Molecular subtypes of breast cancer emerging in young women in Taiwan: evidence for more than just westernization as a reason for the disease in Asia

Associations between Medical Conditions and Breast Cancer Risk in Asians: A Nationwide Population-Based Study in Taiwan

Background

The breast cancer incidence in Asia is rising. To explore whether the etiology of breast cancer is different from the known risk factors from studies in Western countries, we conducted a nested case-control study using data from the Taiwan National Health Insurance Research Database (NHIRD).

Methods

All medical conditions based on the first three digits of the ICD-9 and a list of medical conditions based on literature review were retrieved for each case and control. The odds ratios (OR) and 95% confidence intervals (CI) of the associations between medical conditions and breast cancer risks were estimated using conditional logistic regression and adjusted for occupation, number of breast cancer screening, and the average number of outpatient visits prior the diagnosis. The associations were also estimated for younger (<50 years old) and older subjects separately.

Results

The analyses included 4,884 breast cancer cases and 19,536 age-matched controls. Prior breast diseases (OR, 95% CI: 2.47, 2.26–2.71), obesity (1.43, 1.04–1.96), endometriosis (1.44, 1.15–1.80), uterine leiomyoma (1.20, 1.03–1.40), hypertensive diseases (1.14, 1.05–1.25), and disorders in lipid metabolism (1.13, 1.04–1.24) were associated with increased breast cancer risk. No heterogeneity was observed between age groups (<50 and ≥50 years old).

Conclusions

In addition to benign breast diseases, obesity, endometriosis, uterine leiomyoma, hypertensive diseases, and disorders of lipid metabolism were associated with a subsequent breast cancer risk.

Impacts

Our results suggest that estrogen related factors may play an important role in breast cancer risks in the Taiwanese female population.

An efficient and robust fatty acid profiling method for plasma metabolomic studies by gas chromatography-mass spectrometry

BACKGROUND

Targeted metabolomic analysis of fatty acids has linked the dysregulation of fatty acids to many diseases. This study selected five frequently used fatty acid derivatization methods for comparison.

METHODS

We compared the method precisions and derivatization efficiencies, the most economical and best performing method was subjected to method validation. Twenty-four fatty acid standards were used to validate the method, which was later applied to the investigation of potential fatty acid markers of breast cancer.

RESULTS

The acetyl chloride method was demonstrated to provide the best derivatization efficiency and lowest cost for plasma samples. The ionic liquid column successfully separated positional and geometric fatty acid isomers within 26 min under the optimized conditions. Intra-day and inter-day CVs for most of the fatty acids were <10%. Over 90% of the results showed recoveries within 85%-115%. The validated method was applied to investigate potential fatty acid markers of breast cancer. The fatty acid profiling results revealed that 3 fatty acids (C22:0, C24:0, C18:2n6) were significantly lower in both pre- and post-menopausal breast cancer patients (P<0.05).

CONCLUSIONS

We demonstrated that the proposed method is an accurate, efficient and economical method for plasma metabolomic studies of fatty acids.

Breast cancer in very young women (<30 years): Correlation of imaging features with clinicopathological features and immunohistochemical subtypes

OBJECTIVE

Early diagnosis of breast cancer in very young women (<30 years) is challenging and the characteristic imaging findings are not yet fully understood. We evaluated the imaging findings of breast cancer in very young women (<30 years) and to correlate them with clinicopathological features.

MATERIAL AND METHODS

A total of 50 surgically confirmed breast cancers were included in our retrospective study. The medical records were reviewed and the radiological features were analyzed according to the new 5th edition of the ACR BI-RADS lexicon.

RESULTS

The breast cancers in our study population most commonly presented as a self-detected mass (74%), T2-3 stage (58%), histological grade III (52.3%) and ER-positive (80%) subtype. The most common finding was an irregular (87.5%) hyperdense (66.7%) mass with indistinct margins (50%) on mammography and an irregular (75.6%) indistinct (57.8%) hypoechoic/heterogeneous (77.8%) mass without a posterior acoustic feature (60%) on ultrasonography. MRI revealed an irregular shape (63.3%), irregular margins (43.3%), and heterogeneous enhancement (60%) with washout kinetics (69.4%). Mammographically, microcalcifications were correlated with the HER2-enriched type, and mass-type lesions were correlated with triple-negative cancer (p=0.04). An oval/round mass on ultrasound (p=0.005), rim enhancement (p=0.004) and intralesional T2 high signal intensity (p=0.04) on MRI were associated with the triple-negative type.

CONCLUSIONS

On all imaging modalities, breast cancer in very young women usually presented as an irregular mass, and certain radiological features could be used for predicting the specific tumor type.

Clinicopathologic features and molecular subtypes of breast cancer in young women (age ≤35)

INTRODUCTION

Breast cancer in young women is a relatively rare disease; however it tends to be more aggressive and is the leading cause of cancer death in this population. The aim of this study is to investigate the clinical and biological features of breast cancer arising in young Turkish breast cancer patients.

MATERIALS AND METHODS

Patients with breast cancer aged 35 or less (≤35 years) were selected for the study. In total 211 cases were included. Pathologic features; histologic subtypes, grade, lymphovascular invasion, axillary involvement, and stage were recorded for each.

RESULTS

The most common subtype was luminal B (36.5%), followed by luminal A (30.8%), triple negative (23.2%) and HER2+(9.5%) subtypes. Twelve percent of the patients had stage 4, 32.7% had stage 3, 46.4% had stage 2, and 6.2% had stage 1 disease at the time of diagnosis. Mean tumour diameter was 3.87 cm (range 0.3-13 cm). The axillary lymph nodes were positive in 74.4% of the patients, while lympho-vascular invasion was seen in 56.4%. Some 9.5% of patients had grade 1, 51.2% had grade 2, and 31.8% had grade 3 tumors.

CONCLUSIONS

Young women with breast cancer in Turkey are more likely to present with luminal B subtype. Tumors in young women are more likely to present with advanced disease, to be high grade and and to have more lymphovascular invasion. Further research should focus on whether we need new treatment strategies for young patients with breast carcinoma.

