Decline in US breast cancer rates after the Women's Health Initiative: socioeconomic and racial/ethnic differentials

Early Detection of the Start of the Influenza Epidemic Using Surveillance Systems in Catalonia (PREVIGrip Study)

Sentinel physician networks are the method of influenza surveillance recommended by the World Health Organization. Weekly clinical diagnoses based on clinical history are a surveillance method that provides more immediate information. The objective of this study is to evaluate which influenza surveillance system is capable of the earliest detection of the start of the annual influenza epidemic. We carried out an ecological time-series study based on influenza data from the population of Catalonia from the 2010-2011 to the 2018-2019 seasons. Rates of clinical diagnoses and of confirmed cases in Catalonia were used to study the changes in trends in the different surveillance systems, the differences in area and time lag between the curves of the different surveillance systems using Joinpoint regression, Simpson's 1/3 method and cross-correlation, respectively. In general, changes in the trend of the curves were detected before the beginning of the epidemic in most seasons, using the rates for the complete seasons and the pre-epidemic rates. No time lag was observed between clinical diagnoses and the total confirmed cases. Therefore, clinical diagnoses in Primary Care could be a useful tool for early detection of the start of influenza epidemics in Catalonia.

Associations of Obesity, Physical Activity, and Screening With State-Level Trends and Racial and Ethnic Disparities of Breast Cancer Incidence and Mortality in the US

IMPORTANCE

Breast cancer causes disproportionate disease burden among various racial and ethnic groups in the US. However, state-level temporal trends and racial and ethnic disparities and whether metabolic and lifestyle factors and screening access are associated with temporal changes remain largely unknown.

OBJECTIVES

To investigate temporal trends and racial and ethnic variations at the state level and ecological correlations between obesity, physical activity, and mammography screening and breast cancer incidence and mortality trends among women in the US.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional study was conducted to analyze breast cancer incidence and mortality trends among women in the US from January 1, 1999, to December 31, 2017, whereas an ecological analysis was performed to assess the associations. Data were analyzed from March 1, 2021, to September 30, 2021. Population-based cancer registry data were obtained from US Cancer Statistics incidence and mortality data. Prevalence of obesity, physical activity, and mammography screening were obtained from the Behavioral Risk Factor Surveillance System.

EXPOSURES

Prevalence of obesity, physical activity, and mammography screening.

MAIN OUTCOMES AND MEASURES

Breast cancer incidence and mortality trends from 1999 to 2017 in the 50 US states and the District of Columbia.

RESULTS

A total of 4 136 123 breast cancer cases and 782 454 deaths were included in the analysis, with a significant reduction in incidence (average annual percent change [AAPC], -0.4% [95% CI, -0.6% to -0.2%)]) and mortality (AAPC, -1.7% [95% CI, -1.8% to -1.5%]) during the study period. A significant state-level variation in breast cancer incidence and mortality between White women and those of other races and ethnicities was observed. A significant positive correlation was found between obesity and breast cancer incidence (r = 0.316; P = .02) and mortality (r = 0.400; P = .004) and an inverse correlation was found between physical activity and incidence (r = -0.577; P < .001) in women 55 years or older and mammography screening and mortality trends (r = -0.644; P < .001) in women 40 years or older.

CONCLUSIONS AND RELEVANCE

The findings of this cross-sectional study suggest that racial and ethnic disparities exist at the state level with regard to breast cancer incidence and mortality among women in the US. Metabolic and lifestyle factors and screening access were associated with the observed trends and racial and ethnic disparities. Interventions targeting these factors may help reduce the incidence of breast cancer and related deaths.

Association between long-term ambient air pollution exposure and the risk of breast cancer: a systematic review and meta-analysis

Breast cancer is a complex and multifactorial disease which stems significantly from both environmental and genetic factors. A growing number of epidemiological studies have suggested that ambient air pollution (AAP) exposure may play an important role in breast cancer development. However, no consistency has been reached concerning whether high levels of air pollutant exposure were related to increased breast cancer risk among the current evidence. To further clarify such association of long-term AAP exposure with risk of breast cancer, a systematic review and meta-analysis of available evidence was performed. An extensive literature search in 3 academic databases was conducted before March 10, 2020. The risk of bias (RoB) for each individual study was evaluated with a domain-based assessment tool, developed by the National Toxicology Program/Office of Health Assessment and Translation (NTP/OHAT). Meta-estimates for air pollutant-breast cancer combinations were calculated for a standardized increment in exposure by random-effect models. The confidence level in the body of evidence and the certainty of evidence was also assessed for each air pollutant-breast cancer combination. The initial search identified 5446 studies, and 18 of them were eligible. The pooled analysis found an increased risk of breast cancer was associated with an increase in each 10 μg/m³ in nitrogen dioxide (NO₂) exposure (hazard ratio (HR) = 1.02, 95% confidence interval (CI) = 1.01, 1.04), while particulate matter with aerodynamic diameters ≤ 2.5 μm and 10 μm (PM_2.5, PM₁₀) revealed no statistically significant associations with breast cancer risk. Our evaluation on the certainty of evidence indicates that there was a "moderate level of evidence" in the body of evidence for an association of NO₂ exposure with an increased breast cancer risk and an "inadequate level of evidence" in the body of evidence for an association of PM_2.5 and PM₁₀ exposure with an increased breast cancer risk. Our study suggests long-term exposure to NO₂ is related to an increased risk of breast cancer. However, in consideration of the limitations, further studies, especially performed in developing countries, with improvements in exposure assessment, outcome ascertainment, and confounder adjustment, are needed to draw a definite evidence of a causal relationship.

Utility and Diversity: Challenges for Genomic Medicine

Genomic information is poised to play an increasing role in clinical care, extending beyond highly penetrant genetic conditions to less penetrant genotypes and common disorders. But with this shift, the question of clinical utility becomes a major challenge. A collaborative effort is necessary to determine the information needed to evaluate different uses of genomic information and then acquire that information. Another challenge must also be addressed if that process is to provide equitable benefits: the lack of diversity of genomic data. Current genomic knowledge comes primarily from populations of European descent, which poses the risk that most of the human population will be shortchanged when health benefits of genomics emerge. These two challenges have defined my career as a geneticist and have taught me that solutions must start with dialogue across disciplinary and social divides.

Invited Commentary: What Social Epidemiology Brings to the Table-Reconciling Social Epidemiology and Causal Inference

In response to the Galea and Hernán article, "Win-Win: Reconciling Social Epidemiology and Causal Inference" (Am J Epidemiol. 2020;189(XX):XXXX-XXXX), we offer a definition of social epidemiology. We then argue that methodological challenges most salient to social epidemiology have not been adequately addressed in quantitative causal inference, that identifying causes is a worthy scientific goal, and that quantitative causal inference can learn from social epidemiology's methodological innovations. Finally, we make 3 recommendations for quantitative causal inference.

