Ethnicity and variation in breast cancer incidence

Relationships between Breast Feeding and Breast Cancer Subtypes: Lessons Learned from Studies in Humans and in Mice

There are differential risk relationships between parity and breast cancer according to estrogen receptor (ER) status, with an increased risk of ER^- disease reduced by breastfeeding. This may be particularly relevant for understanding the higher incidence of ER^- tumors in Black women, who are more likely to be parous and less likely to breastfeed than other U.S. groups. Potential mechanisms for these relationships may include effects of disordered breast involution on inflammatory milieu in the breast as well as epigenetic reprogramming in the mammary gland, which can affect cell fate decisions in progenitor cell pools. In normal breast tissue, parity has been associated with hypermethylation of FOXA1, a pioneer transcription factor that promotes the luminal phenotype in luminal progenitors, while repressing the basal phenotype. In breast tumors, relationships between FOXA1 methylation and parity were strongest among women who did not breastfeed. Here, we summarize the epidemiologic literature regarding parity, breastfeeding, and breast cancer subtypes, and review potential mechanisms whereby these factors may influence breast carcinogenesis, with a focus on effects on progenitor cell pools in the mammary gland.

Evaluation of the Families SHARE workbook: an educational tool outlining disease risk and healthy guidelines to reduce risk of heart disease, diabetes, breast cancer and colorectal cancer

BACKGROUND

Common diseases such as heart disease, diabetes, and cancer are etiologically complex with multiple risk factors (e.g., environment, genetic, lifestyle). These risk factors tend to cluster in families, making families an important social context for intervention and lifestyle-focused disease prevention. The Families Sharing Health Assessment and Risk Evaluation (SHARE) workbook was designed as an educational tool outlining family health history based risk of heart disease, type 2 diabetes, breast cancer, and colorectal cancer. The current paper describes the steps taken to develop and evaluate the workbook employing a user-centered design approach.

METHODS

The workbook was developed in four steps, culminating in an evaluation focusing on understanding and usability of the tool. The evaluation was based on two Phases of data collected from a sample of mothers of young children in the Washington, D.C., area. A baseline assessment and follow-up approximately two weeks after receipt of the workbook were conducted, as well as focus groups with participants. The design of the workbook was refined in response to participant feedback from the first evaluation Phase and subsequently re-evaluated with a new sample.

RESULTS

After incorporating user-based feedback and revising the workbook, Phase 2 evaluation results indicated that understanding of the workbook components improved for all sections (from 6.26 to 6.81 on a 7-point scale). In addition, 100% of users were able to use the algorithm to assess their disease risk and over 60% used the algorithm to assess family members' disease risk. At follow-up, confidence to increase fruit, vegetable and fiber intake improved significantly, as well.

CONCLUSIONS

The Families SHARE workbook was developed and evaluated resulting in a family health history tool that is both understandable and usable by key stakeholders. This educational tool will be used in intervention studies assessing the effectiveness of family genomics health educators who use the Families SHARE workbook to disseminate family risk information and encourage risk reducing behaviors.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01498276 . Registered 21 December 2011.

Racial and ethnic disparities in the impact of obesity on breast cancer risk and survival: a global perspective

Obesity is a global concern, affecting both developed and developing countries. Although there are large variations in obesity and breast cancer rates worldwide and across racial/ethnic groups, most studies evaluating the impact of obesity on breast cancer risk and survival have been conducted in non-Hispanic white women in the United States or Europe. Given the known racial/ethnic differences in tumor hormone receptor subtype distribution, obesity prevalence, and risk factor profiles, we reviewed published data for women of African, Hispanic, and Asian ancestry in the United States and their countries of origin. Although the data are limited, current evidence suggests a stronger adverse effect of obesity on breast cancer risk and survival in women of Asian ancestry. For African Americans and Hispanics, the strength of the associations appears to be more comparable to that of non-Hispanic whites, particularly when accounting for subtype and menopausal status. Central obesity seems to have a stronger impact in African-American women than general adiposity as measured by body mass index. International data from countries undergoing economic transition offer a unique opportunity to evaluate the impact of rapid weight gain on breast cancer. Such studies should take into account genetic ancestry, which may help elucidate differences in associations between ethnically admixed populations. Overall, additional large studies that use a variety of adiposity measures are needed, because the current evidence is based on few studies, most with limited statistical power. Future investigations of obesity biomarkers will be useful to understand possible racial/ethnic biological differences underlying the complex association between obesity and breast cancer development and progression.

Energy-Related Indicators and Breast Cancer Risk among White and Black Women

Energy-related indicators, including physical activity, energy intake, body mass index (BMI) and adult weight change, have been linked to breast cancer risk. Very few studies of these associations have been conducted among black women, therefore we used the Nashville Breast Health Study (NBHS) to determine whether similar effects were seen in black and white women. The NBHS is a population-based case-control study of breast cancer among women age 25 to 75 years conducted between 2001 and 2010 in and around the Nashville Metropolitan area. Telephone interviews and self-administered food frequency questionnaires were completed with 2,614 incident breast cancer cases ascertained through hospitals and the statewide cancer registry, and 2,306 controls selected using random digit dialing. Among premenopausal white and black women, there was little effect of adult exercise or other energy-related indicators on breast cancer risk, regardless of tumor estrogen receptor (ER) status. The beneficial effect of adult exercise on postmenopausal breast cancer appeared to be comparable between white and black women (highest tertile relative to none - white odds ratio [OR] 0.8, 95% confidence interval [CI] 0.6-1.0, p for trend=0.05; black OR 0.7, 95% CI 0.4-1.1, p for trend=0.07); however, among black women the reduction was limited to those with ER-positive disease. White and black women should be encouraged to engage in more physical activity to reduce their risk of postmenopausal breast cancer.

Alcohol consumption and breast cancer risk among women in three sub-Saharan African countries

Background

Alcohol drinking is linked to the development of breast cancer. However, there is little knowledge about the impact of alcohol consumption on breast cancer risk among African women.

Methods

We conducted a case-control study among 2,138 women with invasive breast cancer and 2,589 controls in Nigeria, Cameroon, and Uganda from 1998 to 2013. A structured questionnaire was used to collect information on alcohol consumption, defined as consuming alcoholic beverages at least once a week for six months or more. Logistic regression was used to estimate adjusted odds ratio (aOR) and 95% confidence interval (CI).

Results

Among healthy controls, the overall alcohol consumption prevalence was 10.4%, and the prevalence in Nigeria, Cameroon, and Uganda were 5.0%, 34.6%, and 50.0%, respectively. Cases were more likely to have consumed alcohol (aOR = 1.62, 95% CI: 1.33–1.97). Both past (aOR = 1.54; 95% CI: 1.19–2.00) and current drinking (aOR = 1.71; 95% CI: 1.30–2.23) were associated with breast cancer risk. A dose-response relationship was observed for duration of alcohol drinking (P-trend <0.001), with 10-year increase of drinking associated with a 54% increased risk (95% CI: 1.29–1.84).

Conclusion

We found a positive relationship between alcohol consumption and breast cancer risk, suggesting that this modifiable risk factor should be addressed in breast cancer prevention programs in Africa.