Om.breast cancer in very young women aged 25 year-old or below in the center of Tunisia and review of the literature

Breast cancer in very young women under 40 or 35 years attracted a widespread attention. Few studies have focused on women aged below 25 years. The aim of this study was to evaluate the situation of breast cancer in women ≤25 years in the center of Tunisia. Retrospective review from 1993 to 2013. Clinical, histopathological, therapeutic and outcome data were recorded. Cases were classified into different molecular subtypes based on the immunohistochemistry-based definitions. The series included 25 patients. The mean duration of symptoms was 7.5 months. The most common presenting symptom was a palpable mass. Four patients had at least one relative diagnosed with breast cancer. Mammography combined with ultrasound was suggestive of malignancy in 60 % of cases. Curative surgical treatment could be offered in 19 cases. The mean tumor size was 39 mm. Nodal metastases were detected in 9/18 cases. Twenty cases could be classified into: luminal A (5 cases), luminal B (6 cases), Her-2 (1 case), triple negative (6 cases) and unclassified (2 cases). Two women experienced locoregional recurrence and 6 had distant recurrence. Asynchronous contralateral breast cancer occurred in one case. The overall survival at 5 and 10 years was 85 and 75 % respectively. The survival was significantly lower in grade III tumors (p = 0.04) and triple negative tumors (p = 0.03). Breast cancer in women ≤25 years is uncommon. An adequate medical education of young women and physicians is necessary.

High Prevalence of the BIM Deletion Polymorphism in Young Female Breast Cancer in an East Asian Country

Background

A rapid surge of female breast cancer has been observed in young women in several East Asian countries. The BIM deletion polymorphism, which confers cell resistance to apoptosis, was recently found exclusively in East Asian people with prevalence rate of 12%. We aimed to evaluate the possible role of this genetic alteration in carcinogenesis of breast cancer in East Asians.

Method

Female healthy volunteers (n = 307), patients in one consecutive stage I-III breast cancer cohort (n = 692) and one metastatic breast cancer cohort (n = 189) were evaluated. BIM wild-type and deletion alleles were separately genotyped in genomic DNAs.

Results

Both cancer cohorts consistently showed inverse associations between the BIM deletion polymorphism and patient age (≤35 y vs. 36-50 y vs. >50 y: 29% vs. 22% vs. 15%, P = 0.006 in the consecutive cohort, and 40% vs. 23% vs. 13%, P = 0.023 in the metastatic cohort). In healthy volunteers, the frequencies of the BIM deletion polymorphism were similar (13%-14%) in all age groups. Further analyses indicated that the BIM deletion polymorphism was not associated with specific clinicopathologic features, but it was associated with poor overall survival (adjusted hazard ratio 1.71) in the consecutive cohort.

Conclusions

BIM deletion polymorphism may be involved in the tumorigenesis of the early-onset breast cancer among East Asians.

Female breast cancer incidence among Asian and Western populations: more similar than expected

BACKGROUND

Previous reports suggested that female breast cancer is associated with earlier ages at onset among Asian than Western populations. However, most studies utilized cross-sectional analyses that may be confounded by calendar-period and/or birth cohort effects. We, therefore, considered a longitudinal (forward-looking) approach adjusted for calendar-period changes and conditioned upon birth cohort.

METHODS

Invasive female breast cancer data (1988-2009) were obtained from cancer registries in China, Hong Kong, South Korea, Taiwan, Singapore, and the United States. Age-period-cohort models were used to extrapolate longitudinal age-specific incidence rates for the 1920, 1944, and 1970 birth cohorts.

RESULTS

Cross-sectional age-specific incidence rates rose continuously until age 80 years among US white women, but plateaued or decreased after age 50 years among Asian women. In contrast, longitudinal age-specific rates were proportional (similar) among all Asian countries and the United States with incidence rates rising continuously until age 80 years. The extrapolated estimates for the most recent cohorts in some Asian countries actually showed later ages at onset than in the United States. Additionally, over successive birth cohorts, the incidence rate ratios (IRRs) for the longitudinal curves converged (narrowed) between Asian and US white women.

CONCLUSIONS

Similar longitudinal age-specific incidence rates along with converging IRRs indicate that the age effects for invasive breast cancer are more similar among Asian and Western populations than might be expected from a solely cross-sectional analysis. Indeed, the Asian breast cancer rates in recent generations are even surpassing the historically high rates in the United States, highlighting an urgent need for efficient prevention and treatment strategies among Asian populations.

Risk of cancer among HIV-infected patients from a population-based nested case-control study: implications for cancer prevention

Background

The burden of cancer is likely to increase among the human immunodeficiency virus (HIV)-positive population as it ages due to successful antiretroviral therapy (ART). The purpose of this study was to determine the risk of cancer in HIV-infected patients.

Methods

This study was a matched nested case–control study. It was performed using the National Health Insurance Research Database of Taiwan. The control group included non–HIV-infected patients matched by sex, age, and year of enrollment. Logistic regression analyses were performed and simultaneously adjusted for potential confounders (income, urbanization, and Charslon index of comorbidity to evaluate HIV infection as an independent risk of cancer. We calculated the overall and sex-specific standardized incidence ratios (SIR) to investigate the pattern of cancer risk and overall cancer risk in the patients with HIV infection.

Results

Of the 1,115 HIV-infected patients, 104 (9.33%) developed cancer during the 11-year follow-up period. The risk of cancer for patients with HIV infection was significant (adjusted odds ratio = 3.89, 95% confidence interval [CI] = 2.92–5.19) after adjustment for potential confounders. There was a significantly increased risk of developing non-Hodgkin lymphoma (SIR = 25.73, 95% CI = 6.83-90.85), cervical cancer (SIR = 4.01, 95% CI = 1.0-16.06), lymphoma (SIR = 20.26, 95% CI = 5.86-70.10), and respiratory and intrathoracic cancer (SIR = 20.09, 95% CI = 2.34-172.09) compared with the control group. In addition, HIV-infected patients were at significant risk for renal, oral, breast, liver, skin, and colorectal cancer.

Conclusions

Patients with HIV infection are at increased risk for several specific cancers. Our results support the implementation of an active and accelerated cancer screening schedule for patients with HIV infection to increase their life span.

Clinical and histopathological factors associated with Ki-67 expression in breast cancer patients

The aim of the present study was to identify the optimal Ki-67 cut-off value in breast cancer (BC) patients, and investigate the association of Ki-67 expression levels with other prognostic factors. Firstly, a retrospective search was performed to identify patients with stage I–III BC (n=462). A range of Ki-67 index values were then assigned to five groups (<10, 10–14, 15–19, 20–24 and ≥25%). The correlation between the Ki-67 index and other prognostic factors [age, tumor type, histological and nuclear grade, tumor size, multifocality, an in situ component, lymphovascular invasion (LVI), estrogen and progesterone receptor (ER/PR) expression, human epidermal growth factor receptor (HER-2) status, axillary involvement and tumor stage] were investigated in each group. The median Ki-67 value was revealed to be 20% (range, 1–95%). A young age (≤40 years old), tumor type, size and grade, LVI, ER/PR negativity and HER-2 positivity were revealed to be associated with the Ki-67 level. Furthermore, Ki-67 was demonstrated to be negatively correlated with ER/PR expression (P<0.001), but positively correlated with tumor size (P<0.001). The multivariate analysis revealed that a Ki-67 value of ≥15% was associated with the largest number of poor prognostic factors (P=0.036). In addition, a Ki-67 value of ≥15% was identified to be statistically significant in association with certain luminal subtypes. The rate of disease-free survival was higher in patients with luminal A subtype BC (P=0.036). Following the correlation analysis for the Ki-67 index and the other prognostic factors, a Ki-67 value of ≥15% was revealed to be the optimal cut-off level for BC patients.

