Lung cancer and passive smoking

Knowledge, Attitude, and Perception of Passive Smoking Among Medical and Dental Students of Karachi: A Survey-Based Study

Background

Passive smoking, the involuntary inhalation of tobacco smoke, poses significant health risks; however, its prevalence and impact on medical and dental students in Karachi, Pakistan, remain understudied. Therefore, this research aims to understand the knowledge, attitudes, and practices (KAP) regarding passive smoking among medical and dental students and will help shed light on their awareness, perceptions, and behaviours regarding this public health concern.

Methods

A cross-sectional study was conducted over 3 months, involving 378 medical and dental students (303 medical and 75 dental students)from various universities in Karachi. Participants completed a questionnaire to gather information on demographics, awareness of passive smoking, perceptions of its health effects, and actions taken in response to exposure.

Results

The majority of participants demonstrated awareness of passive smoking 320 (84.7%) and believed that it was essentially linked to active smoking 320 (84.7%). Cigarette smoke was identified as the primary contributor to passive smoking 345 (91.3%). A significant proportion of participants believed that children and pregnant women exposed to passive smoking had elevated health risks. In areas where smoking is not permissible, less than half of the participants 173 (45.8%) reminded smokers about the smoking regulations, and a few even referred smokers for counselling 141 (37.3%). Males are usually indifferent to smokers around them, whereas females are found uncomfortable with smoking in their surroundings.

Conclusion

In conclusion, our study highlights the persistent prevalence of passive smoking among medical and dental students in Pakistan. Enforcing strict tobacco control policies, integrating passive smoking education into medical curricula, and improving communication strategies for smoking cessation interventions are crucial steps towards creating smoke-free environments and healthier lifestyles nationwide. Despite awareness among medical and dental students about the dangers of cigarette smoking, their reluctance to urge regular smokers to quit underscores the need for improved communication between smokers and non-smokers to foster a cleaner and hazard-free environment.

Mortality attributable to secondhand smoke exposure in the autonomous communities of Spain

INTRODUCTION AND OBJECTIVES

Exposure to secondhand smoke (SHS) causes cardiovascular disease, respiratory disease, and cancer. The aim of this study was to estimate the mortality attributed to SHS in people aged ≥ 35 years in Spain and its autonomous communities (AC) by sex from 2016 to 2021.

METHODS

Estimates of SHS-attributable mortality were calculated by applying the prevalence-dependent method where SHS exposure was derived from the adjustment of small-area models and based on the calculation of population-attributed fractions. Sex, age group, AC, and cause of death (ischemic heart disease and lung cancer) were included. The estimates of attributed mortality are presented with their 95% confidence interval (95%CI). Crude and age-standardized rates were estimated for each sex and AC.

RESULTS

From 2016 to 2021, SHS exposure caused 4,970 (95%CI, 4,787-5,387) deaths, representing 1.6% of total mortality for ischemic heart disease and lung cancer. The burden of attributed mortality differed widely among the AC, with Andalusia having the highest burden of attributed mortality (crude rate: 46.6 deaths per 100 000 population in men and 17.0/100 000 in women). In all the AC, the main cause of death in both sexes was ischemic heart disease. The highest burden of mortality was observed in nonsmokers.

CONCLUSIONS

The burden of SHS-attributable mortality was high and varied geographically. The results of this study should be considered to advance tobacco control legislation in Spain.

Incidence of Concomitant Neoplastic Diseases, Tumor Characteristics, and the Survival of Patients with Lung Adenocarcinoma or Squamous Cell Lung Carcinoma in Tobacco Smokers and Non-Smokers-10-Year Retrospective Single-Centre Cohort Study

