trends across the life-course and BC grade at diagnosis.

Methods:

Data on 224 BC patients enrolled in the Mechanisms for Established and Novel Risk Factors for Breast Cancer in Nigerian Women (MEND) study was analyzed. Participant and parental (mother and father) education was categorized as low (primary school or less) or high (secondary school or greater). Accordingly, the educational trend across the life-course was determined for each participant relative to each parent: stable high, increasing, decreasing, or stable low. BC grade was classified as high (grade 3) or low (grades 1–2).

Findings:

About 34% of participants, 71% of fathers, and 85% of mothers had low education. Approximately one-third of participants were diagnosed with high-grade BC. Participants with low-grade BC were more likely to have highly educated fathers (p = 0.04). After adjusting for age, comorbidities, marital status and mammogram screening, participants with highly educated fathers were 60% less likely to have high-grade BC (aOR 0.41; 95% CI 0.20 to 0.84) compared to those with less-educated fathers. Stable high life-course education relative to father was also associated with a significantly lower likelihood of having high-grade BC (aOR 0.36; 95% CI 0.15 to 0.87) compared to stable low life-course education. No significant associations were observed for the participant’s education, mother’s education, or life-course education relative to mother.

Conclusions:

Early-life socioeconomic status (SES) may influence BC grade. This deserves further study to inform policies that may be useful in reducing high-grade BC in Nigeria.

Gene Expression Alterations Associated with Oleuropein-Induced Antiproliferative Effects and S-Phase Cell Cycle Arrest in Triple-Negative Breast Cancer Cells

It is known that the Mediterranean diet is effective in reducing the risk of several chronic diseases, including cancer. A critical component of the Mediterranean diet is olive oil, and the relationship between olive oil consumption and the reduced risk of cancer has been established. Oleuropein (OL) is the most prominent polyphenol component of olive fruits and leaves. This compound has been shown to have potent properties in various types of cancers, including breast cancer. In the present study, the molecular mechanism of OL was examined in two racially different triple-negative breast cancer (TNBC) cell lines-African American (AA, MDA-MB-468) and Caucasian American (CA, MDA-MB-231). The data obtained showed that OL effectively inhibits cell growth in both cell lines, concomitant with S-phase cell cycle arrest-mediated apoptosis. The results also showed that OL-treated MDA-MB-468 cells were two-fold more sensitive to OL antiproliferative effect than MDA-MB-231 cells were. At lower concentrations, OL modified the expression of many apoptosis-involved genes. OL was more effective in MDA-MB-468, compared to MDA-MB-231 cells, in terms of the number and the fold-change of the altered genes. In MDA-MB-468 cells, OL induced a noticeable transcription activation in fourteen genes, including two members of the caspase family: caspase 1 (CASP1) and caspase 14 (CASP14); two members of the TNF receptor superfamily: Fas-associated via death domain (FADD) and TNF receptor superfamily 21 (TNFRSF21); six other proapoptotic genes: growth arrest and DNA damage-inducible 45 alpha (GADD45A), cytochrome c somatic (CYCS), BCL-2 interacting protein 2 (BNIP2), BCL-2 interacting protein 3 (BNIP3), BH3 interacting domain death agonist (BID), and B-cell lymphoma/leukemia 10 (BCL10); and the CASP8 and FADD-like apoptosis regulator (CFLAR) gene. Moreover, in MDA-MB-468 cells, OL induced a significant upregulation in two antiapoptotic genes: bifunctional apoptosis regulator (BFAR) and B-Raf proto-oncogene (BRAF) and a baculoviral inhibitor of apoptosis (IAP) repeat-containing 3 (BIRC3). On the contrary, in MDA-MB-231 cells, OL showed mixed impacts on gene expression. OL significantly upregulated the mRNA expression of four genes: BIRC3, receptor-interacting serine/threonine kinase 2 (RIPK2), TNF receptor superfamily 10A (TNFRSF10A), and caspase 4 (CASP4). Additionally, another four genes were repressed, including caspase 6 (CASP6), pyrin domain (PYD), and caspase recruitment domain (CARD)-containing (PAYCARD), baculoviral IAP repeat-containing 5 (BIRC5), and the most downregulated TNF receptor superfamily member 11B (TNFRSF11B, 16.34-fold). In conclusion, the data obtained indicate that the two cell lines were markedly different in the anticancer effect and mechanisms of oleuropein's ability to alter apoptosis-related gene expressions. The results obtained from this study should also guide the potential utilization of oleuropein as an adjunct therapy for TNBC to increase chemotherapy effectiveness and prevent cancer progression.

Endocrine Therapy Nonadherence and Discontinuation in Black and White Women

BACKGROUND

Differential use of endocrine therapy (ET) by race may contribute to breast cancer outcome disparities, but racial differences in ET behaviors are poorly understood.

METHODS

Women aged 20-74 years with a first primary, stage I-III, hormone receptor-positive (HR+) breast cancer were included. At 2 years postdiagnosis, we assessed nonadherence, defined as not taking ET every day or missing more than two pills in the past 14 days, discontinuation, and a composite measure of underuse, defined as either missing pills or discontinuing completely. Using logistic regression, we evaluated the relationship between race and nonadherence, discontinuation, and overall underuse in unadjusted, clinically adjusted, and socioeconomically adjusted models.

RESULTS

A total of 1280 women were included; 43.2% self-identified as black. Compared to white women, black women more often reported nonadherence (13.7% vs 5.2%) but not discontinuation (10.0% vs 10.7%). Black women also more often reported the following: hot flashes, night sweats, breast sensitivity, and joint pain; believing that their recurrence risk would not change if they stopped ET; forgetting to take ET; and cost-related barriers. In multivariable analysis, black race remained statistically significantly associated with nonadherence after adjusting for clinical characteristics (adjusted odds ratio = 2.72, 95% confidence interval = 1.75 to 4.24) and after adding socioeconomic to clinical characteristics (adjusted odds ratio = 2.44, 95% confidence interval = 1.50 to 3.97) but was not independently associated with discontinuation after adjustment. Low recurrence risk perception and lack of a shared decision making were strongly predictive of ET underuse across races.

CONCLUSIONS

Our results highlight important racial differences in ET-adherence behaviors, perceptions of benefits/harms, and shared decision making that may be targeted with culturally tailored interventions.

Differences in race, molecular and tumor characteristics among women diagnosed with invasive ductal and lobular breast carcinomas

BACKGROUND

The dominant invasive breast cancer histologic subtype, ductal carcinoma, shows intrinsic subtype diversity. However, lobular breast cancers are predominantly Luminal A. Both histologic subtypes show distinct relationships with patient and tumor characteristics, but it is unclear if these associations remain after accounting for intrinsic subtype.

METHODS

Generalized linear models were used to estimate relative frequency differences (RFDs) and 95% confidence intervals (95% CIs) for the associations between age, race, tumor characteristics, immunohistochemistry (IHC) and RNA-based intrinsic subtype, TP53 status, and histologic subtype in the Carolina Breast Cancer Study (CBCS, n = 3,182) and The Cancer Genome Atlas (TCGA, n = 808).

RESULTS

Relative to ductal tumors, lobular tumors were significantly more likely to be Luminal A [CBCS RNA RFD: 44.9%, 95% CI (39.6, 50.1); TCGA: RFD: 50.5%, 95% CI (43.9, 57.1)], were less frequent among young (≤ 50 years) and black women, were larger in size, low grade, less frequently had TP53 pathway defects, and were diagnosed at later stages. These associations persisted among Luminal A tumors (n = 242).

CONCLUSIONS

While histology is strongly associated with molecular characteristics, histologic associations with age, race, size, grade, and stage persisted after restricting to Luminal A subtype. Histology may continue to be clinically relevant among Luminal A breast cancers.

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.