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

BACKGROUND

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Body fatness and breast cancer risk in women of African ancestry

BACKGROUND

Obesity has been shown to be inversely associated with breast cancer risk in premenopausal women, while increasing risk in postmenopausal women. However, the current evidence is largely based on studies in Caucasian populations. Associations in women of African ancestry (AA), who have a higher prevalence of obesity, have been evaluated in few studies and results suggest different effects.

METHODS

We evaluated the impact of body size, body fat distribution, and body composition on breast cancer risk among AA women (978 cases and 958 controls) participating in the Women's Circle of Health Study, a multi-site case-control study in New York City (NYC) and New Jersey (NJ). Cases were newly diagnosed with histologically confirmed ductal carcinoma in situ or invasive breast cancer, age 20-75 yrs. In NYC, cases were recruited through hospitals with the largest referral patterns for AA women and controls through random digit dialing (RDD). In NJ, cases were identified in seven counties in NJ thorough the NJ State Cancer Registry, and controls through RDD and community-based recruitment. During in-person interviews, questionnaires were administered and detailed anthropometric measurements were obtained. Body composition was assessed by bioelectrical impedance analysis.

RESULTS

BMI did not have a major impact on pre- or post-menopausal breast cancer, but was significantly associated with reduced risk of ER-/PR- tumors among postmenopausal women (OR: 0.37; 95% CI: 0.15-0.96 for BMI > 30 vs. BMI < 25). Furthermore, increased premenopausal breast cancer risk was found for higher waist and hip circumferences after adjusting for BMI, with ORs of 2.25 (95% CI: 1.07-4.74) and 2.91 (95% CI: 1.39-6.10), respectively, comparing the highest vs. lowest quartile. While ORs for higher fat mass and percent body fat among postmenopausal women were above one, confidence intervals included the null value.

CONCLUSIONS

Our study suggests that in AA women BMI is generally unrelated to breast cancer. However, higher waist and hip circumferences were associated with increased pre-menopausal breast cancer risk, while general obesity was associated with decreased risk of ER-/PR- tumors. Larger studies are needed to confirm findings and to evaluate the impact of obesity on breast cancer subtypes.

Does alcohol increase breast cancer risk in African-American women? Findings from a case-control study

Background:

Alcohol is an important risk factor for breast cancer in Caucasian women, but the evidence in African-American (AA) women is limited and results are inconclusive.

Methods:

Associations between recent and lifetime drinking and breast cancer risk were evaluated in a large sample of AA women from a case–control study in New York and New Jersey. Multivariable logistic regression models provided odds ratios (ORs) and 95% confidence intervals (CIs).

Results:

There was no association between recent drinking and breast cancer risk, even when stratified by menopausal status or by hormone receptor status. A borderline decreased risk with increased lifetime consumption was found (OR=0.77; 95% CI: 0.58–1.03), which was stronger among women who drank when under 20 years of age (OR=0.65; 95% CI: 0.47–0.89), regardless of menopausal or hormone receptor status.

Conclusion:

Breast cancer risk associated with recent alcohol consumption was not apparent in AA women, while early age drinking seemed to decrease risk. This is the first investigation on recent and lifetime drinking in subgroups and drinking during different age periods in AA women. If findings are replicated, racial differences in biological pathways involving alcohol and its metabolites should be explored.

Breast cancer incidence in black and white women stratified by estrogen and progesterone receptor statuses

BACKGROUND

There is increasing evidence that breast cancer is a heterogeneous disease presented by different phenotypes and that white women have a higher breast cancer incidence rate, whereas black women have a higher mortality rate. It is also well known that white women have lower incidence rates than black women until approximately age 40, when rate curves cross over and white women have higher rates. The goal of this study was to validate the risk of white and black women to breast cancer phenotypes, stratified by statuses of the estrogen (ER) and progesterone (PR) receptors.

METHODOLOGY/PRINCIPAL FINDINGS

SEER17 data were fractioned by receptor status into [ER+, PR+], [ER-, PR-], [ER+, PR-], and [ER-, PR+] phenotypes. It was shown that in black women compared to white women, cumulative age-specific incidence rates are: (i) smaller for the [ER+, PR+] phenotype; (ii) larger for the [ER-, PR-] and [ER-, PR+] phenotypes; and (iii) almost equal for the [ER+, PR-] phenotype. Clemmesen's Hook, an undulation unique to women's breast cancer age-specific incidence rate curves, is shown here to exist in both races only for the [ER+, PR+] phenotype. It was also shown that for all phenotypes, rate curves have additional undulations and that age-specific incidence rates are nearly proportional in all age intervals.

CONCLUSIONS/SIGNIFICANCE

For black and white women, risk for the [ER+, PR+], [ER-, PR-] and [ER-, PR+] phenotypes are race dependent, while risk for the [ER+, PR-] phenotype is almost independent of race. The processes of carcinogenesis in aging, leading to the development of each of the considered breast cancer phenotypes, are similar in these racial groups. Undulations exhibited on the curves of age-specific incidence rates of the considered breast cancer phenotypes point to the presence of several subtypes (to be determined) of each of these phenotypes.

Age-specific incidence of breast cancer subtypes: understanding the black-white crossover

BACKGROUND

Breast cancer incidence is higher among black women than white women before age 40 years, but higher among white women than black women after age 40 years (black-white crossover). We used newly available population-based data to examine whether the age-specific incidences of breast cancer subtypes vary by race and ethnicity.

METHODS

We classified 91908 invasive breast cancers diagnosed in California between January 1, 2006, and December 31, 2009, by subtype based on tumor expression of estrogen receptor (ER) and progesterone receptor (PR)-together referred to as hormone receptor (HR)-and human epidermal growth factor receptor 2 (HER2). Breast cancer subtypes were classified as ER or PR positive and HER2 negative (HR(+)/HER2(-)), ER or PR positive and HER2 positive (HR(+)/HER2(+)), ER and PR negative and HER2 positive (HR(-)/HER2(+)), and ER, PR, and HER2 negative (triple-negative). We calculated and compared age-specific incidence rates, incidence rate ratios, and 95% confidence intervals by subtype and race (black, white, Hispanic, and Asian). All P values are two-sided.

RESULTS

We did not observe an age-related black-white crossover in incidence for any molecular subtype of breast cancer. Compared with white women, black women had statistically significantly higher rates of triple-negative breast cancer at all ages but statistically significantly lower rates of HR(+)/HER2(-) breast cancers after age 35 years (all P < .05). The age-specific incidence of HR(+)/HER2(+) and HR(-)/HER2(+) subtypes did not vary markedly between white and black women.

CONCLUSIONS

The black-white crossover in breast cancer incidence occurs only when all breast cancer subtypes are combined and relates largely to higher rates of triple-negative breast cancers and lower rates of HR(+)/HER2(-) breast cancers in black vs white women.

Breast cancer incidence and case fatality among 4.7 million women in relation to social and ethnic background: a population-based cohort study

INTRODUCTION

Incidence of breast cancer is increasing around the world and it is still the leading cause of cancer mortality in low- and middle-income countries. We utilized Swedish nationwide registers to study breast cancer incidence and case fatality to disentangle the effect of socioeconomic position (SEP) and immigration from the trends in native Swedes.