Changes in smoking trends and changes in lifestyle, together with worldwide data regarding the incidence of lung cancer in the group of patients with no previous history of smoking, leads to consideration of the differences in the course of the disease, the time of cancer diagnosis, the survival rate, and the occurrence of comorbidities in this group of patients. This study aimed to determine the occurrence of non-smokers among patients undergoing anatomical resection of the lung tissue due to lung carcinoma and to investigate the differences between the course of lung cancer, survival, and the comorbidities in the groups of patients with lung cancer depending on the history of tobacco smoking. The study included a cohort of 923 patients who underwent radical anatomical resection of the lung tissue with lung primary adenocarcinoma or squamous cell carcinoma. The Chi2 Pearson's test, the t-test, the Mann-Whitney U test, the Kaplan-Meier method, the Log-rank test with Mantel correction, and the Cox proportional hazard model were used for data analysis. We observed a significantly higher mean age of smoking patients compared to the mean age of non-smoking patients. The coexistence of former neoplastic diseases was significantly more frequent in the group of non-smokers compared to the group of smoking patients. We did not observe differences depending on smoking status in the tumor stage, grade, vascular and pleural involvement status in the diagnostic reports. We did not observe differences in the survival between smokers vs. non-smokers, however, we revealed better survival in the non-smoker women group compared to the non-smoker men group. In conclusion, 22.11% of the patients undergoing radical anatomical resection of the lung tissue due to lung cancers were non-smokers. More research on survival depending on genetic differences and postoperative treatment between smokers and non-smokers is necessary.

Epidemiology of lung cancer

Lung cancer is the leading cause of global cancer incidence and mortality, accounting for an estimated 2 million diagnoses and 1.8 million deaths. Neoplasms of the lungs are the second most common cancer diagnosis in men and women (after prostate and breast cancer, respectively). With increasing access to tobacco and industrialization in developing nations, lung cancer incidence is rising globally. The average age of diagnosis is 70 years old. Men are twice as likely to be diagnosed with lung cancer, which largely reflects differences in tobacco consumption, although women may be more susceptible due to higher proportions of epidermal growth factor receptor mutations and the effects of oestrogen. African American men in the US are at the highest risk of lung cancer. Family history increases risk by 1.7-fold, with a greater risk among first-degree relatives. Tobacco smoking is the greatest preventable cause of death worldwide, accounting for up to 90% of lung cancer cases, and continued consumption is projected to increase global cancer incidence, particularly in developing nations such as China, Russia, and India. Second-hand smoke among children and spouses has likewise been implicated. Radon from natural underground uranium decay is the second leading cause of lung cancer in the developed world. Occupational hazards such as asbestos and environmental exposures such as air pollution, arsenic, and HIV and Tb infection have all been implicated in lung carcinogenesis, while cannabis smoking, electronic cigarettes, heated tobacco products, and COVID-19 have been hypothesized to increase risk.

The epidemiology of lung cancer

The incidence and mortality from lung cancer is decreasing in the US due to decades of public education and tobacco control policies, but are increasing elsewhere in the world related to the commencement of the tobacco epidemic in various countries and populations in the developing world. Individual cigarette smoking is by far the most common risk factor for lung carcinoma; other risks include passive smoke inhalation, residential radon, occupational exposures, infection and genetic susceptibility. The predominant disease burden currently falls on minority populations and socioeconomically disadvantaged people. In the US, the recent legalization of marijuana for recreational use in many states and the rapid growth of commercially available electronic nicotine delivery systems (ENDS) present challenges to public health for which little short term and no long term safety data is available.

Polymorphisms in the vitamin D receptor gene and the lung cancer risk

The relationship between the vitamin D receptor (VDR) polymorphisms and the susceptibility to lung cancer remains unclear. The present meta-analysis was performed to estimate the polymorphisms of VDR and lung cancer risk. The pooled odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) were calculated. Subgroup analysis by smoking status was carried out for further elucidation. The VDR BsmI polymorphism seemed to be negatively associated with the lung cancer risk (A vs. G, OR = 0.71, 95 % CI, 0.52-0.96; GA vs. GG, OR = 0.54, 95 % CI, 0.35-0.83; AA + GA vs. GG, OR = 0.55, 95 % CI, 0.36-0.84), particularly among the smokers (AA + GA vs. GG, OR = 0.39, 95 % CI, 0.21-0.72). The VDR ApaI variant genotypes did not alter the risk of lung cancer under all gene models in overall analysis. However, smokers carrying the variant G allele were more susceptible to lung cancer (G vs. T, OR = 1.60, 95 % CI, 1.14-2.25). The polymorphism of VDR TaqI was related to a decreased risk of lung cancer (C vs. T, OR = 0.62, 95 % CI, 0.26-1.46; CC vs. TT, OR = 0.44, 95 % CI, 0.21-0.91; TC vs. TT, OR = 0.58, 95 % CI, 0.38-0.90; CC + TC vs. TT, OR = 0.55, 95 % CI, 0.36-0.84). Besides, the CC + TC carriers in the smokers were at a significantly reduced risk of lung cancer (CC + TC vs. TT, OR = 0.48, 95 % CI, 0.16-1.44). The study supports that the polymorphisms of VDR BsmI and TaqI play protective roles in the lung carcinogenesis, particularly among the smokers. The association of VDR ApaI polymorphism with the lung cancer risk needs to be further elucidated.