Rational Manual and Automated Scoring Thresholds for the Immunohistochemical Detection of TP53 Missense Mutations in Human Breast Carcinomas

Missense mutations in TP53 are common in human breast cancer, have been associated with worse prognosis, and may predict therapy effect. TP53 missense mutations are associated with aberrant accumulation of p53 protein in tumor cell nuclei. Previous studies have used relatively arbitrary cutoffs to characterize breast tumors as positive for p53 staining by immunohistochemical assays. This study aimed to objectively determine optimal thresholds for p53 positivity by manual and automated scoring methods using whole tissue sections from the Carolina Breast Cancer Study. p53-immunostained slides were available for 564 breast tumors previously assayed for TP53 mutations. Average nuclear p53 staining intensity was manually scored as negative, borderline, weak, moderate, or strong and percentage of positive tumor cells was estimated. Automated p53 signal intensity was measured using the Aperio nuclear v9 algorithm combined with the Genie histology pattern recognition tool and tuned to achieve optimal nuclear segmentation. Receiver operating characteristic curve analysis was performed to determine optimal cutoffs for average staining intensity and percent cells positive to distinguish between tumors with and without a missense mutation. Receiver operating characteristic curve analysis demonstrated a threshold of moderate average nuclear staining intensity as a good surrogate for TP53 missense mutations in both manual (area under the curve=0.87) and automated (area under the curve=0.84) scoring systems. Both manual and automated immunohistochemical scoring methods predicted missense mutations in breast carcinomas with high accuracy. Validation of the automated intensity scoring threshold suggests a role for such algorithms in detecting TP53 missense mutations in high throughput studies.

Symptom incidence, distress, cancer-related distress, and adherence to chemotherapy among African American women with breast cancer

BACKGROUND

There is a persistent racial survival disparity between African American (AA) and white women with breast cancer. There is evidence that symptom incidence, associated distress, and overall cancer-related distress may be unexplored, important contributing factors. The purpose of the current study was to: 1) describe and compare the number of chemotherapy-related symptoms and associated distress among AA women with breast cancer over the course of chemotherapy at 3 time points (at baseline before initiating chemotherapy, midpoint, and at the completion of chemotherapy); and 2) to describe the relationship between the number of chemotherapy-related symptoms and overall cancer distress compared with the ability to receive at least 85% of the prescribed chemotherapy within the prescribed timeframe.

METHODS

Descriptive, comparative, and correlational analyses of symptom incidence, symptom distress, cancer-related distress, and prescribed chemotherapy dose received among a cohort of AA women receiving chemotherapy for breast cancer were performed.

RESULTS

AA women (121 women) experienced worsening symptoms from baseline to midpoint in chemotherapy and then stabilized for the duration of therapy. The inability to receive 85% of the prescribed chemotherapy within a prescribed time point was found to be significantly correlated with midpoint symptom distress.

CONCLUSIONS

The main findings of the current study were that AA women experience a deterioration in symptom distress over the course of chemotherapy from baseline (before chemotherapy) to the midpoint, which was found to be associated with less adherence to chemotherapy overall. Thus, the incidence and management of physical and emotional symptoms, as measured through a multidimensional symptom measurement tool, may be contributing to breast cancer dose disparity and should be explored further. Cancer 2017;123:2061-2069. © 2017 American Cancer Society.

Predicted 25-hydroxyvitamin D in relation to incidence of breast cancer in a large cohort of African American women

BACKGROUND

Vitamin D deficiency, which has been linked to an increased risk of colorectal cancer, is particularly common among African Americans. Previous studies of vitamin D status and breast cancer risk, mostly conducted in white women, have had conflicting results. We examined the relationship between predicted vitamin D status and incidence of breast cancer in a cohort of 59,000 African American women.

METHODS

Participants in the Black Women's Health Study have been followed by biennial mail questionnaires since 1995, with self-reported diagnoses of cancer confirmed by hospital and cancer registry records. Repeated five-fold cross-validation with linear regression was used to derive the best 25-hydroxyvitamin D (25(OH)D) prediction model based on measured 25(OH)D in plasma specimens obtained from 2856 participants in 2013-2015 and questionnaire-based variables from the same time frame. In the full cohort, including 1454 cases of incident invasive breast cancer, Cox proportional hazards models were used to compute the incidence rate ratio (IRR) for each quartile of predicted vitamin D score relative to the highest quartile. Predicted vitamin D score for each two-year exposure period was a cumulative average of predicted scores from all exposure periods up to that time.

RESULTS

Twenty-two percent of women with measured 25(OH)D were categorized as "deficient" (<20 ng/mL) and another 25 % as "insufficient" (20-29 ng/mL). The prediction model explained 25 % of variation in measured 25(OH)D and the correlation coefficient for predicted versus observed 25(OH)D averaged across all cross-validation runs was 0.49 (SD 0.026). Breast cancer risk increased with decreasing quartile of predicted 25(OH)D, p for trend 0.015; the IRR for the lowest versus highest quartile was 1.23 (95 % confidence interval 1.04, 1.46).

CONCLUSIONS

In prospective data, African American women in the lowest quartile of cumulative predicted 25(OH)D were estimated to have a 23 % increased risk of breast cancer relative to those with relatively high levels. Preventing vitamin D deficiency may be an effective means of reducing breast cancer incidence in African American women.

Breast cancer biologic and etiologic heterogeneity by young age and menopausal status in the Carolina Breast Cancer Study: a case-control study

BACKGROUND

Young-onset breast cancer (<40 years) is associated with worse prognosis and higher mortality. Breast cancer risk factors may contribute to distinct tumor biology and distinct age at onset, but understanding of these relationships has been hampered by limited representation of young women in epidemiologic studies and may be confounded by menopausal status.

METHODS

We examined tumor characteristics and epidemiologic risk factors associated with premenopausal women's and young women's breast cancer in phases I-III of the Carolina Breast Cancer Study (5309 cases, 2022 control subjects). Unconditional logistic regression was used to assess heterogeneity by age (<40 vs. ≥40 years) and menopausal status.

RESULTS

In both premenopausal and postmenopausal strata, younger women had more aggressive disease, including higher stage, hormone receptor-negative, disease as well as increased frequency of basal-like subtypes, lymph node positivity, and larger tumors. Higher waist-to-hip ratio was associated with reduced breast cancer risk among young women but with elevated risk among older women. Parity was associated with increased risk among young women and reduced risk among older women, while breastfeeding was more strongly protective for young women. Longer time since last birth was protective for older women but not for young women. In comparison, when we stratified by age, menopausal status was not associated with distinct risk factor or tumor characteristic profiles, except for progesterone receptor status, which was more commonly positive among premenopausal women.

CONCLUSIONS

Age is a key predictor of breast cancer biologic and etiologic heterogeneity and may be a stronger determinant of heterogeneity than menopausal status. Young women's breast cancer appears to be etiologically and biologically distinct from that among older women.

Failure patterns and survival outcomes in triple negative breast cancer (TNBC): a 15 year comparison of 448 non-Hispanic black and white women

PURPOSE

Triple negative breast cancer (TNBC) is a distinct subtype of breast cancer with unique pathologic, molecular and clinical behavior. It occurs more frequently in young blacks and has been reported to have a shorter disease-free interval. We undertook this study to analyze the demographic characteristics, failure patterns, and survival outcomes in this disease.

METHODS

A total of 448 non-Hispanic black and white women were identified over a 15 year period from 1996 to 2011. Demographic and clinical information including age, race, menopausal status, stage, tumor characteristics, and treatments were collected. Fisher's exact test and multivariable Cox regression were used to compare failure patterns and survival outcomes between races.

RESULTS

49 % (n = 223) were black. 59 % patients were between 41 and 60 years, with 18 % ≤40 years. 57 % were premenopausal and 89 % had grade 3 tumors. Stage II (47 %) was most frequent stage at diagnosis followed by stage III (28 %). 32 % had lymphovascular invasion. Adjusting for age, stage, and grade, there was no difference in survival outcomes (OS, DFS, LFFS, and DFFS) between the two races. 62 (14 %) patients failed locally either in ipsilateral breast or chest wall, and 19 (4 %) failed in the regional lymphatics. Lung (18 %) was the most frequent distant failure site with <12 % each failing in brain, liver and bones.