METHODS

A nation-wide cohort of women in Sweden was followed between 1961 and 2007 and incidence rate ratio (IRR) and hazard ratio (HR) with 95% confidence intervals (CIs) were estimated using Poisson and Cox proportional regression models, respectively.

RESULTS

Incidence continued to increase; however, it remained lower among immigrants (IRR = 0.88, 95% CI = 0.86 to 0.90) but not among immigrants' daughters (IRR = 0.97, 95% CI = 0.94 to 1.01) compared to native Swedes. Case fatality decreased over the last decades and was similar in native Swedes and immigrants. However, case fatality was significantly 14% higher if cancer was diagnosed after age 50 and 20% higher if cancer was diagnosed in the most recent years among immigrants compared with native Swedes. Women with the highest SEP had significantly 20% to 30% higher incidence but had 30% to 40% lower case fatality compared with women with the lowest SEP irrespective of country of birth. Age at immigration and duration of residence significantly modified the incidence and case fatality.

CONCLUSIONS

Disparities found in case fatality among immigrants by age, duration of residence, age at immigration and country of birth emphasize the importance of targeting interventions on women that are not likely to attend screenings or are not likely to adhere to the therapy suggested by physicians. The lower risk of breast cancer among immigrant women calls for more knowledge about how the lifestyle factors in these women differ from those with high risk, so that preventative measures may be implemented.

The role of anthropometric and nutritional factors on breast cancer risk in African-American women

OBJECTIVE

While the role of nutrition, physical activity and body size on breast cancer risk has been extensively investigated, most of these studies were conducted in Caucasian populations. However, there are well-known differences in tumour biology and the prevalence of these factors between African-American and Caucasian women. The objective of the present paper was to conduct a review of the role of dietary factors, anthropometry and physical activity on breast cancer risk in African-American women.

DESIGN

Twenty-six research articles that presented risk estimates on these factors in African-American women and five articles involving non-US black women were included in the current review.

SETTING

Racial disparities in the impact of anthropometric and nutritional factors on breast cancer risk.

SUBJECTS

African-American and non-US black women.

RESULTS

Based on the few studies that presented findings in African-American women, an inverse association with physical activity was found for pre- and postmenopausal African-American women, while the association for anthropometric and other dietary factors, such as alcohol, was unclear. Studies assessing the effect by molecular subtypes in African-American women were too few and based on sample sizes too small to provide definitive conclusions.

CONCLUSIONS

The effect of certain nutrition and lifestyle factors on breast cancer in African-American women is not starkly distinct from those observed in white women. However, there is an enormous need for further research on this minority group to obtain more confirmatory findings.

Basal phenotype breast cancer: implications for treatment and prognosis

Breast cancer is the most common malignancy in females. The origins and biology of breast carcinomas remain unclear. Cellular and molecular heterogeneity results in different distinct groups of tumors with different clinical behavior and prognosis. Gene expression profiling has delineated five molecular subtypes based on similarities in gene expression: luminal A, luminal B, HER2 overexpressing, normal-like and basal-like. Basal-like breast cancer (BLBC) lacks estrogen receptor, progesterone receptor and HER2 expression, and comprises myoepithelial cells. Specific features include high proliferative rate, rapid growth, early recurrence and decreased overall survival. BLBC is associated with ductal carcinoma in situ, BRCA1 mutation, brain and lung metastasis, and negative axillary lymph nodes. Currently, chemotherapy is the only therapeutic choice, but demonstrates poor outcomes. There is an overlap in definition between triple-negative breast cancer and BLBC due to the triple-negative profile of BLBC. Despite the molecular and clinical similarities, the two subtypes respond differently to neoadjuvant therapy. Although particular morphologic, genetic and clinical features of BLBC have been identified, a variety of definitions among studies accounts for the contradictory results reported. In this article the molecular morphological and histopathological profile, the clinical behavior and the therapeutic options of BLBC are presented, with emphasis on the discordant findings among studies.

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

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

Phytohemagglutinin-induced mitotic index in blood lymphocytes: a potential biomarker for breast cancer risk

Background

Cell proliferation is associated with the pathogenesis of cancer because it provides opportunities for accumulating genetic mutations. However, biomarkers of cell proliferation in response to environmental stimuli have not been adequately explored for breast cancer risk.

Methods

In a case-control study of 200 breast cancer patients and 360 healthy controls, we investigated the association between phytohemagglutinin (PHA)-induced mitotic index in blood lymphocyte and breast cancer risk.

Results

Having high mitotic index (>3.19%) was associated with an increased risk of breast cancer, with adjusted odds ratios (95% confidence interval) of 1.54 (1.03–2.30) and 2.03 (1.18–3.57) for all women and post-menopausal women, respectively. Mitotic index was correlated with some reproductive factors and body mass index in controls.

Conclusions

Our data suggest increased PHA-induced mitotic index in blood lymphocytes is associated with an increased breast cancer risk and that this association may be modulated by reproductive and other hormones.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

IMPACT

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

Comparative analysis of breast cancer risk factors among Hispanic and non-Hispanic white women

BACKGROUND

Hispanic and non-Hispanic white (NHW) populations within the United States have different breast cancer incidence rates, yet there is limited research on how ethnic differences in the prevalence of established risk factors and their associations with breast cancer contribute to the observed differences.

METHODS

Odds ratios and population-attributable risk estimates for breast cancer were determined for Hispanic and NHW women in the population-based, case-control 4-Corners Breast Cancer Study.

RESULTS

When comparing NHW and Hispanic women, the authors observed differences in the prevalence of certain risk factors and in the magnitude and direction of their associations with breast cancer. Hispanic women were more likely to have characteristics associated with lower breast cancer risk, such as younger age at first birth, having more children, shorter height, less hormone use, and less alcohol consumption. Among premenopausal women, ethnic differences in risk were observed with taller height and positive family history, which were not associated with breast cancer among Hispanic women. Among postmenopausal women, associations for certain risk factors were either weaker or were not observed in Hispanics, such as recent estrogen plus progestin hormone therapy use and younger age at menarche. Among NHW women, an estimated 62% to 75% of breast cancers were attributed to the evaluated risk factors compared with 7% to 36% in Hispanic women.

CONCLUSIONS

Breast cancer risk factors established in NHW populations had less influence on breast cancer risk in Hispanic women. These findings reflect the need to further evaluate breast cancer risk factors among different ethnic and racial populations.

Epidemiology of breast cancer subtypes in two prospective cohort studies of breast cancer survivors

Introduction

The aim of this study was to describe breast tumor subtypes by common breast cancer risk factors and to determine correlates of subtypes using baseline data from two pooled prospective breast cancer studies within a large health maintenance organization.

Methods

Tumor data on 2544 invasive breast cancer cases subtyped by estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (Her2) status were obtained (1868 luminal A tumors, 294 luminal B tumors, 288 triple-negative tumors and 94 Her2-overexpressing tumors). Demographic, reproductive and lifestyle information was collected either in person or by mailed questionnaires. Case-only odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression, adjusting for age at diagnosis, race/ethnicity, and study origin.

