Differences In Lung Cancer Mortality Research Articles

Contribution of smoking, disease history, and survival to lung cancer disparities in Black individuals.

Lung cancer is the leading cause of cancer deaths and disproportionately affects self-identified Black or African American ("Black") people, especially considering their relatively low self-reported smoking intensity rates. This study aimed to determine the relative impact of smoking history and lung cancer incidence risk, histology, stage, and survival on these disparities. We used 2 lung cancer models (MichiganLung-All Races and MichiganLung-Black) to understand why Black people have higher rates of lung cancer deaths. We studied how different factors, such as smoking behaviors, cancer development, histology, stage at diagnosis, and lung cancer survival, contribute to these differences. Adjusted for smoking history, approximately 90% of the difference in lung cancer deaths between the overall and Black populations (born in 1960) was the result of differences in the risk of getting lung cancer. Differences in the histology and stage of lung cancer and survival had a small impact (4% to 6% for each). Similar results were observed for the 1950 and 1970 birth cohorts, regardless of their differences in smoking patterns from the 1960 cohort. After taking smoking into account, the higher rate of lung cancer deaths in Black people can mostly be explained by differences in the risk of developing lung cancer. As lung cancer treatments and detection improve, however, other factors may become more important in determining differences in lung cancer mortality between the Black and overall populations. To prevent current disparities from becoming worse, it is important to make sure that these improvements are available to everyone in an equitable way.

Abstract A023: Racial differences in lung cancer burden: A retrospective analysis of TriNetX data

Abstract Background. Lung cancer is the number one cause of cancer-related deaths in the U.S. and many other countries. Lung cancer incidence and mortality rates have decreased for all races over the past 20 years, in part because of decreased tobacco use. Yet, there have been few clinical studies of lung cancer morbidity and mortality by race. The purpose of this study is to examine racial differences in lung cancer mortality in the U.S. using the electronic health records (EHR) database, TriNetX. Method. This retrospective cohort study was conducted based on the data from US Collaborative Network in TriNetX, a real-time, EHR database providing 42.7-million patient data from 49 health care organizations (HCOs). The cohort of interest was lung cancer patients in the U.S., which were identified using the ICD-10 code of C34 with an index diagnosis date of January 1, 2010. Kaplan-Meier curves, log-rank chi-square statistics, and hazard ratio (HR) were compared among different racial groups in the EHR data. Results. Of 42.7-million patients in the U.S., the majority (60.3%) were people who are non-Hispanic white (NHW) followed by people who are Black/African American (15.4%), Hispanic (7.2%), Asian (4.6%), and others (Native Hawaiian/Pacific Islander, 0.5%). 394,560 lung cancer patients were identified. Kaplan-Meier survival curves showed that Asians had the highest survival probability with median overall survival (OS) from the initial lung cancer diagnosis of 127.3 months, compared to 92.1 months for Hispanic, 69.1 months for African American/Black, 61.4 months for others, and 53.8 months for NHW. The HR was highest among NHW (HR=1.71, 95% CI=1.62-1.81), others (HR=1.62, 95% CI=1.41-1.85), African American/Black (HR=1.52, 95% CI=1.43-1.61), and Hispanic patients (HR=1.40, 95% CI=1.30-1.52) compared to Asian patients Conclusion. These findings suggest racial disparities in lung cancer survival, with NHW having the lowest and Asians having the highest median survival. These findings are inconsistent with the results from the Multiethnic Cohort study (prospective population based study), which reported blacks having the lowest median survival. It indicates that there are different racial burdens of lung cancer from clinical data and population data. Further analyses are needed to adjust potential confounders such as smoking status and stage of diagnosis. Citation Format: SoHye Park, Zachary Urdang, Julie Barta, Kuang-Yi Wen, Joseph Curry, Hee-Soon Juon. Racial differences in lung cancer burden: A retrospective analysis of TriNetX data [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr A023.

Work-Related Factors and Lung Cancer Survival: A Population-Based Study in Switzerland (1990-2014).