CONCLUSION

Failure patterns and survival outcomes did not differ by race in this large collection of TNBC cases. Lung was the predominate site of distant failure followed by brain, bone, and liver. Few patients failed in the regional lymphatics.

Breast cancers from black women exhibit higher numbers of immunosuppressive macrophages with proliferative activity and of crown-like structures associated with lower survival compared to non-black Latinas and Caucasians

Racial disparities in breast cancer incidence and outcome are a major health care challenge. Patients in the black race group more likely present with an early onset and more aggressive disease. The occurrence of high numbers of macrophages is associated with tumor progression and poor prognosis in solid malignancies. Macrophages are observed in adipose tissues surrounding dead adipocytes in "crown-like structures" (CLS). Here we investigated whether the numbers of CD163+ tumor-associated macrophages (TAMs) and/or CD163+ CLS are associated with patient survival and whether there are significant differences across blacks, non-black Latinas, and Caucasians. Our findings confirm that race is statistically significantly associated with the numbers of TAMs and CLS in breast cancer, and demonstrate that the highest numbers of CD163+ TAM/CLS are found in black breast cancer patients. Our results reveal that the density of CD206 (M2) macrophages is a significant predictor of progression-free survival univariately and is also significant after adjusting for race and for HER2, respectively. We examined whether the high numbers of TAMs detected in tumors from black women were associated with macrophage proliferation, using the Ki-67 nuclear proliferation marker. Our results reveal that TAMs actively divide when in contact with tumor cells. There is a higher ratio of proliferating macrophages in tumors from black patients. These findings suggest that interventions based on targeting TAMs may not only benefit breast cancer patients in general but also serve as an approach to remedy racial disparity resulting in better prognosis patients from minority racial groups.

Breast Cancer Subtype Variation by Race and Ethnicity in a Diverse Population in British Columbia

BACKGROUND

Breast cancer subtypes occur differentially across different racial and ethnic groups. However, their distribution within a multicultural population is unknown.

MATERIALS AND METHODS

Patients with invasive breast cancer newly diagnosed in 2006 and referred to the British Columbia Cancer Agency were identified from the Breast Cancer Outcomes Unit database. Race/ethnicity data were abstracted from a patient-completed health assessment questionnaire completed at the initial consultation, and grouped as white, East Asian, Aboriginal, South Asian, Southeast Asian, and other. Breast cancer subtypes were created using available data on estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status.

RESULTS

A total of 1829 women had complete data. Of these women, 73% were white, 8% were East Asian, 4% Aboriginal, 3% South Asian, 3% Southeast Asian, and 3% other. The median age at diagnosis was 60 years; the youngest were Southeast Asian (51 years) and the oldest were white (60 years; P < .001). The overall ER positivity rate was 81%, highest in East Asian women (89%) and lowest in South Asian women (73%). The HER2 positivity rate was 16% for all patients and was highest in the South Asian (28%), Southeast Asian (28%), and Aboriginal (24%) women and lowest in the white women (14%; P < .001). Triple-negative (ER-, PR-, and HER2-negative) breast cancer was uncommon in East Asian women (5%) but more common in South Asian women (19%; P < .001). The 5-year breast cancer-specific survival was 90% (95% confidence interval, 89%-92%), with no significant difference among the racial/ethnic groups (P = .136).

CONCLUSION

Breast cancer subtypes varied by race/ethnicity in our cross-sectional cohort of a multicultural population, suggesting that race/ethnicity plays a significant role in the biology of invasive breast cancer.

Triple-negative breast cancer in African-American women: disparities versus biology

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype that disproportionately affects BRCA1 mutation carriers and young women of African origin. There is evidence that African-American women with TNBC have worse clinical outcomes than women of European descent. However, it is unclear whether survival differences persist after adjusting for disparities in access to health-care treatment, co-morbid disease and income. It remains controversial whether TNBC in African-American women is a molecularly distinct disease or whether African-American women have a higher incidence of aggressive biology driven by disparities: there is evidence in support of both. Understanding the relative contributions of biology and disparities is essential for improving the poor survival rate of African-American women with TNBC.

Triple negative breast cancer

Triple-negative breast cancers (TNBC), characterized by absence of the estrogen receptor (ER) and progesterone receptor (PR) and lack of overexpression of human epidermal growth factor receptor 2 (HER2), have a poor prognosis. To overcome therapy limitations of TNBC, various new approaches are needed. This mini-review focuses on discovery of new targets and drugs which might offer new hope for TNBC patients.

A prospective study of physical activity and breast cancer incidence in African-American women

BACKGROUND

Physical activity has been associated with reduced risk of breast cancer. Evidence on the association in African Americans is limited.

METHODS

With prospective data from the Black Women's Health Study, we assessed vigorous exercise and walking in relation to incidence of invasive breast cancer overall (n = 1,364), estrogen receptor-positive (ER(+), n = 688) cancer, and estrogen receptor-negative (ER(-), n = 405) cancer, based on 307,672 person-years of follow-up of 44,708 African-American women ages 30 years or older at enrollment. Cox proportional hazards models estimated incidence rate ratios (IRR) and 95% confidence intervals (CI).

RESULTS

Vigorous exercise at baseline was inversely associated with overall breast cancer incidence (Ptrend = 0.05): the IRR for ≥7 h/wk relative to <1 h/wk was 0.74 (95% CI, 0.57-0.96). The association did not differ by ER status. Brisk walking for ≥7 h/wk was associated with a reduction similar to that for vigorous exercise. Vigorous exercise at the age of 30 years, 21 years, or in high school was not associated with breast cancer incidence. Sitting for long periods at work or watching TV was not significantly associated with breast cancer incidence.

CONCLUSION

High levels of vigorous exercise or brisk walking may be associated with a reduction in incidence of breast cancer in African-American women.

IMPACT

These results provide informative data on a potential modifiable risk factor, exercise, for breast cancer in African-American women.

Enhanced down-regulation of ALCAM/CD166 in African-American Breast Cancer

Background

Variation in tumor biology in African-American (AA) and Caucasian (CAU) women with breast cancer is poorly defined. Activated leukocyte cell adhesion molecule (ALCAM) is a bad prognostic factor of breast cancer yet it has never being studied in the AA population. We tested the hypothesis that ALCAM expression would be markedly lower in cases of AA breast cancer when compared to CAU.

Methods

Cases of breast cancer among AA (n = 78) and CAU (n = 95) women were studied. Immunohistochemical staining was used to semi-quantitatively score ALCAM expression in tumor and adjacent non-tumor breast tissues. Clinico-pathological characteristics including histological type, histological grade, tumor size, lymph node metastasis, estrogen receptor (ER), progesterone receptor (PR), and HER2-neu status were abstracted, and their association with ALCAM expression tested.

Results

Univariate analysis revealed that the level of ALCAM expression at intercellular junctions of primary tumors correlates with histological grade (AA; p = 0.04, CUA; p = 0.02), ER status (AA; p = 0.0004, CAU; p = 0.0015), PR status (AA; p = 0.002, CUA p = 0.034) and triple-negative tumor status (AA; p = 0.0002, CAU; p = 0.0006,) in both ethnic groups. Multivariate analysis demonstrated that ethnicity contribute significantly to ALCAM expression after accounting for basal-like subtype, age, histological grade, tumor size, and lymph node status. Compared to CAU tumors, the AA are 4 times more likely to have low ALCAM expression (p = 0.003).

Conclusions

Markedly low expression of ALCAM at sites of cell-cell contact in primary breast cancer tumors regardless of differentiation, size and lymph node involvement may contribute to the more aggressive phenotype of breast cancer among AA women.

