Profound changes in breast cancer incidence may reflect changes into a Westernized lifestyle: A comparative population-based study in Singapore and Sweden

Differential patterns of reproductive and lifestyle risk factors for breast cancer according to birth cohorts among women in China, Japan and Korea

BACKGROUND

The birth cohort effect has been suggested to influence the rate of breast cancer incidence and the trends of associated reproductive and lifestyle factors. We conducted a cohort study to determine whether a differential pattern of associations exists between certain factors and breast cancer risk based on birth cohorts.

METHODS

This was a cohort study using pooled data from 12 cohort studies. We analysed associations between reproductive (menarche age, menopause age, parity and age at first delivery) and lifestyle (smoking and alcohol consumption) factors and breast cancer risk. We obtained hazard ratios (HRs) with 95% confidence intervals (CIs) using the Cox proportional hazard regression analysis on the 1920s, 1930s, 1940s and 1950s birth cohorts.

RESULTS

Parity was found to lower the risk of breast cancer in the older but not in the younger birth cohort, whereas lifestyle factors showed associations with breast cancer risk only among the participants born in the 1950s. In the younger birth cohort group, the effect size was lower for parous women compared to the other cohort groups (HR [95% CI] 0.86 [0.66-1.13] compared to 0.60 [0.49-0.73], 0.46 [0.38-0.56] and 0.62 [0.51-0.77]). Meanwhile, a higher effect size was found for smoking (1.45 [1.14-1.84] compared to 1.25 [0.99-1.58], 1.06 [0.85-1.32] and 0.86 [0.69-1.08]) and alcohol consumption (1.22 [1.01-1.48] compared to 1.10 [0.90-1.33], 1.15 [0.96-1.38], and 1.07 [0.91-1.26]).

CONCLUSION

We observed different associations of parity, smoking and alcohol consumption with breast cancer risk across various birth cohorts.

Trends and Age-Period-Cohort Effect on Incidence of Male Breast Cancer from 1980 to 2019 in Taiwan and the USA

Although male breast cancer (MBC) is globally rare, its incidence significantly increased from 1990 to 2017. The aim of this study was to examine variations in the trends of MBC incidence between populations in Taiwan and the USA from 1980 to 2019. The Taiwan Cancer Registry database and the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute of the USA were used. The age-standardized incidence rate was calculated using the world standard population in 2000. The long-term trends of the age, time period, and birth cohort effect on MBC incidence rates were estimated using the SEER Age-Period-Cohort Web Tool. The results revealed that the incidence of MBC in both countries increased from 2010 to 2019 (Taiwan: average annual percentage change (AAPC) = 2.59%; USA: AAPC = 0.64%). The age and period effects on the incidence rates in both countries strengthened, but the cohort effect was only identified in Taiwan (Rate ratio: 4.03). The identified cohort effect in this study bears resemblance to that noted in a previous investigation on female breast cancer in Taiwan. This suggests the possible presence of common environmental factors influencing breast cancer incidence in both genders, such as a high fat diet and xenoestrogen.

Will Absolute Risk Estimation for Time to Next Screen Work for an Asian Mammography Screening Population?

Personalized breast cancer risk profiling has the potential to promote shared decision-making and improve compliance with routine screening. We assessed the Gail model's performance in predicting the short-term (2- and 5-year) and the long-term (10- and 15-year) absolute risks in 28,234 asymptomatic Asian women. Absolute risks were calculated using different relative risk estimates and Breast cancer incidence and mortality rates (White, Asian-American, or the Singapore Asian population). Using linear models, we tested the association of absolute risk and age at breast cancer occurrence. Model discrimination was moderate (AUC range: 0.580-0.628). Calibration was better for longer-term prediction horizons (E/O_{long-term ranges}: 0.86-1.71; E/O_{short-term ranges}:1.24-3.36). Subgroup analyses show that the model underestimates risk in women with breast cancer family history, positive recall status, and prior breast biopsy, and overestimates risk in underweight women. The Gail model absolute risk does not predict the age of breast cancer occurrence. Breast cancer risk prediction tools performed better with population-specific parameters. Two-year absolute risk estimation is attractive for breast cancer screening programs, but the models tested are not suitable for identifying Asian women at increased risk within this short interval.

Birth Cohort Effects in Breast Cancer Incidence: Global Patterns and Trends

Breast cancer is the most common neoplasm in the world among women. The age-specific incidences and onset ages vary widely between Asian and Western countries/regions. Invasive breast cancer cases among women from 1997 to 2011 were abstracted from the International Agency for Research on Cancer and the Taiwan Cancer Registry. Age-period-cohort analysis was performed to examine the trends. The cohort effect was prominent in South Korea, Taiwan, Japan, and Thailand, possibly related to the timing of westernization. The risk of breast cancer initially rose with the birth cohorts in Hong Kong and India (both former British colonies), peaked, and then declined in recent birth cohorts. Unlike other Asian countries/regions, virtually no birth cohort effect was identified in the Philippines (a Spanish colony in 1565 and the first Asian country to adopt Western cultural aspects). Moreover, an at-most negligible birth cohort effect was identified for all ethnic groups (including Asian immigrants) in the United States. This global study identified birth cohort effects in most Asian countries/regions but virtually no impact in Western countries/regions. The timing of westernization was associated with the birth cohort effect.

Breast Cancer Epidemiology and Survival Analysis of Shenyang in Northeast China: A Population-Based Study from 2008 to 2017

Background

To investigate the status of breast cancer incidence, trends, and survival in women in urban Shenyang from 2008–2017 using large Cancer Registry data.

Methods

Breast cancer incidence and mortality data were abstracted from the Shenyang Cancer Registry between 2008 and 2017. The crude and age-standardized incidence and mortality rates were calculated for each year. Average annual percentage changes (AAPC) were used to describe the change over time.

Results

A total of 14,255 out of 18,782,956 women were diagnosed with breast cancer between 2008 and 2017 in urban Shenyang. The overall crude and age-standardized incidences were 75.89 and 43.42 per 100,000, respectively. The crude incidence increased from 61.93 per 100,000 in 2008 to 90.07 per 100,000 in 2017, with an AAPC of 5.10%. The crude mortality increased from 11.41 per 100,000 in 2008 to 17.29 per 100,000 in 2017, with an AAPC of 4.60. The highest age-specific incidence occurs in the 55–59 year age group at a rate of 140.67 per 100,000. During the study period, 2,710 women died from breast cancer. The overall crude and age-standardized mortality rates were 14.43 and 7.43 per 100,000, respectively. The highest age-specific mortality occurs at 80–84 years old at a rate of 57.57 per 100,000. The 3-year and 5-year survival rates for female breast cancer in urban Shenyang from 2008 to 2013 were 85.61% and 77.39%, respectively, and both declined with age.

Conclusion

The incidence and mortality rates of breast cancer in Shenyang increased over time. Screening and control strategies should be enhanced, especially for perimenopausal females.

Potential Pro-Tumorigenic Effect of Bisphenol A in Breast Cancer via Altering the Tumor Microenvironment

Simple Summary

Bisphenol A (BPA) is primarily used to produce polycarbonate plastics, such as water bottles. Exposure to BPA has been shown to increase the growth of breast cancer cells that depend on estrogen for growth due to its ability to mimic estrogen. More recent studies have suggested that BPA also affects the cellular and non-cellular components that compose tumor microenvironments (TMEs), namely the environment around a tumor, thereby potentially promoting breast cancer growth via altering the TME. The TME plays an essential role in cancer development and promotion. Therefore, it is crucial to understand the effect of BPA on breast TMEs to assess its role in the risk of breast cancer adequately. This review examines the potential effects of BPA on immune cells, fibroblasts, extracellular matrices, and adipocytes to highlight their roles in mediating the carcinogenic effect of BPA, and thereby proposes considerations for the risk assessment of BPA exposure.