While previous Swiss studies have demonstrated differences in lung cancer mortality between occupational groups, no estimates are available on the association of occupation-related factors with lung cancer survival. This study aimed at determining whether occupation or work-related factors after diagnosis affect lung cancer survival. We used cancer registry records to identify lung cancer patients diagnosed between 1990 and 2014 in western Switzerland (n = 5773) matched with the Swiss National Cohort. The effect of occupation, the skill level required for the occupation, and the socio-professional category on 5-year lung cancer survival was assessed using non-parametric and parametric methods, controlling for histological type and tumour stage. We found that the net survival varied across skill levels and that the lowest skill level was associated with worse survival in both men and women. In the parametric models with minimal adjustment, we identified several occupational groups at higher risk of mortality compared to the reference category, particularly among men. After adjustment for histological type of lung cancer and tumour stage at diagnosis, most hazard ratios remained higher than 1, though non-statistically significant. Compared to top managers and self-employed workers, workers in paid employment without specific information on occupation were identified as the most at-risk socio-professional category in nearly all models. As this study was conducted using a relatively small sample and limited set of covariates, further studies are required, taking into account smoking habits and administrated cancer treatments. Information on return to work and working conditions before and after lung cancer diagnosis will also be highly valuable for analysing their effect on net lung cancer survival in large nationwide or international studies. Such studies are essential for informing health and social protection systems, which should guarantee appropriate work conditions for cancer survivors, beneficial for their quality of life and survival.

The 1964 US Surgeon General's report on smoking and health.

The 1964 report of the US Surgeon General on smoking and health made an authoritative case that tobacco smoking was a cause of premature deaths from lung cancer and chronic bronchitis. It justified the practice of drawing causal inferences from epidemiological studies, specified influential criteria for doing so, and made use of an early form of meta-analysis.

Q&A: Ned Sharpless on COVID-19 and Cancer Prevention.

Q&A: Ned Sharpless on COVID-19 and Cancer Prevention.

Gender and Regional Differences in Lung Cancer Mortality in Brazil.

Background and Objective:This was a population-based ecological with data of deaths from the Mortality Information System. The objective of this study was to analyze the temporal trends of mortality induced by bronchi and lung cancer in Brazil and its geographical regions between 2001 and 2015 and secondly to calculate predictions for 2016-2030. Material and Methods:The mortality trends were analyzed by the Joinpoint regression and calculation of predictions was used the Nordpred software. Results:There was a reduction trend in lung cancer mortality among Brazilian men living in South and Southeast regions of Brazil. However, there was an increasing trend in lung cancer mortality among Brazilian women living in Northeast, Southeast, and South regions of Brazil. When comparing the last observed period and the last foreseen period for males, it is expected an increase of 12.86% in the number of deaths, justified mainly by the change in population structure, with a reduction in the risk of death by the disease. For women, the expected increase is 26.22%, justified both by population structure, and the increased risk of deaths from the disease. The higher rates will be observed in the southern region of the country, for both sexes. Conclusion:The mortality induced by lung and bronchial cancer in Brazil was unevenly distributed. However lung cancer incidence had a reducing trend, the mortality caused following it was increased among men. For women, the rates are rising, and until 2030, the mortality load will continue to rise for both.

Mortality outcomes of low-dose computed tomography screening for lung cancer in urban China: a decision analysis and implications for practice

