Trends in breast cancer incidence in Hong Kong between 1973 and 1999: an age-period-cohort analysis

Systematic Review and Meta-Analysis of Lifestyle and Reproductive Factors Associated with Risk of Breast Cancer in Asian Women

BACKGROUND

Assessing breast cancer risks from lifestyle and reproductive factors is critical for developing population-specific risk prediction tools. However, limited studies have evaluated these risks in recent Asian birth cohorts.

METHODS

We systematically reviewed articles published from January 2010 to December 2023, examining breast cancer risk factors in Asian women. Data were described narratively, estimates pooled, and prevalence and attributable proportions compared across Asian populations.

RESULTS

Of the 128 studies reviewed, 103 reported adjusted effect sizes for meta-analysis. Lifestyle and reproductive factors were predictive of breast cancer risk in Asian women, with varying impacts on premenopausal and postmenopausal women. Relative risks were similar within Asian populations and in comparison to European populations, except for menarche, menopause, and hormone receptor therapy. However, risk factor distributions differed across populations. While alcohol intake (21%) and oral contraceptive use (20%) emerged as the most attributable modifiable risk factors in Europeans, passive smoking (24%) and higher BMI (17%, ≥24 kg/m2 among postmenopausal women) were predominant in Asians.

CONCLUSIONS

Our study shows that while the effects of lifestyle and reproductive breast cancer risk factors are largely similar across different populations, their distributions vary.

IMPACT

Our analysis underscores the importance of considering population-specific risk factor distributions when developing risk prediction tools for Asian populations.

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.

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.

Trends in breast and cervical cancer in India under National Cancer Registry Programme: An Age-Period-Cohort analysis

BACKGROUND

Trend analysis in cancer quantifies the incidence rate and explains the trend and pattern. Breast and cervical cancers are the two most common cancers among Indian women which contributed 39.4 % to the total cancer in India for the year 2020. This study aimed to report the time trends in cancer incidence of breast and cervical cancer using Age-Period-Cohort (APC) model from five Population Based Cancer Registries (PBCRs) in India for the period of 1985-2014.

METHOD

Age-Period-Cohort model was fitted to five PBCRs of Bangalore, Chennai, Delhi, Bhopal and Barshi rural for breast and cervical cancer for 25-74 age-groups. The Estimated Annual Percent Change (EAPC) was calculated. Rate Ratio (RR) of cohort effects were estimated with a constraint of period slope to be zero (p = 0) since cohort has a stronger association with incidence than period.

RESULT

A significant increase was noted in breast cancer in all PBCRs (EAPC, Range: Delhi, 1.2 % to Bangalore, 2.7 %) while significant decrease in cervical cancer (EAPC, Range: Bangalore -2.5 % to Chennai, -4.6 %) from all the PBCRs including Barshi rural during the period. RR estimates for breast cancer showed increasing trend whereas cervical cancer showed decreasing trend in successive birth cohorts across all five PBCRs.

CONCLUSION

In both breast and cervical cancers, a significant age, cohort and period effect was noted in Bangalore, Chennai and Delhi. Despite period effect, the cohort effect was predominant and it may be attributed to the generational changes in risk factors among cancer breast and cervix.

Age-Period-Cohort Analysis on the Time Trend of Hepatitis B Incidence in Four Prefectures of Southern Xinjiang, China from 2005 to 2017

Objective: The influence of age, period, and cohort on Hepatitis B (HB) incidence in four prefectures of southern Xinjiang, China is still not clear. This paper aims to analyze the long-term trend of the HB incidence in four prefectures of southern Xinjiang, China and to estimate the independent impact of age, period and cohort, as well as to predict the development trend of HB incidence in male and female groups, then to identify the targeted population for HB screening by the model fitting and prediction. Method: The data were from the Case List of HB Cases Reported in the Infectious Disease Reporting Information Management System and the Xinjiang Statistical Yearbook of China. The age-period-cohort (APC) model was used to estimate the impacts of age, period and cohort on HB incidence, which could be used to predict the HB incidence in specific age groups of men and women. Results: Under the influence of age effect, the incidence of HB in males had two peaks (20–35 years old and 60–80 years old), the influence of age effect on the incidence of HB in females was lower than that of males and the obvious peak was between 20–30 years old; the period effect on the HB incidence in males and females fluctuated greatly and the fluctuation degree of influence on males was bigger than that of women. The HB incidence among males and females in the four regions tended to be affected by cohort effect, which reached a peak after 1990 and then declined sharply and gradually became stabilized. By predicting the HB incidence from 2018 to 2022, we found that there were significant differences in HB incidence among people over 35 years old, under 35 years old and the whole population in four prefectures of southern Xinjiang, China. Conclusions: Although the incidence of HB in some regions shows a downward trend, there is still an obvious upward trend of incidences in other places. In our paper, results indicate that the burden of HB incidence may be extended in the future, so we hope this can draw the attention of relative departments. These results reveal the differences of incidence between males and females as well, so respective measures of the two groups’ functions are essential.

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.