A targetable androgen receptor-positive breast cancer subtype hidden among the triple-negative cancers

CONTEXT

Triple-negative breast cancer (TNBC) is a subgroup of breast cancers that by definition lack expression of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2). A diverse group of tumors, TNBC shares some morphologic and molecular features with basal-like breast cancer, a category of breast cancer defined by gene expression profiling. More likely to occur in young women and African Americans, TNBCs may exhibit aggressive behavior and are associated with poor prognosis despite their initial response to conventional chemotherapy. Because hormonal or HER2-targeted therapies are ineffective for these tumors, the main therapeutic option is systemic chemotherapy. Therefore, identification of new targets for therapy is urgently needed for this group.

OBJECTIVE

To review and present recent literature along with our own experience regarding the clinical and morphologic characteristics and the prevalence of androgen receptor (AR) expression in TNBC, and to discuss the potential use of AR as a therapeutic target for AR(+) TNBC.

DATA SOURCES

Data sources are published articles from peer-reviewed journals in PubMed (US National Library of Medicine).

CONCLUSIONS

AR is the most commonly expressed hormone receptor among all breast carcinomas, with a prevalence of 25% to 75% among TNBCs. Therefore, we strongly support the routine assessment of AR in TNBC, and preferably in all breast carcinomas.

The prognostic significance of RUNX2 and miR-10a/10b and their inter-relationship in breast cancer

Background

The major cancer related mortality is caused by metastasis and invasion. It is important to identify genes regulating metastasis and invasion in order to curtail metastatic spread of cancer cells.

Methods

This study investigated the association between RUNX2 and miR-10a/miR-10b and the risk of breast cancer relapse. Expression levels of RUNX2 and miR-10a/b in108 pairs of tumor and non-tumor tissue of breast cancer were assayed by quantitative PCR analysis and evaluated for their prognostic implications.

Results

The median expression levels of RUNX2 and miR-10b in tumor tissue normalized using adjacent non-tumor tissue were significantly higher in relapsed patients than in relapse-free patients. Higher expression of these three genes were significantly correlated with the hazard ratio for breast cancer recurrence (RUNX2: 3.02, 95% CI = 1.50 ~ 6.07; miR-10a: 2.31, 95% CI = 1.00 ~ 5.32; miR-10b: 3.96, 95% CI = 1.21 ~ 12.98). The joint effect of higher expression of all three genes was associated with a hazard ratio of 12.37 (95% CI = 1.62 ~ 94.55) for relapse. In a breast cancer cell line, RUNX2 silencing reduced the expression of miR-10a/b and also impaired cell motility, while RUNX2 overexpression elicited opposite effects.

Conclusions

These findings indicate that higher expression of RUNX2 and miR-10a/b was associated with adverse outcome of breast cancer. Expression levels of RUNX2 and miR-10a/b individually or jointly are potential prognostic factors for predicting breast cancer recurrence. Data from in vitro studies support the notion that RUNX2 promoted cell motility by upregulating miR-10a/b.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-014-0257-3) contains supplementary material, which is available to authorized users.

Frequency of 5382insC mutation of BRCA1 gene among breast cancer patients: an experience from Eastern India

The incidence of breast cancer in India is on the rise and is rapidly becoming the number one cancer in females pushing the cervical cancer to the second position. The mutations in two breast cancer susceptibility genes, BRCA1 and BRCA2, are frequently associated with familial breast cancer. The main objective of the study was to determine the frequency of the mutation 5382insC in BRCA1 of eastern Indian breast cancer patients and also study the hormonal receptor status and histopathology of the patients. Altogether 92 patients affected with breast cancer were included in this study. ARMS-PCR based amplification was used to detect the presence of mutation. The mutations were considered only after pedigree analysis. Out of 92 patients (age range: 20-77 years) with family history (57 individuals) and without family history (35 individuals) were screened. Fifty controls have been systematically investigated. Seven patients and two family members were found to be carriers of 5382insC mutation in BRCA1 gene. We have found 42.64 % ER(-)/PR(-) cancer and 20.58 % triple negative cancer. Invasive ductal carcinoma is the most common histology among the investigated individuals. The presented data confirm a noticeable contribution of BRCA1 5382insC mutation in BC development in Eastern India, which may justify an extended BRCA1 5382insC testing within this patient population. We found HER-2/neu negativity and BRCA1 positivity associated with familial breast cancer. From the hospital's patient history, it was revealed that the age of menarche plays an important role in development of breast cancer.

Distinct clinicopathological features and prognosis of emerging young-female breast cancer in an East Asian country: a nationwide cancer registry-based study

BACKGROUND

A rapid surge of young-female breast cancer (YFBC) has been observed in Taiwan and other East Asian countries. We recently reported that these cases of YFBC, in contrast to their Western counterparts, are predominantly luminal A subtype. YFBC in Asia may have distinct clinicopathological features and outcomes.

METHODS

Data collected prospectively by participating hospitals were retrieved from the Taiwan Cancer Database. A total of 15,881 women with newly diagnosed stage I-III breast cancer in 2002-2006 were included. The age at diagnosis was categorized into nine 5-year groups (from <30 years to ≥65 years). Clinicopathological variables and patient disease-free survival (DFS) were compared by age group.

RESULTS

The rates of stage I, estrogen receptor-positive (ER+), and progesterone receptor-positive breast cancer were higher in the younger patients (<50 years) than in the older patients (≥50 years). Univariate analysis showed that the 40-44 and 45-49 age groups were significantly associated with longer DFS than the other age groups. In the ER+ subgroup, multivariate analysis consistently showed that the 40-44 age group was significantly associated with longer DFS than the other age groups except for the 45-49 age group. In contrast, multivariate analysis of the ER-negative subgroup revealed no significant difference of DFS between the 40-44 age group and other age groups.

