Population attributable fraction of mortality associated with tobacco smoking in Japan: a pooled analysis of three large-scale cohort studies

Mortality after partner's cancer diagnosis or death: A population-based prospective cohort study in Japan

BACKGROUND

The health statuses of closely connected individuals are interdependent. Little is known about mortality risk associated with partner's cancer diagnosis and cause-specific mortality risk associated with partner's death.

METHODS

Relative risks for all-cause and cause-specific mortality following a partner's cancer diagnosis or death compared to the period when the partner is cancer-free and alive were investigated in the population-based prospective cohort study that enrolled 140,420 people at the age between 40-69 in 1990-1994.

RESULTS

55,050 participants (27,665 men and 27,385 women) who were identified as married couples were followed-up for 1,073,746.1 (518,368.5 in men and 555,377.6 in women) person-years, during which 9,816 deaths (7,217 in men and 2,599 in women) were observed. After a partner's cancer diagnosis, the mortality rate ratio (MRR) of all-cause mortality was not increased among both men and women, while an increase of externally-caused MRR was observed. The suicide MRR significantly increased among men (MRR = 2.90 [95% CI, 1.70-4.93]) and it persisted for more than 5 years. After a partner's death, the MRRs of all-cause, cardiovascular disease (CVD), respiratory disease (RD), and externally-caused mortality significantly increased only among men. Stratified analysis by smoking status among men showed significantly increased MRRs of CVD and RD mortality among former/current smokers, but not among never-smokers.

CONCLUSION

Partner's cancer diagnosis did not increase all-cause mortality risk, but increased externally-caused mortality risk, especially suicide among men. The impact of partner's death on mortality risk differed by the mortality causes and sex, and smoking affected some of cause-specific mortality risk.

Smoking-attributable Mortality in Korea, 2020: A Meta-analysis of 4 Databases

OBJECTIVES

Estimating the number of deaths caused by smoking is crucial for developing and evaluating tobacco control and smoking cessation policies. This study aimed to determine smoking-attributable mortality (SAM) in Korea in 2020.

METHODS

Four large-scale cohorts from Korea were analyzed. A Cox proportional-hazards model was used to determine the hazard ratios (HRs) of smoking-related death. By conducting a meta-analysis of these HRs, the pooled HRs of smoking-related death for 41 diseases were estimated. Population-attributable fractions (PAFs) were calculated based on the smoking prevalence for 1995 in conjunction with the pooled HRs. Subsequently, SAM was derived using the PAF and the number of deaths recorded for each disease in 2020.

RESULTS

The pooled HR for all-cause mortality attributable to smoking was 1.73 for current men smokers (95% confidence interval [CI], 1.53 to 1.95) and 1.63 for current women smokers (95% CI, 1.37 to 1.94). Smoking accounted for 33.2% of all-cause deaths in men and 4.6% in women. Additionally, it was a factor in 71.8% of men lung cancer deaths and 11.9% of women lung cancer deaths. In 2020, smoking was responsible for 53 930 men deaths and 6283 women deaths, totaling 60 213 deaths.

CONCLUSIONS

Cigarette smoking was responsible for a significant number of deaths in Korea in 2020. Monitoring the impact and societal burden of smoking is essential for effective tobacco control and harm prevention policies.

Smoking is associated with higher risk of contracting bacterial infection and pneumonia, intensive care unit admission and death

BACKGROUND

Smoking has been associated with a higher risk of contracting pneumonia, but contradictory results have shown that smoking may or may not decrease the risk of dying in pneumonia. The aim of this study is to investigate how smoking is associated with contracting any infection and pneumonia and death.

METHOD AND FINDINGS

Participants were drawn from the population-based Cohort of Swedish Men and the Swedish Mammography Cohort, which are representative of the Swedish population. Participants have answered detailed lifestyle questionnaires and have been followed in national registers, such as the Patient Register, Cause of Death register and Swedish Intensive Care Registry. The risks of contracting infection and pneumonia or dying in infection and pneumonia were assessed using Cox regression. Of 62,902 cohort participants, 25,297 contracted an infection of which 4,505 died; and 10,471 contracted pneumonia of which 2,851 died. Compared to never smokers, former smokers at baseline had hazard ratio (HR) 1.08 (95% confidence interval (CI) 1.05-1.12) of contracting and HR 1.19 (95% CI 1.11-1.28) of dying in infection and HR 1.17 (95% CI 1.12-1.23) of contracting and HR 1.16 (95% CI 1.06-1.27) of dying in pneumonia during follow-up. Compared to never smokers, current smokers at baseline had HR 1.17 (95% CI 1.13-1.21) of contracting infection and HR 1.64 (95% CI 1.52-1.77) dying in infection; HR 1.42 (95% CI 1.35-1.49) of contracting pneumonia and HR 1.70 (95% CI 1.55-1.87) of dying in pneumonia during follow-up. The risk of contracting and dying in infection and pneumonia increased in a dose-response manner with number of pack years smoked and decreased with years since smoking cessation.

CONCLUSION

Smoking is associated with contracting and dying in any infection and pneumonia and the risk increases with pack years smoked, highlighting the importance of both primary prevention and smoking cessation.

Projecting the impact of implementation of WHO MPOWER measures on smoking prevalence and mortality in Japan

OBJECTIVE

This study aimed to quantify the long-term impact of implementing the WHO Framework Convention on Tobacco Control (FCTC) compliant tobacco control measures, MPOWER, on smoking prevalence and mortality in men and women aged ≥20 years in Japan.

DESIGN

A Stock-and-Flow simulation model was used to project smoking prevalence and mortality from 2018 to 2050 under eight different scenarios: (1) maintaining the 2018 status quo, (2) implementation of smoke-free policies, (3) tobacco use cessation programmes, (4-5) health warning about the dangers of tobacco (labels, mass media), (6) enforcement of tobacco advertising bans or (7) tobacco taxation at the highest recommended level and (8) all these interventions combined.

RESULTS

Under the status quo, the smoking prevalence in Japan will decrease from 29.6% to 15.5% in men and 8.3% to 4.7% in women by 2050. Full implementation of MPOWER will accelerate this trend, dropping the prevalence to 10.6% in men and 3.2% in women, and save nearly a quarter million deaths by 2050. This reduction implies that Japan will only attain the current national target of 12% overall smoking prevalence in 2033, 8 years earlier than it would with the status quo (in 2041), a significant delay from the national government's 2022 deadline.

CONCLUSIONS

To bring forward the elimination of tobacco smoking and substantially reduce smoking-related deaths, the government of Japan should fulfil its commitment to the FCTC and adopt stringent tobacco control measures delineated by MPOWER and beyond.

Dose-response association between cigarette smoking and gastric cancer risk: a systematic review and meta-analysis

This study aims at providing an accurate and up-to-date quantification of the dose-response association between cigarette smoking and gastric cancer (GC) risk, overall and by subsite. We conducted a systematic review and meta-analysis of case-control and cohort studies on the association between cigarette smoking and GC risk published up to January 2023. We estimated pooled relative risks (RR) of GC and its subsites according to smoking status, intensity, duration, and time since quitting. Among 271 eligible articles, 205 original studies were included in this meta-analysis. Compared with never smokers, the pooled RR for GC was 1.53 (95% confidence interval; CI 1.44-1.62; n = 92) for current and 1.30 (95% CI 1.23-1.37; n = 82) for former smokers. The RR for current compared with never smokers was 2.08 (95% CI 1.66-2.61; n = 21) for gastric cardia and 1.48 (95% CI 1.33-1.66; n = 8) for distal stomach cancer. GC risk nonlinearly increased with smoking intensity up to 20 cigarettes/day (RR:1.69; 95% CI 1.55-1.84) and levelled thereafter. GC risk significantly increased linearly with increasing smoking duration (RR: 1.31; 95% CI 1.25-1.37 for 20 years) and significantly decreased linearly with increasing time since quitting (RR: 0.65; 95% CI 0.44-0.95 for 30 years since cessation). The present meta-analysis confirms that cigarette smoking is an independent risk factor for GC, particularly for gastric cardia. GC risk increases with a low number of cigarettes up to 20 cigarettes/day and increases in a dose-dependent manner with smoking duration.

Dose-risk relationships between cigarette smoking and cervical cancer: a systematic review and meta-analysis

OBJECTIVE

Cervical cancer (CC) is the fourth most frequent cancer worldwide. Cigarette smoking has been shown to influence CC risk in conjunction with human papillomavirus (HPV) infection. The aim of this study is to provide the most accurate and updated estimate of this association and its dose-response relationship.