Sex Differences in Time Trends on Incidence Rates of Oropharyngeal and Oral Cavity Cancers in Hong Kong

Objectives:

Worldwide studies have shown an increasing trend of oropharyngeal squamous cell carcinoma (OPSCC) but a decreasing trend of oral cavity cancers over the past 2 decades, particularly in developed countries with successful tobacco control. This trend has been attributed to the increase in the incidence of human papillomavirus (HPV)–associated OPSCC. The aim of this study was to examine sex differences in incidence trends of oropharyngeal and oral cavity cancers in Hong Kong from 1983 to 2014.

Methods:

Using data from the Hong Kong Cancer Registry from 1983 to 2014, age-standardized incidence rates for potentially HPV-associated sites (oropharyngeal) and non-HPV-associated sites (oral cavity) were calculated, stratified by sex and age groups. Joinpoint regression and an age-period-cohort model were used to assess incidence trends.

Results:

A total of 1,972 cases of oropharyngeal cancer and 7,389 cases of oral cavity cancer were diagnosed from 1983 to 2014. The male/female ratios were 4.16:1 for oropharyngeal cancers and 1.63:1 for oral cavity cancers. A significant increasing trend was observed in oropharyngeal cancers from 1994 to 2014 (average annual percentage change = 2.66, P < .05). In contrast, a significant decreasing trend was observed in oral cavity cancers from 1983 to 1994 (average annual percentage change = −5.36, P < .05). The trends were more significant in men and in patients aged 45 to 69 years. A positive birth cohort effect was observed for oropharyngeal cancer in men.

Conclusions:

The rising trend of oropharyngeal cancer and decreasing trend of oral cavity cancer in Hong Kong from 1983 to 2014 are consistent with worldwide trends. Increase in high-risk sexual behaviors and oral HPV infection may influence the difference in trends.

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.

Lipid raft-mediated miR-3908 inhibition of migration of breast cancer cell line MCF-7 by regulating the interactions between AdipoR1 and Flotillin-1

Background

The mechanisms of lipid raft regulation by microRNAs in breast cancer are not fully understood. This work focused on the evaluation and identification of miR-3908, which may be a potential biomarker related to the migration of breast cancer cells, and elucidates lipid-raft-regulating cell migration in breast cancer.

Methods

To confirm the prediction that miR-3908 is matched with AdipoR1, we used 3’-UTR luciferase activity of AdipoR1 to assess this. Then, human breast cancer cell line MCF-7 was cultured in the absence or presence of the mimics or inhibitors of miR-3908, after which the biological functions of MCF-7 cells were analyzed. The protein expression of AdipoR1, AMPK, and SIRT-1 were examined. The interaction between AdipoR1 and Flotillin-1, or its effects on lipid rafts on regulating cell migration of MCF-7, was also investigated.

Results

AdipoR1 is a direct target of miR-3908. miR-3908 suppresses the expression of AdipoR1 and its downstream pathway genes, including AMPK, p-AMPK, and SIRT-1. miR-3908 enhances the process of breast cancer cell clonogenicity. miR-3908 exerts its effects on the proliferation and migration of MCF-7 cells, which are mediated by lipid rafts regulating AdipoR1’s ability to bind Flotillin-1.

Conclusions

miR-3908 is a crucial mediator of the migration process in breast cancer cells. Lipid rafts regulate the interactions between AdipoR1 and Flotillin-1 and then the migration process associated with miR-3908 in MCF-7 cells. Our findings suggest that targeting miR-3908 and the lipid raft, may be a promising strategy for the treatment and prevention of breast cancer.

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.

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.

Current Status and Future Projections of Breast Cancer in Asia

Asia is the world's largest continent comprising about 3/5 of the human population. Breast cancer is the most common type of cancer and the second leading cause of cancer-related deaths among women in Asia, accounting for 39% of all breast cancers diagnosed worldwide. The incidence of breast cancer in Asia varies widely across the continent and is still lower than in Western countries, but the proportional contribution of Asia to the global breast cancer rates is increasing rapidly in parallel to the socioeconomic development. However, the mortality-to-incidence ratios are much higher for Asia than for Western countries. Most Asian countries are low- and middle-income countries (LMICs) where breast cancer presents at a younger age and a later stage, and where patients are more likely to die from the disease than those in Western countries. Moreover, diagnostic workup, treatment and palliative services are inadequate in most Asian LMICs. In this review, we present an overview of the breast cancer risk factors and epidemiology, control measures, and cancer care among Asian countries.

The Type of Breast Reconstruction May Not Influence Patient Satisfaction in the Chinese Population: A Single Institutional Experience

Background

The goal of this study was to evaluate patient satisfaction with four common types of breast reconstruction performed at our institution: latissimus dorsi myocutaneous (LDM) flap reconstruction with or without implants, pedicled transverse rectus abdominis musculocutaneous (TRAM) flap reconstruction, and free deep inferior epigastric perforator (DIEP) flap reconstruction.

Methods

A custom survey consisting of questions that assessed general and aesthetic satisfaction was sent to patients who had undergone breast reconstruction in the last 5 years. The clinical data and details of the surgery were also collected from the patients who returned the surveys. We compared satisfaction rates across the four breast reconstruction types and analyzed the effects of various factors on overall general and aesthetic satisfaction rates using a binary logistic regression model.

