Age-specific Breast Cancer Mortality Research Articles

Assessing predicted age-specific breast cancer mortality rates in 27 European countries by 2020.

We assessed differences in predicted breast cancer (BC) mortality rates, across Europe, by 2020, taking into account changes in the time trends of BC mortality rates during the period 2000-2010. BC mortality data, for 27 European Union (EU) countries, were extracted from the World Health Organization mortality database. First, we compared BC mortality data between time periods 2000-2004 and 2006-2010 through standardized mortality ratios (SMRs) and carrying out a graphical assessment of the age-specific rates. Second, making use of the base period 2006-2012, we predicted BC mortality rates by 2020. Finally, making use of the SMRs and the predicted data, we identified a clustering of countries, assessing differences in the time trends between the areas defined in this clustering. The clustering approach identified two clusters of countries: the first cluster were countries where BC predicted mortality rates, in 2020, might slightly increase among women aged 69 and older compared with 2010 [Greece (SMR 1.01), Croatia (SMR 1.02), Latvia (SMR 1.15), Poland (SMR 1.14), Estonia (SMR 1.16), Bulgaria (SMR 1.13), Lithuania (SMR 1.03), Romania (SMR 1.13) and Slovakia (SMR 1.06)]. The second cluster was those countries where BC mortality rates level off or decrease in all age groups (remaining countries). However, BC mortality rates between these clusters might diminish and converge to similar figures by 2020. For the year 2020, our predictions have shown a converging pattern of BC mortality rates between European regions. Reducing disparities, in access to screening and treatment, could have a substantial effect in countries where a non-decreasing trend in age-specific BC mortality rates has been predicted.

Checking unimodality using isotonic regression: an application to breast cancer mortality rates

In some diseases it is well-known that a unimodal mortality pattern exists. A clear example in developed countries is breast cancer, where mortality increased sharply until the nineties and then decreased. This clear unimodal pattern is not necessarily applicable to all regions within a country. In this paper, we develop statistical tools to check if the unimodality pattern persists within regions using order restricted inference. Break points as well as confidence intervals are also provided. In addition, a new test for checking monotonicity against unimodality is derived allowing to discriminate between a simple increasing pattern and an up-then-down response pattern. A comparison with the widely used joinpoint regression technique under unimodality is provided. We show that the joinpoint technique could fail when the underlying function is not piecewise linear. Results will be illustrated using age-specific breast cancer mortality data from Spain in the period 1975–2005.

Forecasting age-related changes in breast cancer mortality among white and black US women: A functional data approach

Background: The disparity in breast cancer mortality rates among white and black US women is widening, with higher mortality rates among black women. We apply functional time series models on age-specific breast cancer mortality rates for each group of women, and forecast their mortality curves using exponential smoothing state-space models with damping. Materials and Methods: The data were obtained from the Surveillance, Epidemiology and End Results (SEER) program of the US [1]. Mortality data were obtained from the National Centre for Health Statistics (NCHS) available on the SEER*Stat database. We use annual unadjusted breast cancer mortality rates from 1969 to 2004 in 5-year age groups (45–49, 50–54, 55–59, 60–64, 65–69, 70–74, 75–79, 80–84). Age-specific mortality curves were obtained using nonparametric smoothing methods. The curves are then decomposed using functional principal components and we fit functional time series models with four basis functions for each population separately. The curves from each population are forecast and prediction intervals are calculated. Results: Twenty-year forecasts indicate an overall decline in future breast cancer mortality rates for both groups of women. This decline appears to be steeper among white women aged 55–73 and black women aged 60–84. For black women under 55 years of age, the forecast rates are relatively stable indicating there is no significant change in future breast cancer mortality rates among young black women in the next 20 years. Conclusion: White women have smooth and consistent patterns in breast cancer mortality rates for all age-groups whereas the mortality rates for black women are much more variable. The projections suggest, for some age groups, black American women may not benefit equally from the overall decline in breast cancer mortality in the United States.