BackgroundMortality outcomes in trials of low-dose computed tomography (CT) screening for lung cancer are inconsistent. This study aimed to evaluate whether CT screening in urban areas of China could reduce lung cancer mortality and to investigate the factors that associate with the screening effect.MethodsA decision tree model with three scenarios (low-dose CT screening, chest X-ray screening, and no screening) was developed to compare screening results in a simulated Chinese urban cohort (100,000 smokers aged 45–80 years). Data of participant characteristics were obtained from national registries and epidemiological surveys for estimating lung cancer prevalence. The selection of other tree variables such as sensitivities and specificities of low-dose CT and chest X-ray screening were based on literature research. Differences in lung cancer mortality (primary outcome), false diagnoses, and deaths due to false diagnosis were calculated. Sensitivity analyses were performed to identify the factors that associate with the screening results and to ascertain worst and optimal screening effects considering possible ranges of the variables.ResultsAmong the 100,000 subjects, there were 448, 541, and 591 lung cancer deaths in the low-dose CT, chest X-ray, and no screening scenarios, respectively (17.2% reduction in low-dose CT screening over chest X-ray screening and 24.2% over no screening). The costs of the two screening scenarios were 9387 and 2497 false diagnoses and 7 and 2 deaths due to false diagnosis among the 100,000 persons, respectively. The factors that most influenced death reduction with low-dose CT screening over no screening were lung cancer prevalence in the screened cohort, low-dose CT sensitivity, and proportion of early-stage cancers among low-dose CT detected lung cancers. Considering all possibilities, reduction in deaths (relative numbers) with low-dose CT screening in the worst and optimal cases were 16 (5.4%) and 288 (40.2%) over no screening, respectively.ConclusionsIn terms of mortality outcomes, our findings favor conducting low-dose CT screening in urban China. However, approaches to reducing false diagnoses and optimizing important screening conditions such as enrollment criteria for screening are highly needed.

Lung cancer guidelines in Sweden, Denmark, Norway and Finland: a comparison

Background: The Nordic countries are similar in terms of demographics and health care organization. Yet there are marked differences in lung cancer mortality, for which Denmark historically has had the poorest outcome. One of several possible reasons for these differences could have to do with how lung cancer is diagnosed and treated in the different Nordic countries. However, among the four most populous Nordic countries: Sweden, Denmark, Norway and Finland, there is a paucity of knowledge about differences and similarities in recommendations in the national guidelines for non-small cell lung cancer (NSCLC) and the methodology by which the guidelines are developed.Methods: We identified and evaluated the development and content of the available clinical care guidelines for NSCLC in the four countries. Moreover, we compared the integrated cancer pathways in these countries. We have used case examples to illustrate areas with clear differences in clinical care recommendations.Results: There are notable differences in the methodology by which the guidelines are developed, published and updated to comply with international recommendations. The Norwegian guidelines are developed and updated according to the most rigorous methodology and have so far been updated most frequently. We found that on the basis of recommendations patients with NSCLC are treated differently with regard to bevacizumab therapy and radiation dosing regimens. Cerebral imaging practices in patients with locally advanced NSCLC also differ. There is, moreover, a marked difference with regard to efforts to help patients to quit smoking. All except Finland have integrated cancer pathways for fast track diagnosis and treatment. Guidelines for follow-up of lung cancer patients also differ, with the Danish follow-up regimen as the most comprehensive. To obtain consensus on optimal clinical care, areas with differences in recommendations or where recommendations are based on a low level of evidence should be subjected to further studies.

Comparative effectiveness of surgery and radiosurgery for stage I non-small cell lung cancer.

Although surgery is the standard treatment for early-stage non-small cell lung cancer (NSCLC), stereotactic body radiotherapy (SBRT) has been disseminated as an alternative therapy. The comparative mortalities and toxicities of these treatments for patients of different life expectancies are unknown. The Surveillance, Epidemiology, and End Results-Medicare linked database was used to identify patients who were 67 years old or older and underwent SBRT or surgery for stage I NSCLC from 2007 to 2009. Matched patients were stratified into short life expectancies (<5 years) and long life expectancies (≥5 years). Mortality and complication rates were compared with Poisson regression. Overall, 367 SBRT patients and 711 surgery patients were matched. Acute toxicity (0-1 month) was lower from SBRT versus surgery (7.9% vs 54.9%, P < .001). At 24 months after treatment, there was no difference (69.7% vs 73.9%, P = .31). The incidence rate ratio (IRR) for toxicity from SBRT versus surgery was 0.74 (95% confidence interval [CI], 0.64-0.87). Overall mortality was lower with SBRT versus surgery at 3 months (2.2% vs 6.1%, P = .005), but by 24 months, overall mortality was higher with SBRT (40.1% vs 22.3%, P < .001). For patients with short life expectancies, there was no difference in lung cancer mortality (IRR, 1.01; 95% CI, 0.40-2.56). However, for patients with long life expectancies, there was greater overall mortality (IRR, 1.49; 95% CI, 1.11-2.01) as well as a trend toward greater lung cancer mortality (IRR, 1.63; 95% CI, 0.95-2.79) with SBRT versus surgery. SBRT was associated with lower immediate mortality and toxicity in comparison with surgery. However, for patients with long life expectancies, there appears to be a relative benefit from surgery versus SBRT.