Racial discrimination in medical care settings and opioid pain reliever misuse in a U.S. cohort: 1992 to 2015

BACKGROUND

In the United States whites are more likely to misuse opioid pain relievers (OPRs) than blacks, and blacks are less likely to be prescribed OPRs than whites. Our objective is to determine whether racial discrimination in medical settings is protective for blacks against OPR misuse, thus mediating the black-white disparities in OPR misuse.

METHODS

We used data from 3528 black and white adults in the Coronary Artery Risk Development in Young Adults (CARDIA) study, an ongoing multi-site cohort. We employ causal mediation methods, with race (black vs white) as the exposure, lifetime discrimination in medical settings prior to year 2000 as the mediator, and OPR misuse after 2000 as the outcome.

RESULTS

We found black participants were more likely to report discrimination in a medical setting (20.3% vs 0.9%) and less likely to report OPR misuse (5.8% vs 8.0%, OR = 0.71, 95% CI = 0.55, 0.93, adjusted for covariates). Our mediation models suggest that when everyone is not discriminated against, the disparity is wider with black persons having even lower odds of reporting OPR misuse (OR = 0.63, 95% CI = 0.45, 0.89) compared to their white counterparts, suggesting racial discrimination in medical settings is a risk factor for OPR misuse rather than protective.

CONCLUSIONS

These results suggest that racial discrimination in a medical setting is a risk factor for OPR misuse rather than being protective, and thus could not explain the seen black-white disparity in OPR misuse.

Breast Cancer Statistics: Recent Trends

Breast Cancer is the leading cancer, in terms of incidence, that affects women. Better prognosis is still associated with detection at early stages, resulting in increased emphasis on timely and improved screening strategies. More data is now available on the incidence as well as mortality of almost all cancers, including breast cancer. This article discusses the trends in incidence as well as mortality of breast cancer in the US over last ten reportings i.e. years 2009 through 2018, along with an overview of recently reported numbers globally. The incidence rate is clearly on rise, which is indicative of aggressive screenings and detections. The mortality rate has not increased at the same pace, suggesting better clinical management of breast cancer patients, but the numbers are still too high. While screenings and early diagnoses should still be a point of focus, particularly in developing and poor countries, more efforts are needed to improve the prognosis of patients diagnosed at a later stage.

Impact of individual and neighborhood factors on socioeconomic disparities in localized and advanced prostate cancer risk

PURPOSE

The reasons behind socio-economic disparities in prostate cancer incidence remain unclear. We tested the hypothesis that individual-level factors act jointly with neighborhood-level social and built environment factors to influence prostate cancer risk and that specific social and built environment factors contribute to socio-econmic differences in risk.

METHODS

We used multi-level data, combining individual-level data (including education and known prostate cancer risk factors) for prostate cancer cases (n = 775) and controls (n = 542) from the San Francisco Bay Area Prostate Cancer Study, a population-based case-control study, with contextual-level data on neighborhood socio-economic status (nSES) and specific social and built environment factors from the California Neighborhoods Data System. Multivariable logistic regression models were used to compute adjusted odds ratios separately for localized and advanced stage prostate cancer while controlling for neighborhood clustering.

RESULTS

We found a more than twofold increased risk of both localized and advanced prostate cancer with increasing levels of nSES, and decreased risk of advanced prostate cancer with increasing levels of education. For localized disease, the nSES association was largely explained by known prostate cancer risk factors and specific neighborhood environment factors; population density, crowding, and residential mobility. For advanced disease, associations with education and nSES were not fully explained by any available individual- or neighborhood-level factors.

CONCLUSIONS

These results demonstrate the importance of specific neighborhood social and built environment factors in understanding risk of localized prostate cancer. Further research is needed to understand the factors underpinning the associations between individual- and neighborhood-level SES and risk of advanced prostate cancer.

Macrophage inflammatory factors promote epithelial-mesenchymal transition in breast cancer

The majority of breast cancers (90-95%) arise due to mediators distinct from inherited genetic mutations. One major mediator of breast cancer involves chronic inflammation. M1 macrophages are an integral component of chronic inflammation and the breast cancer tumor microenvironment (TME). Previous studies have demonstrated that up to 50% of the breast tumor comprise of tumor-associated macrophages (TAMs) and increased TAM infiltration has been associated with poor patient prognosis. Furthermore, breast cancer associated deaths are predominantly attributed to invasive cancers and metastasis with epithelial-mesenchymal transition (EMT) being implicated. In this study, we investigated the effects of cellular crosstalk between TAMs and breast cancer using an in vitro model system. M1 polarized THP-1 macrophage conditioned media (CM) was generated and used to evaluate cellular and functional changes of breast cancer lines T47D and MCF-7. We observed that T47D and MCF-7 exhibited a partial EMT phenotype in the presence of activated THP-1 CM. Additionally, MCF-7 displayed a significant increase in migratory and invasive properties. We conclude that M1 secretory factors can promote a partial EMT of epithelial-like breast cancer cells. The targeting of M1 macrophages or their secretory components may inhibit EMT and limit the invasive potential of breast cancer.

Racial/ethnic disparities in de novo metastases sites and survival outcomes for patients with primary breast, colorectal, and prostate cancer

Racial disparities in cancer mortality still exist despite improvements in treatment strategies leading to improved survival for many cancer types. In this study, we described race/ethnic differences in patterns of de novo metastasis and evaluated the association between site of de novo metastasis and breast, prostate, and colorectal cancer mortality. Data were obtained from the Surveillance Epidemiology and Ends Results (SEER) database from 2010 to 2013 and included 520,147 patients ages ≥40 years with primary diagnosis of breast, colorectal, or prostate cancer. Site and frequency of de novo metastases to four sites (bone, brain, liver, and lung) were compared by race/ethnicity using descriptive statistics, and survival differences examined using extended Cox regression models in SAS 9.4. Overall, non‐Hispanic (NH) Blacks (11%) were more likely to present with de novo metastasis compared with NH‐Whites (9%) or Hispanics (10%). Among patients with breast cancer, NH‐Blacks were more likely to have metastasis to the bone, (OR: 1.25, 95% CI: 1.15–1.37), brain (OR: 2.26, 95% CI: 1.57–3.25), or liver (OR: 1.62, 95% CI: 1.35–1.93), while Hispanics were less likely to have metastasis to the liver (OR: 0.76, 95% CI: 0.60–0.97) compared with NH‐Whites. Among patients with prostate cancer, NH‐Blacks (1.39, 95% CI: 1.31–1.48) and Hispanics (1.39, 95% CI: 1.29–1.49) were more likely to have metastasis to the bone. Metastasis to any of the four sites evaluated increased overall mortality by threefold (for breast cancer and metastasis to bone) to 17‐fold (for prostate cancer and metastasis to liver). Racial disparities in mortality remained after adjusting for metastasis site in all cancer types evaluated. De novo metastasis is a major contributor to cancer mortality in USA with racial differences in the site, frequency, and associated survival.

