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Biomedical subjects

Michael Thun

Publications and source records attributed to Michael Thun.

17 recordsLinked to original sources
PubMed2006

A comprehensive analysis of the androgen receptor gene and risk of breast cancer: results from the National Cancer Institute Breast and Prostate Cancer Cohort Consortium (BPC3).

INTRODUCTION: Androgens have been hypothesised to influence risk of breast cancer through several possible mechanisms, including their conversion to estradiol or their binding to the oestrogen receptor and/or androgen receptor (AR) in the breast. Here, we report on the results of a large and comprehensive study of the association between genetic variation in the AR gene and risk of breast cancer in the National Cancer Institute Breast and Prostate Cancer Cohort Consortium (BPC3). METHODS: The underlying genetic variation was determined by first sequencing the coding regions of the AR gene in a panel of 95 advanced breast cancer cases. Second, a dense set of markers from the public database was genotyped in a panel of 349 healthy women. The linkage disequilibrium relationships (blocks) across the gene were then identified, and haplotype-tagging single nucleotide polymorphisms (htSNPs) were selected to capture the common genetic variation across the locus. The htSNPs were then genotyped in the nested breast cancer cases and controls from the Cancer Prevention Study II, European Prospective Investigation into Cancer and Nutrition, Multiethnic Cohort, Nurses' Health Study, and Women's Health Study cohorts (5,603 breast cancer cases and 7,480 controls). RESULTS: We found no association between any genetic variation (SNP, haplotype, or the exon 1 CAG repeat) in the AR gene and risk of breast cancer, nor were any statistical interactions with known breast cancer risk factors observed. CONCLUSION: Among postmenopausal Caucasian women, common variants of the AR gene are not associated with risk of breast cancer.

Aged↗
PubMed2006

Trends in sunburns, sun protection practices, and attitudes toward sun exposure protection and tanning among US adolescents, 1998-2004.

BACKGROUND: Sun exposure in childhood is an important risk factor for developing skin cancer as an adult. Despite extensive efforts to reduce sun exposure among the young, there are no population-based data on trends in sunburns and sun protection practices in the young. The aim of this study was to describe nationally representative trend data on sunburns, sun protection, and attitudes related to sun exposure among US youth. METHODS: Cross-sectional telephone surveys of youth aged 11 to 18 years in 1998 (N = 1196) and in 2004 (N = 1613) were conducted using a 2-stage sampling process to draw population-based samples. The surveys asked identical questions about sun protection, number of sunburns experienced, and attitudes toward sun exposure. Time trends were evaluated using pooled logistic regression analysis. RESULTS: In 2004, 69% of subjects reported having been sunburned during the summer, not significantly less than in 1998 (72%). There was a significant decrease in the percentage of those aged 11 to 15 years who reported sunburns and a nonsignificant increase among the 16- to 18-year-olds. The proportion of youth who reported regular sunscreen use increased significantly from 31% to 39%. Little change occurred in other recommended sun protection practices. CONCLUSIONS: A small reduction in sunburn frequency and modest increases in sun protection practices were observed among youth between 1998 and 2004, despite widespread sun protection campaigns. Nevertheless, the decrease in sunburns among younger teens may be cause for optimism regarding future trends. Overall, there was rather limited progress in improving sun protection practices and reducing sunburns among US youth between 1998 and 2004.

Adolescent↗
PubMed2005

Trends in the leading causes of death in the United States, 1970-2002.