METHODS

Using an innovative approach for the identification of original publications, we conducted a systematic review and meta-analysis of studies published up to January 2021. Random effects models were used to provide pooled relative risks (RRs) of CC for smoking status. Dose-response relationships were evaluated using one-stage random effects models with linear or restricted cubic splines models.

RESULTS

We included 109 studies providing a pooled RR of invasive CC and preinvasive lesions, respectively, of 1.70 [95% confidence interval (CI), 1.53-1.88] and 2.11 (95% CI, 1.85-2.39) for current versus never smokers, and, respectively, 1.13 (95% CI, 1.02-1.24) and 1.29 (95% CI, 1.15-1.46) for former versus never smokers. Considering HPV does not alter the positive association or its magnitude. Risks of CC sharply increased with few cigarettes (for 10 cigarettes/day, RR = 1.72; 95% CI, 1.34-2.20 for invasive CC and RR = 2.13; 95% CI, 1.86-2.44 for precancerous lesions). The risk of CC increased with pack-years and smoking duration and decreased linearly with time since quitting, reaching that of never smokers about 15 years after quitting.

CONCLUSION

This comprehensive review and meta-analysis confirmed the association of smoking with CC, independently from HPV infection. Such association rose sharply with smoking intensity and decreased after smoking cessation.

Health and economic impact of a smoking cessation program in Korean workplaces

Smoking is a leading cause of diseases and death, with significant socioeconomic consequences. The purpose of this study was to evaluate the health and economic effectiveness of a workplace smoking cessation program. A total of 89 smokers from seven workplaces in Korea were the participants of the program. For 4 months, individual counseling based on the transtheoretical model (TTM) was conducted and interpersonal and organizational components were applied to encourage entire workplaces to encourage employee smoking cessation. The primary outcome was whether participants quit smoking or not. We also evaluated the changes in attitude and perceptions related to smoking cessation before and after the program and estimated the program's economic effects. Economic effects were defined as reductions in productivity losses and medical expenses. We calculated the return on investment (ROI) values representing the averted cost through the program compared to program cost. At the end of the program, 40.4% of participants quit smoking. Improvements were observed in TTM-based attitudes and perceptions. The mean reduction in productivity losses was estimated to be $187,609.94 for 2 yr and the mean reduction in medical expenses was $3,136.49 at 20 yr among seven workplaces. When accounting for these reductions, the ROI was 15.39 (ranging from -1.00 to 44.53). These effects were robust under various scenarios. The smoking cessation program should be expanded to a wider variety of workplaces. In the future, more sophisticated economic assessment methods should be developed and applied to facilitate workplace recruitment and attract management support.

Cigarette Smoking and Risk of Different Pathologic Types of Stroke: A Systematic Review and Dose-Response Meta-Analysis

Objectives

To quantify the association of cigarette smoking, including cigarettes per day and quitting duration, with the risk of different types of stroke morbidity and mortality in the general population, and to clarify the shape of the dose-response relations.

Study Selection

Prospective cohort studies and reported on the association between smoking, quitting and the incidence or mortality of stroke were included.

Data Extraction and Synthesis

All available data were converted uniformly to odds ratios (ORs) and were pooled using random-effects meta-analysis with inverse variance weighting. A dose-response meta-analysis was performed to explore the quantitative relationship between different smoking characteristics and the risk of different pathologic types of stroke incidence.

Results

Twenty-five studies with 3,734,216 individuals were included. Compared to never smokers, the pooled ORs of stroke morbidity and mortality were 1.45 (1.24–1.70) and 1.44 (1.23–1.67) among ever smokers and 1.90 (1.55–2.34) and 1.70 (1.45–1.98) among current smokers. The risk of different pathologic types of stroke was also increased among ever and current smokers. There was a significant non-linear dose-response association between the number of cigarette smoking and the risk of stroke incidence. Comparing no smoking, the ORs for smoking five and 35 cigarettes per day were 1.44 (1.35–1.53) and 1.86 (1.71–2.02). Other pathologic types of stroke have a similar dose-response relationship. There was also non-linear dose-response association between the length of time since quitting and risk of stroke. The risk of stroke decreased significantly after quitting for 3 years [OR = 0.56 (0.42–0.74)].

Conclusion

The risk of different types of stroke among smokers is remarkably high. Our findings revealed a more detailed dose-response relationship and have important implications for developing smoking control strategies for stroke prevention.

Systematic Review Registration

https://inplasy.com/inplasy-2020-6-0062/, identifier: INPLASY202060062.

Diabetes Mellitus, Obesity, and Risk of Pancreatic Ductal Adenocarcinoma: a Large Case-Control Study from Iran

BACKGROUND

Pancreatic cancer (PC) is a deadly, globally increasing cancer. The causes of PC are still insufficiently known, however smoking, diabetes mellitus (DM), and obesity have been identified as risk factors of PC, mostly in the developed countries. We evaluated these risk factors and their contribution to PC among an Iranian population.

METHODS

Cases and controls were selected from patients who were registered to a tertiary gastrointestinal diseases referral hospital in Tehran, Iran, from Jan 2012 to Jan 2018. Information on risk factors was collected by personal interview using a structured questionnaire. Logistic regression models were used to calculate adjusted odds ratios (AORs) and 95% confidence intervals (CIs).

RESULTS

We recruited 470 new patients with histopathological PC diagnosis and 526 sex and age-matched controls. Cigarette-smoking [AOR: 1.65 (1.15-2.38)], opium use [AOR: 1.58 (1.06-2.35)], DM [AOR: 1.99 (1.31-3.02)], and having a history of any cancer in a first-degree family member [AOR: 1.53 (1.14-2.05)] were associated with an increased risk of PC. We did not find an association between obesity [AOR: 0.99 (0.71-1.38)] and PC. Approximately 4.6%, 5.9%, 8.2%, and 10.9% risk of PC were related to cigarette-smoking, opium use, DM, and family history of any cancer, respectively.

CONCLUSION

This study supports that DM is associated with PC risk; however, similar to many studies in Asia, obesity is not associated with PC in Iranians. DM has the highest impact on PC development in Iranian women.

Cigarette smoking and risk of infection-related mortality: A cohort study

BACKGROUND

Cigarette smoking is a leading cause of death worldwide and is associated with various diseases. However, studies addressing its impact on infection-related deaths are limited. This study examined the relationship between smoking and infection-related mortality.

METHODS

A cohort of 583,034 South Korean adults who underwent annual or biennial health examinations were followed-up for infection-related deaths using national records. Cox proportional hazards regression assessed hazard ratios (HRs) and 95% confidence intervals (CIs) for infection-related mortality.

RESULTS

The median follow-up was 9.1 years (maximum 18 years), and 335 infection-related deaths were identified. Current smoking, but not former smoking, was positively associated with an increased risk of infection-related mortality. After adjusting for possible confounders, the multivariable-adjusted HRs ( 95% CIs) for infection-related mortality comparing former and current smokers with never smokers were 0.94 (0.68-1.30) and 1.45 (1.05-2.02), respectively; and those for infection-related mortality by number of pack-years comparing 10-19.9 and ≥20 pack-years to <10 pack-years were 1.26 (0.81-1.96) and 1.47 (1.03-2.09), respectively, while those comparing 10-19 and ≥20 cigarettes/day to <10 cigarettes/day were 1.35 (0.86-2.11) and 1.54 (1.13-2.11), respectively (p for trend <0.05). Individuals with ≥20 pack-years had a 2.06 times greater risk of infection-related mortality when changes in smoking status and confounders during follow-up were updated in the analysis as time-varying covariates.

CONCLUSION

Current smoking status, intensity and pack-years were associated with an increased risk of infection-related death, with the highest risk of infection-related mortality found consistently in individuals with ≥20 pack-years.

IMPLICATIONS

In this large-scale cohort study of relatively young and middle-aged South Korean adults, current smoking, smoking intensity, and pack-years were associated with an increased risk of death due to infections; in particular, a significantly increased risk of infection-related mortality was consistently found in individuals with ≥20 pack-years. When appropriate, infection-related mortality should be included in smoking-attributable mortality burdens, and effective smoking control measures should be considered to improve infection-related mortality.