State of the evidence 2017: an update on the connection between breast cancer and the environment

BACKGROUND

In this review, we examine the continually expanding and increasingly compelling data linking radiation and various chemicals in our environment to the current high incidence of breast cancer. Singly and in combination, these toxicants may have contributed significantly to the increasing rates of breast cancer observed over the past several decades. Exposures early in development from gestation through adolescence and early adulthood are particularly of concern as they re-shape the program of genetic, epigenetic and physiological processes in the developing mammary system, leading to an increased risk for developing breast cancer. In the 8 years since we last published a comprehensive review of the relevant literature, hundreds of new papers have appeared supporting this link, and in this update, the evidence on this topic is more extensive and of better quality than that previously available.

CONCLUSION

Increasing evidence from epidemiological studies, as well as a better understanding of mechanisms linking toxicants with development of breast cancer, all reinforce the conclusion that exposures to these substances - many of which are found in common, everyday products and byproducts - may lead to increased risk of developing breast cancer. Moving forward, attention to methodological limitations, especially in relevant epidemiological and animal models, will need to be addressed to allow clearer and more direct connections to be evaluated.

Race, Menopausal Hormone Therapy, and Invasive Breast Cancer in the Carolina Breast Cancer Study

PURPOSE

The use of combined estrogen-progestin menopausal hormone therapy (MHT) has been shown to increase the risk of breast cancer, however, recent observational studies have suggested that the association between MHT and breast cancer may be modified by race. The objective of this study was to investigate the association between MHT use and incidence of invasive breast cancer in Black and White women aged ≥40 years at diagnosis after accounting for racial differences in patterns of MHT use and formulation.

METHODS

Data from the Carolina Breast Cancer Study, a population-based case-control study of Black and White women in North Carolina conducted between 1993 and 2001, was used to analyze 1474 invasive breast cancer cases and 1339 controls using unconditional logistic regression.

RESULTS

Black women were less likely than White women to use any MHT and were more likely to use an unopposed-estrogen formulation. Combined estrogen-progestin MHT use was associated with a greater odds of breast cancer in White (adjusted odds ratio [OR] 1.48, 95% confidence interval [CI]: 1.03-2.13) and Black (OR 1.43, 95% CI: 0.76-2.70) women, although the estimate in Black women was imprecise. In contrast, use of unopposed-estrogen MHT among women with prior hysterectomy was not associated with breast cancer in women of either race.

CONCLUSION

The association between MHT and invasive breast cancer appears to be similar in both Black and White women after accounting for differences in formulation and prior hysterectomy. These findings emphasize the importance of accounting for MHT formulation in race-stratified analyses of breast cancer risk.

Bayesian Inference on Malignant Breast Cancer in Nigeria: A Diagnosis of MCMC Convergence

Background: There has been no previous study to classify malignant breast tumor in details based on Markov Chain Monte Carlo (MCMC) convergence in Western, Nigeria. This study therefore aims to profile patients living with benign and malignant breast tumor in two different hospitals among women of Western Nigeria, with a focus on prognostic factors and MCMC convergence. Materials and Methods: A hospital-based record was used to identify prognostic factors for malignant breast cancer among women of Western Nigeria. This paper describes Bayesian inference and demonstrates its usage to estimation of parameters of the logistic regression via Markov Chain Monte Carlo (MCMC) algorithm. The result of the Bayesian approach is compared with the classical statistics. Results: The mean age of the respondents was 42.2 ±16.6 years with 52% of the women aged between 35-49 years. The results of both techniques suggest that age and women with at least high school education have a significantly higher risk of being diagnosed with malignant breast tumors than benign breast tumors. The results also indicate a reduction of standard errors is associated with the coefficients obtained from the Bayesian approach. In addition, simulation result reveal that women with at least high school are 1.3 times more at risk of having malignant breast lesion in western Nigeria compared to benign breast lesion. Conclusion: We concluded that more efforts are required towards creating awareness and advocacy campaigns on how the prevalence of malignant breast lesions can be reduced, especially among women. The application of Bayesian produces precise estimates for modeling malignant breast cancer.

A Matched Case-Control Study of Risk Factors for Breast Cancer Risk in Vietnam

Background. Vietnam has a low age-standardized incidence of breast cancer, but the incidence is rising rapidly with economic development. We report data from a matched case-control study of risk factors for breast cancer in the largest cancer hospital in Vietnam. Methods. 492 incident breast cancer cases unselected for family history or age at diagnosis and 1306 control women age 25–75 were recruited from the National Cancer Hospital (BVK), Hanoi. Structured interviews were conducted and pathology data was centrally reported at the National Cancer Hospital of Vietnam, in Hanoi. Results. Our analysis included 294 matched pairs. Mean age at diagnosis was 46.7 years. Lower mean parity, older age at first parity, increasing weight and BMI at age 18, and increasing BMI at diagnosis were positively correlated with breast cancer cases compared to controls. Age at first menarche and duration of breastfeeding were not statistically different between cases and controls. Conclusions. In this study we demonstrate that breast cancer in Vietnam is associated with some but not all of the published risk factors from Western populations. Our data is consistent with other studies of breast cancer in Asian populations.

Racial/ethnicity disparities in invasive breast cancer among younger and older women: An analysis using multiple measures of population health

INTRODUCTION

Few studies have examined age and racial/ethnic disparities in invasive breast cancer among younger (age 15-44 years) vs. older (age 45-64 years) women. This study estimates disparities in breast cancer among younger compared with older women by race/ethnicity using five measures of population health: life expectancy (LE), expected years of life lost (EYLL), cumulative incidence rate (CIR), and incidence and mortality rate ratios (IRR and MRR).

METHODS

Using Surveillance, Epidemiology, and End Results data, LE and EYLL were estimated from a cohort of 15-44 and 45-64 years, non-Hispanic black (NHB), non-Hispanic white (NHW), and Hispanic women diagnosed with breast cancer, 2000-2013. Survival function was obtained from the study years and then extrapolated to lifetime using the Monte Carlo method. The CIR, IRR and MRR were calculated using 2009-2013 breast cancer incidence and mortality rates from the Centers for Disease Control and Prevention's National Program of Cancer Registries.