CONTEXT: The decrease in overall death rates in the United States may mask changes in death rates from specific conditions. OBJECTIVE: To examine temporal trends in the age-standardized death rates and in the number of deaths from the 6 leading causes of death in the United States. DESIGN AND SETTING: Analyses of vital statistics data on mortality in the United States from 1970 to 2002. MAIN OUTCOME MEASURE: The age-standardized death rate and number of deaths (coded as underlying cause) from each of the 6 leading causes of death: heart disease, stroke, cancer, chronic obstructive pulmonary disease, accidents (ie, related to transportation [motor vehicle, other land vehicles, and water, air, and space] and not related to transportation [falls, fire, and accidental posioning]), and diabetes mellitus. RESULTS: The age-standardized death rate (per 100,000 per year) from all causes combined decreased from 1242 in 1970 to 845 in 2002. The largest percentage decreases were in death rates from stroke (63%), heart disease (52%), and accidents (41%). The largest absolute decreases in death rates were from heart disease (262 deaths per 100,000), stroke (96 deaths per 100,000), and accidents (26 deaths per 100,000).The death rate from all types of cancer combined increased between 1970 and 1990 and then decreased through 2002, yielding a net decline of 2.7%. In contrast, death rates doubled from chronic obstructive pulmonary disease over the entire time interval and increased by 45% for diabetes since 1987. Despite decreases in age-standardized death rates from 4 of the 6 leading causes of death, the absolute number of deaths from these conditions continues to increase, although these deaths occur at older ages. CONCLUSIONS: The absolute number of deaths and age at death continue to increase in the United States. These temporal trends have major implications for health care and health care costs in an aging population.

Cause of Death↗
PubMed2004

Lung cancer rates in men and women with comparable histories of smoking.

BACKGROUND: Recent case-control studies suggest that, given equal smoking exposure, women may have a higher relative risk of developing lung cancer than men. Despite prospective data that conflict with this hypothesis, mechanistic studies to find a biologic basis for a sex difference continue. METHODS: We addressed the hypothesis directly by analyzing prospective data from former and current smokers in two large cohorts--the Nurses' Health Study of women and the Health Professionals Follow-up Study of men. We calculated incidence rates and hazard ratios of lung cancer in women compared with men, adjusting for age, number of cigarettes smoked per day, age at start of smoking, and time since quitting, using Cox proportional hazards models. We also reviewed published results from prospective analyses. RESULTS: From 1986 through 2000, 955 and 311 primary lung cancers were identified among 60 296 women and 25 397 men, respectively, who ranged in age from 40 to 79 years. Incidence rates per 100 000 person-years for women and men were 253 and 232, respectively, among current smokers and 81 and 73, respectively, among former smokers. The hazard ratio in women ever smokers compared with men was 1.11 (95% confidence interval = 0.95 to 1.31). Six published prospective cohort studies allowed assessment of comparative susceptibility to lung cancer by sex. None supported an excess risk of lung cancer for women. CONCLUSIONS: Women do not appear to have a greater susceptibility to lung cancer than men, given equal smoking exposure. Research should be focused on enhancing preventive interventions for all.

Adult↗
PubMed2004

Individual- and area-level socioeconomic status variables as predictors of mortality in a cohort of 179,383 persons.

The authors have studied whether area-level socioeconomic status predicts mortality independently of individual-level socioeconomic status in 179,383 persons in the American Cancer Society Nutrition Cohort, followed for mortality from 1992 to 2000 (17,383 deaths). They used an area-level variable based on census blocks that was an average of home value, income, education, and occupation. Education was the individual-level socioeconomic status variable. The authors studied socioeconomic status-mortality trends with each socioeconomic status variable adjusted for the other. For all causes, an individual's education was strongly and inversely associated with mortality; a weak but significant inverse trend was also present for area-level socioeconomic status. A similar pattern was seen for all-vascular disease. For all cancers, there was again a significant inverse trend with education but no trend with area-level socioeconomic status. Adjustment for conventional (non-socioeconomic status) individual-level risk factors diminished the effect of both socioeconomic status variables, although significant trends remained for men between education and all-cause, all-cancer, and all-vascular disease mortality. Study data indicate that the predictive value of area-level socioeconomic status variables varies by cause of death but is less important than individual-level socioeconomic status variables. Multivariate models that consider socioeconomic status as a potential confounder may not need to consider area-level socioeconomic status if data are available on individual-level education.

Aged↗
PubMed2004

Cigarette advertising and female smoking prevalence in Spain, 1982-1997: case studies in International Tobacco Surveillance.

