Cancers in Australia in 2010 attributable to tobacco smoke

The incidence trends of oral cancers worldwide from 1988 to 2012 and the prediction up to 2030

BACKGROUND

This paper aims to analyze the time trend of OCs incidence in 43 countries (1988-2012) and predict the incidence trend of OCs (2012-2030).

METHODS

In the database for Cancer Incidence in Five Continents, the annual data on OCs incidence grouped by age and gender were obtained from 108 cancer registries in 43 countries. The age-standardized incidence rates were calculated, and the Bayesian age-period-cohort model was used to predict the incidence in 2030.

RESULTS

South Asia and Oceania had the highest ASR in 1988 (9.24/100 000) and 2012 (6.74/100 000). It was predicted that India, Thailand, the United Kingdom, the Czech Republic, Austria, and Japan would be the countries with an increased incidence of OCs in 2030.

CONCLUSION

Regional custom is an important factor affecting the incidence of OCs. According to our predictions., it is necessary to control risk factors according to local conditions and enhance screening and education.

Cancer types with high numbers of driver events are largely preventable

There is a long-standing debate on whether cancer is predominantly driven by extrinsic risk factors such as smoking, or by intrinsic processes such as errors in DNA replication. We have previously shown that the number of rate-limiting driver events per tumor can be estimated from the age distribution of cancer incidence using the gamma/Erlang probability distribution. Here, we show that this number strongly correlates with the proportion of cancer cases attributable to modifiable risk factors for all cancer types except the ones inducible by infection or ultraviolet radiation. The correlation was confirmed for three countries, three corresponding incidence databases and risk estimation studies, as well as for both sexes: USA, males (r = 0.80, P = 0.002), females (r = 0.81, P = 0.0003); England, males (r = 0.90, P < 0.0001), females (r = 0.67, P = 0.002); Australia, males (r = 0.90, P = 0.0004), females (r = 0.68, P = 0.01). Hence, this study suggests that the more driver events a cancer type requires, the more of its cases are due to preventable anthropogenic risk factors.

Preventable causes of cancer in Texas by race/ethnicity: tobacco smoking

OBJECTIVES

Tobacco smoking is classified as carcinogenic to humans (International Agency for Research on Cancer Group 1). We aimed to estimate the percentage and number of incident cancer cases diagnosed in Texas in 2015 that were attributable to tobacco smoking, and we examined differences in the proportions of smoking-attributable cancers between the major racial/ethnic subgroups of the population.

METHODS

We calculated population-attributable fractions for cancers attributable to tobacco smoking using prevalence data from the Texas Behavioral Risk Factor Surveillance System and relative risks associated with smoking status from pooled analyses of cohort studies or meta-analyses. Cancer incidence data were collected from the Texas Cancer Registry.

RESULTS

We estimated that 19,000 excess cancer cases or 18.4% of all cancers diagnosed in 2015 in Texans aged ≥ 25 years were caused by tobacco smoking. Males had a higher overall proportion of cancers attributable to tobacco smoking than females (male, 23.3%, 11,993 excess cases; female, 13.5%, 7,006 cases). Approximately 20% of cancer cases in non-Hispanic Whites and non-Hispanic Blacks were attributable to tobacco smoking compared to 12.8% among Hispanics.

CONCLUSIONS

Despite ongoing public health campaigns combatting tobacco use, this preventable behavior still contributes significantly to cancer incidence in Texas. Racial/ethnic differences in smoking prevalence and smoking-attributable cancer incidence should be considered when designing cancer prevention programs.

Differences in tobacco smoking status in segments of the Australian population

Purpose

The purpose of this study is to identify correlates of tobacco smoking behaviour across various socio-demographic segments of the Australian population.

Design/methodology/approach

Data from two nationally representative, probability samples of persons 18 and over, surveyed by the Australian Bureau of Statistics in 2001 and 2017–2018 were analysed using multinomial logistic regression.

Findings

Overall, the prevalence of current smokers declined from 24.3 to 15%. More than half of the population had never smoked. The prevalence of ex-smokers increased slightly to 30%. Prevalence of current smoking was higher among older age groups and among those with lower educational achievement, lower income, living in a disadvantaged area and experiencing increasing stress. Females were more likely than males to be never-smokers. Males were more likely than females to be current smokers.

Research limitations/implications

The findings are based on two cross-sectional surveys conducted 17 years apart. It is not possible to draw any conclusions about the actual trajectories of the changes in the values reported or any correlations between those trajectories. Nor is it possible to make any meaningful forecasts about likely future trends in smoking status in these various segments based on these data sets. The classifications used in the surveys generate some heterogeneous groups, which can obscure important differences among respondents within groups. Data are all self-reported, and there is no validation of the self-reported smoking status. This might lead to under-reporting, especially in a community where tobacco smoking is no longer a majority or even a popular habit. Because the surveys are so large, virtually, all the findings are statistically significant. However, the increasing preponderance of never-smokers in many categories might mean that never-smokers could come to dominate the data.