A six-month study of pulmonary cancer in Albanian women

Lung cancer is a potentially lethal disease, whose prevalence in Albania is constantly increasing, especially in women. Early diagnosis is extremely important with regard to life expectancy and quality. The authors conducted a survey on the behaviour in a sample group of Albanian women diagnosed with primary and secondary lung cancers. A discussion upon diagnostic methods, smoking habits, histological type, Karnofsky performance status (KPS), and treatment modalities is made. The data collected by the authors suggest that nonsmokers formed the main group of lung cancer female patients. The most frequent histological type was adenocarcinoma. Mesothelioma was the most frequent of the secondary pulmonary lung cancers, followed from metastasizing breast cancer. Despite a generally good performance of the cases, the diagnosis of pulmonary cancer is delayed. The data collected could not find a convincing etiological role of tobacco smoking, but caution is needed, regarding the short time length of the study and the sustained number of participants.

Trends in the lung cancer incidence and mortality in the Slovak and Czech Republics in the contexts of an international comparison

INTRODUCTION

Lung cancer represents the most frequent cause of cancer-related deaths in the industrialized countries. The aim of this study was to analyze the lung cancer incidence and mortality and the possible reasons for any differences discovered in two neighboring Central European countries-the Slovak Republic.

METHODS

We used linear regression model when analyzing incidence and mortality; the trends are presented with corresponding 95% confidence intervals (CI) and p-value with null hypothesis being constant with time.

RESULTS

Statistically significant increase of age-standardized incidence (0.707/100,000/year, 95% CI 0.107-1.307, p = 0,025) and mortality (1.339/100,000/year, 95% CI 1.050-1.629, p < 0.0001) of the lung cancer was revealed in males in the Slovak Republic (1980-1991). On the contrary, values of both indicators were stabilized in the Czech Republic. Since year 1991-2005 a statistically highly significant decrease of both incidence and mortality values was observed in males, which was greater in the Slovak Republic. Peak of the curve was not reached in women population, while incidence and mortality values have significantly continuous growth in both countries.

CONCLUSIONS

According to the lung cancer incidence and mortality trends in both countries (in correlation with smoking prevalence) we consider the support of efforts to change the attitude towards smoking predominantly in women and younger generation to be the most accurate action to reduce these trends.

Childhood exposure to secondhand smoke and functional mannose binding lectin polymorphisms are associated with increased lung cancer risk

BACKGROUND

Exposure to secondhand smoke during adulthood has detrimental health effects, including increased lung cancer risk. Compared with adults, children may be more susceptible to secondhand smoke. This susceptibility may be exacerbated by alterations in inherited genetic variants of innate immunity genes. We hypothesized a positive association between childhood secondhand smoke exposure and lung cancer risk that would be modified by genetic polymorphisms in the mannose binding lectin-2 (MBL2) gene resulting in well-known functional changes in innate immunity.

METHODS

Childhood secondhand smoke exposure and lung cancer risk was assessed among men and women in the ongoing National Cancer Institute-Maryland Lung Cancer (NCI-MD) study, which included 624 cases and 348 controls. Secondhand smoke history was collected via in-person interviews. DNA was used for genotyping the MBL2 gene. To replicate, we used an independent case-control study from Mayo Clinic consisting of 461 never smokers, made up of 172 cases and 289 controls. All statistical tests were two-sided.

RESULTS

In the NCI-MD study, secondhand smoke exposure during childhood was associated with increased lung cancer risk among never smokers [odds ratio (OR), 2.25; 95% confidence interval (95% CI), 1.04-4.90]. This was confirmed in the Mayo study (OR, 1.47; 95% CI, 1.00-2.15). A functional MBL2 haplotype associated with high circulating levels of MBL and increased MBL2 activity was associated with increased lung cancer risk among those exposed to childhood secondhand smoke in both the NCI-MD and Mayo studies (OR, 2.52; 95% CI, 1.13-5.60, and OR, 2.78; 95% CI, 1.18-3.85, respectively).