BACKGROUND: Compared with northern Europe and the U.S., the widespread initiation of cigarette smoking began 20-40 years later among young women in Spain because of strong cultural prohibitions against female smoking. In this study, the authors examined the correlation between the rapid increase in female smoking prevalence and tobacco industry cigarette marketing practices in Spain during a period of rapid social liberalization. METHODS: The authors examined age-specific, period-specific, and birth cohort-specific increases in cigarette smoking among young women in Spain in relation to internal documents from Philip Morris beginning in 1971, cigarette advertising from 1982 to 1997, and the increase in the market share of blond tobacco and "light" cigarettes preferred by women. RESULTS: Some increase in cigarette smoking occurred among Spanish women before 1970, but the increase was substantially smaller and occurred later than in many Western countries. However, after 1970, the prevalence of cigarette smoking increased rapidly in Spanish women of all ages < 50 years. The rapid increase in female smoking coincided with massive increases in television advertising, especially to women, and increases in the market share of blond tobacco, "light cigarettes," and international tobacco brands. CONCLUSIONS: The increase in cigarette smoking among young Spanish women illustrates how aggressive marketing can exploit periods of social liberalization and rapidly increase cigarette smoking among women, even in countries in which female smoking traditionally has been unacceptable. Strategies are needed to prevent similar increases in smoking by women elsewhere.

Adolescent↗
PubMed2004

Prostate cancer incidence and survival in relation to education (United States).

INTRODUCTION: There are few data on prostate cancer incidence and survival in relation to socioeconomic status in the 1990s, after the introduction of prostate specific Antigen (PSA) testing. MATERIALS AND METHODS: We studied the relation of education to prostate cancer incidence and survival in the Cancer Prevention Study II (CPS-II) Nutrition Cohort. Participants provided questionnaire data on diet, medical history, education, and PSA testing. We followed 72,449 men from 1992-1999 for cancer incidence (4279 incident cases), and through 2000 for survival (158 prostate cancer deaths among incident cases). RESULTS: Multivariate-adjusted rate ratios (RRs) were calculated using Cox proportional hazards models. Self-reported (PSA) tests were more common among the more highly educated. Men with at least a college education had a 15-19% higher prostate cancer incidence than those with a high school education or less, but this association was limited to localized cancers and was attenuated by adjustment for PSA testing. Survival analysis among incident prostate cancer cases adjusted for stage and grade at diagnosis showed much lower prostate cancer mortality for men with at least a high school education compared to those with less than a high school education (RR = 0.49, 95% CI = 0.32-0.76). CONCLUSIONS: This study suggests that higher education is associated with slightly increased incidence of prostate cancer, at least partly due to greater use of PSA screening and a greater detection of localized tumors among more highly educated men. The much lower survival rates from prostate cancer among those with less than a high school education cannot be explained by available data and may reflect disparities in treatment. In 1999, 27% of US males over age 55 and older had less than a high school education.

Cohort Studies↗
PubMed2002

All-cause and cause-specific death rates by educational status for two million people in two American Cancer Society cohorts, 1959-1996.

Low socioeconomic status is associated with high mortality, but the extent to which socioeconomic status affects particular diseases and whether socioeconomic status effects have changed over time are uncertain. The authors used education as a marker for socioeconomic status in a study of two large American Cancer Society cohorts (follow-up, 1959-1996). Low education was associated with higher death rates in both cohorts from all causes and most specific causes, except breast cancer and external causes among women. Life expectancy in the more recent cohort was 4.8 years shorter for men and 2.7 years shorter for women for the least versus the most educated. The inverse relation between education and mortality was strongest for coronary heart disease, lung cancer, diabetes, and chronic obstructive pulmonary disease; moderate for colorectal cancer, external causes (men only), and stroke; weak for prostate cancer; and reversed for external causes among women. The direction of a weak gradient for breast cancer differed for those with and without prevalent breast cancer at baseline. Adjustment for conventional risk factors, probable intermediate variables between education and mortality, diminished but did not eliminate the observed educational/mortality gradients. Temporal trends showed increasing mortality differences by education for coronary heart disease, diabetes, and lung cancer for women.