Associations of hormone-related factors with breast cancer risk according to hormone receptor status among white and African American women

BACKGROUND

Causes of racial disparities in breast cancer incidence and mortality between white and African American women remain unclear. This study evaluated associations of menstrual and reproductive factors with breast cancer risk by race and cancer subtypes.

PATIENTS AND METHODS

Included in the study were 1866 breast cancer cases and 2306 controls recruited in the Nashville Breast Health Study, a population-based case-control study. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

African American women were more likely to have estrogen receptor-negative (ER(-)), progesterone receptor-negative (PR(-)), and triple-negative (ER(-)PR(-)HER2(-)) breast cancer than white women. Age at menarche (≥ 14 years) and multiparity (≥ 3 live births) were inversely associated with ER(+) tumors only, whereas late age at first live birth (> 30 years) and nulliparity were associated with elevated risk; such associations were predominantly seen in white women (OR = 0.70, 95% CI = 0.55-0.88; OR = 0.72, 95% CI = 0.56-0.92; OR = 1.42, 95% CI = 1.13-1.79; OR = 1.32, 95% CI = 1.06-1.63, respectively). Age at menopause between 47 and 51 years was associated with elevated risk of ER(-) tumors in both white and African American women. Among women who had natural menopause, positive association between ever-use of hormone replacement therapy and breast cancer risk was seen in white women only (OR = 1.39, 95% CI = 1.03-1.87).

CONCLUSION

This study suggests that certain hormone-related factors are differentially associated with risk of breast cancer subtypes, and these associations also differ by race.

Locally advanced breast cancer in Jamaica: prevalence, disease characteristics and response to preoperative therapy

Breast cancer is the most common cancer in Jamaican women. Locally advanced breast cancer (LABC) is associated with aggressive biology and poor prognosis, and has a predilection for African-American women. In this retrospective review, we assessed the prevalence of LABC as a breast cancer presentation in a population of mainly Afro-centric ethnicity, and determined disease characteristics and response to pre-operative chemotherapy. LABC was prevalent (20%), and had a low pathological response rate to pre-operative chemotherapy, with a high risk of disease recurrence. Increased utilization of breast cancer screening may help detect cancer at less advanced stages, and optimizing pre-operative chemotherapy is recommended to improve response rates and ultimately survival.

Breast cancer screening, area deprivation, and later-stage breast cancer in Appalachia: does geography matter?

OBJECTIVE

To model the relationship of an area-based measure of a breast cancer screening and geographic area deprivation on the incidence of later stage breast cancer (LSBC) across a diverse region of Appalachia.

DATA SOURCE

Central cancer registry data (2006-2008) from three Appalachian states were linked to Medicare claims and census data.

STUDY DESIGN

Exploratory spatial analysis preceded the statistical model based on negative binomial regression to model predictors and effect modification by geographic subregions.

PRINCIPAL FINDINGS

Exploratory spatial analysis revealed geographically varying effects of area deprivation and screening on LSBC. In the negative binomial regression model, predictors of LSBC included receipt of screening, area deprivation, supply of mammography centers, and female population aged>75 years. The most deprived counties had a 3.31 times greater rate of LSBC compared to the least deprived. Effect of screening on LSBC was significantly stronger in northern Appalachia than elsewhere in the study region, found mostly for high-population counties.

CONCLUSIONS

Breast cancer screening and area deprivation are strongly associated with disparity in LBSC in Appalachia. The presence of geographically varying predictors of later stage tumors in Appalachia suggests the importance of place-based health care access and risk.

Clinicopathological and prognostic characteristics of triple- negative breast cancer (TNBC) in Chinese patients: a retrospective study

AIMS

To determine the clinical, pathological and prognostic features associated with triple-negative breast cancer (TNBC).

METHODS

Clinical and histologic data of 21,749 breast cancer patients who were treated at Tianjin Medical University Cancer Institute and Hospital between July 2002 and December 2011 were collected. Patients were divided into two groups: those with TNBC and those with other types of breast cancer. Patients and tumor characteristics were compared between the two groups using the Chi-square test. The prognostic results of 9,823 patients in the study population were also analyzed to determine long-term survival rates in the two groups of breast cancer patients.

RESULTS

Among the breast cancer patients treated in our hospital between 2003 and 2011, 10.4%-13.5% of them had triple-negative breast cancers. Data analyses revealed significant differences in disease onset age, family history of breast cancer, tumor size, tumor histologic grade, lymph note positivity and metastatic status between TNBC and non-TNBC patients. There were also significant differences in 5-year, 7-year and 9-year disease-free and 7-year and 9-year overall survival probability between the groups.

CONCLUSIONS

TNBC are associated with younger disease onset age, larger tumor size, higher rate of axillary lymph node positivity, and higher tumor histologic grade. TNBC is also related to family history of breast cancer, increased metastatic risk and poor prognosis.

Replication of breast cancer susceptibility loci in whites and African Americans using a Bayesian approach

Genome-wide association studies (GWAS) and candidate gene analyses have led to the discovery of several dozen genetic polymorphisms associated with breast cancer susceptibility, many of which are considered well-established risk factors for the disease. Despite attempts to replicate these same variant-disease associations in African Americans, the evaluable populations are often too small to produce precise or consistent results. We estimated the associations between 83 previously identified single nucleotide polymorphisms (SNPs) and breast cancer among Carolina Breast Cancer Study (1993-2001) participants using maximum likelihood, Bayesian, and hierarchical methods. The selected SNPs were previous GWAS hits (n = 22), near-hits (n = 19), otherwise well-established risk loci (n = 5), or located in the same genes as selected variants (n = 37). We successfully replicated 18 GWAS-identified SNPs in whites (n = 2,352) and 10 in African Americans (n = 1,447). SNPs in the fibroblast growth factor receptor 2 gene (FGFR2) and the TOC high mobility group box family member 3 gene (TOX3) were strongly associated with breast cancer in both races. SNPs in the mitochondrial ribosomal protein S30 gene (MRPS30), mitogen-activated protein kinase kinase kinase 1 gene (MAP3K1), zinc finger, MIZ-type containing 1 gene (ZMIZ1), and H19, imprinted maternally expressed transcript gene (H19) were associated with breast cancer in whites, and SNPs in the estrogen receptor 1 gene (ESR1) and H19 gene were associated with breast cancer in African Americans. We provide precise and well-informed race-stratified odds ratios for key breast cancer-related SNPs. Our results demonstrate the utility of Bayesian methods in genetic epidemiology and provide support for their application in small, etiologically driven investigations.

A collaborative study of the etiology of breast cancer subtypes in African American women: the AMBER consortium

PURPOSE

Breast cancer is a heterogeneous disease, with at least five intrinsic subtypes defined by molecular characteristics. Tumors that express the estrogen receptor (ER+) have better outcomes than ER- tumors, due in part to the success of hormonal therapies that target ER+ tumors. The incidence of ER- breast cancer, and the subset of ER- cancers that are basal-like, is about twice as high among African American (AA) women as among US women of European descent (EA). This disparity appears to explain, in part, the disproportionately high mortality from breast cancer that occurs in AA women. Epidemiologic research on breast cancer in AA women lags behind research in EA women. Here, we review differences in the etiology of breast cancer subtypes among AA women and describe a new consortium of ongoing studies of breast cancer in AA women.

METHODS

We combined samples and data from four large epidemiologic studies of breast cancer in AA women, two cohort and two case-control, creating the African American Breast Cancer Epidemiology and Risk consortium. Tumor tissue is obtained and stored in tissue microarrays, with assays of molecular markers carried out at a pathology core. Genotyping, carried out centrally, includes a whole exome SNP array and over 180,000 custom SNPs for fine-mapping of genome-wide association studies loci and candidate pathways.

RESULTS

To date, questionnaire data from 5,739 breast cancer cases and 14,273 controls have been harmonized. Genotyping of the first 3,200 cases and 3,700 controls is underway, with a total of 6,000 each expected by the end of the study period.