Results

Compared with luminal A cases, luminal B cases were more likely to be younger at diagnosis (P = 0.0001) and were less likely to consume alcohol (OR = 0.74, 95% CI = 0.56 to 0.98), use hormone replacement therapy (HRT) (OR = 0.66, 95% CI = 0.46 to 0.94), and oral contraceptives (OR = 0.73, 95% CI = 0.55 to 0.96). Compared with luminal A cases, triple-negative cases tended to be younger at diagnosis (P ≤ 0.0001) and African American (OR = 3.14, 95% CI = 2.12 to 4.16), were more likely to have not breastfed if they had parity greater than or equal to three (OR = 1.68, 95% CI = 1.00 to 2.81), and were more likely to be overweight (OR = 1.82, 95% CI = 1.03 to 3.24) or obese (OR = 1.97, 95% CI = 1.03 to 3.77) if premenopausal. Her2-overexpressing cases were more likely to be younger at diagnosis (P = 0.03) and Hispanic (OR = 2.19, 95% CI = 1.16 to 4.13) or Asian (OR = 2.02, 95% CI = 1.05 to 3.88), and less likely to use HRT (OR = 0.45, 95% CI = 0.26 to 0.79).

Conclusions

These observations suggest that investigators should consider tumor heterogeneity in associations with traditional breast cancer risk factors. Important modifiable lifestyle factors that may be related to the development of a specific tumor subtype, but not all subtypes, include obesity, breastfeeding, and alcohol consumption. Future work that will further categorize triple-negative cases into basal and non-basal tumors may help to elucidate these associations further.

Risk factors for breast cancer in a black population--the Barbados National Cancer Study

The Barbados National Cancer Study (BNCS) is a nationwide case-control study investigating environmental and genetic factors for breast cancer (BC) in a predominantly African-origin population with similar ancestry as African-Americans. This report evaluates associations of incident BC in the BNCS to various factors, including demographic, anthropometric, reproductive and family history variables, not investigated previously in this population. The BNCS included 241 incident BC cases and 481 age-matched female controls, with mean ages of 57 and 56 years, respectively. In addition to a reported family history of BC in a close relative [odds ratios (OR) = 3.74, 95% CI (1.41, 9.90) in a parent; OR = 3.26 (1.47, 7.21) in a sibling], other factors associated with BC were older age at first full-term pregnancy [OR = 1.04 (1.00, 1.07)] and having a history of benign breast disease [OR = 1.88 (1.19, 2.99)]. Increased parity reduced the risk of BC [OR = 0.34 (0.15, 0.77) among those with >or=3 children]. The reproductive patterns of African-Barbadian (AB) women tended to differ from those of African-American (AA) women (later age of menarche, earlier age at first pregnancy, higher frequency of lactation and infrequent use of exogenous hormones) and could help to explain their considerably lower postmenopausal incidence of BC. The relationship between reported family history and BC, combined with the associations noted for several reproductive and other variables, supports the genetic and environmental contributions to BC, which may vary in populations across the African diaspora. Further investigations of other populations may clarify these issues.

Age-related crossover in breast cancer incidence rates between black and white ethnic groups

BACKGROUND

Although breast cancer incidence is higher in black women than in white women among women younger than 40 years, the reverse is true among those aged 40 years or older. This crossover in incidence rates between black and white ethnic groups has been well described, has not been completely understood, and has been viewed as an artifact.

METHODS

To quantify this incidence rate crossover, we examined data for 440 653 women with invasive breast cancer from the National Cancer Institute's Surveillance, Epidemiology, and End Results database from January 1, 1975, through December 31, 2004. Data on invasive female breast cancers were stratified by race, age at diagnosis, year of diagnosis, and tumor characteristics. Standard descriptive analyses were supplemented with Poisson regression models, age-period-cohort models, and two-component mixture models. All statistical tests were two-sided.

RESULTS

We observed qualitative (ie, crossing or reversing) interactions between age and race. That is, age-specific incidence rates overall (expressed as number of breast cancers per 100 000 woman-years) were higher among black women (15.5) than among white women (13.1) younger than 40 years (difference = 2.4, 95% confidence interval [CI] = 2.4 to 2.4), and then, age-specific rates crossed with rates higher among white women (281.3) than among black women (239.5) aged 40 years or older (difference = 41.8, 95% CI = 41.7 to 41.9). The black-to-white incidence rate crossover was observed for all tumor characteristics assessed, although the crossover occurred at earlier ages of diagnosis for low-risk tumor characteristics than for high-risk tumor characteristics. The incidence rate crossover between ethnic groups was robust (ie, reliable and reproducible) to adjustment for calendar period and birth cohort effects in age-period-cohort models (P < .001 for difference by race).

CONCLUSION

Although this ecologic study cannot determine the individual-level factors responsible for the racial crossover in vital rates, it confirms that the age-related crossover in breast cancer incidence rates between black and white ethnic groups is a robust age-specific effect that is independent of period and cohort effects.

Recent trends in breast cancer among younger women in the United States

Increases in the incidence of postmenopausal breast cancers have been linked to screening and menopausal hormone use, but younger women have received less attention. Thus, we analyzed trends in breast cancer incidence (N = 387 231) using the National Cancer Institute's Surveillance, Epidemiology, and End Results Program 13-Registry database (1992-2004). Whites had higher incidence rates than blacks after age 40 years, but the reverse was true among younger women (black-white crossover). Among younger women, the rate per 100,000 woman-years was 16.8 for black vs 15.1 for white women; the highest black-white incidence rate ratio (IRR) was seen among women younger than 30 years (IRR = 1.52, 95% confidence interval = 1.34 to 1.73). This risk pattern was not observed in other ethnic groups. The black-white crossover among younger women was largely restricted to breast cancers with favorable tumor characteristics. The annual percentage change in the incidence of invasive breast cancers decreased modestly among older women but increased among younger (<40 years) white women. Continued surveillance of trends is needed, particularly for molecular subtypes that preferentially occur among young women.

Adiposity, the metabolic syndrome, and breast cancer in African-American and white American women

Breast cancer, the second most common cause of cancer-related deaths in American women, varies substantially in incidence and mortality according to race and ethnicity in the United States. Although the overall incidence of breast cancer among African-American (AA) women is lower than in white American women, this cancer is more common in young premenopausal AA women, and AA breast cancer patients of all ages are more likely to have advanced disease at diagnosis, higher risk of recurrence, and poorer overall prognosis. Epidemiological studies indicate that these differences may be attributable in part to variation in obesity and body fat distribution. Additionally, AA women more frequently exhibit breast cancer with an aggressive and metastatic phenotype that may also be attributable to the endocrine and metabolic changes associated with upper body obesity. These changes include both elevated estrogen and androgen bioactivity, hyperinsulinemia, and perturbations of the adipokines. Type 2 diabetes and the metabolic syndrome, which are more common in AA women, have also been associated with breast cancer risk. Moreover, each of the individual components of the syndrome has been associated with increased breast cancer risk, including low levels of the adipocytokine, adiponectin. This review explores the specific roles of obesity, body fat distribution (particularly visceral and sc adipose tissue), type 2 diabetes, metabolic syndrome, and adipocytokines in explaining the differential patterns of breast cancer risk and prognosis between AA and white American women.

Qualitative age interactions (or effect modification) suggest different cancer pathways for early-onset and late-onset breast cancers

BACKGROUND

Prior to 1999-2000, breast cancer incidence rates had risen for decades, though more among older than younger women.