Abstract

BPA, a chemical used in the preparation of polycarbonate plastics, is an endocrine disruptor. Exposure to BPA has been suggested to be a risk factor for breast cancer because of its potential to induce estrogen receptor signaling in breast cancer cells. More recently, it has been recognized that BPA also binds to the G protein-coupled estrogen receptor and other nuclear receptors, in addition to estrogen receptors, and acts on immune cells, adipocytes, and fibroblasts, potentially modulating the TME. The TME significantly impacts the behavior of cancer cells. Therefore, understanding how BPA affects stromal components in breast cancer is imperative to adequately assess the association between exposure to BPA and the risk of breast cancer. This review examines the effects of BPA on stromal components of tumors to highlight their potential role in the carcinogenic effect of BPA. As a result, I propose considerations for the risk assessment of BPA exposure and studies needed to improve understanding of the TME-mediated, breast cancer-promoting effect of BPA.

Lifestyle and Socioeconomic Transition and Health Consequences of Breast Cancer in the East Asia Region, From 1990 to 2019

Background

Due to its higher prevalence and heterogeneity, female breast cancer (BC) is the widest disease throughout the world. We sought to assess the epidemiological and sociodemographic transitions of BC and to identify the potential risk factors attributed to burden of BC in East Asia.

Methods

At the regional level of East Asia and at a national level of East Asian countries, we investigated the burden of the incidence of female BC, mortality, and disability-adjusted life years (DALYs) in 2019 and assessed the epidemiological, socioeconomic, and health-linked disparities in incidence of BC and mortality over a 30-year period. The changes in BC’s mortality and DALYs between 1990 and 2019, attributable to varying risk factors, were evaluated in different age groups.

Results

In 2019, the incidence of and mortality from and DALYs of BC were estimated to be 382,321 (95% UI: 303,308–477,173) incidence cases [age-standardized rate (ASR) of 35.69 per 100,000; 28.32–44.54], 98,162 (79,216–120,112) deaths (ASR of 9.12; 7.36–11.13), and 3,024,987 (2,477, 984–3,659,370) DALYs with an ASR of 282.15 (230.81–341.19) in 2019. It was also observed that out of four most representative locations of East Asia, two (China and Japan) showed more than 60% increase in age-standardized incidence rate between 1990 and 2019. While only Japan females showed a significant rise of 15.3% (95% UI: 2.3–28) in ASR of death and 12.6% (95% UI: 0.5–26.9) in ASR of DALYs between 1990 and 2019. Inclusively, 88 and 81% variations were explained in the incidence of BC and death due to change in sociodemographic index (SDI) in 2019, in East Asia. The highest positive percent changes in death and DALYs between 1990 and 2019 were attributable to high body mass index (BMI), high fasting plasma glucose (FPG), and alcohol consumption in East Asia.

Conclusion

The burden of death and disability from female BC is the result of multiple risk factors, mainly due to behavioral and metabolic risk factors. The increase of the incidence is related to the westernized lifestyle and diet habits and the improvement of screening and diagnosis techniques in the recent years, whereas the increase in DALYs is mainly attributed to high BMI, high FPG, alcohol use, and high diet in red meat.

A Dose-Response Meta-Analysis of Dietary Fiber Intake and Breast Cancer Risk

Whether dietary fiber intake could reduce the risk of breast cancer (BC) is still controversial. The articles related to breast cancer and dietary fiber were retrieved through PubMed and Web of Science database. Summary relative risk (RR) and attributable risk percentage (ARP) for dietary fiber intake on the development of breast cancer were calculated. Dose-response meta-analysis modeled the relationship between dietary fiber intake and breast cancer risk. A total of 10 studies were included in this study. Meta-analysis showed that dietary fiber intake was negatively associated with breast cancer (RR = 0.83, 95% confidence interval [CI] [0.74, 0.93]). In dose-response analysis, the risk of breast cancer showed a statistically significant linear trend with increasing dietary fiber dose: when adding 10 g per day, the risk decreased by 4.7% (RR = 0.95, 95% CI [0.93, 0.98]). The ARP results demonstrated that the breast cancer dietary fiber–attributed percentage was 33.33% in Asia, which was higher than 16.28% in North America and 9.89% in Europe. In conclusion, dietary fiber intake may have a positive effect on reducing breast cancer risk, especially in high doses.

Posterior uveal melanoma incidence and survival by AJCC tumour size in a 70-year nationwide cohort

PURPOSE

While early treatment of posterior uveal melanoma can save the eye, the effect of early treatment on survival remains unknown. Therefore, we aimed to determine whether the tumour size at diagnosis has changed over time, and if this has affected survival rates of patients with posterior uveal melanoma in Denmark.

METHODS

Nationwide retrospective cohort study linking data from registry-based resources to data from clinical charts and pathology records. Including all Danish patients diagnosed with posterior uveal melanoma from 1943 to 2017. Incidence rates were estimated as annual percentage change (APC) overall and by American Joint Committee on Cancer (AJCC) tumour sizes. The age-period-cohort model was applied to estimate the relative risk of calendar period. The cox proportional hazards model, relative survival Kaplan-Meier curves and cumulative incidence curves were applied to estimate the effect of calendar period on survival.

RESULTS

An overall increase in incidence rate of uveal melanoma was found (APC = 0.25%, 0.08-0.42; 95% CI). This was due to increasing incidence rate of AJCC T1 + T2 tumours (APC = 0.97%, 0.57-1.37; 95% CI), whereas no increase in incidence rates of AJCC T3 + T4 tumours was found (APC = -0.01%, -0.26 to 0.25; 95% CI). The disease-specific survival improved with calendar period for all tumour sizes (HR = 0.988; 0.984-0.993; 95% CI).

CONCLUSION

Increasing incidence rate and improved survival rate for uveal melanoma was found concordantly with a decrease in tumour size during a 70-year period.

Cohort profile: The Singapore Breast Cancer Cohort (SGBCC), a multi-center breast cancer cohort for evaluation of phenotypic risk factors and genetic markers

This article aims to provide a detailed description of the Singapore Breast Cancer Cohort (SGBCC), an ongoing multi-ethnic cohort established with the overarching goal to identify genetic markers for breast cancer risk, prognosis and treatment response, as well as to understand the ethnic differences in disease risk and outcome in an Asian setting. The cohort comprises of breast cancer patients aged 21 years and above from six public hospitals which diagnose and treat nearly 76% breast cancer cases in Singapore. Self-reported data on sociodemographic and lifestyle, reproductive risk factors, medical history and family history of breast or ovarian cancer is collected using a structured questionnaire. Clinical data on tumour characteristics, and treatment modalities are obtained through medical record. Bio-specimens (blood or saliva) is collected at recruitment. Follow-up on survival information is done through routine linkage with the Registry of Births and Deaths. As of 31 December 2016, 7,768 subjects have been recruited to the study with 76% subjects contributed bio-specimens. The SGBCC provides a valuable platform which offers a unique, large and rich resource for new research ideas on breast cancer related phenotypic risk factors and genetic markers.

Disparity in Tumor Immune Microenvironment of Breast Cancer and Prognostic Impact: Asian Versus Western Populations

BACKGROUND

The clinicopathological features and prognosis of breast cancer in Asia are different from those in the Western countries. Tumor-infiltrating immune cells can influence the outcome of patients with breast cancer, but they have not been systemically evaluated in Asian patients with breast cancer.

METHODS

We compared the immune score, composition, and prognostic impact of infiltrating immune cells between Asian and Western patients with breast cancer by analyzing gene expression profiles from eight Gene Expression Omnibus data sets and The Cancer Genome Atlas data set. The Estimation of Stromal and Immune Cells in Malignant Tumours Using Expression Data (ESTIMATE) and Cell Type Identification by Estimating Relative Subsets of Known RNA Transcripts (CIBERSORT) algorithms were used to determine the immune score and composition of tumor-infiltrating immune cells, respectively.

