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

Cardiovascular health, sleeping duration, and risk of mortality in current and former smokers

BACKGROUND AND AIMS

To investigate the associations of ideal cardiovascular health metrics (ICVHMs) with all-cause mortality among former and current smokers compared with never smokers.

METHODS AND RESULTS

A total of 378,147 participants [mean age (SD) years: 56.3 (8.1); 47.2 % men] were included from the UK Biobank cohort. The ICVHMs were combined Life's simple 7 from the American Heart Association and sleep duration time. The association was explored using COX regression models. During a median follow-up of 13.3 years, we documented 24,594 deaths. Compared with never smokers, among former smokers, the multivariable-adjusted hazard ratio (HR) for all-cause mortality was 1.82 (95%CI 1.71-1.92) for participants who had ≤2 ICVHMs and 1.03 (0.97-1.10) for participants who had ≥6 ICVHMs; among current smokers, the HRs for mortality were 2.74 (2.60-2.89) and 2.18 (1.78-2.67). The phenomenon was more pronounced among participants younger than 60 years [HR (95%CI), 1.82 (1.71-1.95) for ≤2 ICVHMs vs 1.04 (0.96-1.12) for ≥6 ICVHMs with age ≥60 years and 1.83 (1.62-2.06) vs 0.98 (0.88-1.11) with age <60 years among former smokers; 2.66 (2.49-2.85) vs 2.44 (1.84-3.24) with age ≥60 years and 2.85 (2.62-3.10) vs 1.96 (1.47-2.61) with age <60 years among current smokers]. In addition, the HR for mortality of each 1-number increment in ICVHMs was 0.87 (0.86-0.89) among former smokers and 0.91 (0.89-0.94) among current smokers.

CONCLUSION

Our findings indicated the importance of adherence to have more ICVHMs in the mortality risk among former smokers, and priority of smoking cessation in current smokers.

IMPLICATIONS

Studies have found that former smokers still have higher risks of lung cancer and all-cause mortality than never-smokers. The next question is whether the effects of previous or current smoking could be ameliorated by eight ideal cardiovascular health metrics (ICVHMs). We aim to explore whether ICVHMs may counteract the risk of all-cause mortality among former and current smokers. The results showed that only former smokers with ≥6 ICVHMs exhibited a comparable risk of all-cause mortality with never smokers. Furthermore, current smokers even having ≥6 ICVHMs still exhibited a higher risk of all-cause mortality compared with never smokers.

Evidence relating cigarette, cigar and pipe smoking to lung cancer and chronic obstructive pulmonary disease: Meta-analysis of recent data from three regions

BACKGROUND

There is a need to have up-to-date information for various diseases on the risk related to the use of different smoked products and the use of other nicotine-containing products. Here, we contribute to the information pool by presenting up-to-date quantitative evidence for North America, Europe and Japan and for both lung cancer and chronic obstructive pulmonary disease (COPD) on the relative risk (RR) relating to current vs never product use for each of the three smoked tobacco products, cigarettes, cigars and pipes.

AIM

To estimate lung cancer and COPD current smoking RRs for the three products using recent data for the three regions.

METHODS

Publications in English from 2010 to 2020 were considered that, based on epidemiological studies in the three regions, estimated the current smoking RR of lung cancer and/or COPD for one or more of the three products. The studies should involve at least 100 cases of the disease considered, not be restricted to specific lung cancer types or populations with specific medical conditions, and should be of cohort or nested case-control study design or randomized controlled trials. Literature searches were conducted on MEDLINE separately for lung cancer and for COPD, examining titles and abstracts initially, and then full texts. Additional papers were sought from reference lists of selected papers, reviews and meta-analyses. For each study identified, the most recent available data on each product were entered on current smoking, as well as on characteristics of the study and the RR estimates. Combined RR estimates were derived using random-effects meta-analysis. For cigarette smoking, where far more data were available, heterogeneity was studied by a wide range of factors. For cigar and pipe smoking, a more limited heterogeneity analysis was carried out. Results were compared with those from previous meta-analyses published since 2000.