Practical implications

The findings from this paper will help tobacco-control policy-makers to augment whole-of-community initiatives with individual campaigns designed to be more effective with particular socio-demographic segments. They will also assist in ensuring better alignment between initiatives addressing mental health and tobacco smoking problems facing the community.

Originality/value

The examination of smoking behaviour among individual population sub-groups, chosen by the authors, is commonplace in the literature. This paper uses data from two large surveys to model the whole, heterogeneous population, measured at two different points in time.

Projections of the future burden of cancer in Australia using Bayesian age-period-cohort models

BACKGROUND

Accurate forecasts of cancer incidence, with appropriate estimates of uncertainty, are crucial for planners and policy makers to ensure resource availability and prioritize interventions. We used Bayesian age-period-cohort (APC) models to project the future incidence of cancer in Australia.

METHODS

Bayesian APC models were fitted to counts of cancer diagnoses in Australia from 1982 to 2016 and projected to 2031 for seven key cancer types: breast, colorectal, liver, lung, non-Hodgkin lymphoma, melanoma and stomach. Aggregate cancer data from population-based cancer registries were sourced from the Australian Institute of Health and Welfare.

RESULTS

Over the projection period, total counts for these cancer types increased on average by 3 % annually to 100 385 diagnoses in 2031, which is a 50 % increase over 2016 numbers, although there is considerable uncertainty in this estimate. Counts for each cancer type and sex increased over the projection period, whereas decreases in the age-standardized incidence rates (ASRs) were projected for stomach, colorectal and male lung cancers. Large increases in ASRs were projected for liver and female lung cancer. Increases in the percentage of colorectal cancer diagnoses among younger age groups were projected. Retrospective one-step-ahead projections indicated both the incidence and its uncertainty were successfully forecast.

CONCLUSIONS

Increases in the projected incidence counts of key cancer types are in part attributable to the increasing and ageing population. The projected increases in ASRs for some cancer types should increase motivation to reduce sedentary behaviour, poor diet, overweight and undermanagement of infections. The Bayesian paradigm provides useful measures of the uncertainty associated with these projections.

Health Disparities among Australia's Remote-Dwelling Aboriginal People: A Report from 2020

BACKGROUND

Australia has 2 distinct indigenous groups, Torres Strait Islanders and Aborigines. The Aborigines, described in this report, first colonized the continent 65 millennia ago. Those still living in the Northern Territory (NT) retain much ancestrally derived genetic complement but also are the most health-challenged by environment and lifestyle in 21st century. Reports providing overviews of these disparities are, as yet, rare.

CONTENT

This review defines the studied population and then describes and attempts to explain contemporary clinical findings among Australia's remote-dwelling Aborigines, principally in the NT. The report is structured by life stage and then by organ system. Finally, a brief synthesis is advanced concerning the disparities that Australia's Aboriginals face.

SUMMARY

In 2015-2017, NT aboriginal life expectancy for people then born was 66.6 years for men and 69.9 years for women compared with 78.1 and 82.7 years, respectively, among nonindigenous Territorians. Principal causes of the reduced longevity, with nonindigenous comparisons, include adolescent pregnancy, with maternal use of alcohol and tobacco (each 7-fold greater); fetal alcohol spectrum disorder and attention deficit hyperactivity disorder; skin infections, both scabies and impetigo (50-fold greater); rheumatic heart disease (260-fold greater); premature acute myocardial infarction (9-fold greater); bronchiectasis (40-fold greater); lung cancer (2-fold greater); diabetes mellitus (10-fold greater); renal failure (30-fold greater); and suicide (2-fold greater). Some disease has genetic roots, secondary to prolonged genetic drift. Much arises from avoidable stressors and from contemporary environmental disparities in housing. The Europid diet is also not helpful.

Regional differences in tobacco smoking and lung cancer in Portugal in 2018: a population-based analysis using nationwide incidence and mortality data

OBJECTIVES

This study aims to estimate the proportion of lung cancer cases and deaths attributable to tobacco smoking in Portugal in 2018, complemented by trends in incidence and mortality, by sex and region.

DESIGN

Cancer cases for 1998-2011 and cancer deaths for 1991-2018 were obtained from population-based registries and Statistics Portugal, respectively. We projected cases for 2018 and used reported deaths for the same year to estimate, using Peto's method, the number and proportion of lung cancer cases and deaths caused by tobacco smoking in 2018. We calculated the age-adjusted incidence and mortality rates in each year of diagnosis and death. We fitted a joinpoint regression to the observed data to estimate the annual percentage change (APC) in the rates.

SETTING

Portugal.

RESULTS

In 2018, an estimated 3859 cases and 3192 deaths from lung cancer were attributable to tobacco smoking in Portugal, with men presenting a population attributable fraction (PAF) of 82.6% (n=3064) for incidence and 84.1% (n=2749) for mortality, while in women those values were 51.0% (n=795) and 42.7% (n=443), respectively. In both sexes and metrics, the Azores were the region with the highest PAF and the Centre with the lowest. During 1998-2011, the APC for incidence ranged from 0.6% to 3.0% in men and 3.6% to 7.9% in women, depending on region, with mortality presenting a similar pattern between sexes.