Abstract C07: Utilizing state cancer profiles for communicating lung cancer disparities

Abstract Lung cancer is the third most common cancer in the US and is the leading cause of death. The accurate profiling of lung cancer (i.e. depiction of the magnitude of this disease among the different population subgroups at the state and local levels) is necessary to inform the development of effective cancer control programs in the areas most impacted, and subsequently, reduce the cancer burden. One of the prerequisites for accurate profiling of cancer is a high quality cancer data. Unfortunately, researchers often rely on a combination of data sources that may differ in data quality, completeness and other important attributes. The State Cancer Profiles website is perhaps the most comprehensive, and high quality resource that provides national, state and local level cancer data collected from CDC's National Program of Cancer Registries (NPCR) and NCI's Surveillance, Epidemiology and End Results (SEER) Program. Lung cancer data from State Cancer Profiles can be utilized to assess the burden and the risks, identify trends, examine sociodemographic data, expose economic, geographic and racial disparities, identify research opportunities and make important informed decisions. In this particular project, we demonstrate how State Cancer Profiles can be used effectively to profile lung cancer and identify health disparities, using the State of Indiana as an example. Method: We utilized rate/trend comparison, mortality rates, historical trends as well as screening and risk factors data to profile lung cancer mortality. A series of maps and tables were generated to communicate the geographic differences in lung cancer mortality at the local and state levels. Results: Results show how the state of Indiana compares to other states and the within state variation in cancer and risk factors. Indiana is the 7th highest state in lung cancer mortality rates. The death rate in Indiana is above the US average nonetheless, the trend is stable for females and falling for males. Orange, Wayne and White counties have the highest death rates which are above the Indiana and US averages and show rising trends. Marion County, also show death rates above the state and US averages. However, the trend is falling. In Marion County, African Americans (a predominant population in the county) have higher death rates compared to whites, 75.8 vs. 66.3. Similarly, in Allen County, African Americans have high rates compare to whites, 68.5 vs. 48.7. As far as risk factors, Indiana is the 6th highest state in the percentage of current smokers. It is noteworthy, that indoor smoking is legislated by only 30% of the state. Demographic data show that 83% of Indiana's population under the age of 65 is insured. Of the families in Indiana, 10% are below poverty. Marion County shows poverty rate at 14.2. Conclusion: The information offered by State Cancer Profiles is useful for developing a profile of cancer; for identifying the areas where cancer burden is the greatest and subgroups of populations that are most impacted. It reveals that racial disparities in lung cancer exist at both the state and county levels, despite the fact that the overall mortality rates are dropping. Furthermore, it shows the demographic characteristics and risk factors that are relevant for understanding cancer burden. In conclusion, State Cancer Profiles is an excellent tool for communicating health disparities, depicting cancer burden and informing cancer control planning. Citation Format: Antoinette Percy-Laurry, Zaria Tatalovich. Utilizing state cancer profiles for communicating lung cancer disparities. [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr C07. doi:10.1158/1538-7755.DISP13-C07

Regional and socioeconomic inequalities in lung cancer mortality in Belgium, 2001-2009

Introduction Lung cancer is a leading cause of cancer death and lung cancer mortality among Belgian men is the highest in Europe. The association between lung cancer and socioeconomic status has been extensively studied, however, little research has focused on geographical differences in lung cancer mortality. Spatial analysis can provide insight into at risk regions and populations, which could aid health interventions, and can help to develop or prove hypothesis about key determinants …