RESULTS

Current cigarette smoking: For lung cancer, 44 studies (26 North American, 14 European, three Japanese, and one in multiple continents), gave an overall estimate of 12.14 [95% confidence interval (CI) 10.30-14.30]. The estimates were higher (heterogeneity P < 0.001) for North American (15.15, CI 12.77-17.96) and European studies (12.30, CI 9.77-15.49) than for Japanese studies (3.61, CI 2.87-4.55), consistent with previous evidence of lower RRs for Asia. RRs were higher (P < 0.05) for death (14.85, CI 11.99-18.38) than diagnosis (10.82, CI 8.61-13.60). There was some variation (P < 0.05) by study population, with higher RRs for international and regional studies than for national studies and studies of specific populations. RRs were higher in males, as previously reported, the within-study male/female ratio of RRs being 1.52 (CI 1.20-1.92). RRs did not vary significantly (P ≥ 0.05) by other factors. For COPD, RR estimates were provided by 18 studies (10 North American, seven European, and one Japanese). The overall estimate of 9.19 (CI 6.97-12.13), was based on heterogeneous data (P < 0.001), and higher than reported earlier. There was no (P > 0.1) variation by sex, region or exclusive use, but limited evidence (0.05 < P < 0.1) that RR estimates were greater where cases occurring shortly after baseline were ignored; where bronchiectasis was excluded from the COPD definition; and with greater confounder adjustment. Within-study comparisons showed adjusted RRs exceeded unadjusted RRs. Current cigar smoking: Three studies gave an overall lung cancer RR of 2.73 (CI 2.36-3.15), with no heterogeneity, lower than the 4.67 (CI 3.49-6.25) reported in an earlier review. Only one study gave COPD results, the RR (2.44, CI 0.98-6.05) being imprecise. Current pipe smoking: Four studies gave an overall lung cancer RR of 4.93 (CI 1.97-12.32), close to the 5.20 (CI 3.50-7.73) given earlier. However, the estimates were heterogeneous, with two above 10, and two below 3. Only one study gave COPD results, the RR (1.12, CI 0.29-4.40), being imprecise. For both diseases, the lower RR estimates for cigars and for pipes than for current smoking of cigarettes aligns with earlier published evidence.

CONCLUSION

Current cigarette smoking substantially increases lung cancer and COPD risk, more so in North America and Europe than Japan. Limited evidence confirms lower risks for cigars and pipes than cigarettes.

Smoking and severe illness in hospitalized COVID-19 patients in Japan

BACKGROUND

The aim of this study was to identify associations between smoking status and the severity of COVID-19, using a large-scale data registry of hospitalized COVID-19 patients in Japan (COVIREGI-JP), and to explore the reasons for the inconsistent results previously reported on this subject.

METHODS

The analysis included 17 666 COVID-19 inpatients aged 20-89 years (10 250 men and 7416 women). We graded the severity of COVID-19 (grades 0 to 5) according to the most intensive treatment required during hospitalization. The smoking status of severe grades 3/4/5 (invasive mechanical ventilation/extracorporeal membrane oxygenation/death) and separately of grade 5 (death) were compared with that of grade 0 (no oxygen, reference group) using multiple logistic regression. Results were expressed as odds ratios (OR) and 95% confidence intervals (CI) adjusted for age and other factors considering the potential intermediate effects of comorbidities.

RESULTS

Among men, former smoking significantly increased the risk of grade 3/4/5 and grade 5, using grade 0 as a reference group, with age- and admission-date-adjusted ORs (95% CI) of 1.51 (1.18-1.93) and 1.65 (1.22-2.24), respectively. An additional adjustment for comorbidities weakened the ORs. Similar results were seen for women. Current smoking did not significantly increase the risk of grade 3/4/5 and grade 5 in either sex.

CONCLUSIONS

The severity of COVID-19 was not associated with current or former smoking per se but with the comorbidities caused by smoking. Thus, smoking cessation is likely to be a key factor for preventing smoking-related disease and hence for reducing the risk of severe COVID-19.

Smoking Cessation After Lung Cancer Diagnosis and the Risk of Second Primary Lung Cancer: The Multiethnic Cohort Study

Background

Smoking cessation reduces lung cancer mortality. However, little is known about whether diagnosis of lung cancer impacts changes in smoking behaviors. Furthermore, the effects of smoking cessation on the risk of second primary lung cancer (SPLC) have not been established yet. This study aims to examine smoking behavior changes after initial primary lung cancer (IPLC) diagnosis and estimate the effect of smoking cessation on SPLC risk following IPLC diagnosis.