MATERIALS AND METHODS

To further explore the impact of advancing age-at-diagnosis upon breast cancer incidence, we used the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program (1974-2003).

RESULTS

Over time, we observed age interactions by tumor grade, stage, and race. For example, among women ages <40 years, high-grade lesions were more common than low-grade tumors for all time periods. Among women ages 40+ years, high-grade lesions were more common during early time periods then trend lines crossed, after which low-grade tumors were more common than high-grade lesions. Notably, the transition (crossover point) occurred earlier with advancing age-at-diagnosis.

CONCLUSION

The reversal (crossing) of incidence rates from high to low-grade tumors among women 40+ years is a qualitative age interaction, probably due to changing age-related risk factor and/or screening patterns, where mammography preferentially detected tumors of low malignant potential among older women. Though once thought to be rare or artifactual, qualitative age interactions suggest breast cancer heterogeneity. Indeed, if real, qualitative age interactions (effect modifications) imply different etiologic pathways for early-onset and late-onset types of breast cancer.

Breast Cancer and Ethnicity: Strong Association between Reproductive Risk Factors and Estrogen Receptor Status in Asian Patients?A Retrospective Study

Breast cancer characteristics vary in racial/ethnic groups. Reproductive risk factors have been associated with estrogen receptor positive disease. We examined the association between reproductive risk factors and receptor status in different racial/ethnic groups to determine if some of the variation can be explained by a different reproductive risk profile. A retrospective chart review of all new breast cancer cases presenting to Elmhurst Hospital Center (Elmhurst, NY) between 1997 and 2004 was conducted. Data including patient characteristics and tumor characteristics were obtained. Four hundred ninety-nine patients were divided into two groups: the first group consisted of patients with estrogen positive disease and the second of those with estrogen negative disease. Association between reproductive risk factors and estrogen receptor status was examined for each racial group. There was a significant variability in patient age, age at menarche, parity, rates of nulliparity, age at first birth, and rates of menopause between the different ethnic groups. We found a strong, statistically significant association between reproductive risk factors and estrogen positive disease in the Asian group, where 96% of breast cancer patients who were either nulliparous or had late onset of first childbirth were found to have estrogen positive disease, whereas only 52% of those without these risk factors were found to be estrogen positive. For black patients the rates were 55% versus 56%, for Hispanic patients 64% versus 61%, and for non-Hispanic whites 74% versus 81%. In our patient population, differences in breast cancer characteristics could not be ascribed to a different reproductive risk pattern.

A traditional Mediterranean diet decreases endogenous estrogens in healthy postmenopausal women

Breast cancer incidence and mortality rates are markedly lower in the south than in the north of Europe. This has been ascribed to differences in lifestyle and, notably, dietary habits across European countries. However, little information exists on the influence of different dietary regimens on estrogens and, hence, on breast cancer risk. Here we report results of our MeDiet Project, a randomized, dietary intervention study aimed to assess the effect of a Mediterranean diet on the profiles of endogenous estrogens in healthy postmenopausal women. Out of the 230 women who initially volunteered to participate in the study, 115 were found to be eligible and were enrolled. Women were then randomly assigned into an intervention (n = 58) and a control (n = 57) group. Women in the intervention group adhered to a traditional, restricted Mediterranean diet for 6 mo, whereas women in the control group continued to follow their regular diet. Women in the intervention group changed their dietary regimen substantially, and this eventually led to a shift from a prevalent intake of animal fat and proteins to a prevalent intake of vegetable fat and proteins. Regarding urinary estrogens, no significant difference was observed between the intervention and control groups at baseline. After 6 mo, however, control women did not show any major change but women in the intervention group exhibited a significant decrease (over 40%) of total estrogen levels (P < 0.02). The largest part of this modification was based on a marked decrease of specific estrogen metabolites, including hydroxy- and keto-derivatives of estradiol or estrone. To our knowledge, this is the first report to show that a traditional Mediterranean diet significantly reduces endogenous estrogen. This may eventually lead to identify selected dietary components that more effectively decrease estrogens levels and, hence, provide a basis to develop dietary preventive measures for breast cancer.

Cultural Competence Among Staff Nurses Who Participated in a Family-Centered Geriatric Care Program

The purpose of this training program was to prepare nursing staff in family-centered geriatric care that emphasizes providing culturally competent care to hospitalized elders at two major tertiary hospitals in New York. This research report corresponds to the first phase of a 3-year project. In this research project, a descriptive exploratory design was used to identify the levels of cultural awareness and cultural competence of nursing staff who participated in a family-centered geriatric care training program.

An overview of ethnicity and assessment of family history in primary care settings

PURPOSE

To discuss the importance of and the nurse practitioner's (NP's) role in the assessment of ethnicity/family of origin in conducting a multigenerational family history in primary care settings.

DATA SOURCES

A review of the literature on past research results addressing racial and ethnic disparities and current articles from scientific journals exploring the relationship between race and genetics. Web sites were from the National Institutes of Health, the Human Genome Research Institute, the National Cancer Institute, and the Health and Human Services Minority Health and Disparities report.

CONCLUSIONS

The family history has received renewed interest due to the sequencing of the human genome. A multigenerational family history is an important first step in screening for a multitude of disorders impacted by genetic susceptibility, shared environments, and common behaviors. Assessment of the patient's ethnicity/family of origin is an integral part of the multigenerational family history, particularly in the diagnosis of chronic diseases and the assessment of risks for genetic disorders. The multigenerational family history is important in diagnosis, predictive genetic testing, disease prevention, and health promotion. Challenges facing NPs and the utilization of a multigenerational family history in the current U.S. health system include (a) training clinicians on the correct assessment and utilization of a multigenerational family history, (b) assessment of the subtleties of ethnicity and identifying multiple ethnic groups within a family, (c) collection of the family history in a manner that is sensitive to the cultural beliefs of individuals, and (d) avoidance of stereotyping.

IMPLICATIONS FOR PRACTICE

Significant advances in genetics and genetic testing requires that NPs be well versed in collecting and interpreting a multigenerational family history to include assessment of the patient/family's ethnicity/family of origin. The ability to effectively conduct and evaluate the individual's and family's health risk through a multigenerational family history will be important in diagnosis, health promotion, disease prevention, and the determination for genetic counseling referral and predictive testing when appropriate. Assessment of risk and prevention of disease is also important in reducing health disparities.

A comparison of the pattern of occurrence of breast cancer in Nigerian and British women

Studies have suggested a predominance of premenopausal breast cancer in black compared to white women. The aim of the study was to compare the age specific incidence of breast cancer in Nigerian and British women. The mean age at presentation was 43.1 and 64 years for Jos (Nigeria) and Norfolk (United Kingdom), respectively. The age specific incidence rates were higher in women above 50 years compared to women less than 50 years of age in both populations. The odds of having breast cancer for women aged less than 50 years is 3.0 times higher in Norfolk (95% Confidence Interval 2.0-4.4) than Jos and 9.0 times higher for women over 50 years of age in Norfolk (95% Confidence Interval 5.3-18.3) than Jos. The age specific incidence rates are higher for postmenopausal women in both populations; with higher rates for all age groups in the United Kingdom population.