Global trends in pancreas cancer among Asia-Pacific population

The incidence of pancreatic cancer is rising. Understanding trends of pancreatic cancer is crucial prior to putting policies and interventions in place. Countries with a high human development index (HDI) have a higher incidence, prevalence and mortality due to pancreatic cancer. This global trend is replicated in the Asia-Pacific countries with high HDI having higher incidence, prevalence and mortality due to pancreatic cancer. The incidence of pancreatic cancer is rising in the Asia-Pacific population as life expectancy increases with a rising HDI. Lack of good cancer registries has resulted in under reporting of pancreatic cancer in developing countries in the Asia-Pacific region. The mortality still remains high as in the Western world as most pancreatic cancers are diagnosed in an advanced stage of the disease due to non-availability of cost-effective screening tools with few patients receiving definitive care. Smoking, alcohol consumption, poor diet and obesity are significant modifiable risk factors contributing to the development of pancreatic cancer. Population based screening for pancreatic cancer is not cost-effective. Identification of hereditary and genetic factors in the Asia-Pacific population can help in targeted screening of high-risk individuals. Policies and interventions aimed at primary prevention have the greatest potential to be cost-effective yet impactful and reduce the disease burden.

Attributable Causes of Cancer in Vietnam

PURPOSE

Vietnam is undergoing rapid socio-economic transition with an increasing cancer burden. The contribution of modifiable risk factors to cancers in Vietnam has not been studied. Therefore, we sought to evaluate the attributable causes of cancer in Vietnam.

METHODS

We reviewed the data on burden of cancer in Vietnam from 2 cancer registries in Hanoi and Ho Chi Minh City between 1995 and 2012. Next, we calculated the fractions of cancers occurring in 2018 attributable to established modifiable risk factors whose impact could be quantified. Data on exposure prevalence were obtained for the period from 2000 to 2010 from national sources wherever possible.

RESULTS

Cancer incidence in Vietnam has decreased slightly in both sexes. Cancer related to infectious agents decreased sharply, whereas cancer related to nutrition and metabolism has increased. In 2018, established carcinogens included in the analysis explained 47.0% of cancer burden in Vietnam. Chronic infections accounted for 29.1% of cancers (34.7% in men and 22.1% in women), tobacco smoking for 13.5% (23.9% in men and 0.8% in women), and alcohol drinking for 10.3%. Passive smoking was responsible for 8.8% of cancers in women. Other risk factors, including overweight or obesity, nulliparity, and low vegetable and fruit intake, accounted for < 1% of all cancers each.

CONCLUSION

Cancer incidence is slowly decreasing in Vietnam, and the causes of more than half of cancers remain unexplained. This result underlines the need for further epidemiologic and fundamental research. Our findings confirm the notion that controlling oncogenic infections and decreasing tobacco smoking are the most effective approaches to reduce the burden of cancer in Vietnam, but other risk factors, including alcohol drinking and diet, should not be neglected.

Systemic Inflammatory Response and Outcomes in Community-Acquired Pneumonia Patients Categorized According to the Smoking Habit or Presence of Chronic Obstructive Pulmonary Disease

The systemic inflammatory response (SIR) may help to predict clinical progression, treatment failure, and prognosis in community-acquired pneumonia (CAP). Exposure to tobacco smoke may affect the SIR; the role of smoking in CAP has not been consolidated. We evaluated the SIR and outcomes of hospitalized CAP patients stratified by smoking habits and the presence of COPD. This retrospective analysis was conducted at the Hospital Clinic of Barcelona. Baseline, clinical, microbiological, and laboratory variables were collected at admission, using C-reactive protein (CRP) levels as a marker of SIR. The study outcomes were pleural complications, hospital stay, non-invasive and invasive mechanical ventilation (IMV), and intensive care unit (ICU) admission. We also considered the in-hospital and 30-day mortality. Data were grouped by smoking habit (non-, former-, and current-smokers) and the presence of COPD. Current smokers were younger, had fewer comorbidities, and fewer previous pneumonia episodes. CRP levels were higher in current smokers than in other groups. Current smokers had a higher risk of pleural complications independent of CRP levels, the presence of pleuritic pain, and a higher platelet count. Current smokers more often required IMV and ICU admission. Current smokers have a greater inflammatory response and are at increased risk of pleural complications.

Heated Tobacco Products Have Reached Younger or More Affluent People in Japan

Background

The trend of the diffusion of heated tobacco products (HTPs) is a great concern because HTPs have become available worldwide. This study examined the sociodemographic characteristics of HTPs users in Japan, where HTPs were first launched.

Methods

This cross-sectional study used data from an online survey conducted in 2017. A total of 4,926 participants, aged 20–69 years, were included. The dependent variable was the type of tobacco products used. The independent variables were age and equivalent income. Two analyses estimated the odds ratios (ORs) for 1) being smokers compared to “non-smokers,” and 2) being “HTP smokers” compared to “only combustible cigarette smokers.” Analyses were stratified by sex. Educational attainment and occupation were also used in the sensitivity analyses.

Results

The percentages of “non-smokers,” “only combustible cigarette smokers,” and “HTP smokers” were 82.8%, 14.2%, and 3.0%, respectively. When compared to the oldest participants (aged 60–69), the youngest participants (aged 20–29) tended to be “HTP smokers” (OR 7.90; 95% confidence interval [CI], 3.09–20.22 for men and OR 9.28; 95% CI, 2.14–40.28 for women). Compared to participants with the lowest incomes (<2 million), those with the highest incomes (≥4 million) tended to use HTPs (OR 2.93; 95% CI, 1.56–5.49 in men and OR 1.82; 95% CI, 0.73–4.54 in women). These trends were consistent when analyses included only smokers. There were consistent results in other SES measurements, including educational attainment and occupation.

Conclusions

Younger or more affluent people tended to use HTPs, although smoking rates among these populations were generally lower. New tobacco control efforts are required.

Japanese Legacy Cohorts: Six-Prefecture Cohort Study (Hirayama Cohort Study)

Late Dr Takeshi Hirayama and his colleagues conducted a mortality follow-up of a large-scale cohort in six prefectures in Japan. This study is called the six-prefecture cohort study or Hirayama Cohort Study. The study subjects were residents aged 40 years or older at the baseline survey in 1965, which covered 94.8% of residents identified in the study area by the National Census conducted on October 1, 1965. The mortality of 264,118 cohort members was followed until the end of 1982. One of the most important findings made by this study was an association between second-hand smoke exposure and lung cancer. This finding is the origin of the worldwide spread of smoking ban in indoor public venues and workplaces. Other major findings obtained from the study are also briefly described in this article.

Effectiveness of Text-Only Cigarette Health Warnings in Japan: Findings from the 2018 International Tobacco Control (ITC) Japan Survey

Health warnings are an effective strategy for communicating the health harms of smoking, encouraging quitting, and preventing smoking initiation. This study examines the effectiveness of existing text-only health warnings, identifies key predictors of warning effectiveness, and assesses support for pictorial warnings in Japan. Data are from the 2018 International Tobacco Control (ITC) Japan Survey, a cohort survey of adult cigarette smokers (n = 3306), dual users of cigarettes and heated tobacco products (n = 555), and non-cigarette smokers (n = 823). Weighted multivariable logistic regression models were used to assess predictors of warning effectiveness and support for pictorial warnings. Overall, 15.6% of respondents noticed warnings, and 7.9% read or looked closely at warnings. Overall, 10.3% of smokers and dual users said the warnings stopped them from having a cigarette, and 7.2% avoided warnings. Overall, 27.5% of respondents said the warnings made them think about health risks of smoking, but only 2.7% of smokers and dual users said the warnings made them more likely to quit. Overall, 57.6% of respondents supported pictorial warnings. The weak effectiveness of Japan's text-only warnings is consistent with that in other countries with similar warnings. There is majority support for pictorial warnings in Japan, although the level of support is lower than in other countries.

Smoking and Pancreatic Cancer Incidence: A Pooled Analysis of 10 Population-Based Cohort Studies in Japan

BACKGROUND

Detailed prospective evaluation of cigarette smoking associated with pancreatic cancer risk in large Asian populations is limited. The aim of this study was to examine this association in a Japanese population, with a particular focus on evaluating sex differences.

METHODS

We performed a pooled analysis of 10 population-based cohort studies. We calculated study-specific HRs and 95% confidence intervals (CI) using Cox proportional hazards regression, and then estimated summary HRs by pooling these estimates with a random effects model.