Methods

The study cohort consisted of 986 participants in the Multiethnic Cohort Study who were free of lung cancer and active smokers at baseline (1993-1996), provided 10-year follow-up smoking data (2003-2008), and were diagnosed with IPLC in 1993-2017. The primary outcome was a change in smoking status from “current” at baseline to “former” at 10-year follow-up (ie, smoking cessation), analyzed using logistic regression. The second outcome was SPLC incidence after smoking cessation, estimated using cause-specific Cox regression. All statistical tests were 2-sided.

Results

Among 986 current smokers at baseline, 51.1% reported smoking cessation at 10-year follow-up. The smoking cessation rate was statistically significantly higher (80.6%) for those diagnosed with IPLC between baseline and 10-year follow-up vs those without IPLC diagnosis (45.4%) during the 10-year period (adjusted odds ratio = 5.12, 95% confidence interval [CI] = 3.38 to 7.98; P < .001). Incidence of SPLC was statistically significantly lower among the 504 participants who reported smoking cessation at follow-up compared with those without smoking cessation (adjusted hazard ratio = 0.31, 95% CI = 0.14 to 0.67; P = .003).

Conclusion

Lung cancer diagnosis has a statistically significant impact on smoking cessation. Quitting smoking after IPLC diagnosis may reduce the risk of developing a subsequent malignancy in the lungs.

Quantifying the contribution of modifiable risk factors to socio-economic inequities in cancer morbidity and mortality: a nationally representative population-based cohort study

BACKGROUND

Compared with those with a higher socio-economic position (SEP), individuals with a lower SEP have higher cancer morbidity and mortality. However, the contribution of modifiable risk factors to these inequities is not known. This study aimed to quantify the mediating effects of modifiable risk factors to associations between SEP and cancer morbidity and mortality.

METHODS

This study used a prospective observational cohort design. We combined eight cycles of the Canadian Community Health Survey (2000/2001-2011) as baseline data to identify a cohort of adults (≥35 years) without cancer at the time of survey administration (n = 309 800). The cohort was linked to the Discharge Abstract Database and the Canadian Mortality Database for cancer morbidity and mortality ascertainment. Individuals were followed from the date they completed the Canadian Community Health Survey until 31 March 2013. Dates of individual first hospitalizations for cancer and deaths due to cancer were captured during this time period. SEP was operationalized using a latent variable combining measures of education and household income. Self-reported modifiable risk factors, including smoking, excess alcohol consumption, low fruit-and-vegetable intake, physical inactivity and obesity, were considered as potential mediators. Generalized structural equation modelling was used to estimate the mediating effects of modifiable risk factors in associations between low SEP and cancer morbidity and mortality in the total population and stratified by sex.

RESULTS

Modifiable risk factors together explained 45.6% of associations between low SEP and overall cancer morbidity and mortality. Smoking was the most important mediator in the total population and for males, accounting for 15.5% and 40.2% of the total effect, respectively. For females, obesity was the most important mediator.

CONCLUSIONS

Modifiable risk factors are important mediators of socio-economic inequities in cancer morbidity and mortality. Nevertheless, more than half of the variance in these associations remained unexplained. Midstream interventions that target modifiable risk factors may help to alleviate inequities in cancer risk in the short term. However, ultimately, upstream interventions that target structural determinants of health are needed to reduce overall socio-economic inequities in cancer morbidity and mortality.

miR‑139‑5p enhances cisplatin sensitivity in non‑small cell lung cancer cells by inhibiting cell proliferation and promoting apoptosis via the targeting of Homeobox protein Hox‑B2