CONCLUSION

Emerging YFBC in Taiwan is uniquely associated with favorable pathological features and better outcomes and should not be regarded as the mirror image of its Western counterpart.

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.

Effects of age, breast density and volume on breast cancer diagnosis: a retrospective comparison of sensitivity of mammography and ultrasonography in China's rural areas

PURPOSE

Mammography has been confirmed as the only effective mode to improve the prognosis of patients with breast cancer in Western developed countries, but might not be a good choice in other areas of the world. One of the major challenges in China is to determine an optimal imaging modality for breast cancer screening. This study was designed to clarify the sensitivity of ultrasonography compared with that of mammography in rural China.

METHODS

We retrospectively studied the sensitivity of mammography and ultrasonography based on 306 breast cancer patients detected by the program of "screening for cervical cancer and breast cancer" performed in Chinese rural areas between January 2009 and December 2011, and analyzed the effects of age, breast density and volume on the sensitivity.

RESULTS

Stratified analysis showed that the sensitivity of breast ultrasonography was significantly higher than that of mammography in premenopausal patients (81.4% vs. 61.1%, p=0.02), in women ≤ 55 years of age (82.2% vs. 63.4%, p<0.01), in the high breast density group (American College of Radiology [ACR] levels 3-4) (85.9% vs. 60.6%, p<0.01) and in the small breast volume group (≤ 400 ml) (87.1% vs. 66.7%, p<0.01). Age had a significant effect on sensitivity of mammography (breast density and volume-adjusted odds ratio, 6.39; 95% confidence interval, 2.8-14.4 in age group > 55 compared to age group ≤ 45), but not that of ultrasonography. Neither breast density nor volume had significant effect on sensitivity of mammography or ultrasonography.

CONCLUSIONS

Ultrasonography is more sensitive than mammography in detecting breast cancer in women under 55 year-old Chinese, especially in those with high-density and relatively small breasts.

The first two lines of chemotherapy for anthracycline-naive metastatic breast cancer: a comparative study of the efficacy of anthracyclines and non-anthracyclines

For anthracycline-naive metastatic breast cancer (AN-MBC), early anthracycline treatment is a common practice. However, with the availability of newer chemotherapies, comparative studies on the efficacy of anthracyclines and non-anthracyclines as early treatments for AN-MBC are lacking. We collected retrospective clinicopathological data from 253 AN-MBC patients treated at National Taiwan University Hospital between 2001 and 2006. Patients were categorised into anthracycline or non-anthracycline groups according to their regimens in the first two lines of chemotherapy. The overall survival (OS, 33.3 vs. 34.2 months, p = 0.179), time to treatment failure of the first two lines of chemotherapy drugs (13.3 vs. 12.7 months, p = 0.104) and best composite response rate (59.5% vs. 61.1%, p = 0.81) were not significantly different between the two groups. Multivariate analysis showed that early anthracycline treatment was not a significant prognostic factor of OS (p = 0.052). Thus, the results of this study show that anthracyclines may not be necessary as an early treatment option for AN-MBC.

Clinicopathologic features and prognosis of triple-negative breast cancer in patients 40 years of age and younger in Saudi Arabia

BACKGROUND AND OBJECTIVES

Triple-negative breast cancer (TNBC) has a poor prognosis and overall survival (OS) compared to other types of breast cancer tumors. However, there is to date no evidence that this is also the case in Saudi Arabia.

DESIGN AND SETTING

Retrospective review of breast cancer patients who were treated from January 2001 to December 2008 (517 patients) at the King AbdulAziz Medical City, Riyadh, Saudi Arabia.

PATIENTS AND METHODS

Patients were selected as TNBC if all three markers of estrogen receptor (ER), progesterone receptor (PR) and the human epidermal growth factor (HER2) tested by immunohistochemistry as negative. They were then age- and stage-matched, and compared with non-TNBC patients to examine differences, if any, in their clinicopathologic features, prognosis and OS.

RESULTS

Twenty-six patients with a follow up time of at least three years were identified as TNBC. Thirty-three patients who were age- and stage-matched were selected as the non-TNBC controls. Clinicopathologic results illustrated significantly more grade 3 tumors (P=.02) and CK 5/6 expression (P<.001) in the TNBC group compared to the non-TNBC group. TNBC patients aged ≤40 years showed a significantly worse prognosis and OS compared to TNBC patients aged >40 years (P=.01), and when compared to the non-TNBC group (P=.04).

CONCLUSION

The incidence of TNBC in our cohort is similar to what has been illustrated in previous studies in Western population. There was no significant difference in 3-year survival between TNBC and non-TNBC groups. However, the aggressiveness of this type of tumor and OS is significantly higher in younger patients aged ≤40 years, compared to those over 40 years of age.

Clinical significance of ESR1 gene copy number changes in breast cancer as measured by fluorescence in situ hybridisation

AIMS

The ESR1 gene encodes for oestrogen receptor (ER) α, which plays a crucial role in mammary carcinogenesis and clinical outcome in patients with breast cancer. However, the clinical significance of the ESR1 gene copy number change for breast cancer has not been clarified.

METHODS

ESR1 gene copy number was determined by fluorescence in situ hybridisation (FISH) on tissue sections. A minimum of 20 tumour cells were counted per section, and a FISH ratio of ESR1 gene to CEP6 ≥ 2.0 was considered ESR1 amplification. A ratio >1.2 but <2.0 was considered ESR1 gain. The ESR1 copy number was further measured by quantitative real-time PCR (Q-PCR) with ASXL2 as a reference.

RESULTS

FISH revealed ESR1 amplification in six cases (4.0%) and ESR1 gain in 13 cases (8.7%) from a total of 150 cases. ESR1 gain and amplification were more common in older patients (p<0.001), and correlated well with ER protein expression (p=0.03) measured by immunohistochemistry, and ESR1 copy number (p<0.001) measured by Q-PCR. Furthermore, the multivariate analysis revealed that ESR1 amplification was associated with a shorter disease-free survival (HR=5.56, p=0.03) and a shorter overall survival (HR=5.11, p=0.04).

CONCLUSIONS

In general, the frequency of ESR1 amplification in breast cancer is low when measured by FISH in large sections. ESR1 gain and amplification in breast cancer may be associated with older age and poorer outcomes.

Prognostic significance of cyclin D1, β-catenin, and MTA1 in patients with invasive ductal carcinoma of the breast

BACKGROUND

To investigate markers for predicting breast cancer progression, we performed a candidate gene-based study that assessed expression change of three genes, cyclin D1, β-catenin, and metastasis-associated protein-1 (MTA1), involving in aggressive phenotypes of cancerous cells, namely hyperproliferation, epithelial-mesenchymal transition, and global transcriptional regulation.