RESULTS

During 4,695,593 person-years of follow-up in 354,154 participants, 1,779 incident pancreatic cancer cases were identified. We observed an increased pancreatic cancer risk for current smoking compared with never smoking in both males [HR (95% CI), 1.59 (1.32-1.91)] and females [HR (95% CI), 1.81 (1.43-2.30)]. Significant risk elevations for former smoking and small cumulative dose of ≤20 pack-years (PY) were observed only among females, regardless of environmental tobacco smoke exposure. Trend analysis indicated significant 6% and nonsignificant 6% increases in pancreatic cancer risk for every 10 PYs in males and females, respectively. Risk became comparable with never smokers after 5 years of smoking cessation in males. In females, however, we observed no risk attenuation by smoking cessation.

CONCLUSIONS

This study supports the well-known association between smoking and pancreatic cancer and indicates potential sex differences in a Japanese population. Quitting smoking would be beneficial for pancreatic cancer prevention, especially in males.

IMPACT

Pancreatic cancer risk is increased with cumulative smoking exposure and decreased with smoking cessation, with potential sex differences.

Tumor mutation burden and recurrent tumors in hereditary lung cancer

Lung cancer is the leading cause of cancer death worldwide and cancer relapse accounts for the majority of cancer mortality. The mechanism is still unknown, especially in hereditary lung cancer without known actionable mutations. To identify genetic alternations involved in hereditary lung cancer and relapse is urgently needed. We collected genetic materials from a unique hereditary lung cancer patient's blood, first cancer tissue (T1), adjacent normal tissue (N1), relapse cancer tissue (T2), and adjacent normal tissue (N2) for whole genome sequencing. We identified specific mutations in T1 and T2, and attributed them to tumorigenesis and recurrence. These tumor specific variants were enriched in antigen presentation pathway. In addition, a lung adenocarcinoma cohort from the TCGA dataset was used to confirm our findings. Patients with high mutation burdens in tumor specific genes had decreased relapse‐free survival (P = 0.017, n = 186). Our study may provide important insight for designing immunotherapeutic treatment for hereditary lung cancer.

Epidemiology and burden of pancreatic cancer

Pancreatic cancer, although infrequent, has a very poor prognosis, making it currently the fourth common causes of cancer mortality in most developed countries including the European Union (EU). Its incidence varies across regions, which suggests that lifestyle factors play an important role in its etiology, although part of the variation could be ascribed to difference in diagnostic and coding practices. Because pancreatic cancer is strongly age-dependent, increasing population longevity and ageing will lead to an increase of the global burden of pancreatic cancer. It was estimated that, by 2040, the total number of cases in the EU will increase by more than 30%. Pancreatic cancer is a multifactorial disease and many risk factors have been identified. Hereditary factors are responsible for less than 10% of the cases while tobacco smoking and excess body weight, the two most important potentially modifiable risk factors, are responsible for 10 to 30% of the cases, affording a unique opportunity for preventing one of our deadliest cancers.

The Association Between Education and Smoking Prevalence, Independent of Occupation: A Nationally Representative Survey in Japan

Background

Higher smoking prevalence in less educated persons and manual workers is well known. This study examines the independent relationship of education and occupation with tobacco use.

Methods

We used anonymized data from a nationwide population survey (30,617 men and 33,934 women). Education was divided into junior high school, high school, or university attainment. Occupation was grouped into upper non-manual, lower non-manual, and manual. Poisson regression models stratified by age and gender were used to estimate adjusted prevalence ratio (PR) and 95% confidence interval (CI) for current smoking.

Results

After adjustment for covariates, education, and occupation, education was significantly related to current smoking in both genders; compared to university graduates, PRs of junior high school graduates aged 20–39, 40–64, and ≥65 were 1.74 (95% CI, 1.53–1.98), 1.50 (95% CI, 1.36–1.65), and 1.28 (95% CI, 1.08–1.50) among men, and 3.54 (95% CI, 2.92–4.30), 2.72 (95% CI, 2.29–3.23), and 1.74 (95% CI, 1.14–2.66) among women, respectively. However, significantly higher smoking prevalence in manual than in upper non-manual was found only in men aged 20–64; compared to upper non-manual, the PRs of manual workers aged 20–39, 40–64, and ≥65 were 1.11 (95% CI, 1.02–1.22), 1.18 (95% CI, 1.10–1.27), and 1.10 (95% CI, 0.89–1.37) among men, and 0.95 (95% CI, 0.75–1.20), 0.92 (95% CI, 0.75–1.12), and 0.46 (95% CI, 0.22–0.95) among women, respectively.

Conclusions

Independent of occupation, educational disparities in smoking existed, regardless of age and gender. Occupation-smoking relationship varied with age and gender. Our study suggests that we should pay attention to social inequality in smoking as well as national smoking prevalence.

Changes in Smoking Status and Mortality From All Causes and Lung Cancer: A Longitudinal Analysis of a Population-based Study in Japan

BACKGROUND

To update the findings of relative risk associated with smoking for all-cause mortality and that for lung cancer by considering longitudinal changes in smoking status during follow-up.

METHODS

Data from the JPHC study of 98,747 middle-aged Japanese adults, which started in 1990-1993, were analyzed. The information on smoking status was obtained from three questionnaire surveys (baseline, the 5th year, and the 10th year after the start of follow-up). A Poisson regression model was used to investigate the impact of smoking on mortality from all causes and lung cancer using two approaches. Model 1 used information only from baseline, while model 2 used the updated smoking status from all three surveys.

RESULTS

During the 15-year follow-up, 10,702 all-cause deaths (including 870 lung cancer cases) were identified. We compared the results obtained from two models. The relative risks associated with former smokers versus never smokers were 1.42 (95% confidence interval [CI], 1.31-1.54) among men and 1.46 (95% CI, 1.23-1.73) among women for all-cause mortality and 2.98 (95% CI, 2.09-4.24) among men and 1.83 (95% CI, 0.92-3.64) among women for lung cancer mortality, as determined using model 2. All of these were higher than the relative risks obtained from model 1. In addition, former smokers who had quit smoking due to disease during follow-up had a higher mortality risk than continuous smokers did in this study.

CONCLUSIONS

The relative risks of all-cause mortality and mortality due to lung cancer among former smokers be higher than previously documented based on updated smoking status data from repeated surveys.

Modeling and forecasting sex differences in mortality: a sex-ratio approach

Female and male life expectancies have converged in most industrialized societies in recent decades. To achieve coherent forecasts between females and males, this convergence needs to be considered when forecasting sex-specific mortality. We introduce a model forecasting a matrix of the age-specific death rates of sex ratio, decomposed into two age profiles and time indices-before and after age 45-using principal component analysis. Our model allows visualization of both age structure and general level over time of sex differences in mortality for these two age groups. Based on a prior forecast for females, we successfully forecast male mortality convergence with female mortality. The usefulness of the developed model is illustrated by its comparison with other coherent and independent models in an out-of-sample forecast evaluation for 18 countries. The results show that the new proposal outperformed the other models for most countries.

Strong excess risk of pancreatic cancer for low frequency and duration of cigarette smoking: A comprehensive review and meta-analysis

AIM

Cigarette smoking is an established risk factor for pancreatic cancer but an updated quantification of the association is lacking. Our aim is to provide the most accurate and updated estimate of the dose-response relationships between cigarette smoking and pancreatic cancer risk.

METHODS

Using an innovative approach for the identification of original publications, we conducted a systematic review and meta-analysis of epidemiological studies published on the issue up to April 2017. Random effects models were used to provide pooled estimates for the cigarette smoking status; dose-risk relationships were evaluated using one-stage random effects models with restricted cubic splines.

RESULTS

Seventy-eight studies were included, providing a pooled relative risk (RR) of pancreatic cancer of 1.8 (95% confidence interval, CI: 1.7-1.9) for the current and 1.2 (95% CI: 1.1-1.2) for the former vs. never smokers. A sharp increase in pancreatic cancer risk was found already with a low number of cigarettes and up to 30 cigarettes/day (RR 2.2, 95% CI: 1.9-2.4). Similarly, the risk of pancreatic cancer steady increased after a few years of smoking up to 30 years (RR 1.8, 95% CI: 1.6-2.0). The risk rapidly decreased with increasing time since quitting and was 0.6 (95% CI: 0.5-0.7, for the former vs. current smokers) after 20 years of quitting.

CONCLUSIONS

The present meta-analysis indicates that pancreatic cancer risk sharply increases with a low number of cigarettes or after a few years of smoking and that it rapidly decreases a few years after cessation, although it takes almost 20 years to reach that of never smokers.