CONCLUSIONS

The new consortium will likely have sufficient statistical power to assess potential risk factors, both genetic and non-genetic, in relation to specific subtypes of breast cancer in AA women.

Disparities in breast cancer outcomes between Caucasian and African American women: a model for describing the relationship of biological and nonbiological factors

Breast cancer is the most common malignancy in women in the United States but significant disparities exist for African American women compared to Caucasian women. African American women present with breast cancer at a younger age and with a greater incidence under the age of 50 years, develop histologically more aggressive tumors that are at a more advanced stage at presentation, and have a worse disease-free and overall survival than Caucasian women. The biological characteristics of the primary tumor play an important role in determining the outcome of the disparity, and significant differences have been identified between African American and Caucasian breast cancer in steroid receptor and growth factor receptor content, mutations in cell cycle components, chromosomal abnormalities, and tumor suppressor and other cancer genes. The consequences of the biological factors are influenced by a variety of nonbiological factors, including socioeconomic, health care access, reproductive, and confounding factors. The nonbiological factors may act directly to enhance (or inhibit) the consequences of the biological changes, indirectly to facilitate outcome of the disparity, or as a cofounding factor, driving the association between the biological factors and the disparity. The prevention and management of the disparities will require an understanding of the relationship of biological and nonbiological factors. The present review was undertaken to promote this understanding by describing the biological basis of the four major disparities - early age of onset, more advanced stage of disease, more aggressive histologic changes, and worse survival - and the important relationship to the nonbiological factors. A model is proposed to provide a comprehensive view of this relationship, with the goal of facilitating an understanding of each disparity and the issues that need to be addressed to eliminate the disparity.

Estrogen receptor positive tumors: do reproductive factors explain differences in incidence between black and white women?

PURPOSE

The incidence of estrogen receptor positive (ER+) breast cancer is higher among white women relative to black women. In two large prospective cohorts, the Black Women's Health Study (BWHS) and the Nurses' Health Study II (NHSII), we investigated whether reproductive factors explain the difference.

METHODS

During 1,582,083 person-years of follow-up of 140,914 women observed from 1995 to 2007, 327 ER+ breast cancers were identified among black women in BWHS and NHSII and 1,179 among white women in NHSII. Cox proportional hazards regression models, stratified by race and pooled, were used to estimate hazard ratios (HR) and 95 % confidence intervals (CI) for the association of race, parity, age at first birth, and lactation in relation to risk of ER+ cancer with adjustment for age and other breast cancer risk factors.

RESULTS

Age at first birth differed markedly in the two groups, with 66 % of parous black women having their first child before age 25 as compared with 36 % of white women. Each additional year of age at first birth was associated with a 4 % increased risk of ER+ breast cancer among both racial groups. Relative to nulliparous women, parous women were at decreased risk of ER+ breast cancer (HR 0.59, 95 % CI 0.20, 1.77), in black women and (HR 0.63, 95 % CI 0.45, 0.87) in white women. The HR for the association of black race with ER+ cancer was 0.67 (95 % CI 0.53, 0.84) in a model that adjusted for age only, 0.77 (95 % CI 0.61, 0.99) in a model that controlled for parity, age at first birth, and other reproductive/hormonal factors, and 0.83 (95 % CI 0.70, 0.98) in a model that additionally controlled for other breast cancer risk factors such as alcohol consumption and use of hormone supplements. Similar associations were seen among premenopausal women and in an analysis restricted to ER+PR+ tumors.

CONCLUSIONS

Reproductive factors explained some of the higher incidence of ER+ tumors among white women as compared to black women.

Racial differences in outcomes of triple-negative breast cancer

African American (AA) women have a higher incidence of triple-negative breast cancer (TNBC: negative for the expression of estrogen receptor, progesterone receptor, and HER2 gene amplification) than Caucasian (CA) women, explaining in part their higher breast cancer mortality. However, there have been inconsistent data in the literature regarding survival outcomes of TNBC in AA versus CA women. We performed a retrospective chart review on 493 patients with TNBC first seen at the Washington University Breast Oncology Clinic (WUBOC) between January 2006 and December 2010. Analysis was done on 490 women (30 % AA) for whom follow-up data was available. The median age at diagnosis was 53 (23-98) years and follow-up time was 27.2 months. There was no significant difference between AA and CA women in the age of diagnosis, median time from abnormal imaging to breast biopsy and from biopsy diagnosis to surgery, duration of follow-up, tumor stage, grade, and frequency of receiving neoadjuvant or adjuvant chemotherapy and pathologic complete response rate to neoadjuvant chemotherapy. There was no difference in disease free survival (DFS) and overall survival (OS) between AA and CA groups by either univariate or multivariate analysis that included age, race, and stage. The hazard ratio for AA women was 1.19 (CI 0.80-1.78, p = 0.39) and 0.91 (CI 0.62-1.35, p = 0.64) for OS and DFS, respectively. Among the 158 patients who developed recurrence or presented with stage IV disease (AA: n = 36, CA: n = 122), no racial differences in OS were observed. We conclude that race did not significantly affect the clinical presentation and outcome of TNBC in this single center study where patients received similar therapy and follow-up.

A population-based study of Kurdish breast cancer in northern Iraq: hormone receptor and HER2 status. A comparison with Arabic women and United States SEER data

Background

Hormone receptor (HR) and HER2 expression predict the therapeutic response and prognosis of breast cancer. In the Middle-East, breast cancer is diagnosed at a young age, and Arabic women are reported to have a low frequency of HR positive tumors. This study investigates HR and HER2 expression among Kurdish and Arabic women.

Methods

During 2008–2010, the Sulaimaniyah Directorate of Health records identified 514 Sulaimaniyah Kurdish women, 227 Kurdish women of other Governates, and 83 Arabic women with a first diagnosis of breast cancer. The breast cancers of 432 women had immunohistochemistry (IHC) performed for estrogen and progesterone receptors (ER and PR) and HER2. Age specific and age standardized incidence rates were calculated for Sulaimaniyah Kurds. Results were compared with Egypt and with United States (US) SEER data.

Results

The median patient age was 46 years and 60.4% were < 50 years old. Tumors of 65.2% of women were ER+/HER2- with the rate increasing to 78.3% in patients ≥ 60 years old in proportions similar to US whites. The total annual age standardized incidence for breast cancer among Sulaimaniyah Kurds was 40.5/100,000 women, a rate similar to Egypt but much lower than the US. By HR/HER2 subtype, the highest age specific incidence rates were 16.4 and 45.4/100,000 for ER+/PR+/HER2- tumors in women < 50 or ≥ 50 years old, respectively (US whites: 37.7 and 226.1/100,000). Tumors of 20.4% of Sulaimaniyah women were HER2+ with annual incidence rates for ER-/PR-/HER2+ tumors of women <50 or ≥ 50 years old being 4.0 and 6.3/100,000 (US whites: 3.2 and 14.4/100,000). No significant differences in ER or HER2 status were found between Kurdish and Arabic patients.

Conclusions

Compared to the US, low age standardized and age specific breast cancer incidence rates were found in Kurdish women; nevertheless, the proportional expression of HR and HER2 for both Kurds and Arabs was comparable to that of US white women. The great majority of the breast cancer was ER+/HER2- and should respond to anti-estrogen therapy.

Parity and lactation in relation to estrogen receptor negative breast cancer in African American women

BACKGROUND

Estrogen receptor (ER)-negative breast tumors and progesterone receptor (PR)-negative breast tumors occur more commonly in women of African ancestry. Recent research indicates that the effects of reproductive factors may differ by hormone receptor status. We assessed the relation of parity and lactation to incidence of ER(-)/PR(-) and ER(+)/PR(+) breast cancer in a cohort of African American women.

METHODS

From 1995-2009, 457 incident cases of ER(+)/PR(+) and 318 cases of ER(-)/PR(-) breast cancer were confirmed by review of pathology data among 59,000 African American women followed in the Black Women's Health Study through biennial questionnaires. HRs and two-sided 95% CIs for the incidence of breast cancer subtypes were derived from proportional hazards regression models that controlled for age, reproductive variables, and breast cancer risk factors.