METHODS

Specimens were from 150 enrolled female patients, with invasive ductal carcinoma, followed up for more than 10 years. mRNA expression of cyclin D1, β-catenin, and MTA1 in cancerous and noncancerous cells microdissected from the primary tumor site was determined by quantitative real-time PCR. The relationship between mRNA expression levels of the genes and clinicopathologic features was assessed by statistical analysis. Disease-free and overall survival (DFS and OS) were analyzed by Kaplan-Meier analysis with log-rank test and a multivariate Cox regression model.

RESULTS

Cyclin D1 was shown to be overexpressed in late-stage breast cancer (stage III/IV). Breast cancer with lymph node metastasis (LNM) showed significantly higher frequency of overexpressed cyclin D1, β-catenin, and MTA1 (P < 0.05). Patients carrying greater numbers of overexpressed genes had joint effects on increased risk in tumors of advanced stages (P ( trend ) = 0.03) and LNM (P ( trend ) < 0.01). In the LNM-negative group, patients whose tumors with greater number of cyclin D1, β-catenin, and MTA1 overexpressions were associated with poorer clinical outcomes, with hazard ratio of 14.79 for OS (P = 0.015) and 7.54 for DFS (P = 0.015) using multivariate Cox regression analysis during the 10-year follow-up.

CONCLUSIONS

Higher expression of cyclin D1, β-catenin, and MTA1 mRNAs in breast cancers may prove effective in predicting unfavorable outcomes of breast cancer.

Decreased total MKP-1 protein levels predict poor prognosis in breast cancer

BACKGROUND

MKP-1 dephosphorylates and inactivates MAPKs, whose constitutive activations have been associated with human cancers.

RESULTS

We found that total MKP-1 protein levels were decreased in 63.7 % of breast cancer tissues compared with the paired noncancerous breast tissues. Decreased MKP-1 protein levels were correlated with increased tumor stage and positive recurrence and were associated with poor survival, even when using a multivariate Cox regression model. Intriguingly, nuclear MKP-1 staining was positively correlated with ER status. In vitro, tamoxifen increased MKP-1 expression in ER-positive but not ER-negative breast cancer cells. ER-specific siRNA was able to attenuate tamoxifen-induced MKP-1 expression. Furthermore, tamoxifen prolonged the duration of MKP-1 elevation and the binding time of ER to the promoter of the MKP-1/DUSP-1 gene compared with estrogen.

CONCLUSIONS

Our results suggest that alterations of MKP-1 may serve as a prognostic factor in breast cancer. In addition, the regulation of MKP-1 may be related to the ER.

Tumour biomarker expression relative to age and molecular subtypes of invasive breast cancer

Background:

Quantitative differences in biomarker expression relative to age and molecular subtypes have not been well documented in invasive breast cancer (IBCA).

Methods:

Oestrogen receptor (ER), progesterone receptor (PR), HER2, ki67, p53 and DNA ploidy was performed by image analysis in 162 consecutive IBCAs in women (⩽40 years) and compared with women ⩾50 years (100 cases). Molecular subtypes were defined by immunohistochemistry (IHC).

Results:

Among young women, tumours were frequently ER negative (P=0.01) with lower ER (P<0.00), PR (P=0.03), higher ki67 index (KI) (P=0.01) and p53 (P=0.00) compared with older women. Triple negative was more frequent among young women with frequent lymph node involvement compared with older women. Luminal B among young vs old women showed lower ER (67% vs 88%), PR (32% vs 52%), higher KI (48% vs 34%) and p53 (19% vs 7%). Linear regression model showed increasing KI (P<0.0001) and p53 (P=0.0003) according to the molecular subtypes. Survival difference among subtypes was demonstrated by multivariate analysis (P=0.0092) after adjusting for age, race, tumour size, grade and stage.

Conclusion:

We demonstrated significant differences in biomarker expression relative to age and molecular subtypes. Molecular subtype defined by IHC was an independent prognostic factor.

Incidence and risk factors for breast cancer subtypes in three distinct South-East Asian ethnic groups: Chinese, Malay and natives of Sarawak, Malaysia

We determined the incidences of the estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) subtypes among breast cancer cases in Sarawak, Malaysia and their correlation with various risk factors in the three ethnic groups: Chinese, Malay and native. Subtype status was ascertained for 1,034 cases of female breast cancer (93% of all cases diagnosed since 2003), and the age-standardized incidence rates (ASRs) of each subtype were inferred. Case-case comparisons across subtypes were performed for reproductive risk factors. We found 48% luminal A (ER+/PR+/HER2-), 29% triple-negative (ER-/PR-/HER2-), 12% triple-positive (ER+/PR+/HER2+) and 11% HER2-overexpressing (ER-/PR-/HER2+) subtypes, with ASRs of 10.6, 6.0, 2.8 and 2.8 per 100,000, respectively. The proportions of subtypes and ASRs differed significantly by ethnic groups: HER2-positive cases were more frequent in Malays (29%; 95% CI [23;35]) than Chinese (22%; [19;26] and natives (21%; [16;26]); triple-negative cases were less frequent among Chinese (23%; [20;27]) than Malays (33%; [27;39]) and natives (37%; [31;43]). The results of the case-case comparison were in accordance with those observed in western case series. Some uncommon associations, such as between triple-negative subtype and older age at menopause (OR, 1.59; p < 0.05), were found. The triple-negative and HER2+ subtypes predominate in our region, with significant differences among ethnic groups. Our results support the idea that the risk factors for different subtypes vary markedly. Westernized populations are more likely to have factors that increase the risk for the luminal A type, while risk factors for the triple-negative type are more frequent in local populations.

Relationships between serum HER2 ECD, TIMP-1 and clinical outcomes in Taiwanese breast cancer

BACKGROUND

Serum levels of the extracellular domain of HER2/neu (HER2 ECD) have been demonstrated to be associated with clinical outcomes. A disintegrin and metalloproteinase-10, a sheddase of HER2/neu, can drive cancer progression and its activity is inhibited by tissue inhibitor of metalloproteinase-1 (TIMP-1). However, elevated TIMP-1 expression has been associated with a poor prognosis of breast cancer. Therefore, this study was performed to explore the relationships between serum HER2 ECD, TIMP-1 and clinical outcomes.

METHODS

One hundred and eighty-five female breast cancer patients, who received curative mastectomy without neo-adjuvant chemotherapy at Chang-Gung Memorial Hospital, were recruited with informed consent for this study. Pre-operative serum levels of HER2 ECD and TIMP-1 were measured using an enzyme-linked immunosorbent assay.