Smoking as a risk factor for lung cancer in women and men: a systematic review and meta-analysis

OBJECTIVES

To investigate the sex-specific association between smoking and lung cancer.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

We searched PubMed and EMBASE from 1 January 1999 to 15 April 2016 for cohort studies. Cohort studies before 1 January 1999 were retrieved from a previous meta-analysis. Individual participant data from three sources were also available to supplement analyses of published literature.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Cohort studies reporting the sex-specific relative risk (RR) of lung cancer associated with smoking.

RESULTS

Data from 29 studies representing 99 cohort studies, 7 million individuals and >50 000 incident lung cancer cases were included. The sex-specific RRs and their ratio comparing women with men were pooled using random-effects meta-analysis with inverse-variance weighting. The pooled multiple-adjusted lung cancer RR was 6.99 (95% Confidence Interval (CI) 5.09 to 9.59) in women and 7.33 (95% CI 4.90 to 10.96) in men. The pooled ratio of the RRs was 0.92 (95% CI 0.72 to 1.16; I2=89%; p<0.001), with no evidence of publication bias or differences across major pre-defined participant and study subtypes. The women-to-men ratio of RRs was 0.99 (95% CI 0.65 to 1.52), 1.11 (95% CI 0.75 to 1.64) and 0.94 (95% CI 0.69 to 1.30), for light, moderate and heavy smoking, respectively.

CONCLUSIONS

Smoking yields similar risks of lung cancer in women compared with men. However, these data may underestimate the true risks of lung cancer among women, as the smoking epidemic has not yet reached full maturity in women. Continued efforts to measure the sex-specific association of smoking and lung cancer are required.

Smoking, Smoking Cessation, and Risk of Mortality in a Japanese Working Population - Japan Epidemiology Collaboration on Occupational Health Study

BACKGROUND

The effect of smoking on mortality in working-age adults remains unclear. Accordingly, we compared the effects of cigarette smoking and smoking cessation on total and cause-specific mortality in a Japanese working population. Methods and Results: This study included 79,114 Japanese workers aged 20-85 years who participated in the Japan Epidemiology Collaboration on Occupational Health Study. Deaths and causes of death were identified from death certificates, sick leave documents, family confirmation, and other sources. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated via Cox proportional hazards regression. During a maximum 6-year follow-up, there were 252 deaths in total. Multivariable-adjusted HRs (95% CIs) for total mortality, cardiovascular disease (CVD) mortality, and tobacco-related cancer mortality were 1.49 (1.10-2.01), 1.79 (0.99-3.24), and 1.80 (1.02-3.19), respectively, in current vs. never smokers. Among current smokers, the risks of total, tobacco-related cancer, and CVD mortality increased with increasing cigarette consumption (P_trend<0.05 for all). Compared with never smokers, former smokers who quit <5 and ≥5 years before baseline had HRs (95% CIs) for total mortality of 1.80 (1.00-3.25) and 1.02 (0.57-1.82), respectively.

CONCLUSIONS

In this cohort of workers, cigarette smoking was associated with increased risk of death from all and specific causes (including CVD and tobacco-related cancer), although these risks diminished 5 years after smoking cessation.

Proportion and clinical characteristics of non-asthmatic non-smokers among adults with airflow obstruction

Background and objectives

Chronic obstructive pulmonary disease (COPD) mainly develops after long-term exposure to cigarette or biomass fuel smoke, but also occurs in non-smokers with or without a history of asthma. We investigated the proportion and clinical characteristics of non-smokers among middle-aged to elderly subjects with airflow obstruction.

Methods

We retrospectively analyzed 1,892 subjects aged 40–89 years who underwent routine preoperative spirometry at a tertiary university hospital in Japan. Airflow obstruction was defined as a forced expiratory volume in 1 second (FEV₁)/forced vital capacity < 0.7 or as the lower limit of the normal.

Results

Among 323 patients presenting with FEV₁/forced vital capacity < 0.7, 43 had asthma and 280 did not. Among the non-asthmatic patients with airflow obstruction, 94 (34%) were non-smokers. A larger number of women than men with airflow obstruction had asthma (26% vs. 7.6%, p < 0.001), or were non-smokers among non-asthmatics (72% vs. 20%, p < 0.001). Non-asthmatic non-smokers, rather than non-asthmatic smokers, asthmatic non-smokers, and asthmatic smokers, exhibited better pulmonary function (median FEV₁: 79% of predicted FEV₁ vs. 73%, 69%, and 66%, respectively, p = 0.005) and less dyspnea on exertion (1% vs. 12%, 12%, and 28%, respectively, p = 0.001). Pulmonary emphysema on thoracic computed tomography was less common in non-smokers (p < 0.001). Using the lower limit of the normal to define airflow obstruction yielded similar results.

Conclusions

There are a substantial number of non-smokers with airflow obstruction compatible with COPD in Japan. In this study, airflow obstruction in non-smokers was more common in women and likelier to result in mild functional and pathological abnormalities than in smokers. Further studies are warranted to investigate the long-term prognosis and appropriate management of this population in developed countries, especially in women.

International trends in lung cancer incidence from 1973 to 2007

Lung cancer is the commonly diagnosed cancer and one of the most important avoidable causes of death around the world. We conducted the study to investigate the pattern of lung cancer incidence worldwide. Joinpoint analysis was used to extend international lung cancer incidence rates by the latest data from Cancer Incidence in Five Continents over the 35‐year period 1973–2007 from 24 populations from Americas, Asia, Europe, and Oceania. Age‐standardized incidence rates (ASRs) of lung cancer were from 33.3 to 66.8 per 100,000 among males and 10.5 to 37.4 per 100,000 among females in most of Americas, Europe, and Oceania populations during the period 2003–2007. In Asia, ASRs in China (Hong Kong) were the highest, up to 53.3 per 100,000 in males and 21.9 per 100,000 in females during the period 2003–2007. The international trends between 1973 and 2007 showed that ASRs of lung cancer among males were declining in 13 of 18 selected Americas, Oceania, and Europe populations, with AAPC from −0.7% to −2.9%, whereas the rates among females in 18 selected populations were increasing, with AAPC from 1.3% to 5.0%. The increasing and decreasing trends of ASRs of lung cancer in Asia have a geographic variation but no gender differences. Although the decreasing trends in ASRs of lung cancer for males were observed, the ASRs were higher than females. The declining trends in males were mainly attributed to tobacco control, whereas the increasing trends in females should be given more concern and need to be further studied in etiology factors.

Direct adjustment for confounding by smoking reduces radiation-related cancer risk estimates of mortality among male nuclear workers in Japan, 1999-2010

A causal relationship between protracted exposure to low-dose rate radiation and health effects remains unclear despite extensive international studies of nuclear workers. One potential reason is that radiation epidemiological studies that adjust for tobacco smoking, which heavily influences mortality, have been limited. In the present study, we examined radiation-related cancer risk by directly assessing the possible confounding effect of smoking, using data from two questionnaire surveys performed among Japanese nuclear workers in 1997 and 2003. Mortality follow-up was carried out for 71 733 male respondents for an average of 8.2 years during the observation period of 1999-2010. The mean cumulative dose was 25.5 mSv at the end of the follow-up period. Estimates of excess relative risk per Sv (ERRs/Sv) were obtained by Poisson regression. By adjusting for smoking directly on the basis of a linear dose-response model, we quantified the confounding effects of smoking on radiation risks. Statistically significant ERRs/Sv were found for all causes, all diseases, all non-cancer diseases, and liver cancer: 0.97 (90% confidence interval: 0.23, 1.78), 1.32 (0.40, 2.34), 1.87 (0.47, 3.49), and 4.78 (0.09, 11.68), respectively, without adjustment for smoking. However, the ERRs/Sv were no longer statistically significant after adjustment for smoking: 0.45 (-0.22, 1.19), 0.77 (-0.08, 1.72), 1.28 (-0.03, 2.79), and 3.89 (-0.46, 10.34), respectively. The ERRs/Sv for all cancers excluding leukaemia and lung cancer were not significant before adjustment for smoking, but declined after adjustment for smoking. The present study demonstrates that in this cohort of workers, smoking heavily distorts radiation risk estimates of mortality. The possibility of confounding by smoking depends on how strongly smoking is correlated with radiation exposure. If a correlation between smoking and radiation dose is suggested, smoking is an important confounder when assessing the radiation and health risks.