Use of statistics to assess the global burden of breast cancer

A variety of statistics are used to quantify the burden (occurrence and outcome) of cancer generally and of breast cancer specifically. When undertaking any cancer control program, understanding these statistics, their source, and their quality is important for assessing the current situation, allocating resources to different control strategies, and evaluating progress. Two core statistics are the cancer incidence rate and the cancer mortality rate, which provide estimates of the average risk of acquiring and of dying from the disease, respectively. About 16% of the world's population is covered by registration systems that produce cancer incidence statistics, while mortality data are available for about 29%. Breast cancer incidence and mortality vary considerably by world region. In general, the incidence is high (greater than 80 per 100,000) in developed regions of the world and low (less than 30 per 100,000), though increasing, in developing regions; the range of mortality rates is much less (approximately 6-23 per 100,000) because of the more favorable survival of breast cancer in (high-incidence) developed regions. The incidence of breast cancer is increasing almost everywhere. This unfavorable trend is due in part to increases in risk factors (decreased childbearing and breast-feeding, increased exogenous hormone exposure, and detrimental dietary and lifestyle changes, including obesity and less physical activity). On the other hand, mortality is now decreasing in many high-risk countries due to a combination of intensified early detection efforts and the introduction of mammographic screening, resulting in the diagnosis of more small, early stage tumors, and advances in treatment.

Comparative epidemiology of breast cancer among men and women in the US, 1996 to 2000

OBJECTIVE

Few investigations of breast cancer among men have been conducted because of the relative rarity of this malignancy. The objective of this analysis was to compare the demographic, pathological, and clinical features of breast cancer among men and women.

METHODS

Breast cancer among 6379 men and 744,275 women was identified through 34 US population-based registries in the US during the period 1996 to 2000. These registries were estimated to represent 69% of the US population. Age-adjusted incidence rates (AAIR) were calculated per million population using counts derived from the 2000 US census.

RESULTS

The AAIR of breast cancer among men (16.6) was substantially lower than the incidence among women (1557.7). Rates of breast cancer among black men were higher than among white and Asian-Pacific Island men, in contrast to women among whom rates in whites exceeded those among other ethnic groups. Similar to women, breast cancer rates among non-Hispanic men were 50% greater than among Hispanic men. Ductal cancer was the most common histologic type diagnosed in both sexes. The incidence of lobular cancer was rare in men, but Paget's disease and papillary carcinoma occurred with lower relative frequency in women than in men. Lobular breast cancers were less common among black men and women than among other ethnic groups. In situ breast cancer was diagnosed in 10.8% of men and 16.2% of women. Localized breast cancer was the most common stage at diagnosis in both sexes and all ethnic groups, although women were more likely than men to be diagnosed at a localized stage. Cancer was 10% more likely to be diagnosed in the left breast than the right breast among men compared to 4% in women.

CONCLUSIONS

In spite of the rare incidence of breast cancer in men, the descriptive epidemiology of this malignancy is surprisingly similar to that in women. An explanation for the greater relative incidence of breast cancer in black men is a research challenge.

Risk factors for fatal breast cancer in African-American women and White women in a large US prospective cohort

African-American women have a higher lifetime risk of fatal breast cancer than do White women. Recent studies suggest that breast cancer risk factors may vary by race. The authors examined risk factors for fatal breast cancer in postmenopausal African-American women and White women in a large US prospective cohort. In 1982, 21,143 African-American women and 409,093 White women in the Cancer Prevention Study II completed a questionnaire on reproductive, medical, anthropometric, and demographic factors. During a 20-year follow-up, 257 deaths from breast cancer occurred among African-American women and 4,265 among Whites. Cox proportional hazards modeling was used to calculate multivariate-adjusted rate ratios, stratified by race. Higher body mass index, taller height, and physical inactivity were associated with increased breast cancer mortality rates in both groups. A college education was associated with higher mortality from breast cancer only in Africa-American women (hazard ratio = 1.62, 95% confidence interval: 1.13, 2.30; p(trend) = 0.01, vs. less than a high school education). Most other risk factors were associated with breast cancer rates similarly in both groups. With few exceptions, established breast cancer risk factors were similarly associated with risk of death from breast cancer among African-American women and White women.

Risk of breast cancer among enlisted Army women occupationally exposed to volatile organic compounds

BACKGROUND

The military presents a unique opportunity to study the incidence of disease in a population with complete knowledge of person-time and occupation. Women in the Army are employed more frequently in non-traditional, industrial jobs such as auto mechanic and motor transport operators than in the general US population, increasing the probability of exposure to industrial chemicals. A cohort to investigate the risk of breast cancer among active duty Army women occupationally exposed to volatile organic chemicals (VOCs) was constructed.

METHODS

Age-adjusted incidence rates for breast cancer were calculated for more than 270,000 enlisted women who served between 1980-1996. Twenty-one VOCs, described in previously published literature as having a potential risk of breast cancer, were identified in an Army industrial hygiene survey database. Job title histories were linked to workplace chemical evaluations conducted by Army industrial hygienists, which included a subjective exposure potential rating (high, medium, low, and none) for each VOC. Poisson regression analysis was used to evaluate the association between the exposure rating by job title and breast cancer.

RESULTS

The incidence of breast cancer in the cohort was significantly elevated in women younger than 35 years of age, especially among black women, when compared to the age-specific rates in the general population. Women who worked in occupations with a moderate to high exposure potential to at least one VOC had a 48% increased risk (P < 0.05) of breast cancer while on active duty between 1980-1996 when compared to those women with low to no exposure potential.

CONCLUSIONS

This study provides preliminary evidence that exposure to one or more of the study VOCs is associated with an increased risk of breast cancer. Further substance-specific, quantitative analyses are warranted.

Racial and ethnic disparities in breast cancer rates by age: NAACCR Breast Cancer Project

OBJECTIVE

To examine age-specific rates of breast cancer incidence among racial and ethnic groups in the United States.

METHODS

Subjects were 363,801 women diagnosed with invasive breast cancer diagnosed during 1994--1998 and reported in the North American Association of Central Cancer Registries (NAACCR) data set. Variables analyzed included race, ethnicity, 5-year age group (from 10 years through 85+years), and stage at time of diagnosis (localized, regional, distant). Incidence rates per 100,000 women were calculated for each 5--year age group and stratified by stage. Rate ratios and 95% confidence intervals were calculated by comparing each racial group with whites and Hispanics with non-Hispanics.

RESULTS

Black women experience significantly higher breast cancer incidence up to the age of 40 years and significantly lower incidence after age 50 compared with white women of the same ages. This is called the 'crossover' effect. This shifting burden of higher incidence occurs at ages 35--39 for localized stage and at ages 55--59 for regional stage. For distant stage, black women of all ages experience higher incidence compared with white women. Similar crossover effects do not exist for American Indian (AI) or Asian/Pacific Islander (API) women compared with white women. Both AI and API women have significantly lower incidence of breast cancer compared with white women, and Hispanic women have significantly lower incidence compared with non-Hispanic women.