The Effect of Provider Density on Lung Cancer Survival Among Blacks and Whites in the United States

Lung cancer mortality rates may vary with access to specialty providers and local resources. We sought to examine the effect of access to care, using density of lung cancer care providers, on lung cancer mortality among blacks and whites in the United States. We examined U.S. county-level data for age-adjusted lung cancer mortality rates from 2003 to 2007. Our primary independent variable was per capita number of thoracic oncologic providers, adjusting for county-level smoking rates, socioeconomic status, and other geographic factors. Data were obtained from 2009 Area Resource File, National Center for Health Statistics, and the County Health Rankings Project. Providers of lung cancer care were unevenly distributed among the U.S. counties. For example, 41.4% of the U.S. population reside in counties with less than four thoracic surgeons per 100,000 people, 23.4% in counties with 4 to 15 surgeons per 100,000 people, and 35.3% in counties with more than 15 surgeons per 100,000 people. Geographically, 4.3% of whites compared with 11.2% of blacks lived in high lung cancer mortality zones. Lung cancer mortality did not vary by density of thoracic surgeons or oncology services; however, higher primary care provider density was associated with lung cancer mortality reduction of 4.1 per 100,000 for whites. Variation in provider density for thoracic oncology in the United States was not associated with a difference in lung cancer mortality. Lower mortality associated with higher primary care provider density suggests that equitable access to primary care may lead to reduced cancer disparities.

Gender equality, development, and cross-national sex gaps in life expectancy

Female life expectancy exceeds male life expectancy in almost every country throughout the world. Nevertheless, cross-national variation in the sex gap suggests that social factors, such as gender equality, may directly affect or mediate an underlying biological component. In this article, we examine the association between gender equality and the sex gap in mortality. Previous research has not addressed this question from an international perspective with countries at different levels of development. We examine 131 countries using a broad measure of national gender equality that is applicable in both Less Developed Countries (LDCs) and Highly Developed Countries (HDCs). We find that the influence of gender equality is conditional on level of development. While gender equality is associated with divergence between female and male life expectancies in LDCs, it is associated with convergence in HDCs. The relationship between gender equality and the sex gap in mortality in HDCs strongly relates to, but is not explained by, sex differences in lung cancer mortality. Finally, we find that divergence in LDCs is primarily driven by a strong positive association between gender equality and female life expectancy. In HDCs, convergence is potentially related to a weak negative association between gender equality and female life expectancy, though findings are not statistically significant.

Mortality and cancer registration experience of the Sellafield workers known to have beeninvolved in the 1957 Windscale accident: 50 year follow-up

This paper studies the mortality and cancer morbidity of the 470 male workers involved intackling the 1957 Sellafield Windscale fire or its subsequent clean-up. Workers werefollowed up for 50 years to 2007, extending the follow-up of a previously published cohortstudy on the Windscale fire by 10 years. The size of the study population is small, but thecohort is of interest because of the involvement of the workers in the accident. Significantexcesses of deaths from diseases of the circulatory system (standardised mortality ratio(SMR) = 120, 95%CI = 103–138; 194 deaths) driven by ischaemic heart disease (IHD) (SMR = 133, 95%CI = 112–157, 141 deaths) were found when compared with the population of Englandand Wales but not when compared with the population of Northwest England (SMR = 105, 95%CI = 90–120and SMR = 115, 95% CI = 97–136 respectively). When compared with those workers in post at the time of the firebut not directly involved in the fire the mortality rate from IHD among thoseinvolved in tackling the fire was raised but not statistically significantly (rate ratio(RR) = 1.11, 95%CI = 0.92–1.33). A RR of 1.11 is consistent with an excess relative risk of 0.65 Sv − 1 as reported in an earlier study of non-cancer mortality in the British NuclearFuels plc cohort of which these workers are a small but significant part.There was a statistically significant difference in lung cancer mortality (RR = 2.18, 95%CI = 1.05–4.52) rates between workers who had received higher recorded external doses during thefire and those who had received lower external doses. Comparison of the mortality rates ofworkers directly involved in the accident with workers in post, but not so involved, showedno significant differences overall. On the basis of the use of a propensity score theaverage effect of involvement in the Windscale fire on all causes of death was − 2.13% (se = 3.64%,p = 0.56) thoughthis difference is not statistically significant. The average effect of involvement in the Windscale firewas − 5.53% (se = 3.81,p = 0.15) for all cancersmortality and 6.60% (se = 4.03%, p = 0.10) for IHD mortality though neither figure was statistically significant.This analysis of the mortality and cancer morbidity experience of those Sellafield workersinvolved in the 1957 Windscale fire does not reveal any measurable effect of the fire upontheir health. Although this study has low statistical power for detecting small adverseeffects, due to the relatively small number of workers, it does provide reassurance that nosignificant health effects are associated with the 1957 Windscale fire even after 50 years offollow-up.