FINDINGS

This study included 462 Asian patients and 2,186 Western patients. Tumors of Asian patients had significantly higher immune score, particularly in the luminal B and HER2-enriched subtypes. High immune score was associated with favorable prognosis in both Asian and Western patients, and Asian race with a high ESTIMATE immune score provided additional power to predict longer disease-free survival. Activated CD4 T cells and M2 macrophages were the most strongly associated with survival in both Asian and Western patients.

INTERPRETATION

Our study highlights the difference in tumor immune microenvironments between Asian and Western patients. The higher ESTIMATE immune score, which represents more abundant tumor-infiltrating immune cells, in tumors of Asian patients partly explains their favorable prognosis.

IMPLICATIONS FOR PRACTICE

The tumor microenvironment serves as an interface that affects the human body's reaction to cancer cells. Evidence has revealed that tumor-infiltrating immune cells were associated with patient prognosis. This study demonstrated the disparity of tumor microenvironments and their prognostic impact between Asian and Western patients with breast cancer. The differences in immune score partially explained the racial survival differences noted in recent studies. Integrated analysis of tumor cells, tumor microenvironment, and racial effect may significantly improve recurrence risk prediction for patients with stage I-III breast cancer. Because the effect of tumor microenvironment varies across different populations, a model of interaction between immune score and race/ethnicity is recommended in accessing the risk of patients with cancer.

A cross-cultural analysis of salivary cortisol patterns in breast cancer survivors

Aim: In this study, we examined whether Chinese and White women with and without a history of breast cancer exhibit differences in physiological and psychological stress profiles. Methods: Diurnal and reactive salivary cortisol profiles and psychological stress patterns of 41 breast cancer survivors and 58 healthy women were assessed. Results: Breast cancer survivors displayed a blunted acute cortisol response but there was no main effect of ethnocultural membership. Subjective appraisals of stress during the acute stressor revealed a significant interaction between ethnocultural group, health status and time (p = 0.032). Conclusion: Our results support the existing literature though suggest group differences in the appraisal of stress; thus, underscoring the importance of cultural sensitivity and awareness among clinicians and existing programs.

The Potential Influence of Dietary Counseling on Nutritional Status and Dietary Supplement Consumption in Breast Cancer Patients: A Pilot Study

INTRODUCTION

Cancer, in particular breast cancer, is one of the leading causes of death among women. Good nutritional status contributes to the efficacy of treatment and recovery, and nutritional interventions can minimize the adverse effects of cancer therapy.

AIM

The aim of this study was to describe the potential role of dietary counseling in breast cancer patients. The impact of nutritional advice on the nutritional status of patients, the use of dietary supplements, and the knowledge of phytoestrogens were assessed.

MATERIALS AND METHODS

The study was conducted between April and July 2016 in the Lublin Oncology Center on a group of 173 female patients undergoing breast cancer treatment. The patients filled out a questionnaire containing 34 open-ended and closed-ended questions. The collected data were processed in Excel and Statistica 5.0 programs, and the results were regarded as significant at P < 0.05.

RESULTS

The mean age of the evaluated patients was 66.8 ± 11.3 years. The duration of disease was significantly correlated with the patients' nutritional status expressed by the body mass index (P = 0.0368). The main sources of knowledge about nutrition in cancer care were nurses (29.71%), physicians (12.31%), and nutritionists (13.78%). Patients who received nutritional advice had significantly greater knowledge about phytoestrogens (P = 0.0001), and they were of the opinion that a diet rich in phytoestrogens was safe (P = 0.001). More than 85% of the polled subjects used dietary supplements during treatment, and 2/3 of them did so without professional advice. In this study, 73.07% of the respondents regularly monitored their body weight. Patients who did not receive dietary advice less frequently informed their physician about weight changes.

CONCLUSIONS

The nutritional status of patients was correlated with access to nutrition and dietary advice during illness. The risk of malnutrition was minimized when patients received and understood educational materials. The patients who did not receive dietary advice more frequently overdosed on dietary supplements. Phytoestrogens were more widely used by patients who regularly attended a dietitian.

Quantifying temporal trends of age-standardized rates with odds

BACKGROUND

To quantify temporal trends in age-standardized rates of disease, the convention is to fit a linear regression model to log-transformed rates because the slope term provides the estimated annual percentage change. However, such log-transformation is not always appropriate.

METHODS

We propose an alternative method using the rank-ordered logit (ROL) model that is indifferent to log-transformation. This method quantifies the temporal trend using odds, a quantity commonly used in epidemiology, and the log-odds corresponds to the scaled slope parameter estimate from linear regression. The ROL method can be implemented by using the commands for proportional hazards regression in any standard statistical package. We apply the ROL method to estimate temporal trends in age-standardized cancer rates worldwide using the cancer incidence data from the Cancer Incidence in Five Continents plus (CI5plus) database for the period 1953 to 2007 and compare the estimates to their scaled counterparts obtained from linear regression with and without log-transformation.

RESULTS

We found a strong concordance in the direction and significance of the temporal trends in cancer incidence estimated by all three approaches, and illustrated how the estimate from the ROL model provides a measure that is comparable to a scaled slope parameter estimated from linear regression.

CONCLUSIONS

Our method offers an alternative approach for quantifying temporal trends in incidence or mortality rates in a population that is invariant to transformation, and whose estimate of trend agrees with the scaled slope from a linear regression model.

Puerarin promotes DUSP1 expression by regulating miR‑133a‑3p in breast cancer

Previous studies demonstrated that puerarin represents a potential therapeutic drug for breast cancer treatment, due to its ability to inhibit the migration of MCF-7 and MDA-MB-231 cell lines. In order to investigate the mechanism of puerarin in breast cancer cells, the aim of the present study was to examine whether puerarin regulated the dual specificity phosphatase 1 (DUSP1) expression level by promoting the microRNA-133a-3p (miR-133a-3p) expression level in breast cancer. Cell viability and apoptosis were assessed in HCC38 cells by Cell Counting Kit-8 assays and a flow cytometry assay, respectively. In total, four treatment groups were considered: Puerarin treatment, miR-133a-3p mimics transfection, puerarin + miR-133a-3p mimics and negative control. miR-133a-3p expression and DUSP1 mRNA expression levels were analyzed by reverse transcription-quantitative polymerase chain reaction, and western blotting was used to detect the protein expression level. Furthermore, a luciferase reporter gene assay was used to test whether DUSP1 mRNA was a direct target of miR-133a-3p. The present results suggested that treatment with puerarin or miR-133a-3p mimics transfection affected the miR-133a-3p expression level and the activity of the DUSP1/p38 pathway, leading to inhibition of HCC38 cell viability and an increase in apoptosis. miR-133a-3p overexpression enhanced the drug action of peurarin. In conclusion, puerarin may increase DUSP1 expression by promoting the miR-133a-3p expression level in HCC38 breast cancer cells. Therefore, miR-133a-3p may represent a novel molecular marker for diagnosis and treatment of breast cancer, and puerarin may represent a promising clinical drug for treatment of patients with breast cancer.

Patient-reported outcome measures among breast cancer survivors: A cross-sectional comparison between Malaysia and high-income countries

OBJECTIVES

Patient-reported outcomes (PROs) in high-income countries (HICs) suggest that physical, emotional, and psychological needs are important in cancer care. To date, there have been few inconsistent descriptions of PROs in low-income and middle-income Asian countries. Using a standard questionnaire developed by the International Consortium for Health Outcomes Measurement (ICHOM), we compared the perceived importance of PROs between patients in Malaysia and those in HICs and between clusters of Malaysian women.

METHODS

Breast cancer patients were recruited from three Malaysian hospitals between June and November 2017. We compared the proportion of patients who rated PROs as very important (scored 7-9 on a 9-point Likert scale) between Malaysian patients and data collected from patients in HICs via the ICHOM questionnaire development process, using logistic regression. A two-step cluster analysis explored differences in PROs among Malaysian patients.