CONCLUSIONS

This study highlights racial and ethnic differences in breast cancer incidence rates among US women. The crossover effect between black and white women, particularly the lower incidence of localized stage disease diagnosed in older black women, is a significant phenomenon that may be associated with screening practices, and has implications for public health planning and cancer control initiatives to reduce racial/ethnic disparities.

Results of breast cancer screening in first generation migrants in Northwest Netherlands

To determine breast cancer screening results according to country of birth data were used from the breast cancer screening organization of the Comprehensive Cancer Centre Amsterdam, The Netherlands. Overall (age-adjusted) attendance of the breast cancer screening was 76% for women aged 50-69. Attendance was significantly lower for women born in non-western countries (Surinam 59%, Turkey 44% and Morocco 37%) and for women with residence in Amsterdam (68%). Referral and detection rates for women from non-western countries were 5.1 and 2.2 per 1000 screened women, respectively, compared with 8.8 and 4.0 for women born in The Netherlands (P<0.05). The positive predictive value was 45% for women born in The Netherlands and western countries and 43% for women born in non-western countries. Although women born in non-western countries attend breast cancer screening less frequently than women born in The Netherlands, they also have a low detection rate. The latter finding justifies a passive attitude towards the low attendance.

Distinct breast cancer incidence and prognostic patterns in the NCI's SEER program: suggesting a possible link between etiology and outcome

BACKGROUND

Breast cancer is a heterogeneous and chronic disease with relapses and death occurring 25 years or more after primary diagnosis. Standard tumor characteristics are used to predict initial relapse or death, but their ability to estimate long-term patterns of failure may be limited.

METHODS

To further evaluate the significance of standard tumor features, we compared incidence and prognostic patterns in the National Cancer Institute's (NCI's) large-scale population-based Surveillance, Epidemiology, and End Results (SEER) program for high-risk versus low-risk breast cancers, i.e., size > 2.0 versus < or = 2.0 cm, lymph node positive versus negative, high versus low histologic grade, and hormone receptor negative versus positive expression, respectively. Data were stratified by age 50 years to approximate menopause.

RESULTS

High-risk versus low-risk breast cancers demonstrated two very different incidence and prognostic patterns. Age-specific incidence rates among women with high-risk tumors increased until age 50 years then flattened, whereas rates among women with low-risk tumors increased continuously with aging. Hazard rates for breast cancer death spiked sharply two years following primary breast cancer diagnosis among women with high-risk but not with low-risk tumors. Paradoxically, hazard function crossed over 6-8 years following breast cancer diagnosis, with hazard rates lower for high-risk than for low-risk breast cancers.

CONCLUSION

Distinct incidence and prognostic patterns among high-risk and low-risk breast cancers suggest a possible link between breast cancer etiology and outcome. These epidemiologic results appear to complement emerging molecular genetic techniques, showing distinct genotypes for high-risk and low-risk breast cancer phenotypes.

Cancer pattern among hypertensive patients in North Karelia, Finland

The objective of this study was to determine the site-specific cancer incidence of hypertensive patients and examine the effect of blood pressure-related variables on the risk of cancers with elevated incidence among the hypertensive patients. A record linkage study of Hypertension Register of the North Karelia Project and the Finnish Cancer Registry was conducted. The mean follow-up time was 16 years. A total of 20 529 hypertensive patients were studied. Main outcome measures were standardised incidence ratios and hazard ratios. The overall cancer incidence was close to that of the general population for both men and women. The incidence rate for the kidney cancer was significantly increased in hypertensive patients (standardised incidence ratio 1.34, 95% confidence interval (CI) 1.11-1.60), as well as incidence rates for cancers of pancreas (1.26, 1.02-1.54), and endometrium (1.22, 1.01-1.44) in hypertensive women. The incidence of lung cancer was significantly decreased (0.86, 0.77-0.95). The incidence of liver cancer was elevated with borderline significance (1.36, 0.99-1.82). In Cox regression models, the use of antihypertensive drugs at baseline was a significant predictor of kidney (hazard ratio for use of antihypertensive drugs 1.89, 95% CI 0.96-3.75) and pancreatic cancer (1.78, 0.99-3.22) in women but not in men. The incidence of endometrial cancer or liver cancer was not related to blood pressure levels or the use of antihypertensive drugs. In women, obesity was a significant predictor of cancers of the endometrium, kidney and liver. In conclusion, increased occurrence of some cancer types among hypertensive patients seem to be partly explained by obesity and the use of antihypertensive drugs.

Race and family history assessment for breast cancer

OBJECTIVE

Studies have demonstrated disparities in breast cancer screening between racial and ethnic groups. Knowledge of a woman's family history of breast cancer is important for initiating early screening interventions. The purpose of this study was to determine whether differences exist in the collection of family history information based on patient race.

DESIGN

Cross-sectional patient telephone interview and medical record review.

SETTING

Eleven primary care practices in the Greater Boston area, all associated with Harvard Medical School teaching hospitals.

PARTICIPANTS

One thousand seven hundred fifty-nine women without a prior history of breast cancer who had been seen at least once by their primary care provider during the prior year.

MEASUREMENTS AND MAIN RESULTS

Data were collected on patients regarding self-reported race, family breast cancer history information, and breast cancer screening interventions. Twenty-six percent (462/1,759) of the sample had documentation within their medical record of a family history for breast cancer. On multivariate analysis, after adjusting for patient age, education, number of continuous years in the provider's practice, language, and presentation with a breast complaint, white women were more likely to be asked about a breast cancer family history when compared to nonwhite women (odds ratio, 1.68; 95% confidence interval, 1.21 to 2.35).

CONCLUSIONS

The majority of women seen by primary care providers do not have documentation of a family breast cancer history assessment within their medical record. White women were more likely to have family breast cancer information documented than nonwhites.

Health-related quality of life in a multiethnic sample of breast cancer survivors

BACKGROUND

Little is known about the experiences of women from varying ethnic groups following treatment for breast cancer.

PURPOSE

This study provides a comprehensive description of health-related quality of life (HRQL) and identifies problem areas and predictive factors for a multiethnic sample.

METHODS

Six hundred twenty-one breast cancer survivors from 2 major cities participated within 5 years of their diagnosis. Participants were African Americans, Latinas, Asian Americans, and Whites. Patients filled out questionnaire packets comprising standardized instruments related to HRQL, psychological adjustment, cancer-related treatment, and demographic variables. Data were analysed using 2 methods: (a) observation of findings prior to controlling for demographic and treatment variables and (b) observation of findings after controlling for variables confounded with ethnicity.

RESULTS

Findings indicate that most women experienced good HRQL. Group differences revealed that African Americans found more meaning in life as a result of having breast cancer, and Latinas reported more physical symptoms. Age predicted aspects of HRQL for African Americans and Whites.

CONCLUSIONS

This study comprehensively assessed HRQL following breast cancer for ethnic minority women. Most breast cancer survivors in this study reported levels of HRQL comparable to established norms. However, some quality of life impediments surfaced in particular groups. Researchers should not assume that predictive models of breast cancer HRQL are the same across ethnic groups.