RESULTS

Twenty-three cases (12.4%) were classified HER2 ECD positive. HER2 ECD positivity was significantly associated with age, lymph node involvement, histological grade, estrogen receptor status, progesterone receptor status, tissue HER2/neu overexpression, and disease-free survival (DFS). In an age, stage, ER and HER2/neu status matched subgroup (N = 41), the serum level of TIMP-1 was significantly associated with HER2 ECD positivity and DFS.

CONCLUSIONS

A high serum TIMP-1 was significantly associated with HER2 ECD positivity and a poorer DFS among Taiwanese primary breast cancer patients with HER2 overexpression.

Breast cancers detected by breast MRI screening and ultrasound in asymptomatic Asian women: 8 years of experience in Taiwan

BACKGROUND

This study investigated one-stop breast screening combining magnetic resonance imaging (MRI) and ultrasound (US) in asymptomatic Asian women.

METHODS

3,586 asymptomatic women (mean age, 45.3 years) were retrospectively analyzed by breast MRI followed by US. US-guided biopsy was performed when the MRI-detected lesion was confirmed by US. When the lesion was not detected on the initial US, a second-look US guided by MRI findings was performed. Then biopsy was done. MRI-positive and US-negative patients were followed up according to MRI lesion size, MRI lesion morphology, and mammographic diagnosis.

RESULTS

In total, 115 subjects had suspicious malignant lesions and received US-guided biopsy, and 47 malignant lesions, including 35 invasive cancers and 12 carcinoma in situ (CIS) lesions, were diagnosed. More than half (22/35, 63%) of the women with invasive cancer were <50 years of age, and 27 (57.4%) of the 47 cancer cases had early breast cancers. Two invasive cancers (5.7%) and 7 CIS lesions (58.3%) were found at the second-look US. The overall cancer incidence was 1.31% (47/3,586) and increased to 2.2% (78/3,586) if precancerous lesions were included. Subjects aged 41-50 years had the highest incidence of cancer detection (1.97%). Five MRI and US-negative cases had cancers found 1 year after the screening.

CONCLUSIONS

The results from the one-stop breast screening in this study showed that combining MRI and US is an efficient multimodality tool for screening asymptomatic Asian women in a metropolitan area of Taiwan who had concerns about the diagnosis and radiation of mammography.

The emerging epidemic of estrogen-related cancers in young women in a developing Asian country

The incidence of breast and genital tract cancers is increasing among Taiwanese women, but the age specificity and histopathological features of these cancers have not been determined. We used a descriptive epidemiological method and data from the Taiwan Cancer Registry (1979-2007) to examine secular trends in the age-specific incidences of female breast cancer, three major female genital tract cancers and the histopathological subtypes of these cancers. Age-specific incidence rates in the United States (1978-2002) were used as an external reference, and the incidence rates of all malignancies and of malignant brain tumors were used as internal references. We found that age-adjusted incidence rates of female breast, uterine, and ovarian cancers increased in Taiwan from 1979 to 2007, whereas the incidence of cervical cancer decreased after 1998. The largest increase was observed for ductal and lobular carcinomas of the breast and endometrioid carcinomas of the uterus and ovary in women ≤55 years, all of these tumors show a high prevalence of hormone receptor expressions. In addition, hormone-receptor-positive rates of breast cancer were uniquely higher in younger, as opposed to older, Taiwanese women. These findings indicate that estrogen-related cancers rapidly emerge in young women in Taiwan and that incidence rates are catching up with that of women living in the United States.

Distinct distribution and prognostic significance of molecular subtypes of breast cancer in Chinese women: a population-based cohort study

BACKGROUND

Molecular classification of breast cancer is an important prognostic factor. The distribution of molecular subtypes of breast cancer and their prognostic value has not been well documented in Asians.

METHODS

A total of 2,791 breast cancer patients recruited for a population-based cohort study were evaluated for molecular subtypes of breast cancer by immunohistochemical assays. Data on clinicopathological characteristics were confirmed by centralized pathology review. The average follow-up of the patients was 53.4 months. Overall and disease-free survival by molecular subtypes of breast cancer were evaluated.

RESULTS

The prevalence of the luminal A, luminal B, human epidermal growth factor receptor 2 (HER2), and triple-negative subtypes were 48.6%, 16.7%, 13.7%, and 12.9%, respectively. The luminal A subtype was more likely to be diagnosed in older women (P = 0.03) and had a stronger correlation with favorable clinicopathological factors (smaller tumor size, lower histologic grade, and earlier TNM stage) than the triple-negative or HER2 subtypes. Women with triple-negative breast cancer had a higher frequency of family history of breast cancer than women with other subtypes (P = 0.048). The 5-year overall/disease-free survival percentages for the luminal A, luminal B, HER2, and triple-negative subtypes were 92.9%/88.6%, 88.6%/85.1%, 83.2%/79.1%, and 80.7%/76.0%, respectively. A similar pattern was observed in multivariate analyses. Immunotherapy was associated with improved overall and disease-free survival for luminal A breast cancer, but reduced disease-free survival (HR = 2.21, 95% CI, 1.09-4.48) for the HER2 subtype of breast cancer.

CONCLUSIONS

The triple-negative and HER2 subtypes were associated with poorer outcomes compared with the luminal A subtype among these Chinese women. The HER2 subtype was more prevalent in this Chinese population compared with Western populations, suggesting the importance of standardized HER2 detection and anti-HER2 therapy to potentially benefit a high proportion of breast cancer patients in China.

Ethnic disparities in breast tumor phenotypic subtypes in Hispanic and non-Hispanic white women

AIMS

Hispanic women are at a lower risk of getting breast cancer than non-Hispanic white (NHW) women, yet they experience a higher risk of mortality after diagnosis. There is some evidence to suggest differences in tumor pathology; however, very limited research has been published on Hispanic women. This represents one of the first studies to evaluate the prevalence of tumor markers and phenotypic subtypes that are associated with poorer prognosis (human epidermal growth factor receptor 2 [HER2], triple negative and basal-like tumors) among Hispanic women.

METHODS

We reviewed pathology reports, obtained paraffin blocks of breast cancer tissue, and established tissue microarrays from NHW (n=119) and Hispanic women (n=69) who were Colorado participants in the 4-Corners Breast Cancer Study. We evaluated ethnic differences in the prevalence of tumor markers and phenotypic subtypes and assessed the contribution of risk factors in explaining the observed differences.