CONCLUSION

Exposure to tobacco smoking has accounted for most of the lung cancer cases and deaths estimated in Portugal in 2018. Differential patterns of tobacco consumption across the country, varying implementation of primary prevention programmes and differences in personal cancer awareness may have contributed to the disparities observed. Primary prevention of lung cancer remains a public health priority, particularly among women.

Alcohol, smoking and rectal cancer risk in a Mediterranean cohort of adults: the European Prospective Investigation into Cancer and Nutrition (EPIC)-Italy cohort

OBJECTIVE

Colorectal cancer (CRC) is one of the most diagnosed malignant cancers worldwide. Rectal cancers (Rcs) represent one-third of all CRCs. Cigarette smoking and alcohol drinking are two underestimated risk factors for RC. We aimed to evaluate the role of alcohol consumption and cigarette smoking in modulating RC risk and to estimate the attributable fraction in a Mediterranean population.

METHODS

In the Italian section of the European Prospective Investigation into Cancer and Nutrition, 45,553 healthy adults (31,252 women) were recruited and provided information about lifestyle and dietary habits. During 14.0 years of median follow-up, 154 incident RC cases were identified.

RESULTS

In multivariate models, a increase in RC risk emerged among subjects drinking more than 3 drinks/day, overall (hazard ratio [HR] = 1.74; 95% confidence interval [CI] 1.08-2.80), and in females (HR= 2.80; 95% CI 1.23-6.35), compared with drinkers of less than 1 drink/day. A increase in risk also emerged for current- compared with never-smokers, overall (HR = 1.57; 95% CI 1.06-2.35; P for trend 0.03) and among males (HR = 2.04; 95% CI 1.02-4.07; P for trend 0.045). Overall, 9% (95% CI 4-14%) of RC cases were attributable to drinking more than 3 drinks/day and 12% (95% CI 3-19%) were attributable to current smoke and 20% (95% CI 11-27%) of RC cases were attributable to the independent effects of these two exposures.

CONCLUSION

Our study supports a strategy to avoid a relevant proportion of rectal cancer cases through a combined reduction of alcohol consumption and cigarette smoking.

Burden of disease attributable to second-hand smoke exposure: A systematic review

Our aim was to provide a systematic review of studies on the burden of disease due to second-hand smoke (SHS) exposure, reviewing methods, exposure assessment, diseases causally linked to SHS, health outcomes, and estimates available to date. A literature review of studies on the burden of disease from SHS exposure, available in PubMed and SCOPUS, published 2007-2018 in English language, was carried out following the PRISMA recommendations. Overall, 588 studies were first identified, and 94 were eligible. Seventy-two studies were included in the systematic review. Most of them were based on the comparative risk assessment approach, assessing SHS exposure using mainly surveys on exposure at home/workplaces. Diseases more frequently studied were: lung cancer, ischemic heart disease, stroke, chronic obstructive pulmonary disease, asthma and breast cancer in adults; lower respiratory tract infection, otitis media, asthma, sudden infant death syndrome and low birth weight in children. The SHS exposure assessment and the reported population attributable fractions (PAF) were largely heterogeneous. As an example, the PAF from lung cancer varied between 0.6% and 20.5%. Moreover, PAF were estimated applying relative risks and SHS exposures with no consistent definitions or with different age classes. The research gap on the SHS exposure burden is shrinking. However, estimates are not yet available for a number of countries, particularly the Middle Eastern and African countries, and not all diseases with the strongest evidence of causation, such as sudden infant death syndrome, have been explored. Moreover, in some cases the applied methodology revealed relatively low quality of data.

Estimates of the current and future burden of cancer attributable to active and passive tobacco smoking in Canada

Although previous studies have examined the burden of cancer attributable to tobacco smoking, updated estimates are needed given the dramatic changes in smoking behaviours over the last 20 years. In this study, we estimate the proportion of cancer cases in 2015 attributable to past tobacco smoking and passive exposure in Canada and the proportion of cancers in the future that could be prevented through the implementation of interventions targeted at reducing tobacco use. Data from the Canadian Community Health Survey (2003) were used to estimate the prevalence of active tobacco smoking and passive exposure. Population attributable risk estimates were employed to estimate the proportion of cancers attributable to tobacco in 2015. The prevalence of active tobacco smoking and passive exposure was projected to 2032 and cancer incidence was projected from 2016 to 2042 to estimate the future burden of cancer attributable to tobacco. In 2003, 30% and 24% of Canadians were former and current smoker, respectively and 24% had been exposed to tobacco smoke in the past. We estimated that 17.5% (32,655 cases; 95% CI: 31,253-34,034) of cancers were attributable to active tobacco smoking and 0.8% (1408 cases; 95% CI: 1048-1781) to passive tobacco exposure in never smokers. Between 41,191 and 50,696 cases of cancer could be prevented by 2042 under various prevention scenarios. By decreasing passive tobacco exposure by 10-50%, between 730 and 3650 cancer cases could be prevented by 2042. Strategies focused on reducing the prevalence of tobacco smoking are crucial for cancer control in Canada.