CONCLUSIONS

Secondhand smoke exposure during childhood is associated with increased lung cancer risk among never smokers, particularly among those possessing a haplotype corresponding to a known overactive complement pathway of the innate immune system.

Effect of different types of smoking and synergism with hepatitis C virus on risk of hepatocellular carcinoma in American men and women: case-control study

The International Agency for Research on Cancer has declared smoking to be a risk factor for hepatocellular carcinoma (HCC). However, passive exposure to cigarette smoke and use of noncigarette tobacco products on the risk of HCC has not been examined. Therefore, we evaluated the independent effects of different types of smoking exposure along with multiple risk factors for HCC and determined whether the magnitude of smoking was modified by other risk factors in men and women. We conducted a case-control study at The University of Texas M. D. Anderson Cancer Center where 319 HCC patients and 1,061 healthy control subjects were personally interviewed for several HCC risk factors. Multivariate logistic regression analysis was performed to estimate the adjusted odds ratio (AOR) and 95% confidence interval (CI) for each potential risk factor. Use of smokeless tobacco (chewing tobacco and snuff), cigars, pipes and passive smoking exposure were not related to HCC among noncigarette smokers. However, regular cigarette smoking was associated with HCC in men: AOR, 1.9 (95% CI, 1.1-3.1). Heavy alcohol consumption was associated with HCC in women: AOR, 7.7 (95% CI, 2.3-25.1). Cigarette smoking interacted synergistically with chronic infection of hepatitis C virus in men: AOR, 136.3 (95% CI, 43.2-429.6) and with heavy alcohol consumption in women: AOR, 13.7 (95% CI, 3.2-57.9). We conclude that sex differences were observed in HCC relationship with cigarette smoking and alcohol consumption. Controlling for smoking exposure might be a prudent approach to the prevention of HCC, especially in patients with chronic viral hepatitis infections.

Passive smoking and the use of noncigarette tobacco products in association with risk for pancreatic cancer: a case-control study

BACKGROUND

The associations between passive smoking and the use of noncigarette tobacco products with pancreatic cancer are not clear.

METHODS

In this case-control study, the authors collected information on passive smoking and the use of noncigarette tobacco products in 808 patients with pancreatic adenocarcinoma and 808 healthy controls by personal interview. Multivariable logistic regression was performed to estimate the adjusted odds ratio (AOR) and 95% confidence interval (95% CI).

RESULTS

The results confirmed the previously reported association between active smoking and increased risk for pancreatic cancer. The AOR was 1.7 (95% CI, 1.4-2.2) for regular smokers, 1.8 (95% CI, 1.4-2.4) for long-term smokers, and 3.1 (95% CI, 2.2-4.3) for former smokers. Although passive smoking showed a nonsignificantly elevated risk for pancreatic cancer in the entire study population (AOR, 1.3; 95% CI, 0.9-1.7), the association was present among ever smokers (AOR, 1.7; 95% CI, 1.03-2.6) but was absent among never smokers (AOR, 1.1; 95% CI, 0.8-1.6). Neither intensity nor duration of passive smoking modified the risk of pancreatic cancer among never smokers. The use of chewing tobacco, snuff, and pipes showed no significant risk elevation for pancreatic cancer after controlling for the confounding effects of demographics and other known risk factors. The use of cigars in never smokers showed a borderline significant increase of risk for pancreatic cancer (AOR, 2.2; 95% CI, 1.0-4.7; P = .05).

CONCLUSIONS

The current observations did not support a role for passive smoking or the use of noncigarette tobacco products in the etiology of pancreatic cancer. The association between cigar use and the risk of pancreatic cancer needs to be confirmed in other study populations.

Japanese spousal smoking study revisited: how a tobacco industry funded paper reached erroneous conclusions

OBJECTIVES

To provide a participant's account of the development of a paper commissioned by the tobacco industry examining the reliability of self reported smoking status; to redress the distorted report of this Japanese spousal smoking study which evaluated the reliability and validity of self reported smoking status, and estimated confounding by diet and lifestyle factors.

