Age-specific Breast Cancer Incidence Rates Research Articles

Incidence of Breast Cancer in Younger Women: A Canadian Trend Analysis.

Purpose: Breast cancer (BC) incidence is increasing globally. Age-specific BC incidence trend analyses are lacking for women under age 50 in Canada. In this study, we evaluate the incidence trends in breast cancer in women under age 50 in Canada and compare them with corresponding trends among women 50 to 54. Methods: BC case counts were obtained from the National Cancer Incidence Reporting System (1984-1991) and the Canadian Cancer Registry (1992-2019) both housed at Statistics Canada. Population data were also obtained from Statistics Canada. Annual female BC age-specific incidence rates from 1984 to 2019 were derived for the following age groups: 20 to 29, 30 to 39, 40 to 49, 40 to 44, 45 to 49, and 50 to 54. Changes in trends in age-specific BC incidence rates, if any, and annual percent changes (APCs) for each identified trend, were determined using JoinPoint. Results: Statistically significant increasing trends in BC incidence rates were noted for almost all age groups: since 2001 for 20 to 29 (APC = 3.06%, P < .001); since 2009 for 30 to 39 (APC = 1.25%, P = .007); since 1984 for both 40 to 49 (APC = 0.26%, P < .001) and 40 to 44 (APC = 0.19%, P = .011), increased since 2015 for 40 to 49 (APC = 0.77%, P = .047); and since 2005 for 50 to 54 (APC = 0.38%, P = .022). Among women 45 to 49 there was a non-significant increase since 2005 (APC = 0.24, P = .058). Statistically significant average annualized increases in BC incidence rates were observed for each age group studied. Conclusions: Examining age-specific incidence rates formed a more complete picture of BC time trends with significant increasing trends in the incidence of BC among women in their 20s, 30s, 40s, and early 50s. A greater awareness regarding the increasing number of cases of BC in women younger than 50 is critical to allow for earlier diagnosis with its resultant reduced mortality and morbidity.

Burden of breast cancer and attributable risk factors in the North Africa and Middle East region, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019.

Breast cancer (BC) is the most common cancer in women globally. The North Africa and Middle East (NAME) region is coping hard with the burden of BC. We aimed to present the latest epidemiology of BC and its risk factors in this region. We retrieved the data on BC burden and risk factors from the Global Burden of Disease Study 2019 to describe BC status in the 21 countries of the NAME region from 1990 to 2019. We explored BC incidence, prevalence, deaths, disability-adjusted life years (DALYs), and attributable burden to seven risk factors of female BC, namely, alcohol use, diet high in red meat, low physical activity, smoking, secondhand smoke, high body mass index, and high fasting plasma glucose. Decomposition analysis on BC incidence trend was done to find out the contributing factors to this cancer's growth. In 2019, there were 835,576 (95% uncertainty interval: 741,968 to 944,851) female and 10,938 (9,030 to 13,256) male prevalent cases of BC in the NAME region. This number leads to 35,405 (30,676 to 40,571) deaths among female patients and 809 (654 to 1,002) deaths in male patients this year. BC was responsible for 1,222,835 (1,053,073 to 1,411,009) DALYs among female patients in 2019, with a greater proportion (94.9%) of burden in years of life lost (YLLs). The major contributor to female BC incidence increase in the past three decades was found to be increase in age-specific incidence rates of BC (227.5%), compared to population growth (73.8%) and aging (81.8%). The behavioral risk factors were responsible for majority of attributable female BC burden (DALYs: 106,026 [66,614 to 144,247]). High fasting plasma glucose was found to be the risk factor with the largest effect (DALYs: 84,912 [17,377 to 192,838]) on female BC burden. The increasing incidence and burden of BC in the NAME region is remarkable, especially when considering limited resources in the developing countries of this region. Proper policies like expanding screening programs and careful resource management are needed to effectively manage BC burden.

Basic Findings of Incidence of Breast Cancer in Allied Hospital Faisalabad, Pakistan: A Retrospective Study.