The preventable burden of endometrial and ovarian cancers in Australia: A pooled cohort study

OBJECTIVE

Evidence on the endometrial and ovarian cancer burden preventable through modifications to current causal behavioural and hormonal exposures is limited. Whether the burden differs by population subgroup is unknown.

METHODS

We linked pooled data from six Australian cohort studies to national cancer and death registries, and quantified exposure-cancer associations using adjusted proportional hazards models. We estimated exposure prevalence from representative health surveys. We then calculated Population Attributable Fractions (PAFs) with 95% confidence intervals (CIs), accounting for competing risk of death, and compared PAFs for population subgroups.

RESULTS

During a median 4.9 years follow-up, 510 incident endometrial and 303 ovarian cancers were diagnosed. Overweight and obesity explained 41.9% (95% CI 32.3-50.1) of the endometrial cancer burden and obesity alone 34.5% (95% CI 27.5-40.9). This translates to 12,800 and 10,500 endometrial cancers in Australia in the next 10 years, respectively. The body fatness-related endometrial cancer burden was highest (49-87%) among women with diabetes, living remotely, of older age, lower socio-economic status or educational attainment and born in Australia. Never use of oral contraceptives (OCs) explained 8.1% (95% CI 1.8-14.1) or 2500 endometrial cancers. A higher BMI and current long-term MHT use increased, and long-term OC use decreased, the risk of ovarian cancer, but the burden attributable to overweight, obesity or exogenous hormonal factors was not statistically significant.

CONCLUSIONS

Excess body fatness, a trait that is of high and increasing prevalence globally, is responsible for a large proportion of the endometrial cancer burden, indicating the need for effective strategies to reduce adiposity.

The future burden of cancer in Canada: Long-term cancer incidence projections 2013-2042

BACKGROUND

Cancer is the leading cause of death in Canada and the estimated annual spending associated with cancer is approximately $7.5 billion. Projecting the future burden of cancer in Canada is essential for health planning and evaluation. We aimed to estimate the future incidence of cancer in Canada to 2042.

METHODS

Age-sex-region-specific cancer incidence data were obtained for the years 1983-2012 and cancer incidence was projected from 2013 to 2042 for the top five cancer sites. The modelling algorithm combined a mixture of cancer projection methods to select the best-fitted model. When the chosen model produced by the modelling algorithm resulted in estimates that were not consistent with expert opinion, an alternate model was selected that took into consideration historical changes in policy, screening and lifestyle behaviours. Incidence projections were made for Canada and its provinces.

RESULTS

Lung cancer incidence is estimated to rise to 14,866 cases in men and 19,162 in women in 2042. Colorectal cancer incidence is estimated to rise to 28,146 in men and 21,102 in women. Cases of bladder cancer are projected to rise to 10,708 and 3,364 in men and women, respectively. Breast cancer incidence is predicted to rise to 40,712 and prostate cancer incidence is projected to rise to 92,949.

CONCLUSION

These cancer incidence projections up to 2042 can be used for planning cancer control strategies and prevention programs. Given the ongoing changes in the prevalence of risk factors and in cancer prevention policies, these estimates should be interpreted with caution.

Permanence of Modifications in Oral Microcirculation in Ex-Smokers

Background

The aim of this study was to assess the long-term effects of smoking and to investigate the permanence of this damage to the oral microcirculation.

Material/Methods

We recruited 75 patients and divided them into 3 groups: group 1 was composed of 25 healthy non-smokers, group 2 was composed of 25 healthy current smokers, and group 3 was composed of 25 healthy ex-smokers. Video-capillaroscopic examination was performed on all patients.

The video-capillaroscopic investigation was performed on patients in sitting position, always with the same light source, at the same room temperature (23°C), in the morning, with the same operator (GAS), and was repeated many times for every area under investigation. An enlargement of 200× allowed us to explore point-by-point all the morpho-structural characteristics of the capillaroscopic field. For non-parametric data, we evaluated the visibility of the loops and their position in relation to the surface of the mucosa. The evaluated parametric data were length of capillary loop, diameter of the loop, capillary tortuosity, and capillary density.

Results

Our study clearly shows there was no remission of vascular damage, even 13 years after smoking cessation.

Conclusions

Our research shows that that the effects of smoking are still visible in ex-smokers, even at 13 years after cessation and also that ex-smokers are still subject to the risk of oral pathologies in the interval of time that we considered.

The future burden of lung cancer attributable to current modifiable behaviours: a pooled study of seven Australian cohorts

Background

Knowledge of preventable disease and differences in disease burden can inform public health action to improve health and health equity. We quantified the future lung cancer burden preventable by behavioural modifications across Australia.