Result

A total of 207 (72%) patients completed the questionnaires. Overall, significant differences in general and aesthetic satisfaction among the four procedures were not observed. A multivariate analysis revealed that the factor “complications” (p = 0.001) played a significant role in general satisfaction and that the factors “> 2 years since reconstruction” (p = 0.043) and “age > 35 years” (p = 0.05) played significant roles in overall aesthetic satisfaction.

Conclusion

The present study demonstrated that the type of breast reconstruction might not influence satisfaction in Chinese patients.

Oral cavity cancer trends over the past 25 years in Hong Kong: a multidirectional statistical analysis

Background

Even though oral cavity cancer (OCC; ICD 10 codes C01, C02, C03, C04, C05, and C06) ranks eleventh among the world’s most common cancers, accounting for approximately 2 % of all cancers, a trend analysis of OCC in Hong Kong is lacking. Hong Kong has experienced rapid economic growth with socio-cultural and environmental change after the Second World War. This together with the collected data in the cancer registry provides interesting ground for an epidemiological study on the influence of socio-cultural and environmental factors on OCC etiology.

Methods

A multidirectional statistical analysis of the OCC trends over the past 25 years was performed using the databases of the Hong Kong Cancer Registry. The age, period, and cohort (APC) modeling was applied to determine age, period, and cohort effects on OCC development. Joinpoint regression analysis was used to find secular trend changes of both age-standardized and age-specific incidence rates.

Results

The APC model detected that OCC development in men was mainly dominated by the age effect, whereas in women an increasing linear period effect together with an age effect became evident. The joinpoint regression analysis showed a general downward trend of age-standardized incidence rates of OCC for men during the entire investigated period, whereas women demonstrated a significant upward trend from 2001 onwards.

Conclusions

The results suggest that OCC incidence in Hong Kong appears to be associated with cumulative risk behaviors of the population, despite considerable socio-cultural and environmental changes after the Second World War.

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.

Familial risks and estrogen receptor-positive breast cancer in Hong Kong Chinese women

PURPOSE

The role of family history to the risk of breast cancer was analyzed by incorporating menopausal status in Hong Kong Chinese women, with a particular respect to the estrogen receptor-positive (ER+) type.

METHODS

Seven hundred and forty seven breast cancer incident cases and 781 hospital controls who had completed information on family cancer history in first-degree relatives (nature father, mother, and siblings) were recruited. Odds ratio for breast cancer were calculated by unconditional multiple logistic regression, stratified by menopausal status (a surrogate of endogenous female sex hormone level and age) and type of relative affected with the disease. Further subgroup analysis by tumor type according to ER status was investigated.

RESULTS

Altogether 52 (6.96%) breast cancer cases and 23 (2.95%) controls was found that the patients' one or more first-degree relatives had a history of breast cancer, showing an adjusted odds ratio (OR) of 2.41 (95%CI: 1.45-4.02). An excess risk of breast cancer was restricted to the ER+ tumor (OR = 2.43, 95% CI: 1.38-4.28), with a relatively higher risk associated with an affected mother (OR = 3.97, 95%CI: 1.46-10.79) than an affected sister (OR = 2.06, 95%CI: 1.07-3.97), while the relative risk was more prominent in the subgroup of pre-menopausal women. Compared with the breast cancer overall, the familial risks to the ER+ tumor increased progressively with the number of affected first-degree relatives.

CONCLUSIONS

This study provides new insights on a relationship between family breast cancer history, menopausal status, and the ER+ breast cancer. A separate risk prediction model for ER+ tumor in Asian population is desired.

Epidemiological correlates of breast cancer in South India

BACKGROUND

Breast cancer is the most frequent cancer in women globally and represents the second leading cause of cancer death among women (after lung cancer). India is going through epidemiologic transition. It is reported that the incidence of breast cancer is rising rapidly as a result of changes in reproductive risk factors, dietary habits and increasing life expectancy, acting in concert with genetic factors.

MATERIALS AND METHODS

In order to understand the existing epidemiological correlates of breast cancer in South India, a systematic review of evidence available on epidemiologic correlates of breast cancer addressing incidence, prevalence, and associated factors like age, reproductive factors, cultural and religious factors was performed with specific focus on screening procedures in southern India.

RESULTS

An increase in breast cancer incidence due to various modifiable risk factors was noted, especially in women over 40 years of age, with late stage of presentation, lack of awareness about screening, costs, fear and stigma associated with the disease serving as major barriers for early presentation.

CONCLUSIONS

Educational strategies should be aimed at modifying the life style, early planning of pregnancy, promoting breast feeding and physical activity. It is very important to obtain reliable data for planning policies, decision-making and setting up the priorities.

The prevalence and factors for cancer screening behavior among people with severe mental illness in Hong Kong

OBJECTIVES

Screening is useful in reducing cancer incidence and mortality. People with severe mental illness (PSMI) are vulnerable to cancer as they are exposed to higher levels of cancer risks. Little is known about PSMI's cancer screening behavior and associated factors. The present study examined the utilization of breast, cervical, prostate, and colorectal cancer screening among PSMI in Hong Kong and to identify factors associated with their screening behaviors.