RESULTS

The most important PROs for both cohorts were survival, overall well-being, and physical functioning. Compared with HIC patients (n = 1177), Malaysian patients (n = 969) were less likely to rate emotional (78% vs 90%), cognitive (76% vs 84%), social (72% vs 81%), and sexual (30% vs 56%) functioning as very important outcomes (P < 0.001). Cluster analysis suggests that older, parous, Malaysian women, who were less likely to have received breast reconstructive surgery, were more likely to rate body image and satisfaction with the breast as very important outcomes.

CONCLUSION

Taking into account the differences in PROs by cultural and socioeconomic settings could improve patient expectation of services and refine the assessment of cancer care outcomes.

Density and tailored breast cancer screening: practice and prediction - an overview

Mammography, as the primary screening modality, has facilitated a substantial decrease in breast cancer-related mortality in the general population. However, the sensitivity of mammography for breast cancer detection is decreased in women with higher breast densities, which is an independent risk factor for breast cancer. With increasing public awareness of the implications of a high breast density, there is an increasing demand for supplemental screening in these patients. Yet, improvements in breast cancer detection with supplemental screening methods come at the expense of increased false-positives, recall rates, patient anxiety, and costs. Therefore, breast cancer screening practice must change from a general one-size-fits-all approach to a more personalized, risk-based one that is tailored to the individual woman’s risk, personal beliefs, and preferences, while accounting for cost, potential harm, and benefits.

This overview will provide an overview of the available breast density assessment modalities, the current breast density screening recommendations for women at average risk of breast cancer, and supplemental methods for breast cancer screening. In addition, we will provide a look at the possibilities for a risk-adapted breast cancer screening.

Occupational exposure to endocrine disrupting substances and the risk of breast Cancer: the Singapore Chinese health study

Background

Evidence from basic research links exposure to endocrine disrupting chemicals (EDCs) with a higher risk for breast cancer. However, there is less evidence from observational epidemiological research and the results are equivocal. Therefore, we examined the association between occupational exposure to substances where exposure to EDCs is likely and the risk of breast cancer.

Methods

A prospective study consisting of a population-based cohort of 33,458 Singaporean Chinese women aged 45–74 years enrolled in the Singapore Chinese Health Study (SCHS) from 1993 to 98 and followed through 2014. Subjects’ self-reported occupational exposure and duration to industries, job titles, and substance types were garnered at baseline, and cases of incident breast cancer (N = 988) were determined by linkage with the Singapore Cancer Registry. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated for exposure to substances, job titles, and industries.

Results

There was no association between cumulative exposure to substances via occupation where EDC exposure is likely and risk of breast cancer. These results were consistent for hypothesized high (HR 0.94, 95% CI: 0.66–1.35), medium (HR 1.03 95% CI: 0.77–1.38) and low (HR 0.74, 95% CI 0.48–1.13) combined substance exposure groups when compared with those who were not exposed via occupation. Similar null associations were observed when examining job titles and industry categories.

Conclusions

There was no association between EDC related occupational exposures and breast cancer risk in working women of the Singaporean Chinese Health Study. Future studies that employ rigorous methods with regard to exposure assessment of EDCs are needed.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5862-2) contains supplementary material, which is available to authorized users.

Elucidating therapeutic molecular targets in premenopausal Asian women with recurrent breast cancers

Breast cancer is an increasing problem in Asia, with a higher proportion of premenopausal patients who are at higher risk of recurrence. Targeted sequencing was performed on DNA extracted from primary tumor specimens of 63 premenopausal Asian patients who relapsed after initial diagnosis of non-metastatic breast cancer. The most prevalent alterations included: TP53 (65%); PIK3CA (32%); GATA3 (29%); ERBB2 (27%); MYC (25%); KMT2C (21%); MCL1 (17%); PRKDC, TPR, BRIP1 (14%); MDM4, PCDH15, PRKAR1A, CDKN1B (13%); CCND1, KMT2D, STK11, and MLH1 (11%). Sixty of the 63 patients (95%) had at least one genetic alteration in a signaling pathway related to cell cycle or p53 signaling. The presence of MCL1 amplification, HIF-1-alpha transcription factor network pathway alterations, and direct p53 effectors pathway alterations were independent predictors of inferior overall survival from initial diagnosis. Comparison with non-Asian premenopausal tumors in The Cancer Genome Atlas (TCGA) revealed a higher prevalence of TP53 mutations among HER2-positive cancers, and more frequent TP53, TET2, and CDK12 mutations among hormone receptor-positive HER2-negative cancers in our cohort. Given the limited number of non-Asian premenopausal breast cancers that had relapsed in TCGA, we compared the frequency of mutations in our cohort with 43 premenopausal specimens from both TCGA and International Cancer Genome Consortium that had relapsed. There was a trend toward higher prevalence of TP53 mutations in our cohort. Certain genomic aberrations may be enriched in tumors of poor-prognosis premenopausal Asian breast cancers. The development of novel therapies targeting these aberrations merit further research.

Younger women in Asia with recurrent breast cancer seem to have a higher rate of mutations in the tumor suppressor gene TP53 than do women elsewhere—a finding that could guide drug development in Asia. Yoon-Sim Yap from the
 National Cancer Centre Singapore and coworkers sequenced DNA extracted from the tumor samples of 63 premenopausal women from Singapore and South Korea who relapsed following treatment for non-metastatic breast cancer. The researchers analyzed hundreds of cancer-related genes, and found that the vast majority of women harbored mutations in at least one gene linked to regulating the cell cycle of TP53 signaling. The prevalence of mutations in certain genes, including TP53 itself, was higher than observed previously in non-Asian cohorts, highlighting the need to consider ethnic diversity in genomic studies of breast cancer and in drug development.

Expression of pAkt is associated with a poor prognosis in Chinese women with invasive ductal breast cancer

Over the past three decades, numerous patients with breast cancer succumbed to cancer metastasis and recurrence, while, the exact mechanisms underlying this malignancy, and the potential biomarkers for prognosis prediction remain elusive. It was previously demonstrated that phosphorylated RAC-α serine/threonine-protein kinase (pAkt) and Beclin 1 was associated with cancer metastasis, and recurrence. Thus far, the expression patterns of pAkt and Beclin 1 in breast cancer tissues, and their associations with the prognosis of invasive ductal breast cancer remain inconclusive, which may be due to various factors, including ethnicity and pathological types. In the present study, a total of 90 Chinese female patients with invasive ductal breast cancer between June 1999 and August 2002 were enrolled at Shanghai First People's Hospital (Shanghai, China). The patients were followed up from 5 months to 13.5 years for survival analysis. The expressional levels of pAkt and Beclin 1 in invasive ductal breast cancer tissues, and the normal paracancerous tissues were measured by immunohistochemistry. Associations with prognosis following surgery were further evaluated using Cox regression analysis. In 90 invasive ductal breast cancer samples, pAkt was detected in 17 (18.9%) samples and Beclin 1 in 33 (36.7%) samples, but both were not detected in any of the paracancerous samples. Survival analysis revealed that pAkt expression carried a tendency to predict a shorter disease-free survival (DFS) in patients with invasive ductal breast cancer. Additionally, Beclin 1 expression was not significantly associated with survival. Furthermore, univariate Cox regression analysis demonstrated that pAkt expression was negatively associated with DFS and overall survival. Multivariate Cox regression analysis indicated that pAkt expression was an independent risk factor associated with poor prognosis in patients with invasive ductal breast cancer (all P<0.05). pAkt may be used as a potential prognostic biomarker in Chinese women with invasive ductal breast cancer.