RESULTS

The estimated LE ranged from 32.12 to 7.42 years for localized to distant stages among younger NHB women compared to 33.05 to 9.95 years for younger NHW women. The estimated EYLL was 12.78 years for younger women, and 4.99 for older women. By race/ethnicity, it was 15.53 years for NHB, 14.23 years for Hispanic and 11.87 years for NHW (P<0.00025). The CIR for age-group 15-44 years (CIR15-44) indicated a 1 in 86 probability for NHB compared to a 1 in 87 probability for NHW being diagnosed with breast cancer by age 45. The estimated age-adjusted incidence rate for NHB-to-NHW women was IRR=1.10 (95%, CI=1.08-1.11) and the corresponding mortality rate was MRR=2.02 (95%, CI=1.94-2.11).

CONCLUSIONS

The breast cancer disparities between younger NHB compared to NHW women highlight the need for expanded efforts to address these disparities through primary prevention and to improve access to quality healthcare to minority women with breast cancer.

Racial and socio-economic disparities in breast cancer hospitalization outcomes by insurance status

BACKGROUND

Breast cancer remains a major cause of morbidity and mortality among women in the US, and despite numerous studies documenting racial disparities in outcomes, the survival difference between Black and White women diagnosed with breast cancer continues to widen. Few studies have assessed whether observed racial disparities in outcomes vary by insurance type e.g. Medicare/Medicaid versus private insurance. Differences in coverage, availability of networked physicians, or cost-sharing policies may influence choice of treatment and treatment outcomes, even after patients have been hospitalized, effects of which may be differential by race.

PURPOSE

The aim of this analysis was to examine hospitalization outcomes among patients with a primary diagnosis of breast cancer and assess whether differences in outcome exist by insurance status after adjusting for age, race/ethnicity and socio-economic status.

METHODS

We obtained data on over 67,000 breast cancer patients with a primary diagnosis of breast cancer for this cross-sectional study from the 2007-2011 Healthcare Cost and Utilization project Nationwide Inpatient Sample (HCUP-NIS), and examined breast cancer surgery type (mastectomy vs. breast conserving surgery or BCS), post-surgical complications and in-hospital mortality. Multivariable regression models were used to compute estimates, odds ratios and 95% confidence intervals.

RESULTS

Black patients were less likely to receive mastectomies compared with White women (OR: 0.80, 95% CI: 0.71-0.90), regardless of whether they had Medicare/Medicaid or Private insurance. Black patients were also more likely to experience post-surgical complications (OR: 1.41, 95% CI: 1.12-1.78) and higher in-hospital mortality (OR: 1.57, 95%: 1.21-2.03) compared with White patients, associations that were strongest among women with Private insurance. Women residing outside of large metropolitan areas were significantly more likely to receive mastectomies (OR: 1.89, 95% CI: 1.54-2.31) and experience higher in-hospital mortality (OR: 1.74, 95% CI: 1.40-2.16) compared with those in metropolitan areas, regardless of insurance type.

CONCLUSION

Among hospitalized patients with breast cancer, racial differences in hospitalization outcomes existed and worse outcomes were observed among Black women with private insurance. Future studies are needed to determine factors associated with poor outcomes in this group of women, as well as to examine contributors to low BCS adoption in non-metropolitan areas.

Analyzing historical trends in breast cancer biomarker expression: a feasibility study (1947-2009)

Background/Objectives:

Determining long-term trends in tumor biomarker expression is essential for understanding aspects of tumor biology amenable to change. Limiting the availability of such data, currently used assays for biomarkers are relatively new. For example, assays for the estrogen receptor (ER), which are the oldest, extend back only to the 1970s.

Methods:

To extend scant knowledge about the feasibility of obtaining long-term data on tumor biomarkers, we randomly selected 60 breast cancer cases (10 per decade) diagnosed between 1947–2009 among women members of the Kaiser Permanente Northern California health plan to obtain and analyze their formalin-fixed paraffin-embedded (FFPE) tumor specimens. For each tumor specimen, we created duplicate tissue microarrays for analysis.

Results:

We located tumor blocks and pathology reports for 50 of the 60 cases (83%), from which we randomly sampled 5 cases per decade for biomarker analysis (n=30). All 30 cases displayed excellent morphology and exhibited biomarkers compatible with histologic type and grade. Test–retest reliability was also excellent: 100% for ER; 97% for human epidermal growth factor receptor 2 and epidermal growth factor receptor; 93% for progesterone receptor and cytokeratin 5/6; and 90% for Ki67 and molecular phenotype; the kappa statistic was excellent (>0.9) for 4 of the 7 biomarkers, strong (0.6–0.8) for 2, and fair for only 1 (owing to low prevalence).

Conclusions:

These results indicate immunostaining for biomarkers commonly used to evaluate breast cancer biology and assign surrogate molecular phenotypes can reliably be employed on archival FFPE specimens up to 60 years old.

Socioeconomic status and incidence of breast cancer by hormone receptor subtype

Recent developments in genetics and molecular biology have classified breast cancer into subtypes based on tumor markers of estrogen (ER), progesterone (PR) and human epidermal growth Factor-2 receptors (Her-2), with the basal-like (ER-, PR-, Her2-) subtype commonly referred to as "triple negative" breast cancer (TNBC) being the most aggressive. Prior studies have provided evidence that higher socio-economic status (SES) is associated with increased breast cancer risk, likely due to hormone related risk factors such as parity and hormonal contraceptive use. However, it is unclear if the relationship between SES and overall breast cancer incidence exists within each subtype, and if this association varies by race/ethnicity. Analysis was based on data obtained from the SEER database linked to 2008-2012 American Community Survey data, and restricted to women diagnosed with breast cancer in 2010. The NCI SES census tract SES index based on measures of income, poverty, unemployment, occupational class, education and house value, was examined and categorized into quintiles. Age-adjusted incidence rate ratios were calculated comparing the lowest to the highest SES groups by subtype, separately for each race/ethnic group. We identified 47,586 women with breast cancer diagnosed in 2010. The majority was diagnosed with Her2-/HR+ tumors (73 %), while 12 % had triple negative tumors (TNBC). There was a significant trend of higher incidence with increasing SES for Her2-/HR+ (IRR Highest vs. Lowest SES: 1.32, 95 % CI 1.27-1.39; p value trend: 0.01) and Her2+/HR+ tumors (IRR Highest vs. Lowest SES: 1.46, 95 % CI 1.27-1.68; p value trend: 0.01) among White cases. There was no association between SES and incidence of HR- subtypes (Her2+/HR- or TNBC). Similar associations were observed among Black, Hispanic and Asian or Pacific Islander cases. The positive association between SES and breast cancer incidence is primarily driven by hormone receptor positive tumors. To the extent that neighborhood SES is a proxy for individual SES, future studies are still needed to identify etiologic risk factors for other breast cancer subtypes.