METHOD

591 PSMI from community mental health services completed a cross-sectional survey.

RESULTS

The percentage of cancer screening behavior among those who met the criteria for particular screening recommendation was as follows: 20.8% for mammography; 36.5% for clinical breast examination (CBE); 40.5% for pap-smear test; 12.8% for prostate examination; and 21.6% for colorectal cancer screening. Results from logistic regression analyses showed that marital status was a significant factor for mammography, CBE, and pap-smear test; belief that cancer can be healed if found early was a significant factor for pap-smear test and colorectal screening; belief that one can have cancer without having symptoms was a significant factor for CBE and pap-smear test; belief that one will have a higher risk if a family member has had cancer was a significant factor for CBE; and self-efficacy was a significant factor for CBE and pap-smear test behavior.

CONCLUSIONS

Cancer screening utilization among PSMI in Hong Kong is low. Beliefs about cancer and self-efficacy are associated with cancer screening behavior. Health care professionals should improve the knowledge and remove the misconceptions about cancer among PSMI; self-efficacy should also be promoted.

Toremifene in the treatment of breast cancer

Although more widespread screening and routine adjuvant therapy has improved the outcome for breast cancer patients in recent years, there remains considerable scope for improving the efficacy, safety and tolerability of adjuvant therapy in the early stage disease and the treatment of advanced disease. Toremifene is a selective estrogen receptor modifier (SERM) that has been widely used for decades in hormone receptor positive breast cancer both in early and late stage disease. Its efficacy has been well established in nine prospective randomized phase III trials compared to tamoxifen involving more than 5500 patients, as well as in several large uncontrolled and non-randomized studies. Although most studies show therapeutic equivalence between the two SERMs, some show an advantage for toremifene. Several meta-analyses have also confirmed that the efficacy of toremifene is at least as good as that of tamoxifen. In terms of safety and tolerability toremifene is broadly similar to tamoxifen although there is some evidence that toremifene is less likely to cause uterine neoplasms, serious vascular events and it has a more positive effect on serum lipids than does tamoxifen. Toremifene is therefore effective and safe in the treatment of breast cancer. It provides not only a useful therapeutic alternative to tamoxifen, but may bring specific benefits.

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.

Breast cancer risk accumulation starts early: prevention must also

Nearly one in four breast cancers is diagnosed before the age of 50, and many early-stage premalignant lesions are present but not yet diagnosed. Therefore, we review evidence to support the strategy that breast cancer prevention efforts must begin early in life. This study follows the literature review methods and format. Exposures during childhood and adolescence affect a woman's long-term risk of breast cancer, but have received far less research attention than exposures that occur later in life. Breast tissue undergoes rapid cellular proliferation between menarche and first full-term pregnancy, and risk accumulates rapidly until the terminal differentiation that accompanies first pregnancy. Evidence on childhood diet and growth in height, and adolescent alcohol intake, among other adolescent factors is related to breast cancer risk and risk of premalignant proliferative benign lesions. Breast cancer prevention efforts will have the greatest effect when initiated at an early age and continued over a lifetime. Gaps in knowledge are identified and deserve increase attention to inform prevention.

Breast carcinoma in young females below the age of 40 years: A histopathological perspective

Background:

Breast cancer among young women is a rare pathology, but is known to have a more aggressive behavior and poorer outcome.

Aims:

The objective of this study was to evaluate the clinicopathological characteristics of breast carcinoma below 40 years in comparison to that over 40 years in Manipur, India.

Settings and Design:

This retrospective study from the period of January 2005-December 2010 was conducted in the Department of Pathology, Regional Institute of Medical Sciences, Imphal, Manipur.

Materials and Methods:

All cases of mastectomy specimens of carcinoma breast from the period of January 2005-December 2010 were included in the study. Clinical and histopathological data of all cases were reviewed and correlated.

Results:

A total of 507 mastectomy specimens were received, among which, 160 cases (31.56%) were below 40 years; whereas 347 cases (68.44%) were above 40 years of age. Stage III was the commonest stage (47% versus 18%) in the younger group; while in the older group, Stage II was the commonest (64% versus 34%).

Conclusion:

This study shows that young females with breast cancer have higher stage of tumor.

A meta-analysis on dose-response relationship between night shift work and the risk of breast cancer

This study aimed to conduct a systematic review to sum up evidence of the associations between different aspects of night shift work and female breast cancer using a dose-response meta-analysis approach. We systematicly searched all cohort and case-control studies published in English on MEDLINE, Embase, PSYCInfo, APC Journal Club and Global Health, from January 1971 to May 2013. We extracted effect measures (relative risk, RR; odd ratio, OR; or hazard ratio, HR) from individual studies to generate pooled results using meta-analysis approaches. A log-linear dose-response regression model was used to evaluate the relationship between various indicators of exposure to night shift work and breast cancer risk. Downs and Black scale was applied to assess the methodological quality of included studies. Ten studies were included in the meta-analysis. A pooled adjusted relative risk for the association between 'ever exposed to night shift work' and breast cancer was 1.19 [95% confidence interval (CI) 1.05-1.35]. Further meta-analyses on dose-response relationship showed that every 5-year increase of exposure to night shift work would correspondingly enhance the risk of breast cancer of the female by 3% (pooled RR = 1.03, 95% CI 1.01-1.05; Pheterogeneity < 0.001). Our meta-analysis also suggested that an increase in 500-night shifts would result in a 13% (RR = 1.13, 95% CI 1.07-1.21; Pheterogeneity = 0.06) increase in breast cancer risk. This systematic review updated the evidence that a positive dose-response relationship is likely to present for breast cancer with increasing years of employment and cumulative shifts involved in the work.