Development of a risk prediction model for lung cancer: The Japan Public Health Center-based Prospective Study

Although the impact of tobacco consumption on the occurrence of lung cancer is well‐established, risk estimation could be improved by risk prediction models that consider various smoking habits, such as quantity, duration, and time since quitting. We constructed a risk prediction model using a population of 59 161 individuals from the Japan Public Health Center (JPHC) Study Cohort II. A parametric survival model was used to assess the impact of age, gender, and smoking‐related factors (cumulative smoking intensity measured in pack‐years, age at initiation, and time since cessation). Ten‐year cumulative probability of lung cancer occurrence estimates were calculated with consideration of the competing risk of death from other causes. Finally, the model was externally validated using 47 501 individuals from JPHC Study Cohort I. A total of 1210 cases of lung cancer occurred during 986 408 person‐years of follow‐up. We found a dose‐dependent effect of tobacco consumption with hazard ratios for current smokers ranging from 3.78 (2.00‐7.16) for cumulative consumption ≤15 pack‐years to 15.80 (9.67‐25.79) for >75 pack‐years. Risk decreased with time since cessation. Ten‐year cumulative probability of lung cancer occurrence estimates ranged from 0.04% to 11.14% in men and 0.07% to 6.55% in women. The model showed good predictive performance regarding discrimination (cross‐validated c‐index = 0.793) and calibration (cross‐validated χ² = 6.60; P‐value = .58). The model still showed good discrimination in the external validation population (c‐index = 0.772). In conclusion, we developed a prediction model to estimate the probability of developing lung cancer based on age, gender, and tobacco consumption. This model appears useful in encouraging high‐risk individuals to quit smoking and undergo increased surveillance.

Cigarette smoking and smoking-attributable diseases among Estonian physicians: a cross-sectional study

Background

Smoking is a risk factor for several diseases. Physicians are role models for their patients. Physicians who smoke underestimate the health risks of smoking and may be less likely to offer advice to help their patients to quit. The aim of this study was to: provide an overview of smoking behaviour among Estonian physicians; assess the relationship between smoking and ischaemic heart disease (IHD), chronic bronchitis (CB), and lung emphysema (LE); and estimate fractions of prevalences of the three diseases attributable to smoking.

Methods

Self-administered questionnaires were sent to practising physicians (n = 5666) in Estonia in 2014. Prevalence of smoking and relative risks for IHD, CB and LE as well as the risks of IHD, CB and LE attributable to smoking were calculated by age and sex. Post-stratification was used to compensate non-response.

Results

There were 535 male and 2404 female physicians participating. The prevalence of daily smoking was 12.4% (95% CI 10.4–14.4%) among men and 5.0% (95% CI 4.4–5.6%) among women. Mean duration of smoking among male and female daily smokers was 28.6 (95% CI 26.1–31.1) and 28.6 (95% CI 27.1–30.2) years. Compared to lifelong non-smokers, the age-adjusted risk for IHD was 1.29 times (95% CI 0.88–1.89) higher for men, but 1.69 times (95% CI 1.17–2.40) lower for all women who have ever smoked. The risk for CB was 2.29 (95% CI 1.30–4.03) times higher for smokers among men and, 1.32 (95% CI 0.95–1.82) among women; the risk ratio for LE was 4.92 (95% CI 1.14–21.1) among men and 2.45 (95% CI 0.63–9.52) among women. The smoking-attributable risk for IHD was 3.2% (95% CI 2.3–4.1%) among men and − 0.1% (95% CI -0.7–0.4%) among women; for CB 6.9% (95% CI 6.0–7.8%) and 4.2% (95% CI 3.5–4.8%); and for LE 18.8% (95% CI 17.0–22.5%) and 22.6% (95% CI 18.5–26.9%), respectively.

Conclusion

Prevalence of daily smoking was relatively low among Estonian physicians (and twice lower among female physicians). The risk attributable to smoking was higher for LE and CB than for IHD.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5105-6) contains supplementary material, which is available to authorized users.

Smoking cessation and subsequent risk of cancer: A pooled analysis of eight population-based cohort studies in Japan

BACKGROUND

Although East Asia is one of the largest tobacco-epidemic regions in the world, only a few prospective studies from Asia have investigated the impact of smoking and cessation of smoking on cancer. We aimed to assess the effect of cessation of smoking on the risk of cancer using eight population-based cohort studies in Japan.

METHODS

We analyzed pooled data from eight population-based prospective cohort studies in Japan with more than 320,000 participants to assess the effect of smoking cessation on the risk of total cancers and smoking-related cancers.

RESULTS

After adjustment for potential confounders, cancer risks in men with >21years of smoking cessation before baseline were found to decrease to the same level as never smokers for total cancer (never smokers: reference; former smokers with ≥21 years since smoking cessation: HR, 1.01; 95%CI: 0.91, 1.11). Even men who are heavy smokers (more than 20 pack-years) reported a reduced risk of total cancer (never smokers: reference; former smokers with ≥21 years since smoking cessation: HR, 1.06; 95%CI: 0.92, 1.23). In women, the risk of total cancer did not differ from that of never smokers after 11 years of smoking cessation before baseline (never smokers: reference; former smokers with ≥11 years since smoking cessation: HR, 0.96; 95%CI: 0.74, 1.23).

CONCLUSIONS

Our study suggests that longer duration of smoking cessation may attenuate the risk of cancer in both men and women, and that even heavy smokers (more than 20 pack-years) were found to benefit from quitting smoking.

Relationship between Stroke Events during Pachinko Play and Prognosis

BACKGROUND

This study investigated whether pachinko play influences the outcome of stroke events, and identified the significant variables affecting outcomes.

METHODS

We reviewed the medical and imaging records of 2075 consecutive patients with stroke from January 2003 through June 2012. The remaining patients were divided into 2 groups, the pachinko players group (PP) and the non-pachinko players group (NPP). Background factors were recorded on admission. Multivariate logistic regression analysis was used to identify the factors significantly correlated with Glasgow Outcome Scale (GOS) score and risk of death at the time of discharge.

RESULTS

The PP group exhibited higher prevalence of hypertension and current smoking compared with the NPP group. However, no difference was found in outcomes between the PP and NPP groups. Multivariate analysis identified the dependent predictive variables for GOS as age (adjusted β = -.18, 95% confidence interval [CI]: -.22 to -.14, P <.001), Glasgow Coma Scale (GCS) score on admission (adjusted β = .64, 95% CI: .60 to .68, P <.001), and history of hypertension (adjusted β = -.06, 95% CI: -.10 to -.02, P = .007). Logistic regression analysis showed that age (odds ratio = 1.02, 95% CI: 1.01 to 1.04, P <.001) and GCS score on admission (odds ratio = .72, 95% CI: .69 to .75, P <.001) were significantly associated with death at the time of discharge.

CONCLUSIONS

Patients with stroke during playing pachinko have higher prevalence of hypertension and higher smoking rate, but pachinko play itself was not a critical factor determining the outcome of patients with stroke in our emergency center.

Gingival Pigmentation Affected by Smoking among Different Age Groups: A Quantitative Analysis of Gingival Pigmentation Using Clinical Oral Photographs

The presence of any age-related differences in gingival pigmentation associated with smoking, particularly in a young population, remains to be fully investigated. The purpose of this study was to determine the age-related differences in smoking gingival pigmentation. Gingival pigmentation was analyzed using the gingival melanosis record (GMR) and Hedin’s classification with frontal oral photographs taken at 16 dental offices in Japan. Participants were categorized into 10-year age groups, and their baseline photographs were compared. In addition, to evaluate the effect of smoking cessation on gingival pigmentation, subjects were divided into a former smoker group (stopped smoking) and current smoker group. A total of 259 patients 19 to 79 years of age were analyzed. People in their 30s showed the most widespread gingival pigmentation. In addition, subjects in their 20s showed a weak effect of smoking cessation on gingival pigmentation. These findings suggested that the gingival pigmentation induced by smoking was more remarkable in young people than in middle-aged people. This information may be useful for anti-smoking education, especially among young populations with a high affinity for smoking.

Media exposure, interactive health literacy, and adolescents' susceptibility to future smoking

BACKGROUND

Few studies have investigated interactive health literacy (IHL)'s relationship with adolescents' smoking-related behavior. This study investigated IHL's association with adolescents' susceptibility to future smoking.