Methods

We pooled seven Australian cohort studies (n = 367 058) and linked them to national registries to identify lung cancers and deaths. We estimated population attributable fractions and their 95% confidence intervals (CIs) for modifiable risk factors, using risk estimates from the cohort data and risk factor exposure distribution from contemporary national health surveys.

Results

During the first 10-year follow-up, there were 2025 incident lung cancers and 20 349 deaths. Stopping current smoking could prevent 53.7% (95% CI, 50.0-57.2%) of lung cancers over 40 years and 18.3% (11.0-25.1%) in 10 years. The smoking-attributable burden is highest in males, those who smoke <20 cigarettes per day, are <75 years of age, unmarried, of lower educational attainment, live in remote areas or are healthy weight. Increasing physical activity and fruit consumption, if causal, could prevent 15.6% (6.9-23.4%) and 7.5% (1.3-13.3%) of the lung cancer burden, respectively. Jointly, the three behaviour modifications could prevent up to 63.0% (58.0-67.5%) of lung cancers in 40 years, and 31.2% (20.9-40.1%) or 43 300 cancers in 10 years. The preventable burden is highest among those with multiple risk factors.

Conclusions

Smoking remains responsible for the highest burden of lung cancer in Australia. The uneven burden distribution distinguishes subgroups that could benefit the most from activities to control the world's deadliest cancer.

Tackling the tobacco epidemic in the Nordic countries and lower cancer incidence by 1/5 in a 30-year period-The effect of envisaged scenarios changing smoking prevalence

BACKGROUND

Tobacco smoking is a leading cause of cancer and the most preventable cause of cancer worldwide. The aim of this study was to quantify the proportion of the cancer burden in the Nordic countries linked to tobacco smoking and estimate the potential for cancer prevention by changes in smoking prevalence.

METHODS

The Prevent macro-simulation model was used, estimating the future number of cancer cases in the Nordic countries over a 30-year period (2016-2045), for 13 cancer sites, under different scenarios of changing smoking prevalence, and compared to the projected number of cases if constant prevalence prevailed.

RESULTS

A total of 430,000 cancer cases, of the 2.2 million expected for the 13 studied cancer sites, could be avoided in the Nordic countries over the 30-year period if smoking was eliminated from 2016 onwards. If prevalence of smoking is reduced to 5% by year 2030 and to 2% by 2040, 230,000 cancer cases could be avoided. The largest proportion of cancers can be avoided in Denmark, where smoking prevalence is the highest, and similar to the prevalence in many European countries.

CONCLUSION

A large amount of cancers could be avoided in the Nordic countries if smoking prevalence was reduced. The results from this study can be used to understand the potential impact and significance of primary prevention programmes targeted towards reducing the prevalence of tobacco smoking in the Nordic countries.

Differences in cancer survival by sex: a population-based study using cancer registry data

PURPOSE

Few large-scale studies have investigated sex differences in cancer survival and little is known about their temporal and age-related patterns.

METHODS

We used cancer registry data for first primary cancers diagnosed between 1982 and 2015 in Victoria, Australia. Cases were followed until the end of 2015 through linkage to death registries. Differences in survival were assessed for 25 cancers using the Pohar-Perme estimator of net survival and the excess mortality rate ratio (EMRR) adjusting for age and year of diagnosis.

RESULTS

Five-year net survival for all cancers combined was lower for men (47.1%; 95% CI 46.9-47.4) than women (52.0%; 95% CI 51.7-52.3); EMRR 1.13 (95% CI 1.12-1.14; p < 0.001). A survival disadvantage for men was observed for 11 cancers: head and neck, esophagus, colorectum, pancreas, lung, bone, melanoma, mesothelioma, kidney, thyroid, and non-Hodgkin lymphoma. In contrast, women had lower survival from cancers of the bladder, renal pelvis, and ureter. For the majority of cancers with survival differences, the EMRR decreased with increasing age at diagnosis; for colorectal, esophageal, and kidney cancer, the EMRR increased with time since diagnosis.

CONCLUSION

Identifying the underlying reasons behind sex differences in cancer survival is necessary to address inequalities, which may improve outcomes for men and women.

Cancers attributable to tobacco smoking in France in 2015

Background

The evidence on the carcinogenicity of tobacco smoking has been well established. An assessment of the population-attributable fraction (PAF) of cancer due to smoking is needed for France, given its high smoking prevalence.

Methods

We extracted age- and sex-specific national estimates of population and cancer incidence for France, and incidence rates of lung cancer among never smokers and relative risk (RR) estimates of smoking for various cancers from the American Cancer Prevention Study (CPS II). For active smoking, we applied a modified indirect method to estimate the PAF for lung and other tobacco smoking-related cancer sites. Using the RR estimates for second-hand smoking, the proportion of never smokers living with an ever-smoking partner derived from survey, and marital status data, we then estimated the PAF for lung cancer attributable to domestic passive smoking.

Results

Overall in France in 2015, 54 142 and 12 008 cancer cases in males and females, respectively, were attributable to active smoking, accounting for 28 and 8% of all cancer cases observed among adult (30+ years) males and females. Additionally, 36 and 142 lung cancer cases, respectively among male and female never smokers, were attributable to second-hand smoke resulting from their partner's active smoking, corresponding to 4.2 and 6.7% of lung cancer cases which occurred in never smoker males and females, respectively.