Fruits, vegetables and breast cancer risk: a systematic review and meta-analysis of prospective studies

Evidence for an association between fruit and vegetable intake and breast cancer risk is inconclusive. To clarify the association, we conducted a systematic review and meta-analysis of the evidence from prospective studies. We searched PubMed for prospective studies of fruit and vegetable intake and breast cancer risk until April 30, 2011. We included fifteen prospective studies that reported relative risk estimates and 95 % confidence intervals (CIs) of breast cancer associated with fruit and vegetable intake. Random effects models were used to estimate summary relative risks. The summary relative risk (RR) for the highest versus the lowest intake was 0.89 (95 % CI: 0.80-0.99, I (2) = 0 %) for fruits and vegetables combined, 0.92 (95 % CI: 0.86-0.98, I (2) = 9 %) for fruits, and 0.99 (95 % CI: 0.92-1.06, I (2) = 20 %) for vegetables. In dose-response analyses, the summary RR per 200 g/day was 0.96 (95 % CI: 0.93-1.00, I (2) = 2 %) for fruits and vegetables combined, 0.94 (95 % CI: 0.89-1.00, I (2) = 39 %) for fruits, and 1.00 (95 % CI: 0.95-1.06, I (2) = 17 %) for vegetables. In this meta-analysis of prospective studies, high intake of fruits, and fruits and vegetables combined, but not vegetables, is associated with a weak reduction in risk of breast cancer.

Age Interactions in Breast Cancer: An Analysis of a 10-Year Multicentre Study in China

OBJECTIVES: The effects of age at diagnosis on the clinical characteristics of breast cancer and trends over time were investigated in Chinese women. METHODS: Data from 4211 women with pathologically confirmed primary breast cancer collected between 1999 and 2008 for a multicentre retrospective study were analysed according to age at diagnosis. RESULTS: Age at diagnosis ranged from 21 to 86 years, with a mean of 48.7 years, and was shown to be significantly related to tumour size, lymph node status, hormone receptor status and human growth factor receptor-2 status, but not to pathological type or tumour, node, metastasis stage. The age-corrected proportion of patients aged 50 – 64 years at diagnosis increased significantly between 1999 and 2008. There was a significant difference in the age-corrected distribution of age at diagnosis in China compared with Western countries. CONCLUSIONS: Age at diagnosis is related to the clinical and pathological characteristics of breast cancer. The age at diagnosis in China increased over the decade from 1999 to 2008, but is still lower than in Western countries.

Preventability of cancer: the relative contributions of biologic and social and physical environmental determinants of cancer mortality

Whereas models of cancer disparities and variation in cancer burden within population groups now specify multiple levels of action from biologic processes to individual risk factors and social and physical contextual factors, approaches to estimating the preventable proportion of cancer use more traditional direct models often from single exposures to cancer at specific organ sites. These approaches are reviewed, and the strengths and limitations are presented. The need for additional multilevel data and approaches to estimation of preventability are identified. International or regional variation in cancer may offer the most integrated exposure assessment over the life course. For the four leading cancers, which account for 50% of incidence and mortality, biologic, social, and physical environments play differing roles in etiology and potential prevention. Better understanding of the interactions and contributions across these levels will help refine prevention strategies.

Is tamoxifen alone adequate therapy in very young Chinese women with operable breast cancer?

Breast cancer occurs earlier in Chinese women than in Caucasian women. We have compared the clinicopathologic characteristics and prognosis in very young and older premenopausal women with breast cancer in south China. We separated 905 consecutive premenopausal patients with first diagnosis of breast cancer, surgically treated at the Sun Yat-sen University Cancer Center from October 2003 to December 2006, into a very young group (189 [13.7%]; <35 years old) and an older group (716 [52.0%]; 35-57 years old). Approximately, 90% of patients received adjuvant chemotherapy and hormonal therapy with tamoxifen for hormone-receptor (HR)-positive breast cancer. We retrospectively compared the clinicopathologic factors and survival rates of these two groups. The 3-year disease-free survival rate (78.0% versus 89.1%, p < 0.001) was poorer in the very young group, and 3-year overall survival rate (94.3% versus. 96.8%, p = 0.10) was similar. Moreover, the 3-year overall survival rate (p = 0.020) and disease-free survival rate (p < 0.001) were significantly poorer in HR-positive patients in the very young group whereas there was no significant difference in outcomes between the HR-negative groups. In China, age younger than 35 years is an independent predictor of breast cancer recurrence. In very young women with HR-positive breast cancer, chemotherapy plus tamoxifen alone may not be adequate standard treatment.

Dietary fiber and breast cancer risk: a systematic review and meta-analysis of prospective studies

BACKGROUND

Evidence from case-control studies suggest that dietary fiber may be inversely related to breast cancer risk, but it is unclear if this is supported by prospective data. We conducted a systematic review and meta-analysis of the evidence from prospective studies.