Adult↗
PubMedDate not supplied

Spatial regression models for large-cohort studies linking community air pollution and health.

Cohort study designs are often used to assess the association between community-based ambient air pollution concentrations and health outcomes, such as mortality, development and prevalence of disease, and pulmonary function. Typically, a large number of subjects are enrolled in the study in each of a small number of communities. Fixed-site monitors are used to determine long-term exposure to ambient pollution. The association between community average pollution levels and health is determined after controlling for risk factors of the health outcome measured at the individual level (i.e., smoking). We present a new spatial regression model linking spatial variation in ambient air pollution to health. Health outcomes can be measured as continuous variables (pulmonary function), binary variables (prevalence of disease), or time-to-event data (survival or development of disease). The model incorporates risk factors measured at the individual level, such as smoking, and at the community level, such as air pollution. We demonstrate that the spatial autocorrelation in community health outcomes, an indication of not fully characterizing potentially confounding risk factors to the air pollution--health association, can be accounted for through the inclusion of location in the deterministic component of the model assessing the effects of air pollution on health or through a distance-decay spatial autocorrelation function in the stochastic component of the model, or both. We present a statistical approach that can be implemented for very large cohort studies. Our methods are illustrated with an analysis of the American Cancer Society cohort to determine whether the prevalence of heart disease is associated with concentrations of sulfate particles. From a statistical point of view, it appears that a location surface in the deterministic component of the model was preferred to a distance-decay autocorrelation structure in the model's stochastic component.

Air Pollution↗
PubMedDate not supplied

Mortality and long-term exposure to ambient air pollution: ongoing analyses based on the American Cancer Society cohort.

This article provides an overview of previous analysis and reanalysis of the American Cancer Society (ACS) cohort, along with an indication of current ongoing analyses of the cohort with additional follow-up information through to 2000. Results of the first analysis conducted by Pope et al. (1995) showed that higher average sulfate levels were associated with increased mortality, particularly from cardiopulmonary disease. A reanalysis of the ACS cohort, undertaken by Krewski et al. (2000), found the original risk estimates for fine-particle and sulfate air pollution to be highly robust against alternative statistical techniques and spatial modeling approaches. A detailed investigation of covariate effects found a significant modifying effect of education with risk of mortality associated with fine particles declining with increasing educational attainment. Pope et al. (2002) subsequently reported results of a subsequent study using an additional 10 yr of follow-up of the ACS cohort. This updated analysis included gaseous copollutant and new fine-particle measurements, more comprehensive information on occupational exposures, dietary variables, and the most recent developments in statistical modeling integrating random effects and nonparametric spatial smoothing into the Cox proportional hazards model. Robust associations between ambient fine particulate air pollution and elevated risks of cardiopulmonary and lung cancer mortality were clearly evident, providing the strongest evidence to date that long-term exposure to fine particles is an important health risk. Current ongoing analysis using the extended follow-up information will explore the role of ecologic, economic, and, demographic covariates in the particulate air pollution and mortality association. This analysis will also provide insight into the role of spatial autocorrelation at multiple geographic scales, and whether critical instances in time of exposure to fine particles influence the risk of mortality from cardiopulmonary and lung cancer. Information on the influence of covariates at multiple scales and of critical exposure time windows can assist policymakers in establishing timelines for regulatory interventions that maximize population health benefits.

Air Pollution↗
PubMedDate not supplied

Cancer statistics, 2002.

Every year the American Cancer Society estimates the number of new cancer cases and deaths expected in the United States in the current year and compiles the most recent data on cancer incidence, mortality, and survival, using National Cancer Institute (NCI) incidence and National Center for Health Statistics (NCHS) mortality data. Incidence and death rates are age adjusted to the 1970 US standard population. It is estimated that 1,284,900 new cases of cancer will be diagnosed and 555,500 people will die from cancer in the United States in the year 2002. From 1992 to 1998, cancer death rates declined in males and females, while cancer incidence rates decreased among males and increased slightly among females. Most notably, African-American men showed the largest decline for both incidence and mortality. Nevertheless, African Americans still carry the highest burden of cancer with later-stage cancer diagnosis and poorer survival compared with whites. Despite the continued decline in cancer death rates, the total number of recorded cancer deaths in the United States continues to increase slightly due to the aging and expanding population.