DESIGN

Repeated interviews on smoking status and its verification by environmental and biological markers for environmental tobacco smoke (ETS) exposure.

SETTING

Urban wives in Osaka City and Sizuoka City, Japan

PARTICIPANTS

Semi-random sampling of 200 wives in each city. From the Osaka subjects, 100 non-smoking wives were selected for the validity study.

MAIN OUTCOME MEASURES

Kappa coefficient for reliability of self reported smoking status. Correlation coefficients between environmental nicotine concentration, cotinine in saliva and urine, and self reported smoking status.

RESULTS

The kappa coefficient for the repeated interview was high suggesting sufficient reliability of the response. The proportion of self reported current smokers misclassified as non-smokers was equivalent to the misclassified self reported non-smokers. Ambient concentration of nicotine and personal exposure to nicotine correlated with each other and also with salivary cotinine and self reported ETS exposure but not with urinary cotinine/creatinine ratio (CCR). There was no major difference in diet and lifestyle related to husband's smoking status.

CONCLUSION

Self reported smoking status by Japanese wives shows high reliability. It also shows high validity when verified by both nicotine exposure and salivary cotinine, but not by CCR. A previous report questioning the credibility of self reported smoking status, based on questionable CCR, could thus be of dubious validity. In addition, possible dietary and lifestyle confounding factors associated with smoking husbands were not demonstrable, a finding not reported previously. Using all the data from this project changes the conclusion of the previous published report. In addition to the distortion of scientific findings by a tobacco industry affiliated researcher, anti-smoking campaigners made attempts to intimidate and suppress scientific activities. These distortions of science should be counteracted.

Molecular epidemiology of lung cancer in female passive smokers

To clarify etiology of lung cancer in nonsmoker females, various studies have been done. Particularly, host factors and environmental tobacco smoking (ETS) of females have been emphasized. However, traditional epidemiological data showed controversial results of sex or gender differences in lung cancer susceptibility and suggest presence of some confounders. One of them is that most of epidemiology studies are based on self-reports for ETS. To prevent misestimate effects of ETS via the self-report, exposure monitoring of ETS is required. On the other hand, focusing on genetic polymorphisms in metabolic enzymes and DNA repair, molecular epidemiological studies have been done in nonsmoker females. Therefore, this review considered: 1. gender differences in lung cancer; 2. effects of passive smoking on lung cancer; 3. exposure monitoring of ETS including genetic risks of lung cancer to clarify etiology of lung cancer in the nonsmoker females with molecular epidemiological discussion.

Cigarette smoke induces cyclooxygenase-2 and microsomal prostaglandin E2 synthase in human lung fibroblasts: implications for lung inflammation and cancer

Cigarette smoking can lead to many human pathologies including cardiovascular and respiratory disease. Recent studies have defined a role for fibroblasts in the development of colon cancer. Moreover, fibroblasts are now thought of as key "sentinel" cells that initiate inflammation by releasing proinflammatory mediators including prostaglandins (PGs). Pathological overexpression of cyclooxygenase-2 (COX-2) and excess eicosanoid production are found in the early stages of carcinogenesis. By promoting chronic inflammation, COX-2 and eicosanoid production may actually cause a predisposition to malignancy. Furthermore, the associated inflammation induced by production of these mediators is central to the pathogenesis of chronic obstructive pulmonary disease. Little is known of the responses of normal lung fibroblasts to cigarette smoke, despite their abundance. We report herein that normal human lung fibroblasts, when exposed to cigarette smoke extract, induce COX-2 with concurrent synthesis of prostaglandin E2 (PGE2). The mechanisms by which cigarette-derived toxicants lead to increased COX-2 levels and PGE2 synthesis include increases in steady-state COX-2 mRNA levels (approximately four- to fivefold), phosphorylation of ERK1/2, and nuclear translocation of the p50 and p65 subunits of the transcription factor NF-kappaB, which are important elements in COX-2 expression. Furthermore, there was a dramatic 25-fold increase in microsomal prostaglandin E synthase, the key enzyme involved in the production of PGE2. We propose that normal human lung fibroblasts, when exposed to cigarette smoke constituents, elicit COX-2 expression with consequent prostaglandin synthesis, thus creating a proinflammatory environment. This chronic inflammatory state may act as one of the first steps towards epithelial transformation.