Breast cancer risk factors and mammographic density among high-risk women in urban China

Elevated mammographic density (MD) is an established breast cancer risk factor. Studies examining relationships between MD and breast cancer risk factors are limited in China, where established breast cancer risk factors are less prevalent but dense breasts are more prevalent than Western countries. This study included 11,478 women (45-69 years; 36% premenopausal) participating in an ongoing national cancer screening program in 11 urban provinces in China and predicted as having high-risk for breast cancer. Polytomous logistic regression was performed to assess associations between MD and risk factors by comparing each higher Breast Imaging Reporting and Data System (BI-RADS) category (2, 3, or 4) to the lowest category (BI-RADS, 1). We found associations of increasing age, body mass index, weight, postmenopausal status, and parity with lower MD. Higher levels of education, increasing height, and later first birth were associated with higher MD. These associations did not vary by menopausal status. Additionally, the association between longer period of breastfeeding and lower MD was seen among postmenopausal women only (P_interaction = 0.003). Having first-degree relatives with breast cancer diagnosed before 50 years was associated with lower MD only among premenopausal women (P_interaction = 0.061). We found effects of established breast cancer risk factors on MD showed similar directions in Chinese and Western women, supporting the hypothesis that MD represents cumulative exposure to breast cancer risk factors over the life course. Our findings help to understand the biological basis of the association of MD with breast cancer risk and have implications for breast cancer prevention research in China.

Comparison of annual percentage change in breast cancer incidence rate between Taiwan and the United States-A smoothed Lexis diagram approach

Recent studies compared the age effects and birth cohort effects on female invasive breast cancer (FIBC) incidence in Asian populations with those in the US white population. They were based on age-period-cohort model extrapolation and estimated annual percentage change (EAPC) in the age-standardized incidence rates (ASR). It is of interest to examine these results based on cohort-specific annual percentage change in rate (APCR) by age and without age-period-cohort model extrapolation. FIBC data (1991-2010) were obtained from the Taiwan Cancer Registry and the U.S. SEER 9 registries. APCR based on smoothed Lexis diagrams were constructed to study the age, period, and cohort effects on FIBC incidence. The patterns of age-specific rates by birth cohort are similar between Taiwan and the US. Given any age-at-diagnosis group, cohort-specific rates increased overtime in Taiwan but not in the US; cohort-specific APCR by age decreased with birth year in both Taiwan and the US but was always positive and large in Taiwan. Given a diagnosis year, APCR decreased as birth year increased in Taiwan but not in the US. In Taiwan, the proportion of APCR attributable to cohort effect was substantial and that due to case ascertainment was becoming smaller. Although our study shows that incidence rates of FIBC have increased rapidly in Taiwan, thereby confirming previous results, the rate of increase over time is slowing. Continued monitoring of APCR and further investigation of the cause of the APCR decrease in Taiwan are warranted.

Cancer incidence and mortality: A cohort study in China, 2008-2013

The National Central Cancer Registry of China (NCCR) was the only available source of cancer monitoring in China, even though only about 70% of cancer registration sites were qualified by now. In this study, based on a national large prospective cohort-the China Kadoorie Biobank (CKB), we aimed to provide additional cancer statistics and compare the difference of cancer burden between urban and rural areas of China. A total of 497,693 cancer-free participants aged 35-74 years were recruited and successfully followed up from 2004 to 2013 in 5 urban and 5 rural areas across China. Except for traditional registration systems, the national health insurance system and active follow-up were used to determine new cancer incidents and related deaths. The mortality-to-incidence ratio (MIR) was used to compare the differences of cancer burden between urban and rural areas of China. We found that cancer mortality coincided well between our cohort and NCCR, while the incidence was much higher in our cohort. Based on CKB, we found the MIR of all cancers was 0.54 in rural areas, which was approximately one-third higher than that in urban areas with 0.39. Cancer profiles in urban areas were transiting to Western distributions, which were characterized with high incidences of breast cancer and colorectal cancer; while cancers of the esophagus, liver and cervix uteri were still common in rural areas of China. Our results provide additional cancer statistics of China and demonstrate the differences of cancer burden between urban and rural areas of China.

Increased breast cancer mortality only in the lower education group: age-period-cohort effect in breast cancer mortality by educational level in South Korea, 1983-2012

BACKGROUND

A steadily increasing pattern of breast cancer mortality has been reported in South Korea since the late 1980s. This paper explored the trends of educational inequalities of female breast cancer mortality between 1983 and 2012 in Korea, and conducted age-period-cohort (APC) analysis by educational level.

METHODS

Age-standardized mortality rates of breast cancer per 100,000 person-years were calculated. Relative index of inequality (RII) for breast cancer mortality was used as an inequality measure. APC analyses were conducted using the Web tool for APC analysis provided by the Division of Cancer Epidemiology and Genetics at the U.S. National Cancer Institute.

RESULTS

An increasing trend in breast cancer mortality among Korean women between 1983 and 2012 was due to the increased mortality of the lower education groups (i.e., no formal education or primary education and secondary education groups), not the highest education group. The breast cancer mortality was higher in women with a tertiary education than in women with no education or a primary education during 1983-1992, and the reverse was true in 1993-2012. Consequently, RII was changed from positive to negative associations in the early 2000s. The lower education groups had the increased breast cancer mortality and significant cohort and period effects between 1983 and 2012, whereas the highest group did not.

CONCLUSIONS

APC analysis by socioeconomic position used in this study could provide an important clue for the causes on breast cancer mortality. The long-term monitoring of socioeconomic patterning in breast cancer risk factors is urgently needed.

Risk of secondary cancers in women with breast cancer and the influence of radiotherapy: A national cohort study in Taiwan

Breast cancer is the most common cancer in women worldwide; thus, the prolongation of survival, and the incidence and risk factors, including radiotherapy, for developing secondary malignancies are important. We compared the incidence of secondary and new primary cancers in women with breast cancer (CA) and well-matched for age, geographic region, and monthly income cancer-free controls (CA). The risk for secondary cancers with and without radiotherapy was also compared in CA women. We enrolled 2422 CA patients and CA 12,110 controls. In a 4-year follow-up, the secondary cancers risk was significant in the CA group (adjusted hazard ratio [AHR]: 1.59; 95% confidence interval [CI]: 1.17-2.18). Only the risk of uterine cancer was significant compared with the controls (AHR: 6.30; 95% CI: 2.28-17.38). CA patients and <50 years old had a higher risk for secondary cancers. Developing secondary cancers was significant in the first follow-up year (AHR: 1.51; 95% CI: 1.11-2.06). Radiotherapy had no significant effect on the CA group, but it was significant (P = 0.0298) in women ≥60 years old (elderly). We recommend monitoring secondary cancers in CA women, especially those <50 years old, and during the first year of follow-up. Radiotherapy should be used more carefully in elderly CA women.

Differences in mammographic density between Asian and Caucasian populations: a comparative analysis

PURPOSE

Mammographic density is a measurable and modifiable biomarker that is strongly and independently associated with breast cancer risk. Paradoxically, although Asian women have lower risk of breast cancer, studies of minority Asian women in predominantly Caucasian populations have found that Asian women have higher percent density. In this cross-sectional study, we compared the distribution of mammographic density for a matched cohort of Asian women from Malaysia and Caucasian women from Sweden, and determined if variations in mammographic density could be attributed to population differences in breast cancer risk factors.

METHODS

Volumetric mammographic density was compared for 1501 Malaysian and 4501 Swedish healthy women, matched on age and body mass index. We used multivariable log-linear regression to determine the risk factors associated with mammographic density and mediation analysis to identify factors that account for differences in mammographic density between the two cohorts.

RESULTS

Compared to Caucasian women, percent density was 2.0% higher among Asian women (p < 0.001), and dense volume was 5.7 cm³ higher among pre-menopausal Asian women (p < 0.001). Dense volume was 3.0 cm³ lower among post-menopausal Asian women (p = 0.009) compared to post-menopausal Caucasian women, and this difference was attributed to population differences in height, weight, and parity (p < 0.001).