Breast cancer is the most common malignancy among women worldwide. We aimed to know the past trends of age-specific breast cancer incidence rates in Faisalabad city. A retrospective study was designed at Allied Hospital Faisalabad (AHF), Pakistan from 2014-2018. Overall, 12742 cancer patients presented throughout these years, out of which 3390 were breast cancer cases. Descriptive statistics were computed and the results were presented as counts and percentage for categorical variables. Means and standard errors were computed for the continuous variables. For testing the association among categorical variables, a chi-square test of independence was used and the p-values less than 0.05 are reported as significant. 84.70% patients were diagnosed with invasive breast carcinoma and 15.30% were all other types reported in the Allied Hospital Faisalabad. The incidence of breast cancer was outrageous in the 40-49 year-old age group (1021 patients, 30.12%) and the mean age is 45 in all years. An increase of 34.86% was observed from 2014 to 2018. The comprehensive four-year data (2015 to 2018) were further analyzed for histology, surgery, staging and grading pattern as 2014 files data was insufficient to discuss. The stage III and grade III were most common throughout the years from 2015 to 2018 with 33.9% and 55.71% respectively. Breast cancer is diagnosed more commonly in women than in any other type of cancers in Faisalabad city. There is a need to upgrade the existing hospital facilities to make the women diagnose the cancer at an earlier stage.

Recent Increase in the Breast Cancer Incidence Among Japanese Women Seems to Correlate With the Prevalence of Drinking and Smoking Habits, but Not Obesity, as a Modern Lifestyle

ObjectivesWe have recently reported that age-specific incidence rates of breast cancer among Japanese women clearly increased from 2000 to 2015 in a bimodal distribution pattern with two peaks at the age groups of 45 to 49 and 60 to 64 years. The present study aimed to assess the association of age-specific breast cancer incidence rates with the prevalence of obesity and drinking and smoking habits among Japanese women, compared with those of uterine body, colon and lung cancers. MethodsAge-specific cancer incidence and mortality rates and the prevalence of obesity and drinking and smoking habits were obtained from national data published by Cancer Information Services or National Institute of Health and Nutrition of Japan. Linear correlations of annual rates from 2005 to 2015 of the 10-year age-specific cancer incidence and mortality with the prevalence of obesity (body mass index, 25 and over) and drinking (alcohol, 20g and over 3 times or more a week) and smoking habits during the same 10-year period or the 10-year period 10 years before the cancer incidence and mortality were assessed by Pearson’s correlation coefficients. ResultsSignificant (p < 0.05) and positive correlations were found between breast cancer incidence and drinking habits during the same period at the age of 50–59 (r = 0.901), 60–69 (r = 0.808) and 70–79 years (r = 0.643) and during the 10-year-before period at 50–59 (r = 0.676); between the incidence and smoking habits during the 10-year-before period at 40–49 (r = 0.897), 50–59 (r = 0.731) and 60–69 (r = 0.696); between the mortality and drinking habits during the same period at 30–39 (r = 0.739), 60–69 (r = 0.817) and 70–79 (r = 712); and between the mortality and smoking habits during the same period at 30–39 (r = 0.733) and during the 10-year-before period at 60–69 (r = 0.663). Similar but less positive correlations for uterine body cancer or more positive correlations for male lung cancer were found. The prevalence of male drinking and smoking habits was decreasing during the 20 years. No positive correlations were found between the breast cancer incidence or mortality and the prevalence of obesity. ConclusionsThe present ecological study demonstrated that the prevalence of drinking and smoking habits, but not obesity, as a modern lifestyle correlated with the recent increase in the age-specific breast cancer incidence among Japanese women. Funding SourcesNone.

Age-specific breast cancer incidence rate in the world.

Age-specific breast cancer incidence rate in the world.

Association of Increasing Age-Specific Breast Cancer Incidence Rates with Drinking Habits but Not Obesity Prevalence, Based on National Data in Japan

Association of Increasing Age-Specific Breast Cancer Incidence Rates with Drinking Habits but Not Obesity Prevalence, Based on National Data in Japan

Abstract 4636: Breast cancer age-specific incidence rates among Ghanaian women by breast cancer risk factors: A study using census and population-based case-control study data