RESULTS

Consistent with other studies, Hispanic women had a higher prevalence of estrogen receptor-negative tumors compared with NHWs (36.2% vs. 22.7%, p=0.05). Hispanics also had an unexpectedly higher proportion of HER2-positive tumors compared with NHWs (31.9% vs. 14.3%, p<0.01). Independent of other prognostic factors, Hispanics were 2.8 times more likely to have a HER2-positive tumor (95% confidence interval [CI] 0.98-7.86). Hispanics were less likely to have the more favorable luminal A subtype, but no significant differences were observed for the less favorable basal-like or triple negative subtypes. However, there were suggestive differences when considering menopausal status.

CONCLUSIONS

These findings provide evidence that breast cancers among Hispanic women comprise a distinct spectrum of tumor subtypes when compared with NHW women.

Systematic review of breast cancer biology in developing countries (part 2): asian subcontinent and South East Asia

There has been no systematic appraisal of ethnicity-based variations in breast cancer (BC) biology amongst women from developing countries. A qualitative systematic review was conducted of breast cancer size, stage, grade, histological type, extra-mammary involvement, hormone receptor status as well as patient demographics. This review includes patients from Africa, the Middle East, Eastern Europe, Mexico, the Caribbean and South America. BC in these regions present at an earlier age with large aggressive tumours. Distant metastases are frequently present at the time of diagnosis. African women have a higher frequency of triple negative tumours. Over half of Middle Eastern women have lymph node involvement at the time of diagnosis. Despite experiencing a lower incidence compared to the Ashkenazi Jewish population, Palestinian women have poorer five-year survival outcomes. The majority of women from Mexico and South America have stage two or three disease whilst over sixty percent of women from Eastern Europe have either stage one or stage two disease. The biological characteristics of BC in the Caribbean cannot be fully assessed due to a paucity of data from the region. BC amongst the developing world is characterised by an early peak age of onset with aggressive biological characteristics. Strategies that improve breast cancer awareness, address amenable risk factors and improve early detection are essential.

Intrinsic breast tumor subtypes, race, and long-term survival in the Carolina Breast Cancer Study

PURPOSE

Previous research identified differences in breast cancer-specific mortality across 4 intrinsic tumor subtypes: luminal A, luminal B, basal-like, and human epidermal growth factor receptor 2 positive/estrogen receptor negative (HER2(+)/ER(-)).

EXPERIMENTAL DESIGN

We used immunohistochemical markers to subtype 1,149 invasive breast cancer patients (518 African American, 631 white) in the Carolina Breast Cancer Study, a population-based study of women diagnosed with breast cancer. Vital status was determined through 2006 using the National Death Index, with median follow-up of 9 years.

RESULTS

Cancer subtypes luminal A, luminal B, basal-like, and HER2(+)/ER(-) were distributed as 64%, 11%, 11%, and 5% for whites, and 48%, 8%, 22%, and 7% for African Americans, respectively. Breast cancer mortality was higher for participants with HER2(+)/ER(-) and basal-like breast cancer compared with luminal A and B. African Americans had higher breast cancer-specific mortality than whites, but the effect of race was statistically significant only among women with luminal A breast cancer. However, when compared with the luminal A subtype within racial categories, mortality for participants with basal-like breast cancer was higher among whites (HR = 2.0, 95% CI: 1.2-3.4) than African Americans (HR = 1.5, 95% CI: 1.0-2.4), with the strongest effect seen in postmenopausal white women (HR = 3.9, 95% CI: 1.5-10.0).

CONCLUSIONS

Our results confirm the association of basal-like breast cancer with poor prognosis and suggest that basal-like breast cancer is not an inherently more aggressive disease in African American women compared with whites. Additional analyses are needed in populations with known treatment profiles to understand the role of tumor subtypes and race in breast cancer mortality, and in particular our finding that among women with luminal A breast cancer, African Americans have higher mortality than whites.

The association of infrared imaging findings of the breast with hormone receptor and human epidermal growth factor receptor 2 status of breast cancer

RATIONALE AND OBJECTIVES

Evidence on breast infrared (IR) imaging and its association with estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) statuses of breast cancers is limited. The aim of this study was to investigate the association of IR imaging findings and ER, PR, and HER2 status in breast cancers.

MATERIALS AND METHODS

A total of 163 women with 171 pathologically proven breast cancers underwent IR imaging of the breast before surgery. Five IR signs were used to score the lesions: IR1, the temperature difference (ΔT) of the lesion site from that of the contralateral mirror image site; IR2, ΔT of the lesion site from that of the adjacent normal breast tissue in the same breast; IR3, abnormal vascular morphologic patterns; IR4, focal bulge or edge sign with back heat at the lesion site; and IR5, asymmetric thermographic pattern between the lesion site and the contralateral breast. The association of different IR signs with ER, PR, and HER2 status was evaluated using Fisher's exact test.

RESULTS

IR1 was inversely associated with ER (P = .010) and PR status (P = .039). IR2 was inversely related to PR status (P = .020). IR5 was inversely associated with ER (P = .037) and PR (P = .022) status. No IR sign was associated with HER2 status. Triple-negative (ER-negative, PR-negative, and HER2-negative) cancers tended to show higher IR1 scores compared to other types of cancers (P = .029).

CONCLUSION

Breast IR findings were associated with ER and PR status of breast cancers. Triple-negative cancers more frequently featured higher IR1 scores than other types of cancers.

Estrogen receptor-positive breast cancer in Japanese women: trends in incidence, characteristics, and prognosis

BACKGROUND

The incidence of breast cancer in Japanese women has doubled in all age groups over the past two decades.

PATIENTS AND METHODS

We examined the characteristics of the tumors treated in three time periods between 1982 and 2010. Estrogen receptor (ER), progesterone receptor (PgR) and HER2 status were assessed by immunohistochemistry. Correlation of hormone receptor levels with clinicopathological factors and prognosis was analyzed in ER-positive, HER2-negative breast cancer in two age groups (≤50 years versus >50 years).

RESULTS

The frequency of ER-positive breast cancer in women aged 50 years or younger increased greatly over the interval studied (1982-1991: 52.5%, 1992-2001: 72.6%, 2002-2010: 87.1%, P < 0.0001). The frequency of ER-positive tumors also significantly increased in women over 50 years of age (1982-1991: 69.4%, 1992-2001: 73.3%, 2002-2010: 78.6%, P = 0.029). In ER-positive, HER2-negative breast cancer, tumor grade was negatively correlated with expression levels of ER and PgR. Prognosis for patients with ER-positive, HER2-negative disease significantly improved over time, due to advances in adjuvant therapies.