MODELLING COUNTY LEVEL BREAST CANCER SURVIVAL DATA USING A COVARIATE-ADJUSTED FRAILTY PROPORTIONAL HAZARDS MODEL

Understanding the factors that explain differences in survival times is an important issue for establishing policies to improve national health systems. Motivated by breast cancer data arising from the Surveillance Epidemiology and End Results program, we propose a covariate-adjusted proportional hazards frailty model for the analysis of clustered right-censored data. Rather than incorporating exchangeable frailties in the linear predictor of commonly-used survival models, we allow the frailty distribution to flexibly change with both continuous and categorical cluster-level covariates and model them using a dependent Bayesian nonparametric model. The resulting process is flexible and easy to fit using an existing R package. The application of the model to our motivating example showed that, contrary to intuition, those diagnosed during a period of time in the 1990s in more rural and less affluent Iowan counties survived breast cancer better. Additional analyses showed the opposite trend for earlier time windows. We conjecture that this anomaly has to be due to increased hormone replacement therapy treatments prescribed to more urban and affluent subpopulations.

The socioeconomic gradient in all-cause mortality for women with breast cancer: findings from the 1998 to 2006 National Cancer Data Base with follow-up through 2011

PURPOSE

To analyze the association between socioeconomic status (SES) and all-cause mortality among women diagnosed with breast cancer before and after controlling for insurance status, race and ethnicity, stage, treatment modalities, and other demographic and hospital characteristics.

METHODS

Data analyzed included follow-up through 2011 for 582,396 patients diagnosed between 1998 and 2006 with ductal carcinoma in situ or invasive (stage I-IV) breast cancer from the National Cancer Data Base. SES was measured by grouping patients into six income and education-level ZIP code categories. Hierarchical Cox regression models were used to analyze SES survival differences.

RESULTS

Five- and 10-year survival probabilities for the highest SES group were 87.8% and 71.5%, versus 79.5% and 61.5% for the lowest SES group. Controlling for all covariates reduced the highest-to-lowest SES hazard ratio from 1.69 (95% confidence interval: 1.64-1.74) to 1.27 (95% confidence interval: 1.24-1.31). Results were virtually identical in models that included comorbidity and invasive cancer patients only.

CONCLUSIONS

Differences in insurance status, race, and stage at diagnosis are important components of SES disparities and explain about two-thirds of the initial SES survival disparity. The residual SES effect likely mirrors underlying social determinants of health for all American women.

Demographic and socioeconomic factors predictive of compliance with American Thyroid Association guidelines for the treatment for advanced papillary thyroid carcinoma

BACKGROUND

The American Thyroid Association (ATA) publishes evidence-based guidelines for the treatment of papillary thyroid carcinoma (PTC). We sought to identify factors associated with receiving treatment compliant with the 2006 ATA guidelines for advanced-stage PTC.

METHODS

The 2006 ATA guideline compliance was examined in patients with stage III and IV PTC extrapolated from Surveillance, Epidemiology, and End Results (SEER).

RESULTS

Sixty percent of patients received ATA-compliant treatment. A stepwise increase in compliance occurred between 2006 and 2009 (p-value trend = .0003). Age 45 to 64 years versus ≥65 (odds ratio [OR] = 0.682; 95% confidence interval [CI] = 0.57-0.81; p < .0001) and higher income (p trend = .012) were associated with an increased likelihood of receiving ATA-compliant care. African Americans (OR = 0.56; 95% CI = 0.42-0.76; p = .0001) and single patients (OR = 0.81; 95% CI = 0.67-0.97; p = .02) were less likely to receive ATA-compliant care.

CONCLUSION

This study highlights specific populations at risk for receiving non-ATA-compliant care for PTC and underscores the need to further implement guideline-based practice.

A multilevel model of postmenopausal breast cancer incidence

BACKGROUND

Breast cancer has a complex etiology that includes genetic, biologic, behavioral, environmental, and social factors. Etiologic factors are frequently studied in isolation with adjustment for confounding, mediating, and moderating effects of other factors. A complex systems model approach may present a more comprehensive picture of the multifactorial etiology of breast cancer.

METHODS

We took a transdisciplinary approach with experts from relevant fields to develop a conceptual model of the etiology of postmenopausal breast cancer. The model incorporated evidence of both the strength of association and the quality of the evidence. We operationalized this conceptual model through a mathematical simulation model with a subset of variables, namely, age, race/ethnicity, age at menarche, age at first birth, age at menopause, obesity, alcohol consumption, income, tobacco use, use of hormone therapy (HT), and BRCA1/2 genotype.

RESULTS

In simulating incidence for California in 2000, the separate impact of individual variables was modest, but reduction in HT, increase in the age at menarche, and to a lesser extent reduction in excess BMI >30 kg/m(2) were more substantial.

CONCLUSIONS

Complex systems models can yield new insights on the etiologic factors involved in postmenopausal breast cancer. Modification of factors at a population level may only modestly affect risk estimates, while still having an important impact on the absolute number of women affected.

IMPACT

This novel effort highlighted the complexity of breast cancer etiology, revealed areas of challenge in the methodology of developing complex systems models, and suggested additional areas for further study.

Breast cancer mortality among American Indian and Alaska Native women, 1990-2009

OBJECTIVES

We compared breast cancer death rates and mortality trends among American Indian/Alaska Native (AI/AN) and White women using data for which racial misclassification was minimized.

METHODS

We used breast cancer deaths and cases linked to Indian Health Service (IHS) data to calculate age-adjusted rates and 95% confidence intervals (CIs) by IHS-designated regions from 1990 to 2009 for AI/AN and White women; Hispanics were excluded. Mortality-to-incidence ratios (MIR) were calculated for 1999 to 2009 as a proxy for prognosis after diagnosis.

RESULTS

Overall, the breast cancer death rate was lower in AI/AN women (21.6 per 100,000) than in White women (26.5). However, rates in AI/ANs were higher than rates in Whites for ages 40 to 49 years in the Alaska region, and ages 65 years and older in the Southern Plains region. White death rates significantly decreased (annual percent change [APC] = -2.1; 95% CI = -2.3, -2.0), but regional and overall AI/AN rates were unchanged (APC = 0.9; 95% CI = 0.1, 1.7). AI/AN women had higher MIRs than White women.

CONCLUSIONS

There has been no improvement in death rates among AI/AN women. Targeted screening and timely, high-quality treatment are needed to reduce mortality from breast cancer in AI/AN women.

The impact of socioeconomic status on the use of adjuvant radioactive iodine for papillary thyroid cancer

INTRODUCTION

The effect of socioeconomic status (SES) on thyroid cancer treatment has not been studied extensively. The purpose of this study is to determine the impact of SES on the use of adjuvant radioactive iodine (RAI) after total thyroidectomy for papillary thyroid cancer (PTC). We hypothesize that patients of low SES are less likely to receive RAI after total thyroidectomy.