Using Functional Data Analysis Models to Estimate Future Time Trends in Age-Specific Breast Cancer Mortality for the United States and England–Wales

BackgroundMortality/incidence predictions are used for allocating public health resources and should accurately reflect age-related changes through time. We present a new forecasting model for estimating future trends in age-related breast cancer mortality for the United States and England–Wales.MethodsWe used functional data analysis techniques both to model breast cancer mortality-age relationships in the United States from 1950 through 2001 and England–Wales from 1950 through 2003 and to estimate 20-year predictions using a new forecasting method.ResultsIn the United States, trends for women aged 45 to 54 years have continued to decline since 1980. In contrast, trends in women aged 60 to 84 years increased in the 1980s and declined in the 1990s. For England–Wales, trends for women aged 45 to 74 years slightly increased before 1980, but declined thereafter. The greatest age-related changes for both regions were during the 1990s. For both the United States and England–Wales, trends are expected to decline and then stabilize, with the greatest decline in women aged 60 to 70 years. Forecasts suggest relatively stable trends for women older than 75 years.ConclusionsPrediction of age-related changes in mortality/incidence can be used for planning and targeting programs for specific age groups. Currently, these models are being extended to incorporate other variables that may influence age-related changes in mortality/incidence trends. In their current form, these models will be most useful for modeling and projecting future trends of diseases for which there has been very little advancement in treatment and minimal cohort effects (eg. lethal cancers).

By invitation only - the case for breast cancer screening reminders for women over 69 years.

BackgroundBreast cancer is the leading cause of cancer death in women in Australia. Early detection provides the best chance of reducing mortality and morbidity from the disease. Mammographic screening is a population health strategy for the early detection of breast cancer in Australia. Recruitment strategies such as regular advertising and biannual screening invitations are exclusively targeted at women aged 50 – 69 years. Even though they can participate, women 70 years or over are not invited or actively encouraged to undertake screening. Research has found that a routine letter of invitation increases the number of women participating in breast cancer screening.MethodsCancer data analysis and a literature and policy review was conducted to assess age specific breast cancer mortality rates and the legitimacy of rationale used to limit invitations for breast cancer screening to women younger than 70 years.ResultsThe proportion of women over 69 years participating in the BreastScreen program is significantly less than rate of screening in the target age range (50–69 years). Evidence and data indicate that common justifications for limiting screening reminders to the target age range including life expectancy, comorbidities, effectiveness, treatment and cost are, for many women, unreasonable.ConclusionThere is now sufficient data to support a change in the targeted upper age range for breast cancer screening to improve the existing suboptimal surveillance in women aged over 69 years.

The effect of service screening on breast cancer mortality rates

The aim of the study was to estimate the effect of breast screening on routinely collected age-specific breast cancer mortality rates. The relative protection obtained from randomized controlled trials of screening was assigned to a time before diagnosis for women who died of breast cancer to estimate the expected number of deaths that would have been preventable if screening had occurred. Simulation was used to obtain confidence intervals for these estimates. The reduction in age-specific breast cancer mortality rates that can be expected from service screening was also estimated. The reduction in breast cancer mortality was less than that attained in most screening trials except for the 65 to 69-year age group for which the range of expected values was 21.7-24.2%. On average, breast screening from the age of 50 to 69 years reduced the overall number of deaths from breast cancer by 5.7-8.0%. Screening starting at 40 or 45 years of age with a 10-year delay in effect compared with starting at 50 years of age produced a modest reduction in breast cancer mortality. When there was, however, only a 5-year delay in effect from screening younger women the overall effectiveness of screening was greater and more dependent on the age of initial screening with a maximum reduction of 10.6% (95% CI: 8.2-12.1%) in the overall number of deaths from breast cancer. Reductions in the breast cancer mortality rates for women at 60-64, 65-69, and 70-74 years of age provide a simple measure of the effectiveness of breast screening. The percentage reduction in breast cancer mortality rates will not be as great as the reduction observed in screening trials but will be greatest for breast cancer mortality in those between the ages of 65-69 years.