RESULTS

Higher parity was associated with an increased risk of ER(-)/PR(-) breast cancer (HR = 1.48, 95% CI: 0.98-1.84 for 3+ versus 0 births, P(trend) = 0.009), and with a reduced risk of ER(+)/PR(+) cancer (HR = 0.53, 95% CI: 0.39-0.73 for 3+ versus 0 births, P(trend) = 0.0002). Among women who had breastfed, high parity was no longer associated with increased incidence of ER(-)/PR(-) breast, but the inverse association with ER(+)/PR(+) cancer persisted.

CONCLUSIONS

The higher incidence of ER(-)/PR(-) breast cancer in African American women may be explained in part by their higher parity and lower prevalence of breastfeeding relative to white women.

IMPACT

Increased breastfeeding may lead to a reduction in the incidence of this breast cancer subtype.

Triple-negative breast cancer in Hispanic patients: high prevalence, poor prognosis, and association with menopausal status, body mass index, and parity

BACKGROUND

Triple-negative breast cancer (TNBC) is defined as breast cancer that is negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. TNBC represents 15% of all invasive breast cancers, but some studies have suggested that its prevalence differs between races. To the authors' knowledge, no previous studies have determined the prevalence of TNBC and its risk factors among Hispanic women.

METHODS

The authors identified 2074 Hispanic women with breast cancer who attended the National Cancer Institute in Mexico City from 1998 to 2008. All histopathologic and immunohistochemical diagnoses were rereviewed by a breast cancer pathologist. The prevalence of TNBC, its association with clinicopathologic characteristics, and its prognostic impact were determined.

RESULTS

The median patient age at diagnosis (±standard deviation) was 50 ± 12 years. The overall prevalence of TNBC was 23.1%. Younger age (P < .001), premenopausal status (P = .002), increased parity (P = .029), hormonal contraceptive use (P = .04) high histologic grade (P < .001), and advanced disease (P < .001) were associated independently with TNBC. Postmenopausal patients who had a body mass index (BMI) <25 kg/m(2) (P = .027) or <30 kg/m(2) (P < .001) were more likely to have TNBC. In multivariate analysis, patients with TNBC had a higher risk of locoregional recurrence (LRR), lower disease-free survival (DFS) (hazard ratio, 1.62; 95% confidence interval, 1.13-2.32; P = .009), and a lower cancer-specific survival (CSS) rate (hazard ratio, 1.66; 95% confidence interval, 1.20-2.30; P = .002) than patients with non-TNBC.

CONCLUSIONS

The median age at diagnosis of Hispanic women with breast cancer was 11 years younger than the average age reported in the United States. The prevalence of TNBC in this study population was higher than that reported in white women with breast cancer. TNBC was associated with a higher risk of LRR and with lower DFS and CSS than those in patients with non-TNBC.

A nationwide analysis of incidence and outcome of breast cancer in the country of Surinam, during 1994-2003

In this study, we describe the incidence, treatment, and outcome of breast cancer (BC) during the period 1994-2003 in the South-American country of Surinam and compare these with those of BC in the Netherlands. Pathology reports and hospital charts from all BC cases diagnosed between 1994 and 2004 were retrieved from Surinam's single pathology laboratory and its five hospitals. Data on demographics, tumor characteristics, treatment, and follow-up were gathered. We compared our data to BC statistics of first generation immigrants from Surinam to the Netherlands. 421 patients were diagnosed with BC during the study period. The age-adjusted incidence rate was 26 per 100,000 compared to 65/100,000 in first generation Surinamese women in the Netherlands. The majority had a fairly advanced stage at presentation, with 60% of tumors larger than 2 cm, and 41.6% with lymph node involvement. Because of the absence of radiotherapy facilities, local treatment in most patients was radical mastectomy. Adjuvant hormonal therapy (51.6%) was administered more frequently than adjuvant chemotherapy (20.3%). A significant number of patients were lost to follow-up, resulting in a median follow-up duration of only 23 months. The 5-year overall survival was 79%. BC incidence in Surinam is low compared to that in the western world, but the advanced stage at diagnosis, the low utilization of systemic adjuvant therapy, and the inadequate follow-up may lead to poor outcomes. A number of steps are underway to improve the level of cancer care in Surinam.

Screening criteria for breast cancer

Breast cancer screening constitutes an integral part of surgical practice for many surgeons and is an important tool in the war against breast cancer. Among many modalities, mammography plays a central role, with MRI now being increasingly used for women with high risk for breast cancer. Current guidelines for screening are in the process of evolution as more scientific knowledge is gained. The challenge lies in developing cost-effective methods to reach the maximum number of the population at risk.

Pathologic complete response in breast cancer patients receiving anthracycline- and taxane-based neoadjuvant chemotherapy: evaluating the effect of race/ethnicity

BACKGROUND

The current study was conducted to evaluate the influence of race/ethnicity and tumor subtype in pathologic complete response (pCR) following treatment with neoadjuvant chemotherapy.

METHODS

A total of 2074 patients diagnosed with breast cancer between 1994 and 2008 who were treated with neoadjuvant anthracycline- and taxane-based chemotherapy were included. pCR was defined as no residual invasive cancer in the breast and axilla. The Kaplan-Meier product-limit was used to calculate survival outcomes. Cox proportional hazards models were fitted to determine the relationship of patient and tumor variables with outcome.

RESULTS

The median patient age was 50 years; 14.6% of patients were black, were 15.2% Hispanic, 64.3% were white, and 5.9% were of other race. There were no differences in pCR rates among race/ethnicity (12.3% in black, 14.2% in Hispanics, 12.3% in whites, and 11.5% in others, P = .788). Lack of pCR, breast cancer subtype, grade 3 tumors, and lymphovascular invasion were associated with worse recurrence-free survival (RFS) and overall survival (OS) (P </= .0001). Differences in RFS by race/ethnicity were noted in the patients with hormone receptor-positive disease (P = .007). On multivariate analysis, Hispanics had improved RFS (hazard ratio [HR], 0.69; 95% confidence interval [95% CI], 0.49-0.97) and OS (HR, 0.63; 95% CI, 0.41-0.97); blacks had a trend toward worse outcomes (RFS: HR, 1.28 [95% CI, 0.97-1.68] and OS: HR, 1.32 [95% CI, 0.97-1.81]) when compared with whites.

CONCLUSIONS

In this cohort of patients, race/ethnicity was not found to be significantly associated with pCR rates. On a multivariate analysis, improved outcomes were observed in Hispanics and a trend toward worse outcomes in black patients, when compared with white patients. Further research was needed to explore the potential differences in biology and outcomes.

Breast cancer burden in central Sudan

Breast cancer is a worldwide disease resulting in many deaths. Although breast cancer incidence is lower in Sub-Saharan African countries than in developed countries, African women are more likely than women in the developed world to be diagnosed at later stages of the disease and, thus, are more likely to die from it. This is due to the lack of awareness by women, accessibility to screening methods, and availability of African-based research findings that would influence decision making at the governmental level. This descriptive study was undertaken to shed light on the type, stage and age distribution of breast cancer at diagnosis in women living in central Sudan encompassing al-Gezira, Blue Nile, White Nile, and Sennar States. Cases comprised 1255 women from central Sudan diagnosed with breast cancer and referred to and treated at Institute of Nuclear Medicine, Molecular Biology, and Oncology, from January 1999 to December 2006. Data revealed that 74% of the women were <50 years old or premenopausal. Invasive ductal carcinoma was the most common pathology (82%) and women presenting with stage III or higher tumors that had already metastasized, while ductal carcinoma in situ was the least prevalent (0.5%) finding. Estrogen and progesterone receptors expression were performed on a limited number of samples and the overwhelming majority of cases were observed to be negative for estrogen and progesterone receptors expression.