CONCLUSIONS

Our analysis suggests that among post-menopausal women, population differences in mammographic density and risk to breast cancer may be accounted for by height, weight, and parity. Given that pre-menopausal Asian and Caucasian women have similar population risk to breast cancer but different dense volume, development of more appropriate biomarkers of risk in pre-menopausal women is required.

The Pathophysiologic Role of Disrupted Circadian and Neuroendocrine Rhythms in Breast Carcinogenesis

Most physiological processes in the brain and body exhibit daily (circadian) rhythms coordinated by an endogenous master clock located in the suprachiasmatic nucleus of the hypothalamus that are essential for normal health and functioning. Exposure to sunlight during the day and darkness at night optimally entrains biological rhythms to promote homeostasis and human health. Unfortunately, a major consequence of the modern lifestyle is increased exposure to sun-free environments during the day and artificial lighting at night. Additionally, behavioral disruptions to circadian rhythms (ie, repeated transmeridian flights, night or rotating shift work, or sleep disturbances) have a profound influence on health and have been linked to a number of pathological conditions, including endocrine-dependent cancers. Specifically, night shift work has been identified as a significant risk factor for breast cancer in industrialized countries. Several mechanisms have been proposed by which shift work-induced circadian disruptions promote cancer. In this review, we examine the importance of the brain-body link through which circadian disruptions contribute to endocrine-dependent diseases, including breast carcinogenesis, by negatively impacting neuroendocrine and neuroimmune cells, and we consider preventive measures directed at maximizing circadian health.

Environmental and lifestyle risk factors of breast cancer in Malta-a retrospective case-control study

AIM AND BACKGROUND

Environmental exposures are known to play a role in the development of cancer, including breast cancer. There are known associations of breast cancer with environmental factors such as sunlight exposure, diet and exercise and alcohol consumption as well as physiological factors. This study examines the prevalence of risk factors for breast cancer related to dietary intake, environment and lifestyle in the female population of Malta. Malta has had little research in this area, and therefore an exploratory study was carried out.

METHODS

A retrospective case-control design was applied. Two hundred cases and 403 controls were included. Both cases and controls were subjects without a known family history for breast cancer. Controls were age-matched to cases in an age-decade category roughly at a 2:1 ratio. Interviews were carried out face-to-face using a questionnaire designed by Maltese and Sicilian researchers, encompassing various factors including diet, lifestyle, physiological factors and medical history. Breast cancer risk was then analysed using both univariate and multivariate analyses. For factors having a metric scale, the Mann-Whitney test was used to compare mean scores, while for categorical factors, the chi-square test was used to compare percentages between the case and control groups. Statistical modelling was carried out using binary logistic regression to relate the likelihood of breast cancer to over 50 risk/protective factors analysed collectively.

RESULTS

Univariate analysis showed around 20 parameters of interest, 14 of which were statistically significant at a 0.05 level of significance. Logistic regression analysis identified 11 predictors of interest that were statistically significant. Tomato, coffee and canned meat consumption were associated with lower likelihood of breast cancer (OR = 0.988, 0.901, 0.892, respectively), whereas beans and cabbage consumption and low sodium salt were positively associated with breast cancer (OR = 1.045, 1.834, 1.028, respectively). Premenopausal status was associated with a lower risk of breast cancer compared to postmenopausal status (OR = 0.067). Not having experienced myocardial infarction was associated with lower odds of breast cancer (OR = 0.331). Increased height was also found to have a strong association with risk of breast cancer, with the odds of having breast cancer increasing for every centimetre increase in height (OR = 1.048). In terms of quantity, odds of having breast cancer were lower in those exposed to sunlight (OR = 0.891). The odds of having breast cancer were also lower in those not using the oral contraceptive pill (OR = 0.454).

CONCLUSIONS

Various factors in this exploratory study were found to be associated with development of breast cancer. While causal conclusions cannot be made, tomato consumption is of particular interest, as these results corroborate findings found in other studies. A negative association of breast cancer with sunlight exposure and oral contraceptive pill use corroborates findings in other studies. Other associations with dietary intake can be explained by dietary changes. More robust studies in this area, including possible longitudinal studies, are warranted.

Descriptive epidemiology of breast cancer in China: incidence, mortality, survival and prevalence

Breast cancer is the most common neoplasm diagnosed amongst women worldwide and is the leading cause of female cancer death. However, breast cancer in China is not comprehensively understood compared with Westernised countries, although the 5-year prevalence statistics indicate that approximately 11 % of worldwide breast cancer occurs in China and that the incidence has increased rapidly in recent decades. This paper reviews the descriptive epidemiology of Chinese breast cancer in terms of incidence, mortality, survival and prevalence, and explores relevant factors such as age of manifestation and geographic locations. The statistics are compared with data from the Westernised world with particular emphasis on the United States and Australia. Potential causal agents responsible for differences in breast cancer epidemiology between Chinese and other populations are also explored. The need to minimise variability and discrepancies in methods of data acquisition, analysis and presentation is highlighted.

COHORT EFFECTS OF SUICIDE MORTALITY ARE SEX SPECIFIC IN THE RAPIDLY DEVELOPED HONG KONG CHINESE POPULATION, 1976-2010

BACKGROUND

To examine temporal variations of age, period, and cohort on suicide mortality rate in Hong Kong (HK) from 1976 to 2010, and speculate the macroenvironmental mechanisms of the observed trends.

METHODS

Poisson age-period-cohort modeling was used to delineate the effects of age, period, and cohort on suicide mortality. Analysis by sex was also conducted to examine if gender difference exists for suicidal behaviours.

RESULTS

Age-cohort model provides the best fit to the mortality data, implying that the cohort effect is likely to explain more of the contributions to HK's suicide mortality pattern than the period effect. Risk of suicide mortality increases nonlinearly with age and accelerates after age 65-69 for both sexes. Moreover, the cohort effects differ between the sexes-risk of mortality increases continually for men born after 1961, but no change is observed for women since the 1941 cohort.

CONCLUSIONS

With increased risk of suicide mortality in younger cohorts and the age effect of suicide mortality, we may see future increase in suicide mortality as these younger cohorts age. Further studies are needed to clarify plausible associations between broader sociohistorical changes in the population impacting psychological risk factors and suicidal behaviour to better inform suicide prevention strategies.

The impact of breast cancer-specific birth cohort effects among younger and older Chinese populations

Historically low breast cancer incidence rates among Asian women have risen worldwide; purportedly due to the adoption of a "Western" life style among younger generations (i.e., the more recent birth cohorts). However, no study has simultaneously compared birth cohort effects between both younger and older women in different Asian and Western populations. Using cancer registry data from rural and urban China, Singapore and the United States (1990-2008), we estimated age-standardized incidence rates (ASR), annual percentage change (EAPC) in the ASR, net drifts, birth cohort specific incidence rates and cohort rate ratios (CRR). Younger (30-49 years, 1943-1977 birth cohorts) and older women (50-79 years; 1913-1957 birth cohorts) were assessed separately. CRRs among Chinese populations were estimated using birth cohort specific rates with US non-Hispanic white women (NHW) serving as the reference population with an assigned CRR of 1.0. We observed higher EAPCs and net drifts among those Chinese populations with lower ASRs. Similarly, we observed the most rapidly increasing cohort-specific incidence rates among those Chinese populations with the lowest baseline CRRs. Both trends were more significant among older than younger women. Average CRRs were 0.06-0.44 among older and 0.18-0.81 among younger women. Rapidly rising cohort specific rates have narrowed the historic disparity between Chinese and US NHW breast cancer populations particularly in regions with the lowest baseline rates and among older women. Future analytic studies are needed to investigate risk factors accounting for the rapid increase of breast cancer among older and younger women separately in Asian populations.