Abstract Introduction: Although breast cancer incidence in sub-Saharan African countries, including Ghana, has been historically low, incidence is rising. Evaluating age-specific incidence rates by breast cancer risk factors may provide etiologic insights. Here we present age-specific incidence rates for breast cancer estimated from the Ghana Breast Health Study (GBHS) for key breast cancer risk factors. Methods: GBHS is a population-based case-control study with 1,071 pathologically confirmed incident invasive breast cancer cases (18-74 years old) diagnosed between 2013-2015 in three hospitals in Accra and Kumasi. A total of 2,094 controls were sampled from the population, and frequency matched by site and age to the cases. Sample weights for controls were calculated using data from the 2010 Ghana Census, adjusted for non-response. Data on incident breast cancer cases in Accra (2012-2014) and Kumasi (2013-2015) were obtained from their respective cancer registries and compared to the incidence rates observed in the GBHS. Using data from GBHS adjusted by sampling weights, we estimated 5-year age-specific breast cancer incidence rates and 95% confidence intervals overall and according to breast cancer risk factors. Results: Age-specific breast cancer incidence rates estimated from the GBHS rose quickly until approximately age 50 when the rate plateaued but still rose (Clemmeson's hook), which was consistent with cancer registry data from Kumasi and Accra. The rates from the GBHS are not significantly different from the cancer registry rates under age 50 but are significantly higher after age 50. While the rates from the GBHS and Accra and Kumasi cancer registries were much lower than rates observed in the SEER registries for African American women, the trends were consistent. Analyses of overall rates by breast cancer risk factors showed that age-specific breast cancer risk was elevated among women with a family history of breast cancer across all ages. Data suggested cross-over interactions for other factors, particularly parity, and breastfeeding among parous women. Specifically, incidence rates were higher for parous than nulliparous women aged 20-35 years, while incidence rates were lower for parous and breastfeeding (among parous) women older than 35 years. Conclusions: Age-specific incidence rates of breast cancer that demonstrate cross-over interactions by risk factors may be important in understanding racial disparities in breast cancer incidence, overall as well as for specific breast cancer subtypes. Elevated risk among young parous women may be indicative of the higher risk associated with early-onset (triple-negative) breast cancer. Citation Format: Brittny Davis Lynn, Jonine Figueroa, Richard Biritwum, Beatrice Wiafe Addai, Baffour Awuah, Joe Net Clegg-Lamptey, Robertson Adjei, Lucy Afriyie, Joel Yarney, Naomi Oyoe Ohene Oti, Daniel Ansong, Seth Wiafe, Louise Brinton, Montserrat Garcia-Closas, Barry Graubard. Breast cancer age-specific incidence rates among Ghanaian women by breast cancer risk factors: A study using census and population-based case-control study data [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4636.

Breast cancer risk after hysterectomy with and without salpingo-oophorectomy for benign indications

Breast cancer risk has been extensively studied in women with genetic predisposition, that is, mutations in breast cancer genes 1 and 2. Although there are guidelines for performing bilateral salpingo-oophorectomies in individuals with specific genetic risks, oophorectomies are also performed in many women considered to be at average risk of developing breast cancer. The risk of breast cancer in women with average risk who undergo hysterectomy with bilateral salpingo-oophorectomy for benign indications is less clear. This study aimed to estimate breast cancer risk after hysterectomy with and without concomitant bilateral salpingo-oophorectomy for benign indications. From 2001 to 2015, women aged 18 years and older from Kaiser Permanente Northern California who underwent hysterectomy alone and hysterectomy with bilateral salpingo-oophorectomy were identified using the International Classification of Diseases, Ninth Revision, procedure and Current Procedural Terminology codes. Women with a breast cancer gene mutation and previous history of breast cancer or gynecologic cancer were excluded. Descriptive and bivariate analyses were used to describe and compare demographic and clinical characteristics. Breast cancer incidence rates were calculated per 100,000 person-years. Survival analysis and Cox proportional hazard models were conducted to compare the risk of developing breast cancer. Of 49,215 women who underwent hysterectomy, 19,826 had hysterectomy with bilateral salpingo-oophorectomy. Whites, Hispanics, blacks, Asians, and other or unknown comprised 51.2%, 20.3%, 12.7%, 10.4%, and 5.3% of the study population, respectively. The average age of women with hysterectomy alone was 45.5 years compared with 50.8 years for those who had hysterectomy with bilateral salpingo-oophorectomy. During the study period, 915 women received a diagnosis of breast cancer. Age-specific breast cancer incidence rates were higher in women older than 60 years with oophorectomy than hysterectomy alone (471.2 [95% confidence interval, 386.2-556.2] vs 463.0 [95% confidence interval, 349.6-576.5], respectively). After controlling for age, race, income, and Charlson Comorbidity Index, women with bilateral salpingo-oophorectomy had a 14% lower risk of breast cancer than women with hysterectomy alone (hazard ratio, 0.86; 95% confidence interval, 0.75-0.98). All-cause mortality was higher with oophorectomy than hysterectomy alone (64.4% vs 35.6%, P<.0001, respectively). Women with concurrent bilateral salpingo-oophorectomy for benign indications had a lower risk of breast cancer than those who had hysterectomy alone. However, all-cause mortality was higher in women with oophorectomy. Perimenopausal patients undergoing hysterectomy for benign indications should be counseled on the risks and benefits of oophorectomy at the time of surgery.