Changing trends in incidence of lung cancer by histologic type in Scotland

Lung cancer is a major public health concern worldwide. Our study aims to examine trends in incidence of lung cancer in Scotland during 1959-97 and by histologic type for 1975-97. In Scotland, lung cancer is the most commonly diagnosed cancer in men and is the second most commonly diagnosed cancer in women. Due to poor survival rates, trends in incidence and mortality display similar patterns. Within the United States and many parts of Europe, falls in the incidence of squamous cell carcinoma have occurred whilst the incidence of adenocarcinoma has increased. Data were extracted from the Scottish Cancer Registry. Trends in incidence were examined by standardising rates to the World Standard Population. Age-specific rates were examined by year of diagnosis and mid year of birth. In Scotland the incidence of lung cancer in men has fallen since the late 1970s, whereas incidence in women has continued to increase. Incidence rates of adenocarcinoma have increased over time but squamous cell carcinoma remains the predominant type of lung cancer in Scotland. The quality of lung cancer registration data has improved over time, although a large proportion of lung cancers (>20%) are not microscopically verified. Changes in histologic types are unlikely to be solely due to diagnostic advances. Rates of adenocarcinoma have increased steadily over time, and this may be due to changes in cigarette design during the 1950s.

Cancer risks among long-standing spouses

We estimated risks for concordant and discordant cancers in spouses in order to quantify cancer risks from the shared environment. The study was restricted to spouses who had one or more children in common and who lived together for at least 15 years after the first child's birth. The nation-wide Family-Cancer Database was used as the source of family and cancer data. Standardised incidence ratios were calculated for concordant and discordant cancers in spouses after 50 years of age. Among the 18 cancer sites considered, only three sites, stomach, lung and bladder, showed concordant increases of cancer among spouses, standardised incidence ratios ranging only from 1.19 to 1.38. Additionally, gastric and pancreatic cancer were associated among spouses, as did many cancers which were related to tobacco smoking or human papilloma virus infection. By contrast, standardised incidence ratios of colon, rectal, renal and skin cancers showed no increases among spouses. Shared lifestyle among family members seems to explain only a small proportion of familial cancer susceptibility. Because lifestyles are likely to differ more between parents and offspring than between spouses, familial cancer risks between parents and offspring are even more likely to be due to heritable than environmental effects.

Environmental tobacco smoke and periodontal disease in the United States

OBJECTIVES

Cigarette smoking is a leading risk factor for periodontal disease. This cross-sectional study investigated the relation between environmental tobacco smoke (ETS) and periodontal disease in the United States.

METHODS

Data were obtained from the Third National Health and Nutrition Examination Survey (1988-1994). The outcome was periodontal disease, defined as 1 or more periodontal sites with attachment loss of 3 mm or greater and a pocket depth of 4 mm or greater at the same site. Exposure to ETS at home and work was self-reported. The study analyzed 6611 persons 18 years and older who had never smoked cigarettes or used other forms of tobacco.

RESULTS

Exposure to ETS at home only, work only, and both was reported by 18.0%, 10.7%, and 3.8% of the study population, respectively. The adjusted odds of having periodontal disease were 1.6 (95% confidence interval = 1.1, 2.2) times greater for persons exposed to ETS than for persons not exposed.

CONCLUSIONS

Among persons in the United States who had never used tobacco, those exposed to ETS were more likely to have periodontal disease than were those not exposed to ETS.

The miseries of passive smoking

Passive smoking is defined as an involuntary exposure to a combined but diluted cigarette sidestream smoke (SS, gas and particle phases that are evolved from the smoldering end of a cigarette while the smoker is not puffing) and the exhaled smoke from smokers. SS contains numerous cytotoxic substances such as polycyclic aromatic hydrocarbons (PAHs), aromatic amines, nitrosamines, heavy metals, poisonous gases, pesticide residues, and radioactive elements in quantities much higher than those found from the cigarette mainstream smoke (MS) which is puffed by smokers. Passive smoking is found to be the cause of death from cancers and cardiac disease. Furthermore, it damagingly involves reproductive organs, the nervous system, genetic materials, and is particularly hazardous to mother and child during pregnancy and to those with a history of asthma, chronic infections, induced or earned immune deficiency, or predisposed susceptibility.