Lung cancer mortality and fine particulate air pollution in Europe

Inspired by the recent report from the EPIC cohort1 and 5 other prospective studies,2, 3, 4, 5 on the association between lung cancer and fine particulate air pollution, we plotted the mortality rates of lung cancer of 15 European countries against their average air concentration of fine particulates (PM2.5). Age standardized rates for lung cancer were derived from the EUCAN database (International Agency on Research on Cancer) for the year 1998, which included data for Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands, Portugal, Spain, Sweden and the United Kingdom.7 We standardized for smoking by the indirect method using the reported smoking prevalence across European countries.8 Mean annual PM2.5 concentrations were based on grid-averaged PM2.5 (annual mean, μg/m3), which was estimated for the year 2002 by the International Institute for Applied Systems Analysis.9 It is reasonable to assume that the mean annual PM2.5 across countries measured in 2002 is representative for exposures in the past decennia. The age and smoking standardized lung cancer rates across the countries ranged from 15 to 115 per 100,000 men and from 7 to 57 per 100,000 women, in line with previous estimates.10 Mean annual PM2.5 concentrations ranged from 1 to 22 μg/m3. Spearman correlation coefficients between the countries' age and smoking standardized mortality rates for lung cancer and annual mean PM2.5 were 0.57 for men (p = 0.028, Fig. 1a), while the association was not significant for women (r = 0.37, p = 0.18; Fig. 1b). For men, mortality standardized for age and smoking prevalence at the country level showed that a 5 μg/m3 higher mean annual PM2.5 was associated with an increased risk for lung cancer of 17.7% (95% CI: 3.7–31.7). Mean annual PM2.5 explained 36% of the variation in the age and smoking standardized lung cancer rates in men across the 15 European countries. Age and smoking standardized lung cancer rates for men (a) and women (b) plotted by mean annual fine particulate air pollution (PM2.5) for Austria (AT), Belgium (BE), Denmark (DK), France (FR), Finland (FI), Germany (DE), Greece (EL), Ireland (IE), Italy (IT), Luxembourg (LU), The Netherlands (NL), Portugal (PT), Spain (ES), Sweden (SE) and United Kingdom (UK). Our analysis is based on aggregated data, which are prone to ecological bias, associated with attempting to deduce individual-level effects from group level data. Note that the large countries (FR, DE, UK and IT) where the within country heterogeneity in air pollution is likely to be greatest, are situated in the middle of the distribution, and thus, do not greatly influence the association (Fig. 1). In these larger countries, it would be interesting to do the analysis at a regional level, but we do not have such data. Obviously, our analysis cannot prove causality, but it may nevertheless provide guidance on how to design further detailed epidemiological studies, based on individual level data. Most of the prospective cohort studies have been conducted in countries with relatively low pollution levels, e.g. United States1, 2, 3 and Norway.5 Our analysis shows the relevance to include Belgium in future large scale European studies, given that this region has the highest mean annual PM2.5 concentration of Europe9, 11 and shows high standardized mortality rates for lung cancer. In conclusion, at an ecological level the heterogeneity in lung cancer mortality across European countries could not be entirely explained by differences in the age distribution and/or smoking habits across the countries. Our ecological analysis suggests that some of the differences in lung cancer mortality in Europe could be explained by fine particulate air concentrations. Yours sincerely, Tim S. Nawrot, Kristiaan Nackaerts, Peter H.M. Hoet, Benoit Nemery.