MATERIALS AND METHODS

We conducted a school-based cross-sectional study of Japanese students enrolled in public junior high school, grades 7-9 (n=1937), who completed a self-report questionnaire. Variables were grade, gender, media exposure [television (TV), internet, and magazines], IHL (interest in learning about health, understanding what they hear about health, trying to follow what is taught about health), and susceptibility to future smoking.

RESULTS

Significant findings were: [1] media exposure was positively associated with adolescents' susceptibility to future smoking (TV: p<0.01, internet: p<0.01, magazines: p<0.01); [2] IHL was negatively associated with adolescents' susceptibility to future smoking (interest in learning about health: p<0.001; understanding what they hear about health: p<0.05; trying to follow what is taught about health: p<0.001). IHL's influence on susceptibility to future smoking was found to be marginally stronger than that of media exposure.

CONCLUSION

School health-education programs that promote adolescents' IHL may effectively reduce adolescents' susceptibility to future smoking.

Combination of ALDH2 and ADH1B polymorphisms is associated with smoking initiation: A large-scale cross-sectional study in a Japanese population

BACKGROUND

Aldehyde dehydrogenase 2 (ALDH2; rs671, Glu504Lys) and alcohol dehydrogenase 1B (ADH1B; rs1229984, His47Arg) polymorphisms are known to strongly influence alcohol　drinking behavior. Given evidence of an association between smoking and drinking behaviors, we hypothesized that ALDH2/ADH1B polymorphisms might also be associated with smoking initiation, and conducted a cross-sectional study to examine this hypothesis.

METHODS

Study subjects were first-visit outpatients diagnosed not to have cancer at Aichi Cancer Center Hospital between 2001 and 2005, including 4141 never smokers and 2912 ever smokers. Unconditional logistic regression models were applied to estimate odds ratios (OR) and 95% confidence intervals (CI) for smoking initiation by comparing ever smokers with never smokers.

RESULTS

Excessive alcohol drinking was associated with a higher likelihood of ever smoking. After adjustment for drinking behaviors, compared to individuals with ALDH2 Glu/Glu, the ORs of ever smoking were 1.71 (95% CI, 1.49-1.95) and 2.28 (1.81-2.87) among those with ALDH2 Glu/Lys and Lys/Lys, respectively. Combination of ALDH2 Lys/Lys and ADH1B His/His (i.e., the most alcohol-intolerant subpopulation) showed the highest OR [2.44 (1.84-3.23)], whereas combination of ALDH2 Glu/Glu and ADH1B Arg/Arg (i.e., the most alcohol-tolerant subpopulation) showed the lowest OR [0.83 (0.57-1.21)] compared with ALDH2 Glu/Glu and ADH1B His/His.

CONCLUSION

Besides the amount and frequency of alcohol drinking, the combination of ALDH2 and ADH1B polymorphisms predicts smoking initiation. This study suggests that alcohol tolerance regulated by ALDH2 and ADH1B polymorphisms is associated with smoking initiation, and facilitates the development of targeted interventions to reduce smoking prevalence.

Similarities and differences between coronary heart disease and stroke in the associations with cardiovascular risk factors: The Japan Collaborative Cohort Study

BACKGROUND AND AIMS

Coronary heart disease (CHD) and stroke have common risk factors, but some of these differ in the magnitude or direction of associations between CHD and stroke. We assessed whether the impact of each risk factor differed between CHD and stroke mortality in Asians.

METHODS

In total, 104 910 subjects aged 40-79 years without histories of cancer, CHD and stroke at baseline were followed between 1988 and 2009. Competing-risks analysis was used to test for differences in the associations of each risk factor with two endpoints (CHD and stroke). Population attributable fractions (PAFs) were also calculated for these endpoints to estimate the population impact of each risk factor.

RESULTS

During a median 19.1-year follow-up, 1554 died from CHD and 3163 from stroke. The association of hypertension with CHD was similar to that with stroke in terms of the magnitude and direction (multivariable-adjusted hazard ratio for CHD: 1.63 vs. stroke: 1.73 in men and 1.70 vs. 1.66 in women). Conversely, the magnitude of these associations differed for smoking (CHD: 1.95 vs. stroke: 1.23 in men and 2.45 vs. 1.35 in women) and diabetes (1.49 vs. 1.09 in men and 2.08 vs. 1.39 in women). The highest PAF for CHD was caused by smoking in men and by hypertension in women; that for stroke was caused by hypertension in both sexes.

CONCLUSIONS

Hypertension associations and PAFs were consistent between CHD and stroke, but not for other risk factors. These findings may be useful to optimize public health intervention strategies.

Systematic review of pancreatic cancer epidemiology in Asia-Pacific Region: major patterns in GLOBACON 2012

Pancreatic cancer is one of the deadliest cancers with short-term survival rates. Trends for pancreatic cancer incidence and mortality varied considerably in the world. To date, the causes of pancreatic cancer are not known sufficiently, although certain risk factors have been identified such as, smoking, obesity, life style, diabetes mellitus, alcohol, dietary factors and chronic pancreatitis. Since there are no current screening recommendations for pancreatic cancer, primary prevention is very important. Therefore, up-to-date statistics on pancreatic cancer occurrence and outcome are essential for the primary prevention of this disease. Due to the lack of information on epidemiology of pancreatic cancer in most Asian countries, and limited of statistics and registration system in this area, we conducted a systematic review study to evaluate the most recent data concerning epidemiology of pancreatic cancer in Asia-Pacific region. In this review we focused on collected recent data on incidence, mortality, survival and risk factors of pancreatic cancer in this region. In addition, we reviewed and used the data of GLOBOCAN 2012 in this paper to complete the information as a source of compiling pancreatic cancer incidence and mortality rate.

Associations of smoking status with other lifestyle behaviors are modified by sex and occupational category among urban civil servants in Japan

OBJECTIVES

The aim of the present study was to examine the associations of current smoking with five other unhealthy lifestyle behaviors among urban civil servants in Japan according to sex and occupational category.

METHODS

The study included 10,232 urban civil servants in Japan who presented for a health check-up in 2011. We analyzed data on anthropometric measurements and self-reported lifestyle factors.

RESULTS

Current smokers had a higher BMI than never smokers in white-collar workers, but not in blue-collar workers of both sexes. There were strong associations of current smoking with irregular breakfasting regardless of sex and occupational category. In males, current smokers were less likely to take exercise than ex-smokers in both occupational categories.

CONCLUSIONS

The associations of current smoking with other unhealthy behaviors were modified by sex and occupational category. These results are useful for understanding the health risks among smokers according to sex and occupational category.

Nociceptin/orphanin FQ receptor gene variation is associated with smoking status in Japanese

Aim: The endogenous opioid system has been reportedly implicated in tobacco/nicotine dependence. Materials & methods: We examined the genetic effects of eight SNPs in opioid receptor-related genes on smoking status and smoking-related traits in Japanese. Results: The genotypic and allelic variations of the rs2229205 SNP in the OPRL1 gene were significantly associated with smoking status, but no significant differences were found in the genetic variations of any of the SNPs with regard to smoking-related traits. The rs2229205 SNP did not show high linkage disequilibrium with the other SNPs in the linkage disequilibrium block that contained the SNP. Conclusion: The rs2229205 SNP in the OPRL1 gene may be a genetic factor that contributes to individual differences in the vulnerability to smoking in Japanese individuals.

Measurement of Reduced Gingival Melanosis after Smoking Cessation: A Novel Analysis of Gingival Pigmentation Using Clinical Oral Photographs

Background: Due to moisture and the anatomical complexity of the oral mucosa, it is difficult to measure the extent of gingival melanosis in an optical manner. Therefore, we developed a new quantitative method using clinical oral photographs and compared the extent of gingival melanosis before and after smoking cessation. Methods: A new analysis method, which we named the gingival melanosis record (GMR), is a quantitative analysis method using clinical oral photographs. We obtained 659 clinical photographs from 263 patients from 16 general dental offices in Japan. Standardized measuring sites were automatically spotted on the screen, and the presence of gingival melanosis was determined at the measuring sites. We assessed the validity of the GMR with the previously reported Hedin’s classification using Spearman’s rank correlation and intraclass correlation coefficients. Results: The GMR showed a significant association with Hedin’s classification (p < 0.01, correlation coefficient = 0.94). The GMR also showed excellent reproducibility of the substantial repeated agreement intraclass correlation coefficients (ICC) (1,1) and ICC (2,1), p > 0.61). The longitudinal loss of gingival melanosis was confirmed by a change in the GMR among patients who successfully achieved smoking cessation for a mean of 4.5 years. Conclusion: The GMR is an effective method to assess gingival melanosis. The loss of gingival melanosis after smoking cessation can be objectively confirmed with the use of the GMR.