Estimates of past and future time trends in age-specific breast cancer incidence among women in Karachi, Pakistan: 2004\u20132025

BackgroundThe current demographic trends indicate that breast cancer will pose an even greater public health concern in future for Pakistan. Details on the incidence, disease severity and mortality in respect of breast cancer are limited and without such data, therefore, future health policies or systems in respect of this disease cannot be strategically planned or implemented. The aim of this study was to examine past trends of age-specific breast cancer incidence rates (2004–2015), and to estimate the future volume of breast cancer cases in Karachi through the year 2025.MethodsTwo statistical methods, namely the functional time series models and the log-linear regression model were used; additionally, their real forecasting efficacy in epidemic time series was also evaluated.ResultsIn the past, women aged 60–64 years had the highest overall breast cancer incidence rates, while from 2016 to 2025, large increases in breast cancer rates among women aged 50 to 64 years are expected. The total projected breast cancer incidence will increase by approximately 23.1% in 2020 to 60.7% in 2025. Cases of breast cancer diagnosed in younger women, aged 30–34 years, will increase from 70.7 to 130.6% in 2020 and 2025 relative to 2015.ConclusionsThe breast cancer incidence appeared to have been rising more rapidly among post-menopausal women (aged 55 to 59), while a stable increase in incidence in the youngest age group (15–29 years) of women is expected. The results also infer an expected increase in incidence cases of breast cancer among middle aged women in Karachi, Pakistan. An increase in the number of incident cases of cancer has implications for understanding the health-care needs of growing population and the subsequent demands on health-care system.

Are Global Breast Cancer Incidence and Mortality Patterns Related to Country-Specific Economic Development and Prevention Strategies?

PurposeThere remains considerable international variation in breast cancer incidence and mortality, but a comprehensive examination of rates by country level economic, development and cancer prevention policies is lacking.Materials and MethodsWe compared GLOBOCAN 2012 age-specific breast cancer incidence and mortality rates for 177 countries by using development and policy data available from the WHO Global Cancer Country Profiles data base. We classified each country on the basis of gross national income per capita from the World Development Indicators data base, as follows: low-income country (LIC), lower-middle–income country (LMIC), upper-middle–income country (UMIC), and high-income country (HIC).ResultsThere were 1,651,326 breast cancer cases and 516,868 breast cancer deaths estimated in 2012. Approximately three quarters of all breast cancer cases and 60% of the breast cancer deaths were in women from HICs and UMICs. Age and country-level income explained approximately 60% of the international variation in breast cancer incidence and mortality in women of all ages (adjusted R2 = 58% and 60%, respectively). Economic development indicators additionally increased the overall variation in incidence and mortality by approximately 5%. In women younger than age 50 years, country-level income explained 68% of incidence and 59% of mortality; economic development indicators additionally increased this percentage by approximately 4%. Country-level cancer prevention policy indicators contributed little to explanation of the overall variation in incidence and mortality after analysis accounted for age and country-level income; however, an overall resource summary index of greater economic development and cancer prevention policies was related to lower mortality within each major income level.ConclusionAlthough breast cancer incidence increases with higher income levels in all ages, women in the poorest countries bear a relatively higher burden of breast cancer mortality, particularly women younger than age 50 years.

Obligate Overdiagnosis Due to Mammographic Screening: A Direct Estimate for U.S. Women.