METHODS

Case characteristics of 9011 patients with PTC ≥ 1 cm in size and undergoing total thyroidectomy were extrapolated from the Surveillance, Epidemiology and End Results database. Chi-square test and multivariate analyses were performed to compare demographics, clinicopathologic features, and use of RAI by county-level measures of SES.

RESULTS

Low-SES patients were more likely to present with positive lymph nodes in the <45-year age group and with advanced American Joint Committee on Cancer stage, positive lymph nodes, multifocal tumors, extrathyroidal extension, and larger tumors in the ≥ 45-year age group. Among patients <45 years of age, those from counties with a higher median household income and a higher SES composite score had significantly higher rates of RAI use (odds ratio [OR] 1.36, [95% confidence interval (CI) 1.09-1.70], p=0.006, and OR 1.29 [CI 1.11-1.49], p<0.001, respectively). Among patients ≥ 45 years of age, those residing in counties with higher education levels were associated with higher rates of RAI use (OR 1.27 [CI 1.05-1.54], p=0.015), while the association between SES composite score and RAI use approached statistical significance (OR 1.13 [CI 1.00-1.28], p=0.053).

CONCLUSIONS

This study demonstrates that low SES is associated with more advanced PTC at presentation and a lower rate of adjuvant RAI after total thyroidectomy, particularly among patients <45 years of age from areas with a low median household income. Future studies are needed to address these disparities, as well as to determine appropriate indications for the use of adjuvant RAI for PTC.

Trends in breast cancer stage and mortality in Michigan (1992-2009) by race, socioeconomic status, and area healthcare resources

The long-term effect of socioeconomic status (SES) and healthcare resources availability (HCA) on breast cancer stage of presentation and mortality rates among patients in Michigan is unclear. Using data from the Michigan Department of Community Health (MDCH) between 1992 and 2009, we calculated annual proportions of late-stage diagnosis and age-adjusted breast cancer mortality rates by race and zip code in Michigan. SES and HCA were defined at the zip-code level. Joinpoint regression was used to compare the Average Annual Percent Change (AAPC) in the median zip-code level percent late stage diagnosis and mortality rate for blacks and whites and for each level of SES and HCA. Between 1992 and 2009, the proportion of late stage diagnosis increased among white women [AAPC = 1.0 (0.4, 1.6)], but was statistically unchanged among black women [AAPC = −0.5 (−1.9, 0.8)]. The breast cancer mortality rate declined among whites [AAPC = −1.3% (−1.8,−0.8)], but remained statistically unchanged among blacks [AAPC = −0.3% (−0.3, 1.0)]. In all SES and HCA area types, disparities in percent late stage between blacks and whites appeared to narrow over time, while the differences in breast cancer mortality rates between blacks and whites appeared to increase over time.

A trend analysis of breast cancer incidence rates in the United States from 2000 to 2009 shows a recent increase

Recent reports have shown that the breast cancer incidence rate in the US stabilized after a sharp reduction in 2002 and 2003. It is important to continue monitoring breast cancer incidence rates according to age group, race/ethnicity, estrogen receptor (ER) status, and tumor stage. Age-standardized breast cancer incidence rates were calculated using data from the surveillance, epidemiology, and end results 18 registries from 2000 to 2009, for 677,774 female breast cancer patients aged 20 and above. Jointpoint regression models were used to fit a series of joined straight lines on a log scale to annual age-standardized rates. The incidence rates of all breast cancer significantly increased for non-Hispanic blacks from 2005 to 2009 (annual percentage change, APC = 2.0 %, p = 0.01) and Asian/Pacific Islanders from 2000 to 2009 (APC = 1.2 %, p = 0.02). Since 2004, incidence rates in women aged 40-49 years significantly increased for most racial/ethnic groups (overall APC = 1.1 %, p = 0.001). The incidence rate of carcinoma in situ significantly increased in all racial/ethnic groups, with an APC range from 2.3 to 3.0 % (p < 0.005). The localized breast cancer incidence significantly increased in non-Hispanic blacks (APC = 1.3 %, p = 0.004) and Asians (APC = 1.2 %, p = 0.03). ER-positive breast cancer significantly increased in almost all age/race sub-groups after 2005 (APC by race: non-Hispanic whites 1.5 %, non-Hispanic blacks 4.3 %, Asian/Pacific Islanders 1.7 %, and Hispanics 1.8 %; all p values <0.05), while ER-negative breast cancer decreased in most sub-groups (APC by race: non-Hispanic whites-3.9 %, non-Hispanic blacks-3.7 %, Asian/Pacific Islanders-1.5 %, and Hispanics-4.3 %; all p values <0.05). Recently the incidence of breast cancer appears to be increasing in certain subgroups, including ER-positive, early-stage breast cancers, in particular among non-Hispanic blacks and Asian/Pacific Islanders. Further studies are warranted to examine possible reasons for these changes, such as changes in mammography screening methods and risk factors prevalence.

Individual and neighborhood socioeconomic status and healthcare resources in relation to black-white breast cancer survival disparities

Background. Breast cancer survival has improved significantly in the US in the past 10–15 years. However, disparities exist in breast cancer survival between black and white women. Purpose. To investigate the effect of county healthcare resources and SES as well as individual SES status on breast cancer survival disparities between black and white women. Methods. Data from 1,796 breast cancer cases were obtained from the Surveillance Epidemiology and End Results and the National Longitudinal Mortality Study dataset. Cox Proportional Hazards models were constructed accounting for clustering within counties. Three sequential Cox models were fit for each outcome including demographic variables; demographic and clinical variables; and finally demographic, clinical, and county-level variables. Results. In unadjusted analysis, black women had a 53% higher likelihood of dying of breast cancer and 32% higher likelihood of dying of any cause (P < 0.05) compared with white women. Adjusting for demographic variables explained away the effect of race on breast cancer survival (HR, 1.40; 95% CI, 0.99–1.97), but not on all-cause mortality. The racial difference in all-cause survival disappeared only after adjusting for county-level variables (HR, 1.27; CI, 0.95–1.71). Conclusions. Improving equitable access to healthcare for all women in the US may help eliminate survival disparities between racial and socioeconomic groups.

Variations in use of PET among Medicare beneficiaries with non-small cell lung cancer, 1998-2007

PURPOSE

To explore demographic and regional factors associated with the use of positron emission tomography (PET) in patients with non-small cell lung cancer (NSCLC) and to determine whether their associations with PET use has changed over time.

MATERIALS AND METHODS

The Office of Human Research Ethics at the University of North Carolina and the institutional review board of the Duke University Health System approved (with waiver of informed consent) this retrospective analysis of Surveillance Epidemiology and End Results Medicare data for Medicare beneficiaries given a diagnosis of NSCLC between 1998 and 2007. The primary outcome was change in the number of PET examinations 2 months before to 4 months after diagnosis, examined according to year and sociodemographic subgroup. PET use was compared between demographic and geographic subgroups and between early (1998-2000) and late (2005-2007) cohorts by using χ(2) tests. Factors associated with use of PET during the study period were further examined by using logit and linear probability multivariable regression analyses.