Extended Lung Cancer Incidence Follow-up in the Mayo Lung Project and Overdiagnosis

A troubling aspect of cancer screening is the potential for overdiagnosis, i.e., detection of disease that, in the absence of screening, would never have been diagnosed. Overdiagnosis is of particular concern in lung cancer screening because newer screening modalities can identify small nodules of unknown clinical significance. Previously published analyses of data from the Mayo Lung Project, a large randomized controlled trial conducted among 9211 male cigarette smokers in the 1970s and early 1980s indicated that overdiagnosis might exist in lung cancer screening. At the end of follow-up (July 1, 1983), no difference in lung cancer mortality was observed, but an excess of 46 cases in the intervention arm suggested overdiagnosis. Because that excess could instead have resulted from short follow-up time, we investigated this possibility by conducting long-term lung cancer incidence follow-up. We investigated the lung cancer status through 1999 of the 7118 participants in the Mayo Lung Project who were alive and without diagnosed lung cancer in 1983 by use of medical records, surveys mailed to participants or next-of-kin, and state death certificates. Information was available for 6101 participants, including 811 with inconclusive lung cancer status. From November 1971 through December 31, 1999, 585 participants in the intervention arm and 500 in the usual-care arm were diagnosed with lung cancer. The persistence of excess cases in the intervention arm after 16 additional years of follow-up provides continued support for overdiagnosis in lung cancer screening.

Statistical modeling and projections of lung cancer mortality in 4 industrialized countries

The purpose of this work was to model lung cancer mortality as a function of past exposure to tobacco and to forecast age-sex-specific lung cancer mortality rates. A 3-factor age-period-cohort (APC) model, in which the period variable is replaced by the product of average tar content and adult tobacco consumption per capita, was estimated for the US, UK, Canada and Australia by the maximum likelihood method. Age- and sex-specific tobacco consumption was estimated from historical data on smoking prevalence and total tobacco consumption. Lung cancer mortality was derived from vital registration records. Future tobacco consumption, tar content and the cohort parameter were projected by autoregressive moving average (ARIMA) estimation. The optimal exposure variable was found to be the product of average tar content and adult cigarette consumption per capita, lagged for 25-30 years for both males and females in all 4 countries. The coefficient of the product of average tar content and tobacco consumption per capita differs by age and sex. In all models, there was a statistically significant difference in the coefficient of the period variable by sex. In all countries, male age-standardized lung cancer mortality rates peaked in the 1980s and declined thereafter. Female mortality rates are projected to peak in the first decade of this century. The multiplicative models of age, tobacco exposure and cohort fit the observed data between 1950 and 1999 reasonably well, and time-series models yield plausible past trends of relevant variables. Despite a significant reduction in tobacco consumption and average tar content of cigarettes sold over the past few decades, the effect on lung cancer mortality is affected by the time lag between exposure and established disease. As a result, the burden of lung cancer among females is only just reaching, or soon will reach, its peak but has been declining for 1 to 2 decades in men. Future sex differences in lung cancer mortality are likely to be greater in North America than Australia and the UK due to differences in exposure patterns between the sexes.