A Comparative Study on Cancer Prevention Principles Between Iranian Traditional Medicine and Classic Medicine

Cancer is one of the three main causes of mortality in most human communities whose prevalence is being increased. A significant part of health budget in all countries has been allocated to treat the cancer, which is incurable in many cases. It has led the global health attitude to cancer prevention. Many cancer-related risk factors have been identified for which preventive recommendations have been offered by international organizations such as World Health Organization. Some of the most important of these risk factors are smoking and alcohol consumption, hypercaloric and low-fiber diet, obesity, inactivity, environmental and industrial pollution, some viral infections, and hereditary factors. Exact reviewing of Iranian-Islamic traditional medicine (IITM) resources determines that preventive rules, which named as six essential rules (Sitteh-e-Zarurieah) are abundantly found, including all identified cancer-related risk factors. These preventive rules are: Air (Hava), body movement and repose, sleep and wakefulness, food and drink, evacuation and retention, and mental movement and repose (A'raz-e-Nafsani). The associated risk factors in classic medicine are: Smoking and air pollution, sedentary life, sleep disturbance, improper nutrition and alcohol, chronic constipation, and psychoneurotic stresses. Moreover, these rules are comprehensive enough to include many of the other harmful health-related factors whose roles have been confirmed in the occurrence of different diseases, except cancer. Apparently, cancer prevention in Iran would be more successful if the sextet necessary rules of IITM are promoted among the populations and health policy makers.

A Geographic Analysis about the Spatiotemporal Pattern of Breast Cancer in Hangzhou from 2008 to 2012

BACKGROUND

Breast cancer (BC) is the most common female malignant tumor. Previous studies have suggested a big incidence disparity among different cities in China. The present work selected a typical city, Hangzhou, to study BC incidence disparity within the city.

METHODS

Totally, 8784 female breast cancer cases were obtained from the Hangzhou Center for Disease Control and Prevention during the period 2008-2012. Analysis of Variance and Poisson Regression were the statistical tools implemented to compare incidence disparity in the space-time domain (reference group: township residents during 2008, area: subdistrict, town, and township, time frame: 2008-2012), space-time scan statistics was employed to detect significant spatiotemporal clusters of BC compared to the null hypothesis that the probability of cases diagnosed at a particular location was equal to the probability of cases diagnosed in the whole study area. Geographical Information System (GIS) was used to generate BC spatial distribution and cluster maps at the township level.

RESULTS

The subdistrict populations were found to have the highest and most stable BC incidence. Although town and township populations had a relatively low incidence, it displayed a significant increasing trend from 2008 to 2012. The BC incidence distribution was spatially heterogeneous and clustered with a trend-surface from the southwest low area to the northeast high area. High clusters were located in the northeastern Hangzhou area, whereas low clusters were observed in the southwestern area during the time considered.

CONCLUSIONS

Better healthcare service and lifestyle changes may be responsible for the increasing BC incidence observed in towns and townships. One high incidence cluster (Linping subdistrict) and two low incidence clusters (middle Hangzhou) were detected. The low clusters may be attributable mainly to developmental level disparity, whereas the high cluster could be associated with other risk factors, such as environmental pollution.

PAX6 overexpression is associated with the poor prognosis of invasive ductal breast cancer

Paired box 6 (PAX6) plays a significant role in the development of human neuroectodermal epithelial tissues. Previous studies have suggested that the PAX6 promoter is hypermethylated in breast cancer and that it is involved in breast cancer cell proliferation. The present study aimed to investigate the expression of PAX6 in invasive breast cancer tissues, and to evaluate its prognostic significance. Immunohistochemistry (IHC) was used to detect PAX6 expression on a breast cancer tissue microarray containing tissues from 111 patients. Associations of PAX6 expression with staging and prognosis were analyzed. PAX6 was mainly expressed in the nucleus. The PAX6 staining intensity was not associated with age, histological grade, lymph node status, tumor size, or progesterone receptor and human epidermal growth factor receptor 2 expression (all P>0.05). A high level of PAX6 staining was more frequent in estrogen receptor (ER)-negative cases compared with ER-positive cases (43.9 vs. 25.7%; P=0.049). After a median follow-up time of 110 months, the patients with low PAX6 expression exhibited an improved survival rate compared with the patients with high PAX6 expression (P<0.001). Cox analysis showed a worse survival rate in the patients with high PAX6 staining (hazard ratio, 3.458; 95% confidence interval, 1.575-7.593; P=0.002). In conclusion, high tumor PAX6 staining intensity by IHC was associated with a poor prognosis in breast cancer patients.

Age-Period-Cohort Analysis of Female Breast Cancer Mortality in Korea

Purpose

Despite the low mortality rate of breast cancer among women in Korea, the breast cancer mortality rate has increased. The aim of this study was to examine trends in breast cancer mortality from 1983 to 2012 in Korea, assessing the importance of age, period, and birth cohort as risk factors.

Materials and Methods

Data on the annual number of deaths due to female breast cancer and on female population statistics from 1983 to 2012 were obtained from Statistics Korea. A log-linear Poisson age-period-cohort model was used to estimate age, period, and cohort effects.

Results

The increasing breast cancer mortality can be explained predominantly by a birth cohort effect: the risk of breast cancer death showed a steady increase until the 1968 birth cohort, and decreased thereafter. There was a sharp increase in the magnitude of the age effect up to 60 years old, then a moderate increase in the effect during the sixties, followed by another sharp increase from 70 years old. The period effect on breast cancer mortality seems negligible based on its adjusted relative risk, even though it was statistically significant after adjusting for age and cohort effects.

Conclusion

In this study, the mortality pattern of breast cancer in Korea can be explained predominantly by a birth cohort effect. Hence, the overall mortality rate of breast cancer may increase for a while, and show a gradual decrease in the future, which will start from the younger age group.

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.

The contribution of mammography screening to breast cancer incidence trends in the United States: an updated age-period-cohort model

BACKGROUND

The impact of screening mammography on breast cancer incidence is difficult to disentangle from cohort- and age-related effects on incidence.

METHODS

We developed an age-period-cohort model of ductal carcinoma in situ (DCIS) and invasive breast cancer incidence in U.S. females using cancer registry data. Five functions were included in the model to estimate stage-specific effects for age, premenopausal birth cohorts, postmenopausal birth cohorts, period (for all years of diagnosis), and a mammography period effect limited to women ages ≥ 40 years after 1982. Incidence with and without the mammography period effect was calculated.

RESULTS

More recent birth cohorts have elevated underlying risk compared with earlier cohorts for both pre- and postmenopausal women. Comparing models with and without the mammography period effect showed that overall breast cancer incidence would have been 23.1% lower in the absence of mammography in 2010 (95% confidence intervals, 18.8-27.4), including 14.7% (9.5-19.3) lower for invasive breast cancer and 54.5% (47.4-59.6) lower for DCIS. Incidence of distant-staged breast cancer in 2010 would have been 29.0% (13.1-48.1) greater in the absence of mammography screening.

CONCLUSIONS

Mammography contributes to markedly elevated rates of DCIS and early-stage invasive cancers, but also contributes to substantial reductions in the incidence of metastatic breast cancer.

IMPACT

Mammography is an important tool for reducing the burden of breast cancer, but future work is needed to identify risk factors accounting for increasing underlying incidence and to distinguish between indolent and potentially lethal early-stage breast cancers that are detected via mammography.

Breast cancer in low and middle income countries (LMICs): a shifting tide in global health

Cancer control planning has become a core aspect of global health, as rising rates of noncommunicable diseases in low-resource settings have fittingly propelled it into the spotlight. Comprehensive strategies for cancer control are needed to effectively manage the disease burden. As the most common cancer among women and the most likely reason a woman will die from cancer globally, breast cancer management is a necessary aspect of any comprehensive cancer control plan. Major improvements in breast cancer outcomes in high-income countries have not yet been mirrored in low-resource settings, making it a targeted priority for global health planning. Resource-stratified guidelines provide a framework and vehicle for designing programs to promote early detection, diagnosis, and treatment using existing infrastructure and renewable resources. Strategies for evaluating the current state and projecting future burden is a central aspect of developing national strategies for improving breast cancer outcomes at the national and international levels.

