Smoking trajectory and cancer risk: A population-based cohort study

Abstract

INTRODUCTION Smoking behavior can change with time and lead to different health outcomes. This study explored the trajectory of smoking and its relationship with cancer incidence and mortality among Korean male adults. METHODS We used 2002–2018 data from the National Health Insurance Service (NHIS). Smoking status was repeatedly measured in four waves of general health examinations provided by the NHIS between 2002 and 2009. Cancer incidence and mortality were tracked from 2010 to 2018. Trajectory analysis was used to identify the patterns of smoking. The hazard ratio was calculated using Cox proportional regression models. RESULTS For the 2448548 men (≥20 years), 137788 cases of cancers and 41146 cancer deaths were found. We identified six trajectory groups: never smokers, former smokers, new current smokers, decreasing light smokers, steady moderate smokers, and steady heavy smokers. All smoking groups had an increased risk of cancer. The steady heavy smokers showed higher cancer incidence and mortality rate than the steady non-smokers (hazard ratio, HR=1.53; 95% CI: 1.49–1.58 and HR=2.64; 95% CI: 2.50–2.79, respectively). The cancer-specific analysis showed that the larynx and lung cancer incidence and mortality rate of the smoking group were higher than in never smokers. CONCLUSIONS Smoking, even at low doses, increases the risk of most cancers in men. Quitting or reducing smoking, especially at a young age, can lower cancer incidence and mortality. This study may provide more objective results on the relationship between smoking and cancer, because smoking behavior was examined at multiple time points.

Evaluation of cancer incidence among Marines and Navy personnel and civilian workers exposed to contaminated drinking water at USMC Base Camp Lejeune: a cohort study

“…Adjusting for a smoking prevalence difference of 6% and assuming RRs for smoking and lung cancer and laryngeal cancer between 7.00 and 12.00, the HR of 1.16 for lung cancer would decrease to between 1.05 and 1.06 and the HR of 1.21 for laryngeal cancer would decrease to between 1.10 and 1.11 (Supplemental file 2, Figures 2 and 3). Assuming RRs for smoking and esophageal cancer around 2.5 [27, 45], the HR of 1.27 for esophageal cancer would decrease to between 1.18 and 1.25 (Supplemental file 2, Figure 4).…”

Evaluation of mortality among Marines, Navy personnel, and civilian workers exposed to contaminated drinking water at USMC Base Camp Lejeune: a cohort study

“…Assuming a 6% difference in smoking prevalence and a range of RRs for smoking and kidney cancer between 1.25 and 1.75 [44], the observed adjusted HR for kidney cancer of 1.21 would be reduced to between 1.17 and 1.18, a change of about 3.3% (Supplemental le, Figure S2). Assuming a range of RRs for smoking and esophageal cancer between 1.5 and 3.5 [44][45], the observed adjusted HR of 1.24 would be reduced to between 1.17 and 1.21, a change of no more than 5.6% (Supplemental le, Figure S3).…”

A Systematic Review of the Effects of Smoking on the Cardiovascular System and General Health

“…Smoking cessation or reduction, particularly when done at a young age, can reduce the incidence and mortality of cancer. Men who completed four health tests in 2002-2003, 2004-2005, 2006-2007, and 2008-2009 were included in their analyses, along with all covered individuals under the national health insurance plan [ 8 ]. According to a population-based cohort study conducted by Jee et al on 430,951 people, the risk of bladder cancer did not change significantly according to the trajectory, with the exception of the low stable group.…”

“…It can also increase the risk of oral cavity problems like periodontitis [ 7 ]. Furthermore, smoking increases the risk of cancer [ 8 , 9 ]. Tobacco smoke is a complex mix of chemicals that includes many mutagens and carcinogens, such as polycyclic aromatic hydrocarbons (PAHs) and tobacco-specific nitrosamines (TSNAs), which are found in all tobacco products, including cigarettes, cigars, and smokeless tobacco.…”