METHODS

PubMed was searched for prospective studies of fiber intake and breast cancer risk until 31st August 2011. Random effects models were used to estimate summary relative risks (RRs).

RESULTS

Sixteen prospective studies were included. The summary RR for the highest versus the lowest intake was 0.93 [95% confidence interval (CI) 0.89-0.98, I(2) = 0%] for dietary fiber, 0.95 (95% CI 0.86-1.06, I(2) = 4%) for fruit fiber, 0.99 (95% CI 0.92-1.07, I(2) = 1%) for vegetable fiber, 0.96 (95% CI 0.90-1.02, I(2) = 5%) for cereal fiber, 0.91 (95% CI 0.84-0.99, I(2) = 7%) for soluble fiber and 0.95 (95% CI 0.89-1.02, I(2) = 0%) for insoluble fiber. The summary RR per 10 g/day of dietary fiber was 0.95 (95% CI 0.91-0.98, I(2) = 0%, P(heterogeneity) = 0.82). In stratified analyses, the inverse association was only observed among studies with a large range (≥13 g/day) or high level of intake (≥25 g/day).

CONCLUSION

In this meta-analysis of prospective studies, there was an inverse association between dietary fiber intake and breast cancer risk.

How does socioeconomic development affect COPD mortality? An age-period-cohort analysis from a recently transitioned population in China

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a leading cause of death, particularly in developing countries. Little is known about the effects of economic development on COPD mortality, although economic development may potentially have positive and negative influences over the life course on COPD. We took advantage of a unique population whose rapid and recent economic development is marked by changes at clearly delineated and identifiable time points, and where few women smoke, to examine the effect of macro-level events on COPD mortality.

METHODS

We used Poisson regression to decompose sex-specific COPD mortality rates in Hong Kong from 1981 to 2005 into the effects of age, period and cohort.

RESULTS

COPD mortality declined strongly over generations for people born from the early to mid 20th century, which was particularly evident for the first generation to grow up in a more economically developed environment for both sexes. Population wide COPD mortality decreased when air quality improved and increased with increasing air pollution. COPD mortality increased with age, particularly after menopause among women.

CONCLUSIONS

Economic development may reduce vulnerability to COPD by reducing long-lasting insults to the respiratory system, such as infections, poor nutrition and indoor air pollution. However, some of these gains may be offset if economic development results in increasing air pollution or increasing smoking.

Younger age as a prognostic indicator in breast cancer: a cohort study

Background

The debate continues as to whether younger women who present with breast cancer have a more aggressive form of disease and a worse prognosis. The objectives of this study were to determine the incidence of breast cancer in women under 40 years old and to analyse the clinicopathological characteristics and outcome compared to an older patient cohort.

Methods

Data was acquired from a review of charts and the prospectively reviewed GUH Department of Surgery database. Included in the study were 276 women diagnosed with breast cancer under the age of forty and 2869 women over forty. For survival analysis each women less than 40 was matched with two women over forty for both disease stage and grade.

Results

The proportion of women diagnosed with breast cancer under the age of forty in our cohort was 8.8%. In comparison to their older counterparts, those under forty had a higher tumour grade (p = 0.044) and stage (p = 0.046), a lower incidence of lobular tumours (p < 0.001), higher estrogen receptor negativity (p < 0.001) and higher HER2 over-expression (p = 0.002); there was no statistical difference as regards tumour size (p = 0.477). There was no significant difference in overall survival (OS) for both groups; and factors like tumour size (p = 0.026), invasion (p = 0.026) and histological type (p = 0.027), PR (p = 0.031) and HER2 (p = 0.002) status and treatment received were independent predictors of OS

Conclusion

Breast cancer in younger women has distinct histopathological characteristics; however, this does not result in a reduced survival in this population.

Trends in breast, ovarian and cervical cancer incidence in Mumbai, India over a 30-year period, 1976-2005: an age-period-cohort analysis

Background:

Demographic, socioeconomic and cultural changes in India have increased longevity, delayed childbearing, decreased parity and resulted in a more westernised lifestyle, contributing to the increasing burden of cancer, especially among women.

Methods:

We evaluated secular changes in the incidence of breast, cervical and ovarian cancer in Mumbai women aged 30–64 between 1976 and 2005. Age-standardised incidence rates were calculated and presented by site and calendar period. An age–period–cohort (APC) analysis quantified recent time trends and the significance of birth cohort and calendar period effects. The estimated annual percent change (EAPC) was obtained from the drift parameter, expressing the linear time trend common to both calendar period and birth cohort.

Results:

Over the 30-year study period, the age-standardised rates significantly increased for breast cancer (EAPC: 1.1% (95% confidence interval (CI): 1.0, 1.3)), significantly decreased for cervical cancer (EAPC: −1.8% (95% CI: −2.0, −1.6)) and there was no statistically significant change for ovarian cancer (EAPC: 0.3% (95% CI: −0.1, 0.6)). For breast and cervical cancer, the best-fitting model was the APC model.

Conclusions:

The rates of breast, cervical and ovarian cancer remain low in comparison with western countries, and the divergent trends of breast (increasing) and cervical cancer (decreasing) in Mumbai were similar to those observed in several other Asian countries. The changing risk profile in successive generations – improved education, higher socioeconomic status, later age at marriage and at first child, and lower parity – may in combination partially explain the diverging generational changes in breast and cervical cancer in Mumbai in the last decades.