Forecasting age‐specific breast cancer mortality using functional data models

Accurate estimates of future age-specific incidence and mortality are critical for allocation of resources to breast cancer control programmes and evaluation of screening programmes. The purpose of this study is to apply functional data analysis techniques to model age-specific breast cancer mortality time trends, and forecast entire age-specific mortality functions using a state-space approach. We use annual unadjusted breast cancer mortality rates in Australia, from 1921 to 2001 in 5 year age groups (45 to 85+). We use functional data analysis techniques where mortality and incidence are modelled as curves with age as a functional covariate varying by time. Data are smoothed using non-parametric smoothing methods then decomposed (using principal components analysis) to estimate basis functions that represent the functional curve. Period effects from the fitted coefficients are forecast then multiplied by the basis functions, resulting in a forecast mortality curve with prediction intervals. To forecast, we adopt a state-space approach and an automatic modelling framework for selecting among exponential smoothing methods.Overall, breast cancer mortality rates in Australia remained relatively stable from 1960 to the late 1990s, but have declined over the last few years. A set of four basis functions minimized the mean integrated squared forecasting error and account for 99.3 per cent of variation around the mean mortality curve. Twenty year forecasts suggest a continuing decline, but at a slower rate, and stabilizing beyond 2010. Forecasts show a decline in all age groups with the greatest decline in older women. The proposed methods have the potential to incorporate important covariates such as hormone replacement therapy and interventions to represent mammographic screening. This would be particularly useful for evaluating the impact of screening on mortality and incidence from breast cancer.

Die Brustkrebsmortalität der Frauen in den Kreisen Schleswig-Holsteins von 1981 bis 1995

The present descriptive study evaluates breast cancer mortality among women in the northernmost German Federal State of Schleswig-Holstein over the period from 1981 to 1995 based on data provided by the Schleswig-Holstein State Office for Statistics. Starting from the results of the second Cancer Atlas for the Federal Republic of Germany [11], covering the period 1976-1980, breast cancer mortality rates rose sharply until the beginning of our investigation. A moderate rise in breast-cancer mortality in Schleswig-Holstein continued until the third period under investigation (1987-1989), while after that time breast cancer mortality decreased again towards the end of the investigation period. In Schleswig-Holstein as a whole, the mortality rate increased by approximately 12% during the last 20 years. When reviewing age-specific breast-cancer mortality for each rural district ('Kreis') or, respectively, for each self-administrative town (kreisfreie Stadt), different patterns were observed, particularly among younger women. In the 40- to 44-year and 45- to 49-year age group a rise in breast cancer mortality was observed in several, but not all districts. Mortality patterns do not tend to be representative for breast cancer incidence because mortality reflects only a small proportion of the women actually suffering from breast cancer. The standardised incidence of breast cancer in Germany--calculated on the basis of data provided by the Saarland cancer registry--is currently over 60/100,000 and is thus 2-3 times the mortality rate. However, presently it is not possible to evaluate the breast cancer incidence (Schleswig-Holstein) because the first population-based cancer registration was initiated only in 1999. In contrast to other German Federal States, notification of all cancer cases is compulsory in Schleswig-Holstein. A valid analysis of breast cancer incidence should be possible in 5-10 years conditional on a registration rate of at least 90%. Further investigations into the causes of breast cancer should be carried out to test specific hypotheses on exposure to risk factors, including nutrition and life style to clarify the regional differences observed in this study.

Racial trends in age-specific breast cancer mortality rates in US women.

This study examined recent trends in age- and race-specific patterns of breast cancer mortality. We analyzed breast cancer mortality data for 1979 through 1996. From 1993 to 1996, White women of all age groups experienced average annual decreases in breast cancer mortality. Throughout the study, young Black women had higher rates of breast cancer mortality than young White women. Older Black women had lower mortality rates than older White women in the earlier years of the study but experienced higher rates in the later years (1993-1996). Trends in risk factors and early detection do not provide an adequate explanation for this recent substantial increase in breast cancer mortality among older Black women.