Purpose To determine obligate overdiagnosis rates, defined as the percentage of women diagnosed with screen-detected breast cancer who die of causes other than breast cancer prior to clinical presentation of that cancer, for ductal carcinoma in situ (DCIS), invasive breast cancer, and all breast cancers. Materials and Methods Age-specific all-cause mortality rates from the Human Mortality Database, age-specific breast cancer incidence and mortality rates from Surveillance, Epidemiology, and End Results data, and estimates of mean lead times and lead time distributions from breast cancer screening trials are used to estimate obligate (or type 1) overdiagnosis rates for DCIS, invasive breast cancer, and all breast cancers (DCIS plus invasive) for U.S. women undergoing screening mammography. Mortality rates by age are used to estimate the number of women who die of causes other than breast cancer during the lead time afforded by screening mammography. Resulting age-dependent overdiagnosis rates, along with screen-detected breast cancer incidence by age, are used to estimate type 1 overdiagnosis rates for the U.S. screening population. Results Obligate overdiagnosis rates depend strongly on the age at which a woman is screened, ranging from less than 1% at age 40 years to 30%, 21%, and 22.5% at age 80 years for DCIS, invasive breast cancer, and all breast cancers, respectively. Type 1 overdiagnosis rates among screened women in the United States are estimated to be 9% for DCIS and approximately 7% for both invasive breast cancer and all breast cancers. Screening of women ages 40-49 years (or premenopausal women, as determined from patient history, starting at age 40 years) adds little to obligate overdiagnosis rates (0.15% for DCIS and less than 0.1% for invasive breast cancer and all breast cancers). Conclusion Type 1 overdiagnosis rates increase rapidly with age at screening. Obligate overdiagnosis occurs in 9% of DCIS and approximately 7% of both invasive breast cancer and all breast cancers in the U.S. mammographic screening population, with screening of women ages 40-49 years (or premenopausal women starting at age 40 years) making a negligible contribution of 0.15% to obligate overdiagnosis of DCIS and a contribution of less than 0.1% to the obligate overdiagnosis rates of invasive breast cancer and all breast cancers. © RSNA, 2017 Online supplemental material is available for this article.

Predicting Breast Cancer Incidence Rates Among White and Black Women in the United States: An Application of FTS Model

Development of statistical model for cancer incidence trend predictions can provide a sound and accurate foundation for planning a comprehensive national strategy for optimal partitioning of research resources. Several studies in the past showed that that there are racial/ethnic disparities exist between breast cancer incidence rates among black and white women in the United States. Some of the studies also showed that the disparity in breast cancer incidence rates among white and black US women is widening, with relatively higher incidence rates among black women. In this paper, we apply functional time series (FTS) models on the age-specific breast cancer incidence rates for these two major groups of women in US, and forecast their age-incidence curves. The data are obtained from the Surveillance, Epidemiology and End Results (SEER) program of the United States. We use annual unadjusted breast cancer incidence rates from 1973 to 2013 in 5-year agegroups (15-19, 20-24, 25-29, 30-34, 35-39, 40-44, 45–49, 50–54, 55–59, 60–64, 65–69, 70–74, 75–79, 80–84 and 85+). Age-specific cancer incidence curves are obtained using nonparametric smoothing methods. The curves are then decomposed using functional data paradigm and we fit functional time series (FTS) models for each population of women separately. The smoothed incidence curves are then forecasted and prediction intervals are calculated. Fifteen-year forecasts indicate an overall increase in future breast cancer incidence rates for both groups of women. This increase appears to be faster among black women and relatively slower among the whites. The projections suggest a need for equal delivery of quality care to eliminate breast cancer disparities among the two major groups of women in US.

The proportion of postmenopausal breast cancer cases in the Netherlands attributable to lifestyle-related risk factors