Conclusions

Tobacco smoking is responsible for a significant number of potentially avoidable cancer cases in France in 2015. More effective tobacco control programmes are critical to reduce this cancer burden.

Temporal Associations of Alcohol and Tobacco Consumption With Cancer Mortality

IMPORTANCE

Understanding whether the population-level consumption of alcohol and tobacco is associated with cancer mortality is a crucial question for public health policy that has not been answered by previous studies.

OBJECTIVE

To examine temporal associations of alcohol and tobacco consumption with overall cancer mortality in the Australian population, looking across different sex and age groups.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study conducted a time series analysis (autoregressive integrated moving average models) using aggregate-level annual time series data from multiple sources. Data on alcohol consumption and tobacco consumption per capita between 1935 and 2014 among the Australian population aged 15 years and older were collected from the Australian Bureau of Statistics and Cancer Council Victoria. Analysis was conducted from June 1, 2017, to October 30, 2017.

EXPOSURES

Sex- and age-specific cancer mortality rates from 1968 to 2014 were collected from the Australian Institute Health and Welfare.

MAIN OUTCOMES AND MEASURES

Population-level cancer mortality in different sex and age groups in Australia, controlling for the effects of health expenditure.

RESULTS

Among the Australian total population aged 15 years and older in this study, 50.5% were women. Cancer death rates per 100 000 persons increased from 199 in 1968 to 214 in 1989 and then decreased steadily to 162 in 2014. Taking into account lagged effects, 1-L decreases in alcohol consumption per capita were associated with a decline of 3.9% in overall cancer mortality over a 20-year period, and 1-kg decreases in tobacco consumption per capita were associated with a 16% reduction. Alcohol consumption per capita was significantly associated with overall cancer mortality among men aged 50 to 69 years and women aged 50 years and older. Tobacco consumption per capita was found to be significantly associated with overall cancer mortality only among men aged 50 years and older.

CONCLUSIONS AND RELEVANCE

In this study, alcohol consumption per capita was positively associated with overall cancer mortality among older men and women, and tobacco consumption per capita was positively associated with overall cancer mortality among older men over a 20-year period. This study provides evidence that a decrease in population-level drinking and tobacco smoking could lead to a reduction in cancer mortality.

NSAID use and somatic exomic mutations in Barrett's esophagus

Background

Use of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) has been shown to protect against tetraploidy, aneuploidy, and chromosomal alterations in the metaplastic condition Barrett’s esophagus (BE) and to lower the incidence and mortality of esophageal adenocarcinoma (EA). The esophagus is exposed to both intrinsic and extrinsic mutagens resulting from gastric reflux, chronic inflammation, and exposure to environmental carcinogens such as those found in cigarettes. Here we test the hypothesis that NSAID use inhibits accumulation of point mutations/indels during somatic genomic evolution in BE.

Methods

Whole exome sequences were generated from 82 purified epithelial biopsies and paired blood samples from a cross-sectional study of 41 NSAID users and 41 non-users matched by sex, age, smoking, and continuous time using or not using NSAIDs.

Results

NSAID use reduced overall frequency of point mutations across the spectrum of mutation types, lowered the frequency of mutations even when adjusted for both TP53 mutation and smoking status, and decreased the prevalence of clones with high variant allele frequency. Never smokers who consistently used NSAIDs had fewer point mutations in signature 17, which is commonly found in EA. NSAID users had, on average, a 50% reduction in functional gene mutations in nine cancer-associated pathways and also had less diversity in pathway mutational burden compared to non-users.

Conclusions

These results indicate NSAID use functions to limit overall mutations on which selection can act and supports a model in which specific mutant cell populations survive or expand better in the absence of NSAIDs.

Electronic supplementary material

The online version of this article (10.1186/s13073-018-0520-y) contains supplementary material, which is available to authorized users.

Curcumin reverses tobacco smoke‑induced epithelial‑mesenchymal transition by suppressing the MAPK pathway in the lungs of mice

Tobacco smoke is a major risk factor for lung cancer. Epithelial‑mesenchymal transition (EMT) is decisive in cancer invasion and metastasis, and therefore promotes cancer progression. Mitogen‑activated protein kinase (MAPK) pathways are implicated in various aspects of cancer development and progression, including the EMT process. The chemopreventive effect of curcumin on carcinogenesis has been reported in vivo and in vitro. The present study investigated tobacco smoke‑induced alterations in the MAPK/activator protein‑1 (AP‑1) pathways, and pulmonary EMT changes in the lungs of mice, and further observed the chemopreventive effect of curcumin. The protein expression levels analyzed by western blot analysis demonstrated that 12 weeks of tobacco smoke exposure activated extracellular‑signal‑regulated kinase (ERK) 1/2, c‑Jun N‑terminal kinase (JNK) and p38 MAPK pathways, in addition to AP‑1, in the lungs of mice, while reducing the activation of ERK5/MAPK pathways. The results also indicated that the mRNA and protein levels of the epithelial markers E‑cadherin and zona occludens‑1 were reduced following tobacco smoke exposure. Conversely, the expression levels of mRNA and protein for the mesenchymal markers vimentin and N‑cadherin were increased. Curcumin treatment inhibited tobacco smoke‑induced MAPK/AP‑1 activation, including ERK1/2, JNK and p38 MAPK pathways, and AP‑1 proteins, and reversed EMT alterations in lung tissue. The results of the present study provide new insights into the molecular mechanisms of tobacco smoke‑associated lung cancer and may open up new avenues in the search for potential therapeutic targets in lung tumorigenesis.