Adolescent↗
PubMedDate not supplied

American Cancer Society guidelines on nutrition and physical activity for cancer prevention: Reducing the risk of cancer with healthy food choices and physical activity.

The American Cancer Society (ACS) has set aggressive challenge goals for the nation to decrease cancer incidence and mortality--and to improve the quality of life of cancer survivors--by the year 2015. To address these critical goals, the ACS publishes the Nutrition and Physical Activity Guidelines to serve as a foundation for its communication, policy, and community strategies and ultimately, to affect dietary and physical activity patterns among Americans. These guidelines, published every five years, are developed by a national panel of experts in cancer research, prevention, epidemiology, public health, and policy, and as such, they represent the most current scientific evidence related to dietary and activity patterns and cancer risk. The American Cancer Society guidelines include recommendations for individual choices regarding diet and physical activity patterns, but those choices occur within a community context that either facilitates or interferes with healthy behaviors. Therefore, this committee presents one key recommendation for community action to accompany the four recommendations for individual choices for nutrition and physical activity to reduce cancer risk. This recommendation for community action underscores just how important community measures are to the support of healthy behaviors by means of increasing access to healthful food choices and opportunities to be physically active. The ACS guidelines are consistent with guidelines from the American Heart Association for the prevention of coronary heart disease as well as for general health promotion, as defined by the Department of Health and Human Services' 2000 Dietary Guidelines for Americans.

Alcohol Drinking↗
PubMedDate not supplied

Trends in breast cancer by race and ethnicity.

In this article, the American Cancer Society (ACS) describes trends in incidence, mortality, and survival rates of female breast cancer in the United States by race and ethnicity. It also provides estimates of new cases and deaths and shows trends in screening mammography. The incidence and survival data derive from the National Cancer Institute's Surveillance, Epidemiology, and End Results program; mortality data are from the National Center for Health Statistics. Approximately 211,300 new cases of invasive breast cancer, 55,700 in situ cases, and 39,800 deaths are expected to occur among women in the United States in 2003. Breast cancer incidence rates have increased among women of all races combined and white women since the early 1980s. The increasing rate in white women predominantly involves small (< or = 2 cm) and localized-stage tumors, although a small increase in the incidence of regional-stage tumors and those larger than five cm occurred since the early 1990s. The incidence rate among African American women stabilized during the 1990s for all breast cancers and for localized tumors. African American women are more likely than white women to be diagnosed with large tumors and distant-stage disease. Other racial and ethnic groups have lower incidence rates than do either white or African American women. However, the proportion of disease diagnosed at advanced stage and with larger tumor size in all minorities is greater than in white persons. Death rates decreased by 2.5% per year among white women since 1990 and by 1% per year among African American women since 1991. The disparity in mortality rates between white and African American women increased progressively between 1980 and 2000, so that by 2000 the age-standardized death rate was 32% higher in African Americans. Clinicians should be aware that 63% and 29% of breast cancers are diagnosed at local- and regional-stage disease, for which the five-year relative survival rates are 97% and 79%, respectively. This information, coupled with decreasing mortality rates and improvements in treatment, may motivate women to have regular mammographic and clinical breast examinations. Continued efforts are needed to increase the availability of high-quality mammography and treatment to all segments of the population.

Adult↗
PubMedDate not supplied

Cancer disparities by race/ethnicity and socioeconomic status.