We aimed to estimate the proportion of Dutch postmenopausal breast cancer cases in 2010 that is attributable to lifestyle-related risk factors. We calculated population attributable fractions (PAFs) of potentially modifiable risk factors for postmenopausal breast cancer in Dutch women aged >50 in 2010. First, age-specific PAFs were calculated for each risk factor, based on their relative risks for postmenopausal breast cancer (from meta-analyses) and age-specific prevalence in the population (from national surveys) around the year 2000, assuming a latency period of 10 years. To obtain the overall PAF, age-specific PAFs were summed in a weighted manner, using the age-specific breast cancer incidence rates (2010) as weights. 95 % confidence intervals for PAF estimates were derived by Monte Carlo simulations. Of Dutch women >40 years, in 2000, 51 % were overweight/obese, 55 % physically inactive (<5 days/week 30 min activity), 75 % regularly consumed alcohol, 42 % ever smoked cigarettes and 79 % had a low-fibre intake (<3.4 g/1000 kJ/day). These factors combined had a PAF of 25.7 % (95 % CI 24.2–27.2), corresponding to 2,665 Dutch postmenopausal breast cancer cases in 2010. PAFs were 8.8 % (95 % CI 6.3–11.3) for overweight/obesity, 6.6 % (95 % CI 5.2–8.0) for alcohol consumption, 5.5 % (95 % CI 4.0–7.0) for physical inactivity, 4.6 % (95 % CI 3.3–6.0) for smoking and 3.2 % (95 % CI 1.6–4.8) for low-fibre intake. Our findings imply that modifiable risk factors are jointly responsible for approximately one out of four Dutch postmenopausal breast cancer cases. This suggests that incidence rates can be lowered substantially by living a more healthy lifestyle.Electronic supplementary materialThe online version of this article (doi:10.1007/s10549-015-3447-7) contains supplementary material, which is available to authorized users.

A method for determining weights for excess relative risk and excess absolute risk when applied in the calculation of lifetime risk of cancer from radiation exposure

Radiation-related risks of cancer can be transported from one population to another population at risk, for the purpose of calculating lifetime risks from radiation exposure. Transfer via excess relative risks (ERR) or excess absolute risks (EAR) or a mixture of both (i.e., from the life span study (LSS) of Japanese atomic bomb survivors) has been done in the past based on qualitative weighting. Consequently, the values of the weights applied and the method of application of the weights (i.e., as additive or geometric weighted means) have varied both between reports produced at different times by the same regulatory body and also between reports produced at similar times by different regulatory bodies. Since the gender and age patterns are often markedly different between EAR and ERR models, it is useful to have an evidence-based method for determining the relative goodness of fit of such models to the data. This paper identifies a method, using Akaike model weights, which could aid expert judgment and be applied to help to achieve consistency of approach and quantitative evidence-based results in future health risk assessments. The results of applying this method to recent LSS cancer incidence models are that the relative EAR weighting by cancer solid cancer site, on a scale of 0-1, is zero for breast and colon, 0.02 for all solid, 0.03 for lung, 0.08 for liver, 0.15 for thyroid, 0.18 for bladder and 0.93 for stomach. The EAR weighting for female breast cancer increases from 0 to 0.3, if a generally observed change in the trend between female age-specific breast cancer incidence rates and attained age, associated with menopause, is accounted for in the EAR model. Application of this method to preferred models from a study of multi-model inference from many models fitted to the LSS leukemia mortality data, results in an EAR weighting of 0. From these results it can be seen that lifetime risk transfer is most highly weighted by EAR only for stomach cancer. However, the generalization and interpretation of radiation effect estimates based on the LSS cancer data, when projected to other populations, are particularly uncertain if considerable differences exist between site-specific baseline rates in the LSS and the other populations of interest. Definitive conclusions, regarding the appropriate method for transporting cancer risks, are limited by a lack of knowledge in several areas including unknown factors and uncertainties in biological mechanisms and genetic and environmental risk factors for carcinogenesis; uncertainties in radiation dosimetry; and insufficient statistical power and/or incomplete follow-up in data from radio-epidemiological studies.

Higher population‐based incidence rates of triple‐negative breast cancer among young African‐American women

Differences in the breast cancer burden of African-American women compared with white American women are well documented. Recent controversies have emerged regarding age-appropriate mammographic screening guidelines, and these surveillance recommendations may influence future breast cancer disparities. The objective of the current study was to evaluate age-specific breast cancer stage distributions and incidence rates of triple-negative breast cancer (TNBC) in a population-based tumor registry. The authors analyzed breast cancers from the California Cancer Registry (CCR) that were diagnosed between 1988 and 2006. The results were stratified by age and race/ethnicity, with white Americans identified as non-Hispanic whites (NHWs) and African Americans identified as non-Hispanic blacks (NHBs). Breast cancer stage distributions and TNBC incidence rates also were analyzed. In total, 375,761 invasive breast cancers were evaluated (including 276,938 in NHWs and 21,681 in NHBs). NHBs and Hispanics tended to be younger than NHWs (median ages 57 years, 54 years, and 64 years, respectively). Lifetime incidence rates were higher for NHWs compared with NHBs and Hispanics; however, for women aged <44 years, incidence was highest among NHBs. NHBs also had higher incidence rates of stage III and IV disease and a higher incidence of TNBC in all age categories. Population-based data demonstrated that African-American women had a more advanced stage distribution for breast cancer compared with white American women and higher incidence rates for TNBC. These patterns were observed for women ages 40 to 49 years and for older women, and they suggest that mammographic screening for the early detection of breast cancer will be particularly relevant for younger African-American women.