All-Cause Mortality of Low Birthweight Infants in Infancy, Childhood, and Adolescence: Population Study of England and Wales

BACKGROUND

Low birthweight (LBW) is associated with increased mortality in infancy, but its association with mortality in later childhood and adolescence is less clear. We investigated the association between birthweight and all-cause mortality and identified major causes of mortality for different birthweight groups.

METHODS AND FINDINGS

We conducted a population study of all live births occurring in England and Wales between 1 January 1993 and 31 December 2011. Following exclusions, the 12,355,251 live births were classified by birthweight: 500-1,499 g (very LBW [VLBW], n = 139,608), 1,500-2,499 g (LBW, n = 759,283), 2,500-3,499 g (n = 6,511,411), and ≥3,500 g (n = 4,944,949). The association of birthweight group with mortality in infancy (<1 y of age) and childhood/adolescence (1-18 y of age) was quantified, with and without covariates, through hazard ratios using Cox regression. International Classification of Diseases codes identified causes of death. In all, 74,890 (0.61%) individuals died between birth and 18 y of age, with 23% of deaths occurring after infancy. Adjusted hazard ratios for infant deaths were 145 (95% CI 141, 149) and 9.8 (95% CI 9.5, 10.1) for the VLBW and LBW groups, respectively, compared to the ≥3,500 g group. The respective hazard ratios for death occurring at age 1-18 y were 6.6 (95% CI 6.1, 7.1) and 2.9 (95% CI 2.8, 3.1). Male gender, the youngest and oldest maternal age bands, multiple births, and deprivation (Index of Multiple Deprivation score) also contributed to increased deaths in the VLBW and LBW groups in both age ranges. In infancy, perinatal factors, particularly respiratory issues and infections, explained 84% and 31% of deaths in the VLBW and LBW groups, respectively; congenital malformations explained 36% and 23% in the LBW group and ≥2,500 g groups (2,500-3,499 g and ≥3,500 g groups combined), respectively. Central nervous system conditions explained 20% of deaths in childhood/adolescence in the VLBW group, with deaths from neoplasms and external conditions increasingly prevalent in the 1,500-2,499 g and ≥2,500 g birthweight groups. The study would have benefited had we had access to information on gestational age and maternal smoking, but since the former is highly correlated with birthweight and the latter with deprivation, we believe that our findings remain robust despite these shortcomings.

CONCLUSIONS

LBW is associated with infant and later child and adolescent mortality, with perinatal factors and congenital malformations explaining many of the deaths. By understanding and ameliorating the influences of upstream exposures such as maternal smoking and deprivation, later mortality can be decreased by reducing the delivery of vulnerable infants with LBW.

Trends in Lung Cancer Incidence Rates by Histological Type in 1975-2008: A Population-Based Study in Osaka, Japan

Background

Monitoring trends in lung cancer incidence and mortality is important for the evaluation of cancer control activities. We investigated recent trends in age-standardized incidence rates by histological type of lung cancer in Osaka, Japan.

Methods

Cancer incidence data for 1975–2008 were obtained from the Osaka Cancer Registry. Lung cancer mortality data with population data in Osaka during 1975–2012 were obtained from vital statistics. We examined trends in age-standardized incidence and mortality rates for all histological types and age-standardized incidence rates by histological type and age group using a joinpoint regression model.

Results

The age-standardized incidence rate of lung cancer levelled off or slightly increased from 1975–2008, with an annual percentage change of 0.3% (95% confidence interval [CI], 0.1%–0.4%) for males and 1.1% (95% CI, 0.9%–1.3%) for females, and the mortality rate decreased by 0.9% (95% CI, 1.2%–0.7%) for males and 0.5% (95% CI, 0.8%–0.3%) for females. The incidence rates of squamous cell carcinoma (SQC) and small cell carcinoma (SMC) significantly decreased for both genders, whereas that of adenocarcinoma (ADC) significantly increased among almost all age groups in both genders.

Conclusions

The incidence rates of SQC and SMC decreased with the decline in smoking prevalence, which probably explains the change in trends in the incidence rates of lung cancer from the mid-1980s. However, the reason for the increase in ADC remains unclear. Therefore, trends in incidence rates of lung cancer should be carefully monitored, especially for ADC, and the associations between ADC and its possible risk factors should be studied.

Brush biopsy of human oral mucosal epithelial cells as a quality control of the cell source for fabrication of transplantable epithelial cell sheets for regenerative medicine

Autologous oral mucosal epithelial cell sheets have been used for treating epithelial defects such as cornea and esophagus. The cell source of patients' oral mucosal epithelial cell sheet should be examined in normality because it has individual difference. In this study, oral mucosal epithelial cells were less invasively collected by brush biopsy from the buccal, gingival, labial, and palate mucosa of four healthy volunteer donors without anesthesia, and analyzed the keratin expressions by western blotting and the obtained results were compared with those by immunohistochemistry of each of the native tissues. All of the oral mucosal epithelial cells expressed keratin 4 (K4) and K13, which were mucosal stratified squamous epithelial cell markers. K1 and K10, keratinized epithelial cell markers, were also detected in keratinized tissues such as gingival and palate mucosa. The markers of epithelial basal cells such as p63 and K15 were not detected by brush biopsy-western blotting. Although this method does not include basal layers of oral mucosa, protein expressions of upper layer of lesion area are different from normal. Therefore, brush biopsy-western blotting was extremely less invasive and would contribute to quality control of the fabrication of autologous oral mucosal epithelial cell sheets.

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Cell sheet source of patient oral mucosal condition has individual difference.

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A new less invasive method for quality check of human oral mucosal epithelial cells.

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Keratin expressions were examined by brush biopsy western blot.

Secondary Data Analysis of National Surveys in Japan Toward Improving Population Health

Secondary data analysis of national health surveys of the general population is a standard methodology for health metrics and evaluation; it is used to monitor trends in population health over time and benchmark the performance of health systems. In Japan, the government has established electronic databases of individual records from national surveys of the population’s health. However, the number of publications based on these datasets is small considering the scale and coverage of the surveys. There appear to be two major obstacles to the secondary use of Japanese national health survey data: strict data access control under the Statistics Act and an inadequate interdisciplinary research environment for resolving methodological difficulties encountered when dealing with secondary data. The usefulness of secondary analysis of survey data is evident with examples from the author’s previous studies based on vital records and the National Health and Nutrition Surveys, which showed that (i) tobacco smoking and high blood pressure are the major risk factors for adult mortality from non-communicable diseases in Japan; (ii) the decrease in mean blood pressure in Japan from the late 1980s to the early 2000s was partly attributable to the increased use of antihypertensive medication and reduced dietary salt intake; and (iii) progress in treatment coverage and control of high blood pressure is slower in Japan than in the United States and Britain. National health surveys in Japan are an invaluable asset, and findings from secondary analyses of these surveys would provide important suggestions for improving health in people around the world.

Smoking: additional burden on aging and death

Tobacco smoking is a major cause of lung cancer. It has been suggested that there is an approximately linear dose–response relationship between the number of cigarettes smoked per day and clinical outcome such as lung cancer mortality. It has also been proposed that there is a greater increase in mortality at high doses when the dose is represented by the duration of the smoking habit rather than the number of cigarettes. The multistep carcinogenesis theory indicates that a greater increase in mortality rate at high doses is possible, as is the case between aging and cancer, even though each dose–response relationship between a carcinogenic factor and a carcinogenic step forward is linear. The high incidence of lung cancer after long-term smoking and the decreased relative risk after smoking cessation suggests a similarity between the effects of smoking and aging. Prediction of lung cancer risk in former smokers by simple integration of smoking effects with aging demonstrated a good correlation with that estimated from the relative risk of the period of smoking cessation. In contrast to the smoking period, there appears to be a linear relationship between smoking strength and cancer risk. This might arise if the dose–response relationship between smoking strength and each carcinogenic step is less than linear, or the effects become saturated with a large dose of daily smoking. Such a dose–response relationship could lead to relatively large clinical effects, such as cardiovascular mortality, by low-dose tobacco smoke exposure, e.g., second-hand smoking. Consideration of the dose–response of each effect is important to evaluate the risk arising from each carcinogenic factor.