Oral contraceptive use and estrogen/progesterone receptor-negative breast cancer among African American women

BACKGROUND

Oral contraceptive formulations have changed over time, making it relevant to assess the effect of more recent formulations on breast cancer risk. In addition, some studies have found stronger positive associations of oral contraceptive use with estrogen receptor-negative (ER(-)) than with ER-positive (ER(+)) breast cancer. We carried out the first assessment of the effect of oral contraceptive use on the incidence of breast cancer classified by receptor status among African American women, a group disproportionately affected by ER(-) cancer.

METHODS

We followed 53,848 Black Women's Health Study participants from 1995 to 2007 through biennial health questionnaires, in which participants reported information about incident breast cancer, oral contraceptive use, and breast cancer risk factors. Pathology information was obtained on receptor status for 789 incident cases. Incidence rate ratios (IRR) with 95% confidence intervals (95% CI) were derived from Cox regression models with control for confounding factors.

RESULTS

Ever use of oral contraceptives was more strongly associated with ER(-)PR(-) breast cancer (279 cases; IRR, 1.65; 95% CI, 1.19-2.30) than with ER(+)PR(+) cancer (386 cases; IRR, 1.11; 95% CI, 0.86-1.42). The risk of ER(-)PR(-) breast cancer increased with increasing duration of use among recent users.

CONCLUSIONS

These results indicate that the oral contraceptive formulations used in recent decades increase breast cancer risk in African American women, with a greater effect for ER(-) than ER(+) cancer.

IMPACT

Mechanisms to explain the adverse influence of oral contraceptive use on ER(-) breast cancer need to be elucidated.

Disparities in medical care among commercially insured patients with newly diagnosed breast cancer: opportunities for intervention

BACKGROUND

African-American women have increased breast cancer mortality compared with white women. Diagnostic and treatment gaps may contribute to this disparity.

METHODS

In this retrospective, longitudinal cohort study, Southern US health plan claims data and linked medical charts were used to identify racial disparities in the diagnoses, treatment, and mortality of commercially insured women with newly diagnosed breast cancer. White women (n = 476) and African-American women (n = 99) with newly diagnosed breast cancer were identified by breast cancer claims codes (International Classification of Diseases, Ninth Revision, Clinical Modification codes 174, 233.0, 238.3, and 239.3) between January 2000 and December 2004. Race, diagnoses (breast cancer stage, estrogen/progesterone receptor [ER/PR]-positive status), treatment (breast-conserving surgery, antiestrogen therapy, and chemotherapy interruption or reduction), and all-cause mortality were assessed from medical charts. Multivariate regression analyses were adjusted for age, geography, and socioeconomic status to test the association of race with diagnoses/treatment.

RESULTS

White women were older (P < .001) and had higher rates of diagnosis at stage 0/I (55.2% vs 38.4%; P < .05) than African-American women. More white women had positive ER/PR status (75% vs 56% African-American; P = .001) and received antiestrogen therapy if they were positive (37.2% vs 27.3% African-American; P < .001). White women received slightly more breast-conserving surgery and chemotherapy dose modification than African-American women (P value nonsignificant). African-American women had a higher mortality rate (8.1%) than white women (3.6%; P = .06). In adjusted analyses, African-American women were diagnosed at later stages (odds ratio, 1.71; P = .02), and white women received more antiestrogen therapy (odds ratio, 2.1; P = .03).

CONCLUSIONS

Disparities in medical care among patients with newly diagnosed breast cancer were evident between African-American women and white women despite health plan insurance coverage. Interventions that address the gaps identified are needed.

Identification of novel kinase targets for the treatment of estrogen receptor-negative breast cancer

PURPOSE

Previous gene expression profiling studies of breast cancer have focused on the entire genome to identify genes differentially expressed between estrogen receptor (ER) alpha-positive and ER-alpha-negative cancers.

EXPERIMENTAL DESIGN

Here, we used gene expression microarray profiling to identify a distinct kinase gene expression profile that identifies ER-negative breast tumors and subsets ER-negative breast tumors into four distinct subtypes.

RESULTS

Based on the types of kinases expressed in these clusters, we identify a cell cycle regulatory subset, a S6 kinase pathway cluster, an immunomodulatory kinase-expressing cluster, and a mitogen-activated protein kinase pathway cluster. Furthermore, we show that this specific kinase profile is validated using independent sets of human tumors and is also seen in a panel of breast cancer cell lines. Kinase expression knockdown studies show that many of these kinases are essential for the growth of ER-negative, but not ER-positive, breast cancer cell lines. Finally, survival analysis of patients with breast cancer shows that the S6 kinase pathway signature subtype of ER-negative cancers confers an extremely poor prognosis, whereas patients whose tumors express high levels of immunomodulatory kinases have a significantly better prognosis.

CONCLUSIONS

This study identifies a list of kinases that are prognostic and may serve as druggable targets for the treatment of ER-negative breast cancer.

Risk factors for triple-negative breast cancer in women under the age of 45 years

Little is known about the etiologic profile of triple-negative breast cancer (negative for estrogen receptor/progesterone receptor/human epidermal growth factor), a breast cancer subtype associated with high mortality and inadequate therapeutic options. We undertook this study to assess the risk for triple-negative breast cancer among women 45 years of age and younger in relation to demographic/lifestyle factors, reproductive history, and oral contraceptive use. Study participants were ascertained in two previous population-based, case-control studies. Eligible cases included all primary invasive breast cancers among women ages 20 to 45 years in the Seattle-Puget Sound area, diagnosed between January 1983 and December 1992, for whom complete data was obtained for estrogen receptor, progesterone receptor, and human epidermal growth factor status (n = 897; including n = 187 triple-negative breast cancer cases). Controls were age matched and ascertained via random digit dialing. Oral contraceptive use > or =1 year was associated with a 2.5-fold increased risk for triple-negative breast cancer (95% confidence interval, 1.4-4.3) and no significantly increased risk for non-triple-negative breast cancer (P(heterogeneity) = 0.008). Furthermore, the risk among oral contraceptive users conferred by longer oral contraceptive duration and by more recent use was significantly greater for triple-negative breast cancer than non-triple-negative breast cancer (P(heterogeneity) = 0.02 and 0.01, respectively). Among women < or =40 years, the relative risk for triple-negative breast cancer associated with oral contraceptive use > or =1 year was 4.2 (95% confidence interval, 1.9-9.3), whereas there was no significantly increased risk with oral contraceptive use for non-triple-negative breast cancer among women < or =40 years, nor for triple-negative breast cancer or non-triple-negative breast cancer among women 41 to 45 years of age. In conclusion, significant heterogeneity exists for the association of oral contraceptive use and breast cancer risk between triple-negative breast cancer and non-triple-negative breast cancer among young women, lending support to a distinct etiology.

Racial disparities in the development of breast cancer metastases among older women: a multilevel study

BACKGROUND

Distant metastases are the most common and lethal type of breast cancer relapse. The authors examined whether older African American breast cancer survivors were more likely to develop metastases compared with older white women. They also examined the extent to which 6 pathways explained racial disparities in the development of metastases.

METHODS

The authors used 1992-1999 Surveillance, Epidemiology, and End Results (SEER) data with 1991-1999 Medicare data. They used Medicare's International Classification of Diseases, Ninth Revision, Clinical Modification codes to identify metastases of respiratory and digestive systems, brain, bone, or other unspecified sites. The 6 pathways consisted of patient characteristics, tumor characteristics, type of treatment received, access to medical care, surveillance mammography use, and area-level characteristics (poverty rate and percentage African American) and were obtained from the SEER or Medicare data.

RESULTS

Of the 35,937 women, 10.5% developed metastases. In univariate analysis, African American women were 1.61 times (95% confidence interval [CI], 1.54-1.83) more likely to develop metastasis than white women. In multivariate analysis, tumor grade, stage at diagnosis, and census-tract percentage African American explained why African American women were more likely to develop metastases than white women (hazard ratio, 0.84; 95% CI, 0.68-1.03).