RESULTS

The final cohort included 46 544 patients with 46 935 cases of NSCLC. By 2005, more than half of patients underwent one or more PET examinations, regardless of demographic subgroup. In multivariable logistic regression analysis, patients who underwent PET were more likely to be married, nonblack, and younger than 80 years and to live in census tracts with higher education levels or in the Northeast (P < .001 for all). Living within 40 miles of a PET facility was initially associated with undergoing PET (P < .001), but this association disappeared by 2007. Imaging rates increased more rapidly in patients who were nonblack (P ≤ .01), patients who were younger than 81 years (P < .001), and patients who lived in the Northeast and South (P < .001).

CONCLUSION

PET imaging among Medicare beneficiaries with NSCLC was initially concentrated among nonblack patients younger than 81 years. Despite widespread adoption among all subgroups, differences within demographic subgroups remained.

Impact of enhanced detection on the increase in thyroid cancer incidence in the United States: review of incidence trends by socioeconomic status within the surveillance, epidemiology, and end results registry, 1980-2008

BACKGROUND

In the past 3 decades, the incidence of thyroid cancer in the United States has been increasing. There has been debate on whether the increase is real or an artifact of improved diagnostic scrutiny. Our hypothesis is that both improved detection and a real increase have contributed to the increase.

METHODS

Because socioeconomic status (SES) may be a surrogate for access to diagnostic technology, we compared thyroid cancer incidence trends between high- and low-SES counties within the Surveillance, Epidemiology, and End Results 9 (SEER 9) registries. The incidence trends were assessed using joinpoint regression analysis.

RESULTS

In high-SES counties, thyroid cancer incidence increased moderately (annual percentage change 1 [APC1]=2.5, p<0.05) before the late 1990s and more pronounced (APC2=6.3, p<0.05) after the late 1990s. In low-SES counties, incidence increased steadily with an APC of 3.5 (p<0.05) during the entire study period (1980-2008). For tumors ≤4.0 cm, incidence was higher in high-SES counties, and APC was higher for high- than low-SES counties after the late 1990s. For tumors >4.0 cm, high- and low-SES counties had similar increasing incidence trends. Similarly, for tumors ≤2.0 cm, the incidence trends differed between counties that are in or adjacent to metropolitan areas and counties that are in rural areas, whereas for tumors >2.0 cm, all counties regardless of area of residence had similar increasing trends.

CONCLUSIONS

Enhanced detection likely contributed to the increased thyroid cancer incidence in the past decades, but cannot fully explain the increase, suggesting that a true increase exists. Efforts should be made to identify the cause of this true increase.

Who and what is a "population"? Historical debates, current controversies, and implications for understanding "population health" and rectifying health inequities

CONTEXT

The idea of "population" is core to the population sciences but is rarely defined except in statistical terms. Yet who and what defines and makes a population has everything to do with whether population means are meaningful or meaningless, with profound implications for work on population health and health inequities.

METHODS

In this article, I review the current conventional definitions of, and historical debates over, the meaning(s) of "population," trace back the contemporary emphasis on populations as statistical rather than substantive entities to Adolphe Quetelet's powerful astronomical metaphor, conceived in the 1830s, of l'homme moyen (the average man), and argue for an alternative definition of populations as relational beings. As informed by the ecosocial theory of disease distribution, I then analyze several case examples to explore the utility of critical population-informed thinking for research, knowledge, and policy involving population health and health inequities.

FINDINGS

Four propositions emerge: (1) the meaningfulness of means depends on how meaningfully the populations are defined in relation to the inherent intrinsic and extrinsic dynamic generative relationships by which they are constituted; (2) structured chance drives population distributions of health and entails conceptualizing health and disease, including biomarkers, as embodied phenotype and health inequities as historically contingent; (3) persons included in population health research are study participants, and the casual equation of this term with "study population" should be avoided; and (4) the conventional cleavage of "internal validity" and "generalizability" is misleading, since a meaningful choice of study participants must be in relation to the range of exposures experienced (or not) in the real-world societies, that is, meaningful populations, of which they are a part.

CONCLUSIONS

To improve conceptual clarity, causal inference, and action to promote health equity, population sciences need to expand and deepen their theorizing about who and what makes populations and their means.

β-Estradiol unmasks metabotropic receptor-mediated metaplasticity of NMDA receptor transmission in the female rat dentate gyrus

Loss of estrogen in women following menopause is associated with increased risk for cognitive decline, dementia and depression, all of which can be prevented by estradiol replacement. The dentate gyrus plays an important role in cognition, learning and memory. The gatekeeping function of the dentate gyrus to filter incoming activity into the hippocampus is modulated by estradiol in a frequency-dependent manner and involves activation of metabotropic glutamate receptors (mGluR). In the present study, we investigated whether estradiol (EB) modulates the metaplastic effect of inducing synaptic long-term potentiation (LTP) on subsequent propensity for expression of LTP in the dentate gyrus. At medial perforant path-dentate granule cell synapses in hippocampal slices of ovariectomized female rats, EB replacement was critical for an initial induction of LTP to enhance the magnitude of subsequent LTP elicited by a second high-frequency stimulation, metaplasticity, which was not present in slices from oil-treated control animals. EB enhanced expression of group I mGluRs, and the metaplastic effect of EB on LTP required activation of group I mGluRs that led to Src-family tyrosine kinase-mediated phosphorylation of NR2B subunits of N-methyl-d-aspartate receptors (NMDAR) that enhanced the magnitude of NMDAR-dependent LTP. Our data show that EB effects on LTP in the hippocampal dentate gyrus require activation of group I mGluRs, which in turn leads to functional metaplastic regulation of NR2B subunit-containing NMDARs, as opposed to direct effects of EB on NMDARs.

Breast cancer and screening in American Indian and Alaska Native women

Data relative to breast cancer among American Indian and Alaska native (AI/AN) women are limited and vary by regions. Despite national decreases in breast cancer incidence and mortality rates, declines in these measures have not yet appeared among AI/AN women. Health disparities in breast cancer persist, manifest by higher stage at diagnosis, and lower screening rates compared to other racial and ethnic groups. Disproportionately more AI/AN are younger at diagnosis. Screening beginning at age 40, improving access, annual rescreening, community education and outreach, and mobile mammography for rural areas are ways to improve these disparities in breast cancer.

Shrinking, widening, reversing, and stagnating trends in US socioeconomic inequities in cancer mortality for the total, black, and white populations: 1960-2006

OBJECTIVES OF STUDY

To test recent claims that cancer inequities are bound to increase as population health improves.