First Epidemiological Analysis of Breast Cancer Incidence and Tumor Characteristics after Implementation of Population-Based Digital Mammography Screening

PURPOSE: To epidemiologically evaluate the impact of digital mammography screening on incidence rates and tumor characteristics for breast cancer. MATERIALS AND METHODS: The first German digital screening units in the clinical routine were evaluated during the implementation period by using data from the cancer registry to compare the incidence rate of breast cancers and prognostic characteristics. 74 % of women aged 50 - 69 within the region of Muenster/Coesfeld/Warendorf were invited between 10 / 2005 and 12 / 2007 for initial screening; 55 % participated (n = 35 961). RESULTS: In 2002 - 2004 the average breast cancer incidence rate (per 100 000) was 297.9. During the implementation of screening, the rate rose to 532.9 in 2007. Of the 349 cancers detected with screening, 76 % (265 / 349) were invasive compared to 90 % (546 / 608) of cases not detected with screening during the same period. 37 % (97 / 265) of cancers detected in the screening program had a diameter of ≤ 10 mm and 75 % (198 / 265) were node-negative compared to 15 % (79 / 546) and 64 % (322 / 503), respectively, in cancers detected outside the screening program. The distribution of invasive tumor size (pT categories) and the nodal status differed with statistical significance between cancers detected in and outside the program (p = 0.005 and p = 0.004, respectively). CONCLUSION: Epidemiological data shows that the implementation of a population-based screening program led to a relevant increase in the age-specific breast cancer incidence rate. The characteristics of breast cancers detected in the screening program comply with the requirements of the European guidelines and are significantly favorable compared to tumors diagnosed outside the program. These findings indicate that digital mammography screening fulfills the requirements for an early tumor detection tool.

Effect of Changing Breast Cancer Incidence Rates on the Calibration of the Gail Model

The Gail model combines relative risks (RRs) for five breast cancer risk factors with age-specific breast cancer incidence rates and competing mortality rates from the Surveillance, Epidemiology, and End Results (SEER) program from 1983 to 1987 to predict risk of invasive breast cancer over a given time period. Motivated by changes in breast cancer incidence during the 1990s, we evaluated the model's calibration in two recent cohorts. We included white, postmenopausal women from the National Institutes of Health (NIH) -AARP Diet and Health Study (NIH-AARP, 1995 to 2003), and the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PLCO, 1993 to 2006). Calibration was assessed by comparing the number of breast cancers expected from the Gail model with that observed. We then evaluated calibration by using an updated model that combined Gail model RRs with 1995 to 2003 SEER invasive breast cancer incidence rates. Overall, the Gail model significantly underpredicted the number of invasive breast cancers in NIH-AARP, with an expected-to-observed ratio of 0.87 (95% CI, 0.85 to 0.89), and in PLCO, with an expected-to-observed ratio of 0.86 (95% CI, 0.82 to 0.90). The updated model was well-calibrated overall, with an expected-to-observed ratio of 1.03 (95% CI, 1.00 to 1.05) in NIH-AARP and an expected-to-observed ratio of 1.01 (95% CI: 0.97 to 1.06) in PLCO. Of women age 50 to 55 years at baseline, 13% to 14% had a projected Gail model 5-year risk lower than the recommended threshold of 1.66% for use of tamoxifen or raloxifene but >or= 1.66% when using the updated model. The Gail model was well calibrated in PLCO when the prediction period was restricted to 2003 to 2006. This study highlights that model calibration is important to ensure the usefulness of risk prediction models for clinical decision making.