Breast cancer clusters in the northeast United States: a geographic analysis.

High breast cancer mortality rates have been reported in the northeastern part of the United States, with recent attention focused on Long Island, New York. In this study, the authors investigate whether the high breast cancer mortality is evenly spread over the Northeast, in the sense that any observed clusters of deaths can be explained by chance alone, or whether there are clusters of statistical significance. Demographic data and age-specific breast cancer mortality rates for women were obtained for all 244 counties in 11 northeastern states and for the District of Columbia for 1988-1992. A recently developed spatial scan statistic is used, which searches for clusters of cases without specifying their size or location ahead of time, and which tests for their statistical significance while adjusting for the multiple testing inherent in such a procedure. The basic analysis is adjusted for age, with further analyses examining how the results are affected by incorporating race, urbanicity, and parity as confounding variables. There is a statistically significant and geographically broad cluster of breast cancer deaths in the New York City-Philadelphia, Pennsylvania, metropolitan area (p = 0.0001), which has a 7.4% higher mortality rate than the rest of the Northeast. The cluster remains significant when race, urbanicity, and/or parity are included as confounding variables. Four smaller subclusters within this area are also significant on their own strength: Philadelphia with suburbs (p = 0.0001), Long Island (p = 0.0001), central New Jersey (p = 0.0001), and northeastern New Jersey (p = 0.0001). The elevated breast cancer mortality on Long Island might be viewed less as a unique local phenomenon and more as part of a more general situation involving large parts of the New York City-Philadelphia metropolitan area. The several known and hypothesized risk factors for which we could not adjust and that may explain the detected cluster are most notably age at first birth, age at menarche, age at menopause, breastfeeding, genetic mutations, and environmental factors.

Declining Breast Cancer Mortality Among Young American Women

Changes in age-specific breast cancer mortality rates among white females in the United States during 1950-80 were shown to be correlated with changes in patterns of childbearing in early adulthood. However, for the most recent 5-year period among women below age 40 years, small declines in breast cancer mortality were observed in the late 1970's, despite a predicted increase following delays in childbearing that began in the 1960's and despite evidence of a rising incidence of the cancer. Although correlation analyses have inherent limitations, the findings raise the possibility that recent changes in the detection and management of breast cancer have contributed to a lowered mortality from this cancer among young American women.

Breast cancer mortality in relation to a measure of early childbearing.

Mortality rates for breast cancer have been calculated for white women at ages 35-44, 45-54, 55-64 and 65-74 for the 50 states of the United States based on deaths in 1969-1971. To test the extent of association of breast cancer death rates with the possible low-risk factor of early age at first full-term pregnancy, the proportions of women who entered marriage before age 20 were calculated for women at these ages living in each state. Statistically significant negative correlations were observed between breast cancer mortality rates by state and proportions of all women first married before age 20. States with low age-specific breast cancer mortality rates and high proportions of women married in their teens tend to be in the South and Southwest; those with high mortality rates and later marriage (and childbearing) tend to be in the Northeast. The limitations of correlation data are discussed.

Breast cancer and fertility trends in Canada.

The age-standardized breast cancer mortality rate for Canadian females increased only slightly during the period 1941-1971. In contrast, the age-standardized breast cancer incidence rate for Saskatchewan females more than doubled during the same period. In the interval 1954-1973 there were significant increases in the age-specific mortality rates for females 50-64 years old and in the age-specific incidence rates for five of the six age groups in the 45 to 74 year range. Breast cancer mortality rates during 1970-1972 varied considerably by province. Age-specific rates in the 30-69 year range were significantly and negatively correlated with the proportions by province of married women first married at age 15-19. In Canada and Saskatchewan, respectively, the age-specific breast cancer mortality and incidence rates for females 40-59 years old were significantly and negatively correlated with cohort fertility rates at age 20-24. These data support the hypothesis that early pregnancy protects against breast cancer. The sharp decline in fertility rates since 1960 may result in an increased incidence of breast cancer in the future.