METHODS

We analyzed 1960-2006 age-standardized US county cancer mortality data, total and site-specific (lung, prostate, colorectal, breast, cervix, stomach), stratified by county income quintile for the US total, black, and white populations.

RESULTS

Between 1960 and 2006, US socioeconomic inequities in cancer mortality variously shrunk, widened, reversed, and stagnated, depending on time period and cancer site. For all cancers combined and most, but not all, sites, absolute, but not relative, socioeconomic gaps were greater for the black compared to white population. Compared to the yearly age-specific mortality rates among whites in the most affluent counties, the percent of excess cancer deaths among whites in the lower four county income quintiles first rose above 0 in 1990 and in 2006 equaled 5.4% (95% CI 4.8, 6.0); among blacks, it rose from 6.0% (95% CI 4.5, 7.4) in 1960 to 24.7% (95% CI 23.9, 25.5) in 1990 and remained at this level through 2006.

CONCLUSIONS

The hypothesis that cancer mortality inequities are bound to increase is refuted by long-term data on total and site-specific cancer mortality stratified by socioeconomic position and race/ethnicity.

Increased mortality among Hispanic testis cancer patients independent of neighborhood socioeconomic status: a SEER study

Testis cancer-specific survival (CSS) varies by Hispanic ethnicity. Our goal was to assess whether neighborhood socioeconomic status (SES) accounts for elevated testis CSS among Hispanic patients. We queried the Surveillance, Epidemiology, and End Results (SEER) database for Hispanic (HW) and Non-Hispanic white (NHW) patients. Multivariate Cox regression analyses evaluated Hispanic ethnicity's impact on tCSS while adjusting for neighborhood socioeconomic status (education and income levels). HWs constituted 14.3% of the 26,258 patients in the cohort. Neighborhood SES factors such as county income (P < 0.001) and education level (P < 0.001) were significant predictors of testis cancer-specific survival (tCSS). Controlling for SES and other variables, Hispanic ethnicity remained a significant predictor of tCSS. Compared to NHWs, HWs experienced a 41% greater cancer-specific mortality (HR: 1.406, 95% CI: 1.178-1.678, P < 0.001). The mechanism underlying the increased testis cancer mortality experienced by Hispanic patients remains unknown.

The racial disparity in breast cancer mortality

Black women die of breast cancer at a much higher rate than white women. Recent studies have suggested that this racial disparity might be even greater in Chicago than the country as a whole. When data describing this racial disparity are presented they are sometimes attributed in part to racial differences in tumor biology. Vital records data were employed to calculate age-adjusted breast cancer mortality rates for women in Chicago, New York City and the United States from 1980-2005. Race-specific rate ratios were used to measure the disparity in breast cancer mortality. Breast cancer mortality rates by race are the main outcome. In all three geographies the rate ratios were approximately equal in 1980 and stayed that way until the early 1990s, when the white rates started to decline while the black rates remained rather constant. By 2005 the black:white rate ratio was 1.36 in NYC, 1.38 in the US, and 1.98 in Chicago. In any number of ways these data are inconsistent with the notion that the disparity in black:white breast cancer mortality rates is a function of differential biology. Three societal hypotheses are posited that may explain this disparity. All three are actionable, beginning today.

Global cancer statistics

The global burden of cancer continues to increase largely because of the aging and growth of the world population alongside an increasing adoption of cancer-causing behaviors, particularly smoking, in economically developing countries. Based on the GLOBOCAN 2008 estimates, about 12.7 million cancer cases and 7.6 million cancer deaths are estimated to have occurred in 2008; of these, 56% of the cases and 64% of the deaths occurred in the economically developing world. Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death among females, accounting for 23% of the total cancer cases and 14% of the cancer deaths. Lung cancer is the leading cancer site in males, comprising 17% of the total new cancer cases and 23% of the total cancer deaths. Breast cancer is now also the leading cause of cancer death among females in economically developing countries, a shift from the previous decade during which the most common cause of cancer death was cervical cancer. Further, the mortality burden for lung cancer among females in developing countries is as high as the burden for cervical cancer, with each accounting for 11% of the total female cancer deaths. Although overall cancer incidence rates in the developing world are half those seen in the developed world in both sexes, the overall cancer mortality rates are generally similar. Cancer survival tends to be poorer in developing countries, most likely because of a combination of a late stage at diagnosis and limited access to timely and standard treatment. A substantial proportion of the worldwide burden of cancer could be prevented through the application of existing cancer control knowledge and by implementing programs for tobacco control, vaccination (for liver and cervical cancers), and early detection and treatment, as well as public health campaigns promoting physical activity and a healthier dietary intake. Clinicians, public health professionals, and policy makers can play an active role in accelerating the application of such interventions globally.

Temporal trends in the black/white breast cancer case ratio for estrogen receptor status: disparities are historically contingent, not innate

OBJECTIVE

For at least three decades, many investigators have reported on the US black/white breast cancer case ratio for estrogen receptor (ER) status as if it reflected an intrinsic biological difference. In light of racial/ethnic differences in declines in the incidence of ER+ breast cancer, as linked to changing use of hormone therapy, we empirically tested whether the black/white breast cancer estrogen receptor ratio has changed over time.

METHODS

We examined temporal trends in the odds of being ER+ among white as compared to black women among all cases of invasive breast cancer occurring among women residing in the catchment area of the SEER 13 Registries Database between 1992 and 2005.

RESULTS

During the study period, the odds of being ER+ among the white compared to black cases increased from 1992 to 2002 (a statistically significant joinpoint; p < 0.05; peak odds ratio (2002) = 2.25 (95% confidence interval 2.13, 2.39)). Thereafter, the odds ratio leveled off (post-2002 slope not significantly different from zero; p = 0.326). Among women aged 45-54, moreover, the post-2002 decline tended toward statistical significance (p = 0.0891).

CONCLUSIONS

The results suggest the black/white breast cancer case estrogen receptor ratio is historically contingent, not innate.

Social conditions as fundamental causes of health inequalities: theory, evidence, and policy implications

Link and Phelan (1995) developed the theory of fundamental causes to explain why the association between socioeconomic status (SES) and mortality has persisted despite radical changes in the diseases and risk factors that are presumed to explain it. They proposed that the enduring association results because SES embodies an array of resources, such as money, knowledge, prestige, power, and beneficial social connections that protect health no matter what mechanisms are relevant at any given time. In this article, we explicate the theory, review key findings, discuss refinements and limits to the theory, and discuss implications for health policies that might reduce health inequalities. We advocate policies that encourage medical and other health-promoting advances while at the same time breaking or weakening the link between these advances and socioeconomic resources. This can be accomplished either by reducing disparities in socioeconomic resources themselves or by developing interventions that, by their nature, are more equally distributed across SES groups.