Lung cancer decreased sharply in first 5 years after smoking cessation in chinese men.
Journal - Journal of thoracic oncology : official publication of the International Association for the Study of Lung Cancer (United States )
: The rate of decline in lung cancer risk after smoking cessation among male population and the importance of the magnitude of the early decline were not sufficiently defined in the earlier studies. We evaluated the detailed duration-response relationship between years since smoking cessation and lung cancer risk across major histological types in a population-based case-referent study.: We recruited 1208 consecutive incident cases of primary lung cancer among Chinese males from the largest oncology center in Hong Kong during 2004-2006, and 1069 male community referents frequency-matched in 5-year age groups. We performed unconditional multiple logistic regression and generalized additive model incorporating smoothing spline to model the potential nonlinear effect of years since cessation on lung cancer.: All histological types of lung cancer were strongly associated with current smoking. We observed a rapidly decreasing odds ratio of lung cancer (>50%) across all major histological types of lung cancer (except for the large cell type) within the first 5 years of quitting; the odds ratio continued to decrease but at a slower rate in the subsequent years.: The substantial benefits obtainable within a short period of 5 years' abstinence should convey an encouraging message to chronic smokers, clinicians, and public health workers.
Occupational risks and lung cancer burden for Chinese men: a population-based case-referent study.
Journal - Cancer causes & control : CCC
OBJECTIVE: We aimed to fill in the gap of knowledge on the lung cancer burden resulting from occupational exposures among Chinese men through a population-based case-referent study. METHODS: Detailed information on lifestyle and full occupational histories of 1,208 male lung cancer incident cases and 1,069 age-matched male community referents were obtained through interviews during 2004-2006. The associations between lung cancer risk and exposures to specific or group of agents that were confirmed or suspected occupational carcinogens were analyzed. RESULTS: After adjustment of smoking and other potential confounding factors, significant odds ratio of lung cancer was observed for workers employed in major industrial divisions of "construction" (1.37, 95% CI: 1.00-1.89) and "financing, insurance, real estate, and business services" (0.48, 95% CI: 0.23-0.97), as well as in the occupational groups of "bricklayers, carpenters, and other construction workers" (1.49, 95% CI: 1.07-2.06). Significantly elevated odds ratios were found for occupational exposures to silica dust (1.75, 95% CI: 1.16-2.62), welding fumes (1.74, 95% CI: 1.13-2.68), diesel exhaust (2.18, 95% CI: 1.23-3.84), and man-made mineral fibers (7.45, 95% CI: 1.63-34.00), while a significantly reduced risk (OR = 0.67, 95% CI: 0.47-0.95) was linked to cotton dust. The population attributable fraction of lung cancer was 3.2% (95% CI: 0.1-7.3%) for construction workers and 9.5% (95% CI: 4.8-15.1%) for the four significant specific exposures. CONCLUSIONS: Our study indicates that previous exposure to occupational carcinogens remains an important determinant of lung cancer burden for Hong Kong Chinese men. However, results obtained from this study should be confirmed by future analyses based on job exposure matrix.