Cancers Attributable to Alcohol Consumption in Nigeria: 2012-2014

Introduction

Alcohol consumption has been identified as a risk factor for many cancers but less attention has been paid to the fraction of those cancers that are attributable to alcohol consumption. In this study, we evaluated the incidence and population attributable fraction (PAF) of cancers associated with alcohol consumption in Nigeria.

Methods

We obtained data on incidence of cancers from two population-based cancer registries (PBCRs) in Nigeria and identified cancer sites for which there is strong evidence of an association with alcohol consumption based on the International Agency for Research on Cancer Monograph 100E. We computed the PAF for each cancer site by age and sex, using prevalence and relative risk estimates from previous studies.

Results

Between 2012 and 2014 study period, the PBCRs reported 4,336 cancer cases of which 1,627 occurred in males, and 2,709 occurred in females. Of these, a total of 1,808 cancer cases, 339 in males and 1,469 in females, were associated with alcohol intake. The age standardized incidence rate (ASR) of alcohol associated cancers was 77.3 per 100,000. Only 4.3% (186/4,336) of all cancer cases or 10.3% (186/1,808) of alcohol associated cancers were attributable to alcohol consumption. Some 42.5% (79/186) of these cancers occurred in males while 57.5% (107/186) occurred in females. The ASR of cancers attributable to alcohol in this population was 7.2 per 100,000. The commonest cancers attributable to alcohol consumption were cancers of the oral cavity and pharynx in men and cancer of the breast in women.

Conclusion

Our study shows that 4.3% of incident cancers in Nigeria can be prevented by avoiding alcohol consumption. While the incidence of cancers associated with alcohol intake is high, the proportion attributable to alcohol consumption is much lower suggesting that the number of cancers that may be prevented by eliminating alcohol intake in this population is relatively low.

Age-related macular degeneration and mortality: the Melbourne Collaborative Cohort Study

AimsTo assess associations between features of age-related macular degeneration (AMD) and mortality.MethodsA total of 21 129 participants from the Melbourne Collaborative Cohort Study aged 47-85 years (60% female) were assessed for AMD (2003-2007). Mortality data to December 31, 2012 were obtained through linkage with the National Death Index. Associations were assessed using Cox regression, adjusting for age, sex, smoking, region of birth, education, physical activity, diet and alcohol.ResultsLate AMD was identified in 122 (0.6%) participants, including those with choroidal neovascularisation (n=55, 0.3%), geographic atrophy (n=87, 0.4%) and reticular pseudodrusen (n=87, 0.4%). After a median follow-up period of 8.1 years, 1669 (8%) participants had died, including those from cardiovascular diseases (386), tobacco-related cancers (179), and neurodegenerative disease (157). There was evidence of an increased rate of all-cause mortality for those with choroidal neovascularisation (Hazard Ratio (HR) 1.71 95% CI 1.06-2.76) and geographic atrophy (HR 1.46 95% CI 0.99-2.16). Choroidal neovascularisation was also associated with an increased rate of cardiovascular mortality (HR 3.16 95% CI 1.62-6.15) and geographic atrophy was associated with an increased rate of death from tobacco-related cancer (HR 2.86 95% CI 1.15-7.09). Weak evidence was also present for an association between choroidal neovascularisation and death from neurodegenerative disease (HR 2.49 95% CI 0.79-7.85). Neither reticular pseudodrusen nor the earlier stages of AMD were associated with mortality.ConclusionsLate AMD is associated with an increased rate of all-cause mortality. Choroidal neovascularisation and geographic atrophy were associated with death from cardiovascular disease and tobacco-related cancer, respectively.

Widening socioeconomic disparity in lung cancer incidence among men in New South Wales, Australia, 1987-2011

Objective

We assessed the trends in lung cancer incidence over a 25-year period by socioeconomic groups for men in New South Wales (NSW), Australia.

Methods

Men diagnosed with lung cancer between 1987 and 2011 were divided into five quintiles according to an Index of Education and Occupation (IEO). We assessed relative socioeconomic differences over time by calculating age-standardized incidence ratios (SIRs) by 5-year period of diagnosis, and estimated absolute differences by comparing the observed and expected numbers of cases using the highest IEO quintile as the reference.