International variation

There were an estimated 10 million new cases, 6 million deaths and 22 million persons living with cancer in the year 2000. The most common cancers are, in terms of new cases, lung (1.2 million), breast (1.05 million), colon-rectum (945 000), stomach (876 000) and liver (564 000). The geographic distributions of some 20 types of cancer for which national estimates have been made are summarized. These patterns are examined with respect to the likely reasons in terms of variation in exposure to carcinogens (in the external environment or through lifestyle choices) or in genetic susceptibility to them. Related data from studies of migrant populations (that allow comparisons of genetically similar populations living in different environments) and from comparisons between different ethnic groups living in the same country are used to help in the interpretation of the geographic patterns. Information on the burden of disease also has a very important role in the planning and monitoring of programmes of cancer control.

Breast cancer risk among first-generation migrants in the Netherlands

We investigated breast cancer incidence in migrants in the Netherlands in 1988–1998. The standardised incidence ratio for breast cancer in Northwest-Netherlands was statistically significantly reduced for women born in Surinam (0.56), Turkey (0.29) and Morocco (0.22). The proportion of women with advanced stages (III and IV) did not differ significantly between migrants and women born in the Netherlands.

Comparison of Age-Specific Incidence Rate Patterns for Different Histopathologic Types of Breast Carcinoma

Objective: The age-specific incidence rate curve for breast carcinoma overall increases rapidly until age 50 years, and then continues to increase at a slower rate for older women. In this analysis, our objective was to compare age-specific incidence rate patterns for different morphologic types of breast carcinoma. Materials and methods: We analyzed age-specific incidence rate curves by histopathologic subclassification using records from 11 standard National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) registries, diagnosed during the years 1992 to 1999. Data were examined by age &lt;50 and ≥50 years to simulate menopause. Results: Age-specific incidence rate curves showed three dominant patterns: (1) Rates for infiltrating duct carcinoma of no special type (duct NST), tubular, and lobular carcinomas increased rapidly until age 50 years then rose more slowly. (2) Rates for medullary and inflammatory breast carcinomas increased rapidly until age 50 years then failed to increase. (3) Rates for papillary and mucinous carcinomas increased steadily at all ages. Rate patterns varied by estrogen receptor expression but were unaffected by SEER registry, race, nodal status, or grade. Conclusion: Age-specific incidence rates for breast carcinomas differed by histopathologic type. Rates that failed to increase after 50 years suggested that menopause had greater impact on medullary and inflammatory carcinomas than on duct NST, tubular, and lobular carcinomas. Menopause did not seem to have any effect on papillary or mucinous carcinomas as evidenced by steadily rising rates at all ages. Future etiologic and/or prevention studies should consider the impact of age-specific risk factors and/or exposures on different histopathologic types of breast carcinomas.

Is Male Breast Cancer Similar or Different than Female Breast Cancer?

OBJECTIVE

To determine if male breast carcinogenesis was similar to its more common female counterpart, we compared incidence patterns among men and women with breast cancer.

METHODS

Breast cancer records were obtained from the SEER database. Women were stratified by age < 50 and > or = 50 years to simulate premenopausal and postmenopausal breast cancer.

RESULTS

Age-adjusted incidence trends were stable among men but increased among women. Male to female breast cancer ratio was higher for blacks than for whites. Favorable prognostic factors reflective of tumor biology (nuclear grade and hormone receptor expression) were more common for men and postmenopausal women than for premenopausal women. For example, low nuclear grade, estrogen and progesterone receptor-positive expression were more common among men and postmenopausal women than among premenopausal women. The age-specific incidence rate curve for men increased steadily for all ages with a constant slope. On the other hand, age-specific rates for women increased rapidly until age 50 years then rose at a slower rate for postmenopausal women. Age-frequency distribution for male breast cancer was unimodal, with peak incidence at age 71 years. Age-frequency distribution for women was bimodal with early-onset and late-onset incidence at 52 and 71 years, respectively.

CONCLUSIONS

Gender-specific incidence trends differed, most likely reflective of female-related changes in surveillance and/or reproductive risk factors. On the other hand, similar prognostic factor profiles reflective of tumor biology, age-specific incidence rate patterns, and age-frequency distributions suggested that male breast cancer was more like postmenopausal than premenopausal female breast cancer.

Racial disparities in breast carcinoma survival rates: seperating factors that affect diagnosis from factors that affect treatment

BACKGROUND

Black females have lower breast carcinoma survival rates compared with white females. One possible reason is that black females have more advanced-stage breast disease. Another factor may be racial differences in the utilization of cancer treatments.

METHODS

The authors determined racial differences in 6-year stage specific survival rates, adjusting for age and treatments (using estrogen receptor [ER] status), to determine whether there were racial differences in treatment. Racial differences in the stage distributions of breast disease were used to examine the impact of racial factors on breast carcinoma diagnosis.

RESULTS

For all breast carcinoma cases, the stage specific 6-year survival rates, in general, were significantly lower for black females for all stages combined and for Stages I-III in every age group. However, examination by different treatments, as measured by ER status, revealed some different results. Only black women younger than age 50 years with ER-positive tumors and women younger than age 65 years with ER-negative tumors had significantly lower stage-specific survival rates. In addition, the stage distribution analyses showed that black females of every age group had less Stage I breast disease.

CONCLUSIONS

For younger black women (younger than age 50 years), there was evidence of racial differences in treatment for both women with ER-positive tumors and women with ER-negative tumors, as indicated by their lower stage-specific survival rates. In contrast, for black females age 65 years or older with ER-positive or ER-negative tumors, the lack of a significant difference in the stage-specific survival rate suggests that Medicare may help to alleviate racial disparities in cancer treatment. Furthermore, racial differences in the stage distributions indicated the need for earlier diagnosis for black females of every age.

Dual effect of parity on breast cancer risk in African-American women

BACKGROUND

In the United States, breast cancer incidence is higher among African-American women than among white women before age 45 but lower at older ages. To explore whether differences in childbearing patterns can explain this observation, we assessed the relation of several childbearing variables to breast cancer risk in a large prospective cohort study of U.S. African-American women.

METHODS

Black Women's Health Study participants were enrolled in 1995 and were followed by mailed questionnaires every 2 years (in 1997 and 1999). Of the 64,500 women enrolled, 56,725 (88%) completed at least one of the follow-up questionnaires. During 214,862 person-years of follow-up, participants reported 349 breast cancers, of which 128 were among women younger than 45 years and 221 were among women aged 45-70 years. Incidence rate ratios (IRRs) with 95% confidence intervals (CIs) were derived from age-stratified Cox regression models that adjusted for each of the childbearing variables (parity, age at first birth, and time since last birth).

RESULTS

Compared with primiparity, high parity was associated with an increased risk of breast cancer among women younger than 45 years (IRR for four or more births = 2.4, 95% CI = 1.1 to 5.1) and a decreased risk among women aged 45 years and older (IRR = 0.5, 95% CI = 0.3 to 0.9). The IRR for late age at first birth compared with early age was 2.5 (95% CI = 1.1 to 5.8) among the younger women and was not elevated among older women. We found no statistically significant association of time since last birth with breast cancer risk among either younger or older women.

CONCLUSIONS

Parity has a dual association with breast cancer risk in African-American women; among women younger than 45 years, parity is associated with an increased risk and among women 45 years and older it is associated with a decreased risk. This dual effect may explain some of the observed differences in breast cancer incidence rates among African-American and white women.