First Epidemiological Analysis of Breast Cancer Incidence and Tumor Characteristics after Implementation of Population-Based Digital Mammography Screening

To epidemiologically evaluate the impact of digital mammography screening on incidence rates and tumor characteristics for breast cancer. The first German digital screening units in the clinical routine were evaluated during the implementation period by using data from the cancer registry to compare the incidence rate of breast cancers and prognostic characteristics. 74 % of women aged 50 - 69 within the region of Muenster/Coesfeld/Warendorf were invited between 10 / 2005 and 12 / 2007 for initial screening; 55 % participated (n = 35 961). In 2002 - 2004 the average breast cancer incidence rate (per 100,000) was 297.9. During the implementation of screening, the rate rose to 532.9 in 2007. Of the 349 cancers detected with screening, 76 % (265 / 349) were invasive compared to 90 % (546 / 608) of cases not detected with screening during the same period. 37 % (97 / 265) of cancers detected in the screening program had a diameter of <or= 10 mm and 75 % (198 / 265) were node-negative compared to 15 % (79 / 546) and 64 % (322 / 503), respectively, in cancers detected outside the screening program. The distribution of invasive tumor size (pT categories) and the nodal status differed with statistical significance between cancers detected in and outside the program (p = 0.005 and p = 0.004, respectively). Epidemiological data shows that the implementation of a population-based screening program led to a relevant increase in the age-specific breast cancer incidence rate. The characteristics of breast cancers detected in the screening program comply with the requirements of the European guidelines and are significantly favorable compared to tumors diagnosed outside the program. These findings indicate that digital mammography screening fulfills the requirements for an early tumor detection tool.

Breast Cancer Overdiagnosis With Screening Mammography

Zahl et al’s study in four Norwegian counties suggests that some of the occult invasive breast cancers detected by mammography screening might ultimately have undergone spontaneous regression (1). Population-based statistics in the United States support this hypothesis as well (2). Indeed, since the advent of mammography screening, age-specific breast cancer incidence rates in Europe have increased dramatically among women in those age groups targeted for screening (3). For example, in many western European countries, systematic screening programs were introduced in the late 1980s and early 1990s for women aged 50–69, and this was followed by sharp increases in the incidence of invasive breast cancer in these women (3). This trend is also observed in the United States, as illustrated in figure 1, using data from the Connecticut Historical database of the National Cancer Institute’s Surveillance, Epidemiology, End Results (SEER, http://seer.cancer.gov/) program. This figure shows that, since the late 1970s, with increasing utilization of mammography screening among women aged 40–80, age-specific incidence rates for this age group have increased from their baseline rate during 1966 to 1975. Figure 1 Although mammography screening might be expected to transiently increase the incidence of invasive breast cancer, assuming constant risks, it should also ultimately result in a corresponding decrease in invasive cancer incidence among the elderly. Yet the Connecticut data indicate that, in the elderly population, incidence rates for invasive breast cancers during the latest time period (490 per 100,000 woman-years in 1996–2005) has not dropped below the baseline rate prior to the advent of mammography screening (363 per 100,000 woman-years in 1966–2005), figure 1. Similar incidence patterns have also been observed in Europe (3). Taken together, these incidence patterns might be interpreted to mean that mammography screening results in a significant diagnosis of occult, non-lethal invasive breast cancers. Furthermore, the improved prognosis of screen-detected cancers, as described by Shen et al. and Joensuu et al, might partly be attributable to the effects of this over-diagnosis (4, 5). It has long been accepted that mammography screening results in a significant over-diagnosis of ductal carcinoma in situ (DCIS) (6). We must now accept the possibility that screening may result in the over-diagnosis of occult, non-lethal invasive breast cancers as well. Newer screening technology (such as digital mammography and magnetic resonance imaging) may further increase the detection rate of these occult, non-lethal invasive cancers.

Increase of hormone-dependent cancer incidence in population under the age of forty

1518 Background: Due to the synthesis and introduction of new compounds over the last few decades, environmental human exposure has been increasingly complex. In these settings, some xenobiotics express oestrogen-like activity. As these compounds are present in the living environment and diet, exposure starts in utero and continues over the childhood with still unknown health effects in the adulthood. Methods: Based on recently published data on increased breast cancer incidence in women under the age of forty (Bouchardy, 2007) we analysed age-specific breast and testicular cancer incidence rates in Croatia for the period between 1994 and 2005. Additionally to crude rates age-standardized rates were defined (World population) for age groups 25–54 years for breast cancer and 20–54 years for testicular cancer. Results: Age-standardized breast cancer incidence rates increased by 21% (from 55.55 per 100,000 women in 1994 to 67.39 per 100,000 women in 2005.). Increase was even more pronounced in population wit...