CONCLUSIONS

Interventions to reduce late-stage breast cancer among African Americans also may reduce racial disparities in subsequent increased risk of developing metastasis. African Americans diagnosed with high-grade breast cancer could be targeted to reduce their risk of metastasis. Future studies should identify specific reasons why the racial distribution in census tracts was associated with racial disparities in the risk of breast cancer metastases.

African-American and low-socioeconomic status patients have a worse prognosis for invasive ductal and lobular breast carcinoma: do screening criteria need to change?

BACKGROUND

Determine the effect of race, socioeconomic status (SES) and other demographic variables on outcomes of patients with invasive ductal and lobular breast cancer.

STUDY DESIGN

Florida cancer registry and inpatient hospital data were queried for patients diagnosed with invasive breast cancer from 1998 to 2002.

RESULTS

A total of 63,472 patients with breast cancer were identified. Overall, 90.5% of patients were Caucasian, 7.6% African American, and 8.7% Hispanic. African-American patients presented at a younger age and with more-advanced disease, 10.5% presented with breast cancer before the age of 40 years, and 22.4% before 45 years of age. African-American patients were less likely to undergo operations. Similarly, low-SES patients were less likely to have operations and presented more often with larger tumors. Stepwise multivariate analysis revealed a substantial drop in the hazard ratio for African-American patients once correction for stage of presentation was made, suggesting that disparities in breast cancer outcomes are, in part, a result of advanced stage at presentation. Race and low SES were independent predictors of worse prognosis when controlling for patient comorbidities and treatment.

CONCLUSIONS

Dramatic disparities by patient race and SES exist in breast cancer. Our study integrates previous smaller studies, providing comprehensive insight into African-American patients and their outcomes for breast cancer. Earlier screening programs and greater access to cancer care for the poor and African Americans are needed. Successful institution of such programs will not completely erase disparities in outcomes for breast cancer in African-American patients.

Triple receptor-negative breast cancer: the effect of race on response to primary systemic treatment and survival outcomes

PURPOSE

The goal of this study was to describe the effect of race on pathologic complete response (pCR) rates and survival outcomes in women with triple receptor-negative (TN) breast cancers.

PATIENTS AND METHODS

Four hundred seventy-one patients with TN breast cancer diagnosed between 1996 and 2005 and treated with primary systemic chemotherapy were included. pCR was defined as no residual invasive cancer in the breast and axillary lymph nodes. Overall survival (OS) and recurrence-free survival (RFS) were estimated using the Kaplan-Meier product-limit method and compared between groups using the log-rank test. Cox proportional hazards models were fitted for each survival outcome to determine the relationship of patient and tumor variables with outcome.

RESULTS

Median follow-up time was 24.5 months. One hundred patients (21.2%) were black, and 371 patients (78.8%) were white/other race. Seventeen percent of black patients (n = 17) and 25.1% of white/other patients (n = 93) achieved a pCR (P = .091). Three-year RFS rates were 68% (95% CI, 56% to 76%) and 62% (95% CI, 57% to 67%) for black and white/other patients, respectively, with no significant difference observed between the two groups (P = .302). Three-year OS was similar for the two racial groups. After controlling for patient and tumor characteristics, race was not significantly associated with RFS (hazard ratio [HR] = 1.08; 95% CI, 0.69 to 1.68; P = .747) or OS (HR = 1.08; 95% CI, 0.69 to 1.68; P = .735) when white/other patients were compared with black patients.

CONCLUSION

Race does not significantly affect pCR rates or survival outcomes in women with TN breast cancer treated in a single institution under the same treatment conditions.

Expression of EGFR and c-kit is associated with the basal-like phenotype in breast carcinomas of African women

Epidermal growth factor receptor (EGFR) and c-kit are tyrosine kinase growth factor receptors which are frequently expressed in basal-like breast carcinomas, and tyrosine kinase inhibition is now a promising strategy in treatment of breast cancer. The aim of this study was to evaluate the expression of EGFR and c-kit in breast cancer with special focus on the basal-like phenotype (BLP) and other prognostic factors in an African population. We analyzed 65 archival tissues immunohistologically. EGFR and/or c-kit were expressed in 55% of basal-like tumors. Expression of EGFR and/or c-kit was strongly associated with high histologic grade (P=0.001), high nuclear grade (P=0.017), high mitotic counts (P=0.002), ER negativity (P=0.003), PR negativity (P=0.007), and HER2 negativity (P=0.014). EGFR and/or c-kit positive tumors were more likely to express the BLP (OR 9.1, CI 2.6-32.0, P<0.0005) than the negative tumors. In conclusion, there is a high expression of EGFR and/or c-kit in basal-like breast carcinoma in this series from Uganda and their expression is associated with features of poor prognosis. More studies are required to assess the clinical significance of EGFR and c-kit in breast cancer patients in Uganda.

High prevalence of triple-negative tumors in an urban cancer center

BACKGROUND

A disparate proportion of breast cancer deaths occur among young women, those of African-American (AA) ancestry, and particularly young AA women. Estrogen receptors (ER), progesterone receptors (PR), and human epidermal growth factor receptor-2 (HER-2) are key clinically informative biomarkers. The triple-negative (ER-/PR-/HER-2-) tumor subgroup is intrinsically resistant to treatment and portends a poor prognosis. Age, race, and socioeconomic status have been associated with triple-negative tumors (TNT). In the current study, the authors investigated breast cancer subgroups among patients in an urban cancer center serving a multiracial, low socioeconomic population.

METHODS

This case series analyzed female invasive breast cancers diagnosed and/or treated between 2003 and 2004 in the AVON Comprehensive Breast Center at Grady Hospital in Atlanta, Georgia. Data were obtained from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program, and augmented by the hospital registry and pathology reports. Statistical analyses utilized frequency distributions and logistic regression.

RESULTS

Of 190 breast cancers; 167 (88%) were diagnosed among AA and 23 (12%) were diagnosed among non-AA women. The median age at diagnosis in the 2 groups was 58 years and 57 years, respectively. TNT prevalence was found to differ by race (29.3% among AA women and 13.0% among non-AA women; P = .010). Differences persisted after adjustment for age and stage (odds ratio [OR] of 3.1; 95%confidence interval [95% CI], 0.8-11.6). The majority of recurrences (40.0%) occurred among women with TNT, who were also most likely to experience a fatal event (OR of 3.7; 95%CI, 1.1-13.0).

CONCLUSIONS

Despite a similarity in their age at diagnosis, AA women in our urban cancer center presented with a higher prevalence of TNT and TNT was found to predict the poorest outcomes. Institutional interactive breast conferences and intervention/navigation programs could help to dispel breast cancer disparities and improve outcomes.

Race/ethnicity and breast cancer estrogen receptor status: impact of class, missing data, and modeling assumptions

OBJECTIVE

To test whether reported associations between race/ethnicity and breast cancer estrogen receptor (ER) status are inflated due to missing ER data, lack of socioeconomic data, and use of the odds ratio (OR) rather than the prevalence ratio (PR).

METHODS

We geocoded and added census tract socioeconomic data to all cases of primary invasive breast cancer (n = 42,420) among women diagnosed between 1998 and 2002 in two California cancer registries (San Francisco Bay Area; Los Angeles County) and analyzed the data using log binomial regression.

RESULTS

Adjusting for socioeconomic position and tumor characteristics, in models using the imputed data, reduced the PR for the black versus white excess risk of being ER--from 1.76 (95% CI: 1.66, 1.86; adjusted for age and catchment area) to 1.47 (95% CI: 1.38, 1.56). The latter parameter estimate was 16% greater (i.e., 1.56) in models excluding women with missing ER data, and was 43% greater when estimated using the OR (i.e., 1.82).

CONCLUSION(S)

Studies on race/ethnicity and ER status that fail to account for missing data and socioeconomic data and report the OR are likely to yield inflated estimates of racial/ethnic disparities in ER status.