Nutritional and unhealthy behaviors in women with and without breast cancer

Background:

Breast cancer is the most common malignancy in women. Global statistics indicate increasing rates of this cancer. Nutrition, diet, and healthy behaviors are among influential factors in prevalence of breast cancer, and possibly affect its incidence through inflammatory and immune system responses.

Objectives:

This study was designed to compare nutritional and unhealthy behaviors in women with and without breast cancer referred to Mahdieh Imaging Center in Hamadan in 2013.

Patients and Methods:

This cross-sectional study is conducted on 232 women with r and without breast cancer referred to Mahdieh Imaging Center of Hamadan, Iran) in 2013 using random sampling method. Data were collected using nutritional and unhealthy behaviors questionnaires, and analyzed with SPSS-17 software using descriptive statistics and Mann-Whitney, independent t, and chi-square tests.

Results:

The mean scores of feeding type in the patients with and without breast cancer was 56.14 and 66.25, respectively. Results obtained from data analysis showed that there was statistically significant difference between the two groups in terms of nutrition (P < 0.001), but no relationship was observed between breast cancer and unhealthy behaviors.

Conclusions:

Given the results, improving skills, training and awareness is necessary for women and emphasis on modified diet is recommended as a non-medical option for prevention of breast cancer.

Breast cancer in China

The health burden of cancer is increasing in China, with more than 1·6 million people being diagnosed and 1·2 million people dying of the disease each year. As in most other countries, breast cancer is now the most common cancer in Chinese women; cases in China account for 12·2% of all newly diagnosed breast cancers and 9·6% of all deaths from breast cancer worldwide. China's proportional contribution to global rates is increasing rapidly because of the population's rising socioeconomic status and unique reproductive patterns. In this Review we present an overview of present control measures for breast cancer across China, and emphasise epidemiological and socioeconomic diversities and disparities in access to care for various subpopulations. We describe demographic differences between China and high-income countries, and also within geographical and socioeconomic regions of China. These disparities between China and high-income countries include younger age at onset of breast cancer; the unique one-child policy; lower rates of provision and uptake for screening for breast cancer; delays in diagnosis that result in more advanced stage of disease at presentation; inadequate resources; and a lack of awareness about breast cancer in the Chinese population. Finally, we recommend key measures that could contribute to improved health outcomes for patients with breast cancer in China.

Breast cancer in adolescent and young adult women

Breast cancer is one of the most frequently diagnosed malignancy among adolescent and young adult (AYA) women, accounting for approximately 14% of all AYA cancer diagnoses and 7% of all breast cancer. Breast cancer in AYA women is believed to represent a more biologically aggressive disease, but aside from commonly known hereditary predispositions, little is still known about the underlying molecular genetic causes. This review examines the current trends of breast cancer in AYA women as they relate to clinical, social, genetic, and molecular pathologic characteristics. We highlight existing trends, treatment and imaging approaches, and health burdens as they relate to breast cancer in AYA women and provide a discussion on ways to help improve the overall management of this breast cancer cohort.

Higher incidence of premenopausal breast cancer in less developed countries; myth or truth?

Background

Fundamental etiologic differences have been suggested to cause earlier onset of breast cancer in less developed countries (LDCs) than in more developed countries (MDCs). We explored this hypothesis using world-wide breast cancer incidence data.

Methods

We compared international age-standardized incidence rates (ASR) of pre- (<50 years) and postmenopausal (≥50 years) breast cancers as well as temporal trends in ASRs of pre-and postmenopausal breast cancer among selected countries during 1975–2008. We used joinpoint log-linear regression analysis to estimate annual percent changes (APC) for premenopausal and postmenopausal breast cancer in the northern Europe and in Black and White women population in the US.

Results

Premenopausal breast cancers comprised a substantially higher proportion of all incident breast cancers in LDCs (average 47.3%) compared to MDCs (average 18.5%). However, the ASR of premenopausal breast cancer was consistently higher in MDCs (29.4/100,000) than LDCs (12.8/100,000). The ASR of postmenopausal cancer was about five-fold higher in the MDCs (307.6/100,000) than the LDCs (65.4/100,000). The APC of breast cancer in Denmark was substantially higher in postmenopausal (1.33%) than premenopausal cancer (0.98%). Higher incidence of breast cancer among the white than black women in the US was pertained only to the postmenopausal cancer.

Conclusion

The substantial and consistent lower age-specific incidence of breast cancer in LDCs than in MDCs contradicts the theory of earlier onset. Demographic differences with fewer old women in LDCs and lower prevalence of risk factors of postmenopausal cancer are the most likely explanation to the lower mean age at diagnosis in these countries.

Addressing the younger age at onset in breast cancer patients in Asia: an age-period-cohort analysis of fifty years of quality data from the international agency for research on cancer

Introduction. There is an established fact that Asian breast cancer patients are, on average, younger than their European counterparts. This study aimed to utilize the data from the Cancer Incidence in Five Continents I through XIII (published by the International Agency for Research on Cancer) to examine what contributes to the younger age at onset in the Asian population. Material and Methods. Data (number of breast cancer cases and corresponding population figures) for 29 registries in Europe and 9 registries in Asia for the period of 1953–2002 was accessioned and pooled to form two distinct populations, Asia and Europe. The age specific rates were defined and analyzed cross-sectionally (period wise) and longitudinally (cohort wise). The magnitude and the pattern of age specific rates were analyzed using the age-period-cohort analysis. The constrained generalized linear model with a priority assumption of cohort effect as contributing factor to changing rates was used to analyze the data. Result. During the last 50 years, the rate of breast cancer increased for both populations with an estimated annual percent change of 1.03% (with 95% CI of 1.029, 1.031) for Asia and 1.016% (95% CI of 1.015, 1.017) for Europe. There were stronger cohort effects in the magnitude of rates among the Asian population compared to the European population. The cohort effects, expressed as the rate ratio with cohort born in 1970 as reference, ranged from 0.06 (95% CI 0.05, 0.08) to 0.94 (95% CI 0.93, 0.96) for Asians and 0.35 (95% CI 0.33, 0.36) to 1.03 (95% CI 1.02, 1.04) for Europeans. The estimated longitudinal age specific rates (adjusted for cohort and period effects) showed similar patterns between the two populations. Conclusion. It was concluded that a strong cohort effect contributes to the younger age at onset among Asian breast cancer patients.

Time trends of cancer incidence in urban beijing, 1998-2007

OBJECTIVE

To report the time trends of cancer incidence in urban Beijing from 1998 to 2007.

METHODS

All data were obtained from Beijing Cancer Registry from 1998-2007 in urban Beijing. Time trends of incidence rate of cancer were assessed by annual percentage change (APC) of age-standardized incidence rate (ASR) of world standard population during this 10-year period.

RESULTS

For all 156851 cancer cases combined, the incidence rate rose in both males and females, with an APC of 2.23% and 3.74%, respectively. The incidence rate of upper gastrointestinal cancers declined significantly, with an APC of -2.83% in esophageal cancer and -1.37% in male gastric cancer, while lower gastrointestinal cancer, such as colorectal cancer, increased with an APC of 4.08%. The rates of kidney and bladder cancer increased with an APC of 7.93% and 5.57%, respectively. For women, the APC continued to rise in breast cancer (4.98%), ovary cancer (6.16%), cervix uteri cancer (11.74%), corpus uteri cancer (6.96%) and thyroid gland cancer (13.39%). The rate of prostate cancer among men increased with an APC of 8.58%; the rate of lymphoma and leukemia increased with APC of 5.48% and 5.44%, respectively.

CONCLUSION

Because of population aging and urban modernization, the cancer burden in Beijing has become more and more severe and similar to the western developed countries.