Results

Lung cancer incidence for men decreased from 1987 to 2011 for all IEO quintiles, with a greater rate of decline for men living in the highest IEO areas. Thus, the relative disparity increased significantly over the 25-year period (P=0.0006). For example, the SIR for the lowest IEO quintile increased from 1.28 during 1987-1991 to 1.74 during 2007-2011. Absolute differences also increased with the proportion of " potentially preventable" cases doubling from 14.5% in 1987-1991 to 30.2% in 2007-2011.

Conclusions

Despite the overall decline in lung cancer incidence among men in NSW over the past 25 years, there was a significant increase in disparity across socioeconomic areas in both relative and absolute terms.

The fractions of cancer attributable to modifiable factors: A global review

Worldwide, the burden of cancer is rising, stimulating efforts to develop strategies to control these diseases. Primary prevention, a key control strategy, aims to reduce cancer incidence through programs directed towards reducing population exposure to known causal factors. Before enacting such strategies, it is necessary to estimate the likely effect on cancer incidence if exposures to known causal factors were reduced or eliminated. The population attributable fraction (PAF) is the epidemiological measure which quantifies this potential reduction in incidence. We surveyed the literature to document and summarise the proportions of cancers across the globe attributable to modifiable causes, specifically tobacco smoke, alcohol, overweight/obesity, insufficient physical activity, solar ultraviolet (UV) radiation and dietary factors (insufficient fruit, non-starchy vegetables and fibre; red/processed meat; salt). In total, we identified 55 articles that presented PAF estimates for one or more causes. Information coverage was not uniform, with many articles reporting cancer PAFs due to overweight/obesity, alcohol and tobacco, but fewer reporting PAFs for dietary factors or solar UV radiation. At all cancer sites attributable to tobacco and alcohol, median PAFs were markedly lower for women than men. Smoking contributed to very high median PAFs (>50%) for cancers of the lung and larynx. Median PAFs for men, attributable to alcohol, were high (25-50%) for cancers of the oesophagus, oral cavity/pharynx, larynx and liver. For cancers causally associated with overweight/obesity, high median PAFs were reported for oesophageal adenocarcinoma (men 29%, women 37%), gallbladder (men 11%, women 42%) and endometrium (36%). The cancer PAF literature is growing rapidly. Repeating this survey in the future should lead to more precise estimates of the potentially preventable fractions of cancer.

Cancers in Australia in 2010 attributable to modifiable factors: introduction and overview

OBJECTIVE

To describe the approach underpinning a national project to estimate the numbers and proportions of cancers occurring in Australia in 2010 that are attributable to modifiable causal factors.

METHODS

We estimated the population attributable fraction (PAF) (or prevented fraction) of cancers associated with exposure to causal (or preventive) factors using standard formulae. Where possible, we also estimated the potential impact on cancer incidence resulting from changes in prevalence of exposure. Analyses were restricted to factors declared causal by international agencies: tobacco smoke; alcohol; solar radiation; infectious agents; obesity; insufficient physical activity; insufficient intakes of fruits, vegetables and fibre; red and processed meat; menopausal hormone therapy (MHT); oral contraceptive pill (OCP); and insufficient breast feeding. Separately, we estimated numbers of cancers prevented by: aspirin; sunscreen; MHT; and OCP use. We discuss assumptions pertaining to latent periods between exposure and cancer onset, choices of prevalence data and risk estimates, and approaches to sensitivity analyses.

RESULTS

Numbers and population attributable fractions of cancer are presented in accompanying papers.

CONCLUSIONS

This is the first systematic assessment of population attributable fractions of cancer in Australia.

Cancers in Australia in 2010 attributable to modifiable factors: summary and conclusions

OBJECTIVE

To estimate the numbers and proportions of cancers occurring in Australia in 2010 attributable to modifiable causal factors.

METHODS

We estimated the population attributable fraction (PAF) of cancers associated with exposure to 13 causal factors using standard formulae incorporating exposure prevalence and relative risk data. We also calculated the potential impact of changing exposure to some factors.

RESULTS

A total of 32% of all cancers diagnosed in Australia in 2010 (excluding keratinocyte cancers) were attributable to the 13 factors assessed (men 33%; women 31%). Leading factors were tobacco smoke (PAF all cancers: 13.4%), solar radiation (6.2%), inadequate diet (6.1%) and overweight/obesity (3.4%). Factors conferring highest PAFs differed by sex: highest PAFs for men were tobacco smoke (15.8%), solar radiation (7.1%) and alcohol (3.0%); while highest PAFs for women were tobacco smoke (10.1%), solar radiation (5.0%) and overweight/obesity (4.5%). Sites with the highest counts of potentially preventable cancers were lung (8,569), colorectal (7,404), melanoma of the skin (7,220) and breast (3,233).

CONCLUSIONS

At least one in three cancers in Australia is attributable to exposure to known modifiable factors.

IMPLICATIONS

Up to 37,000 cancers could be prevented in Australia each year if the population avoided exposure to 13 common factors known or strongly suspected to cause cancer.