Trends in invasive breast cancer incidence among French women not exposed to organized mammography screening: an age-period-cohort analysis

BACKGROUND

The long tenure of the Doubs cancer registry (France) and the late implementation of a mass screening program provide a unique opportunity to assess the relative contributions of age, period and cohort effects to the increase in female invasive breast cancer incidence, while avoiding the influence of an organized screening program.

METHODS

Population and incidence data were provided for the Doubs region during the 1978-2003 period. Breast cancer counts and person-years were tabulated into 1-year classes by age and time period. Age-period-cohort models with parametric smooth functions were fitted to the data, assuming a Poisson distribution for the number of observed cases.

RESULTS

A total of 5688 incident cases of invasive breast cancer in women were diagnosed in women aged 30-84 years in the Doubs region between 1978 and 2003. The annual percentage increase in incidence is 2.09%. Age effects rise dramatically until age 50, and at a slower pace afterwards. Large cohort curvature effects (p<10(-6)), show departure from linear trends, with a significant peak for women born around 1940. Period curvature effects are lower in magnitude (p=0.01).

CONCLUSION

Both cohort and period effects are involved in the marked increase in breast cancer incidence over a 25-year period in the Doubs region. Although the future trend for breast cancer incidence is difficult to predict, the introduction of an organized screening program, and the sharp decline in hormone replacement therapy use will likely contribute to period effects in future analyses.

CacyBP/SIP expression is involved in the clinical progression of breast cancer

OBJECTIVE

Calcyclin-binding protein or Siah-1-interacting protein (CacyBP/SIP) is a target protein of the S100A6, which is a member of the S100 family. It has been shown that CacyBP/SIP plays important roles in cell cycle progression, differentiation, and carcinogenesis. The purpose of this study was to explore the correlation of CacyBP/SIP expression and clinical significance in breast cancer.

METHODS

Immunohistochemistry was performed to detect the CacyBP/SIP expression in 79 pairs of breast cancer tissues and adjacent nontumor tissues. Western blot analysis and semiquantitative RT-PCR were used to measure CacyBP/SIP protein and mRNA levels in three pairs of fresh breast cancer tissues and adjacent nontumor tissues. The clinical data were collected by telephone follow-up for 5 years.

RESULTS

CacyBP/SIP mRNA and protein levels in breast cancer tissues were significantly higher compared with adjacent nontumor tissues. Poor cellular differentiation, lymph node invasion, and clinicopathological staging in breast cancer were associated with CacyBP/SIP expression. Other factors, such as age, menses, and tumor size, were not related to CacyBP/SIP expression. The up-regulation of CacyBP/SIP expression also was shown to increase recurrence and metastasis of breast cancer and to correlate with short overall survival rate.

CONCLUSIONS

CacyBP/SIP expression is evident in more advanced clinical progression of breast cancer, and it might be a biomarker for poor prognosis and a potential therapeutic target in breast cancer.

Is breast cancer the same disease in Asian and Western countries?

A mini-symposium was held in Montreal, Canada, at the International Surgical Week for the Breast Surgical International in 2007 addressing the question whether breast cancer is the same disease in Asian and Western countries. Numerous investigators from Asian and Western countries presented the epidemiologic and clinical outcome data of women with breast cancer. Although there are significant similarities, the striking difference is that the peak age for breast cancer is between 40 and 50 years in the Asian countries, whereas the peak age in the Western countries is between 60 and 70 years. Also, the incidence of breast cancer in Asia is rising and is associated with increased mortality. In the West, although the incidence is increasing, the mortality rate is definitely decreasing. Future prospective data collection from Asian and Western countries may provide further interesting epidemiologic and outcome data regarding the outcome of women with breast cancer from Asian and Western countries.

BACKGROUND

Whether breast cancer is the same disease in Asian and Western countries was the topic of a 2007 Breast Surgery International symposium at International Surgical Week.

METHODS

Participating investigators from China, Taiwan, India, Japan, South Korea, Sweden, Canada, and the United States were asked beforehand to provide data on the epidemiology and treatment outcome of women in their countries.

RESULTS

Comparisons of the epidemiologic and clinical outcome data of women with breast cancer showed significant similarities, but the striking difference is that the peak age is between 40 and 50 years in Asian countries, but is between 60 and 70 years in Western countries. The incidence of breast cancer in Asia is rising and is associated with increased mortality. In the West, although the incidence is also increasing, the mortality rate is definitely decreasing.

DISCUSSION

Future prospective data collection from Asian and Western countries may provide further interesting epidemiologic and outcome data regarding the outcome of women with breast cancer from Asian and Western countries.

Recent trends and patterns in breast cancer incidence among Eastern and Southeastern Asian women

BACKGROUND

Incidence of breast cancer is rising in Asian countries, and breast cancer is the most common cancer among Asian women. However, there are few recent descriptive reports on the epidemiology of breast cancer among Eastern and Southeastern Asian populations.