CONCLUSION

It is necessary to establish risk factors, both genetic and environmental, capable of predicting the risk of ER-positive breast cancer and thus enable the efficient selection of candidates for hormone receptor-targeted chemoprevention.

Epigenetic influences of low-dose bisphenol A in primary human breast epithelial cells

Substantial evidence indicates that exposure to bisphenol A (BPA) during early development may increase breast cancer risk later in life. The changes may persist into puberty and adulthood, suggesting an epigenetic process being imposed in differentiated breast epithelial cells. The molecular mechanisms by which early memory of BPA exposure is imprinted in breast progenitor cells and then passed onto their epithelial progeny are not well understood. The aim of this study was to examine epigenetic changes in breast epithelial cells treated with low-dose BPA. We also investigated the effect of BPA on the ERα signaling pathway and global gene expression profiles. Compared to control cells, nuclear internalization of ERα was observed in epithelial cells preexposed to BPA. We identified 170 genes with similar expression changes in response to BPA. Functional analysis confirms that gene suppression was mediated in part through an ERα-dependent pathway. As a result of exposure to BPA or other estrogen-like chemicals, the expression of lysosomal-associated membrane protein 3 (LAMP3) became epigenetically silenced in breast epithelial cells. Furthermore, increased DNA methylation in the LAMP3 CpG island was this repressive mark preferentially occurred in ERα-positive breast tumors. These results suggest that the in vitro system developed in our laboratory is a valuable tool for exposure studies of BPA and other xenoestrogens in human cells. Individual and geographical differences may contribute to altered patterns of gene expression and DNA methylation in susceptible loci. Combination of our exposure model with epigenetic analysis and other biochemical assays can give insight into the heritable effect of low-dose BPA in human cells.

The prevalence and assessment of ErbB2-positive breast cancer in Asia: a literature survey

Overexpression of the epidermal growth factor receptor-related gene ErbB2 occurs in 18% to 25% of patients with breast cancer in Western countries and is associated with a poor prognosis. The prevalence of ErbB2-positive tumors in Asia is unclear, partly because data are limited. The objective of this review was to summarize the reported prevalence of ErbB2-positive tumors from a large sample of Asian patients and to examine ErbB2 assessment methods in Asia. From searches of MEDLINE, local language journals, and local and international conference proceedings as well as locoregional breast cancer experts' recommendations, the authors selected up to 5 studies each from India, Korea, Malaysia, the Philippines, Singapore, Taiwan, and Thailand that reported ErbB2 results based on assessment with immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH). The reported prevalence of ErbB2-positive tumors in 22 studies on 24,671 patients, of whom 14,398 patients were assessed for ErbB2 status, varied widely (range, 6%-65%) as did the assessment methods used. Most studies (n = 21) used IHC to assess ErbB2 status, but definitions for positivity varied. When robust assessment methods were used, the median prevalence was 19% based on strong IHC staining (IHC3+; n = 9812 patients) and 25% based on FISH (n = 681 patients). Data on the prevalence of ErbB2-positive breast cancer in Asia are limited. The current survey indicated that the prevalence in Asia may be similar to that in Western countries; thus, up to 1 in 4 Asian patients with breast cancer potentially could benefit from ErbB2-targeted treatment. A standard, reliable ErbB2 assessment method available to patients across Asia is urgently required. Cancer 2010;116:5348–57. © 2010 American Cancer Society.

Breast cancer histology and receptor status characterization in Asian Indian and Pakistani women in the U.S.--a SEER analysis

Background

Recent reports suggest increase in estrogen receptor (ER), progesterone receptor (PR) negative breast cancer yet little is known about histology or receptor status of breast cancer in Indian/Pakistani women.in the U.S.

Methods

We examined the United States National Cancer Institute's Surveillance Epidemiology and End Results (SEER) Cancer program to assess: a) frequency of breast cancer by age, b) histologic subtypes, c) receptor status of breast cancer and, d) survival in Indians/Pakistanis compared to Caucasians. There were 360,933 breast cancer cases diagnosed 1988-2006. Chi-Square analyses and Cox proportional hazards models, to estimate relative risks for breast cancer mortality after adjusting for confounders, were performed using Statistical Analysis Software 9.2.

Results

Among Asian Indian/Pakistani breast cancer patients, 16.2% were < 40 yrs. old compared to 6.23% in Caucasians (p < 0.0001). Asian Indian women had more invasive ductal carcinoma (69.1 vs. 65.7%, p < 0.0001), inflammatory cancer (1.4% vs. 0.8, p < 0.0001) and less invasive lobular carcinoma (4.2% vs. 8.1%, p < 0.0001) than Caucasians. Asian Indian/Pakistani women had more ER/PR negative breast cancer (30.6% vs. 21.8%, p = 0.0095) than Caucasians. Adjusting for stage at diagnosis, age, tumor grade, nodal status, and histology, Asian Indian/Pakistani women's survival was similar to Caucasians, while African Americans' was worse.

Conclusions

Asian Indian/Pakistani women have higher frequency of breast cancer (particularly in age < 40), ER/PR negative invasive ductal and inflammatory cancer than Caucasians.

Secular trends in breast cancer mortality in five East Asian populations: Hong Kong, Japan, Korea, Singapore and Taiwan

Breast cancer risk is increasing in most Asian female populations, but little is known about the long-term mortality trend of the disease among these populations. We extracted data for Hong Kong (1979-2005), Japan (1963-2006), Korea (1985-2006), and Singapore (1963-2006) from the World Health Organization (WHO) mortality database and for Taiwan (1964-2007) from the Taiwan cancer registry. The annual age-standardized, truncated (to > or =20 years) breast cancer death rates for 11 age groups were estimated and joinpoint regression was applied to detect significant changes in breast cancer mortality. We also compared age-specific mortality rates for three calendar periods (1975-1984, 1985-1994, and 1995-2006). After 1990, breast cancer mortality tended to decrease slightly in Hong Kong and Singapore except for women aged 70+. In Taiwan and Japan, in contrast, breast cancer death rates increased throughout the entire study period. Before the 1990s, breast cancer death rates were almost the same in Taiwan and Japan; thereafter, up to 1996, they rose more steeply in Taiwan and then they began rising more rapidly in Japan than in Taiwan after 1996. The most rapid increases in breast cancer mortality, and for all age groups, were in Korea. Breast cancer mortality trends are expected to maintain the secular trend for the next decade mainly as the prevalence of risk factors changes and population ages in Japan, Korea, and Taiwan. Early detection and treatment improvement will continue to reduce the mortality rates in Hong Kong and Singapore as observed in Western countries.