The development of chemotherapeutic dug resistance hinders the clinical treatment of cancer. MicroRNAs (miRNAs/miRs) have been revealed to serve essential roles in the drug resistance of numerous types of cancer. miR‑139‑5p was previously reported to be associated with cisplatin (DDP) sensitivity in human nasopharyngeal carcinoma cells and colorectal cancer cells. However, the effect and underlying mechanism of miR‑139‑5p in DDP sensitivity in non‑small cell lung cancer (NSCLC) cells has not yet been fully elucidated. In the present study, the expression of miR‑139‑5p and Homeobox protein Hox‑B2 (HOXB2) in NSCLC tissues was examined by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blotting. Subsequently, the effect of miR‑139‑5p on the DDP sensitivity of NSCLC cells in vitro was investigated. Cell proliferation was examined using a Cell Counting Kit‑8 assay. Western blotting was used to evaluate the protein expression of HOXB2, phosphorylated (p)‑PI3K, p‑AKT, caspase‑3 and cleaved‑caspase‑3, and RT‑qPCR was used to evaluate the expression of miR‑139‑5p, and the mRNA expression levels of HOXB2, PI3K, AKT and caspase‑3. The apoptotic rate of the cells was detected using flow cytometry. miR‑139‑5p expression in NSCLC tissues was shown to be significantly lower compared with that in adjacent tissues. Additionally, miR‑139‑5p increased cell apoptosis and inhibited NSCLC cell proliferation induced by DDP in vitro via modulating the PI3K/AKT/caspase‑3 signaling pathway. Furthermore, HOXB2 was identified to be a target of miR‑139‑5p, and miR‑139‑5p was revealed to sensitize NSCLC cells to DDP via the targeting of HOXB2. Taken together, the results of the present study demonstrated that regulating the expression of miR‑139‑5p could provide a novel approach to reverse DDP resistance and increase chemosensitivity in the treatment of NSCLC.

Short-term association between ambient air pollution and lung cancer mortality

RATIONALE

Long-term exposure to air pollution has been associated with increased lung cancer incidence and mortality. However, the short-term association between air pollution and lung cancer mortality (LCM) remains largely unknown.

METHODS

We collected daily data on particulate matter with diameter <2.5 μm (PM_2.5), particulate matter with diameter < 10 μm (PM₁₀), sulfur dioxide (SO₂), and ozone (O₃), and LCM in three of the biggest cities in China, i.e. Beijing, Chongqing, and Guangzhou, from 2013 to 2015. We first estimated city-specific relationships between air pollutants and LCM using time-series generalized linear models, adjusting for potential confounders. A classification and regression tree (CART) model was used to stratify LCM risk based on combinations of air pollutants and meteorological factors in each city. Then we pooled the city-specific associations using random-effects meta-analysis. Meta regression was used to explore if city-specific characteristics modified the air pollution-LCM association. Finally, we stratified the analyses by season, age, and sex.

RESULTS

Over the entire period, the current-day concentrations of PM_2.5 and PM₁₀ in Chongqing and PM_2.5, PM₁₀, and SO₂ in Guangzhou were positively associated with LCM (Excess risk ranged from 0.72% (95% CI 0.27%-1.17%) to 6.06% (95% CI 0.76%-11.64%) with each 10 μg/m³ increment in different pollutants), but the association between current-day air pollution and LCM in Beijing was not significant (P > 0.05). When considering the environmental and weather factors simultaneously, current-day PM_2.5, relative humidity, and PM₁₀ were the most important factors associated with LCM in Beijing, Chongqing, and Guangzhou, respectively. LCM risk related with daily PM_2.5, PM₁₀, and SO₂ significantly increased with the increasing annual mean temperature and humidity of the city, while LCM risk related with daily O₃ significantly increased with the increases of latitude, annual mean O₃ concentration, and socioeconomic level. After stratification, the current-day PM_2.5, PM₁₀, and O₃ during the warm season in Beijing and PM_2.5, PM₁₀, and SO₂ during the cool season in Chongqing and Guangzhou were positively associated with LCM (Excess risk ranged from 0.93% (95% CI 0.42%-1.45%) to 7.16% (95% CI 0.64%-14.09%) with each 10 μg/m³ increment in different pollutants). Male and the elderly lung cancer patients were more sensitive to the short-term effect of air pollution.

CONCLUSIONS

Lung cancer patients should enhance protection measures against air pollution. More attentions should be paid for the high PM_2.5, PM₁₀, and O₃ during the warm season in Beijing, and high PM_2.5, PM₁₀, and SO₂ during the cool season in Chongqing and Guangzhou.