Lung cancer death rates by smoking status: Comparison of the Three‐Prefecture Cohort study in Japan to the Cancer Prevention Study II in the USA

Cigarette smoking is an established risk factor for lung cancer. However, the magnitude of the relative risk (RR) on lung cancer mortality in relation to cigarette smoking is reported to be lower in Japan than in Western countries. We investigated whether this discrepancy could be explained by differences in the exposure to cigarettes smoked, by differences in sensitivity to smoking, or by differences in lung cancer mortality among non-smokers. We examined the 10-year follow-up data on 88,153 participants in a Japanese population-based prospective study conducted in three prefectures. Data used as a Western counterpart was retrieved from a published report of the US Cancer Prevention Study (CPS)-II. Although there was a significant increased risk of lung cancer death among current smokers compared with non-smokers, the observed RR in the Three-Prefecture Study were much lower than RR reported in the CPS-II. Lung cancer mortality of our Japanese sample was lower among current smokers and higher among non-smokers regardless of age and sex. Current smokers in our sample had initiated smoking at an older age and smoked fewer cigarettes per day for shorter durations than those in the CPS-II sample. The Poisson regression model (controlling for age, number of cigarettes smoked per day and duration of smoking) showed that male current smokers in our sample had a lower risk of lung cancer compared with those in the CPS-II sample (rate ratio 0.34 [95%CI 0.27-0.43]). These findings might explain why Japanese risks of lung cancer are lower than those observed in Western countries.

Silicosis and lung cancer: a mortality study of compensated men with silicosis in New South Wales, Australia.

Lung cancer mortality has been found to be in excess in several groups with silicosis, but allowance for smoking was not always possible. We investigated the lung cancer mortality in men with silicosis in New South Wales, Australia, who were compensated, making allowance for smoking habits. A mortality study of 1467 men with silicosis in New South Wales who were compensated was carried out comparing observed mortality with that expected from the New South Wales death rates adjusting for age and period. Their smoking habits were compared with national survey smoking rates and the expected number of lung cancer deaths adjusted for smoking. Cases were coded for occupation and industry. The observed mortality was higher than expected, but the only site of cancer showing a significant excess was the lung. The group with silicosis had smoked more than the national rates. After adjusting for smoking the standardized mortality ratio for lung cancer was 1.9 (95% confidence interval 1.5-2.3). Although there were differences in lung cancer mortality between industries and occupations, these differences were not statistically significant. The excess lung cancer death rate may not be entirely due to silica exposure because compensation may have been influenced by the presence of chronic obstructive respiratory disease and there is some evidence that the presence of this disease increases lung cancer risk independently of smoking.

Vermont granite mortality study: an update with an emphasis on lung cancer.

This mortality study extends the period of observation of an article published in 1988 of 5414 workers in Vermont granite sheds and quarries to assess whether previously reported reductions in silicosis and tuberculosis mortality were maintained. The relationship between lung cancer and quartz exposure is also examined by comparing mortality in workers hired before and after 1940, when dust controls were introduced and exposures were reduced by 80% to 90%. Before 1940, general stone shed air contained 20 million particles/cubic foot (mppcf) (approximately equivalent to 0.2 mg/m of quartz), and pneumatic chisel workers were exposed on average to 60 mppcf (approximately equivalent to 0.6 mg/m of quartz). Other workers had variable exposures. After 1940, a period of decline occurred in dust levels and then stabilized in approximately 1955, when average dust levels were 5 to 6 mppcf (equivalent to 0.05-.06 mg/m of quartz). Dust exposures in the Vermont industry is considered to be free of confounding occupational substances such as arsenic, although cigarette smoking was common. By the end of 1996, 2539 workers, or 46.9% of the cohort, had died. There were no silicosis deaths in workers hired after 1940 who were exposed only in the Vermont granite industry, illustrating the effect of lowering quartz exposures. Tuberculosis caused 2 deaths in those hired after 1940 (standardized mortality ratio [SMR] = 0.52; not significant). Overall lung cancer mortality was elevated in shed workers who had been exposed both to high levels of quartz before 1940 and to the lower levels prevailing after 1940 (SMR = 1.32; P < 0.01). Quarry workers did not show an excess of lung cancer (SMR = 0.73; not significant). When shed workers with high and low exposure histories (before and after 1940) but with comparable latency and tenure were contrasted, lung cancer mortality was similar. Differing levels of quartz exposure, which resulted in large differences in the mortality experience from silicosis, did not result in differences in lung cancer mortality. The results do not support the hypothesis that granite dust exposure has a causal association with lung cancer.