This article highlights disparities in cancer incidence, mortality, and survival in relation to race/ethnicity, and census data on poverty in the county or census tract of residence. The incidence and survival data derive from the National Cancer Institute's (NCI) Surveillance, Epidemiology, and End Results (SEER) Program; mortality data are from the National Center for Health Statistics (NCHS); data on the prevalence of major cancer risk factors and cancer screening are from the National Health Interview Survey (NHIS) conducted by NCHS. For all cancer sites combined, residents of poorer counties (those with greater than or equal to 20% of the population below the poverty line) have 13% higher death rates from cancer in men and 3% higher rates in women compared with more affluent counties (less than 10% below the poverty line). Differences in cancer survival account for part of this disparity. Among both men and women, five-year survival for all cancers combined is 10 percentage points lower among persons who live in poorer than in more affluent census tracts. Even when census tract poverty rate is accounted for, however, African American, American Indian/Alaskan Native, and Asian/Pacific Islander men and African American and American Indian/Alaskan Native women have lower five-year survival than non-Hispanic Whites. More detailed analyses of selected cancers show large variations in cancer survival by race and ethnicity. Opportunities to reduce cancer disparities exist in prevention (reductions in tobacco use, physical inactivity, and obesity), early detection (mammography, colorectal screening, Pap tests), treatment, and palliative care.

Delivery of Health Care↗
PubMedDate not supplied

Progress and opportunities in tobacco control.

Much progress has been made in reducing tobacco use in the United States. Despite the continuing challenges of tobacco control and the massive burden of illness, death, and economic costs caused by tobacco products, there are now unprecedented opportunities to prevent and treat tobacco dependence through a combination of interventions that have proven effective at both the population and individual levels. This report briefly reviews population trends in tobacco use by youth and adults, describes some of the policy measures that have proven effective in comprehensive tobacco control, and discusses the role of clinicians in the diagnosis and treatment of tobacco dependence in patients.

Adolescent↗
PubMedDate not supplied

Trends in breast cancer by race and ethnicity: update 2006.

In this article, the American Cancer Society (ACS) provides estimates of new breast cancer cases and deaths in 2006 and describes trends in incidence, mortality, and survival for female breast cancer in the United States. These estimates are based on incidence data from the National Cancer Institute (NCI) and the North American Association of Central Cancer Registries, which includes state data from NCI and the National Program of Cancer Registries of the Centers for Disease Control and Prevention and mortality data from the National Center for Health Statistics for the most recent years available (1975 to 2002). This article also shows trends in screening mammography. Approximately 212,920 new cases of invasive breast cancer, 61,980 in situ cases, and 40,970 deaths are expected to occur among US women in 2006. As previously reported, breast cancer incidence rates increased rapidly among women of all races from 1980 to 1987, a period when there was increasing uptake of mammography by a growing proportion of US women, and then continued to increase, but at a much slower rate, from 1987 to 2002. Trends in incidence vary by age, race, socioeconomic status, and stage. The continuing increase in incidence (all stages combined) is limited to White women age 50 and older; recent trends are stable for African American women age 50 and older and White women under age 50 years and are decreasing for African American women under age 50 years. Although incidence rates (all races combined) are substantially higher for women age 50 and older (375.0 per 100,000 females) compared with women younger than 50 years (42.5 per 100,000 females), approximately 23% of breast cancers are diagnosed in women younger than 50 years because those women represent 73% of the female population. For women age 35 and younger, age-specific incidence rates are slightly higher among African Americans compared with Whites but then cross over so that Whites have substantially higher incidence at all later ages. Among women of all races and ages, breast cancer mortality rates declined at an average rate of 2.3% per year between 1990 and 2002, a trend that reflects progress in both early detection and treatment. However, death rates in African American women remain 37% higher than in Whites, despite lower incidence rates. Although, in national surveys, approximately 70% of women age 40 years and older report having had a mammogram in the past 2 years, rates vary by race/ethnicity and are markedly lower among women with lower levels of education, without health insurance, and in recent immigrants. Furthermore, a recent study suggests that the true percentage of women having regular mammography is lower than reported in survey data. Encouraging patients age 40 years and older to have annual mammography and clinical breast exam is the single most important step that clinicians can take to reduce suffering and death from breast cancer. Clinicians should also ensure that patients at high risk of breast cancer are identified and offered appropriate referrals and treatment. Continued progress in the control of breast cancer will require sustained and increased efforts to provide high-quality screening, diagnosis, and treatment to all segments of the population.

Adult↗