METHODS

We examined incidence trends for invasive breast cancer in women aged ≥20 years from 15 registries in Eastern (China, Japan, the Republic of Korea, Taiwan) and Southeastern Asia (the Philippines, Singapore, Thailand) for the period 1993-2002 mainly using data from Cancer Incidence in Five Continents, Volumes VIII and IX. We compared trends in annual incidence rates and age-specific incidence curves over a 10-year period. We also compared the incidence rates of Asian-Americans with the rates of their Asian counterparts.

RESULTS

Breast cancer incidence rates increased gradually over time in all study populations. Rates were relatively high in Southeastern Asia and became progressively lower along a south-to-north gradient, with a fourfold geographic variation within the study populations. Age-specific incidence curves showed patterns that gradually changed according to incidence rates. Breast cancer incidence among Asian women living in the United States was 1.5-4 times higher than the corresponding incidence rate in the women's respective countries of origin.

CONCLUSION

Breast cancer incidence is expected to continue to increase for the next 10 years in Asia and may approach rates reported among Asian-Americans. The number and mean age of breast cancer cases is expected to increase as the female Asian population ages, the prevalence of certain risk factors changes (early menarche, late menopause, low parity, late age at first live birth, and low prevalence of breastfeeding), and as Asian countries introduce mass screening programs.

The detection of dioxin- and estrogen-like pollutants in marine and freshwater fishes cultivated in Pearl River Delta, China

In this study we aimed to assess the dioxin- and estrogen-like activities of contaminants extracted from twenty species of freshwater and seawater fishes, using luciferase reporter assays. Transfected MCF7 cells were treated with sample extracts and luciferase activities were then measured at 24-h of post-treatment. The mean values of the detected dioxin- and estrogen-like activities in the freshwater fishes were 25.3 pg TEQ/g ww and 102.3 pM EEQ/g ww whereas in the seawater fishes, the values were 46.2 pg TEQ/g ww and 118.8 pM EEQ/g ww. Using sample-relevant dosage of estrogen, inductions of cell proliferation markers (i.e. retinoblastoma, cyclin D) and stimulations of cell growth were revealed by Western blotting, colony formation and BrdU uptake assays. A cotreatment with TCDD significantly reduced these effects. Using the sample extracts with different dioxin- and estrogen-like activities, similar observation was revealed. The data highlighted the mixture effect of food contaminants on human health.

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.

Risk factors for breast cancer among Filipino women in Manila

Age-adjusted incidence rates of breast cancer vary greatly worldwide with highest rates found in the typically 'westernised' countries of North America and Europe. Much lower rates are observed in Asian and African populations but an exception to this has been reported for the Manila Cancer Registry in the Philippines. The reason for this high rate is unknown but may be associated with the change in lifestyle that has occurred in urban Manila since the 1960s. In 1995, a randomised controlled trial was set up in Manila to evaluate the feasibility of a screening intervention by clinical breast examination as an alternative to mammography. The cohort of 151,168 women was followed-up to 2001 for cancer incidence and a nested case-control study carried out. This aimed to evaluate the increase in breast cancer risk associated with known risk factors. Increased risks were seen for a high level of education (OR = 1.9 95%CI 1.1-3.3 for education stopped at > or =13 versus <13 years), nulliparity (OR = 5.0 95% CI 2.5-10.0 for nulliparity versus five or more children), and late age at first birth (OR = 3.3 95% CI 1.3-8.3 for age > or =30 versus <20 years). We found no association with excess body weight, height, use of exogenous hormones or alcohol consumption. From this study, the recognised "classical" risk factors do not fully explain the high breast cancer incidence in Metro Manila, especially when compared to other urban Asian populations. We conclude that it is too simplistic to ascribe the high risk to 'westernisation'.

Use of Bayesian modeling to estimate the sensitivity of stereotactic directional vacuum-assisted breast biopsy when the gold standard is incomplete

RATIONALE AND OBJECTIVES

This study is conducted to estimate the sensitivity of stereotactic directional vacuum-assisted breast biopsy (ST DVAB) using Bayesian modeling and to predict how many more cancers can be inferred from those lesions without surgical correlation.

MATERIALS AND METHODS

We retrospectively reviewed the 103 lesions from 84 women who underwent ST DVAB. The study was approved by the Institutional Review Board of our hospital. We estimated the sensitivity and prevalence of the study population for ST DVAB by two types of approaches: for the type I approach, the gold standards were surgical correlation or postbiopsy mammographic follow-up. For the type II approach using Bayesian modeling by a beta-binomial model, the only gold standard was surgical correlation and the predicted number of cancerous lesions in those patients without surgical correlation was estimated.

RESULTS

For the type I approach, the sensitivity was 92.3%, and the prevalence 12.6%. For the type II approach, the mean sensitivity of ST DVAB was 89%, and the mean prevalence was 15%. We predicted that an average of 1.7 cancerous lesions occurred among those lesions without surgical correlation by the Bayesian estimation.

CONCLUSIONS

The mean sensitivity of ST DVAB using the Bayesian (type II) approach was lower than that using the type I approach, because we regarded the surgery as the only gold standard in Bayesian modeling and the nonoperated lesions were thought to be with unknown true disease status. The Bayesian approach is thus more appropriate to use than the type I approach when the gold standard is incomplete.