Body mass index and mortality from lung cancer in smokers and nonsmokers: A nationally representative prospective study of 220,000 men in China

Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), University of Oxford, Oxford, United Kingdom.
International Journal of Cancer (Impact Factor: 5.09). 11/2009; 125(9):2136-43. DOI: 10.1002/ijc.24527
Source: PubMed


Low body mass index (BMI) has been associated with increased risk of lung cancer. However, the nature of the association, especially in populations with relatively low BMI, is less well characterized, as is the relevance to it of smoking. A nationally representative prospective cohort study included 217,180 Chinese men aged 40-79 years in 1990-91 who had no prior history of cancer and were followed up for 15 years. Standardized hazard ratios (HRs) were calculated for lung cancer mortality by baseline BMI. The mean baseline BMI was 21.7 kg/m(2), and 2,145 lung cancer deaths were recorded during 15 years of follow-up. The prevalence of smoking was strongly inversely associated with BMI, but no apparent relationship was seen between amount smoked (or other measures of smoking intensity) and BMI among smokers. Overall there was a strong inverse association between BMI and lung cancer mortality (p < 0.0001 for trend) after excluding the first 3 years of follow-up. This association appeared to be confined mainly to current smokers, with no apparent relationship in nonsmokers (p < 0.001 for difference between slopes). Among current smokers, the inverse association appeared to be log-linear, with each 5 kg/m(2) lower BMI associated with a 35% (95% confidence interval: 24-46%; p < 0.0001) higher lung cancer mortality, and it persisted after excluding those who had reported poor health status or history of any disease or respiratory symptoms at baseline. In this relatively lean Chinese male population, low BMI was strongly associated with increased risk of lung cancer only among current smokers.

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Available from: Maigeng Zhou, Sep 08, 2014
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    • "The mortality rate of lung cancer in China is high with approximately 400,000 patient deaths annually (Yang et al. 2009). While the mechanism of lung cancer carcinogenesis remains unclear, smoking has been identified as an important environmental risk factor for development of lung cancer (Pandey et al. 1999; Spiro and Silvestri 2005; Freedman et al. 2008). "
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    Mitochondrial DNA 06/2012; 23(4):251-4. DOI:10.3109/19401736.2012.674120 · 1.21 Impact Factor
    • "The results show a positive relation between lung cancer incidence and old age. The high incidence of lung cancer among elderly subjects may be related to factors like smoking status, food habits, occupational exposure and infectious diseases.[202124–26] Moreover, the lack of observed gender predisposition for lung cancer types among subjects more than 50 years of age supplements ours assumption that the elderly in China are predisposed to malignancy.[27] "
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    ABSTRACT: Auto-fluorescence bronchoscopy (AFB) has been used for the identification and localization of intra-epithelial pre-neoplastic and neoplastic lesions within the bronchus. To determine the applicability of AFB for the detection and localization of precancerous and cancerous lesions, in addition to analyzing the morphologic presentation, their association to histological type and the variation between genders. A five-year study involving 4983 patients, who underwent routine bronchoscopy [B] examination in a local tertiary teaching hospital, was done. The B examination was performed under intratracheal lidocaine, and samples were obtained using suitable approach. One thousand four hundred and eighty-five pathologically confirmed lung cancer patients were included in the study. The following parameters were studied: Morphological presentation, biopsy sites, histology. Differences between the groups were analyzed using Chi square test. One thousand four hundred and eighty-five patients who had hyperplasia or neoplastic lesions were further confirmed as lung cancer pathologically. Lung cancer was more commonly found in the right lung (51.58% vs. 42.82%). The lesion occurred more frequently in the upper lobe than the lower lobe (44.17% vs. 22.42%). Male patients with squamous cell carcinoma showed upper lobe involvement more commonly, while the left main bronchus was more commonly involved in female patients. Adenocarcinoma mostly involved lesion of the upper lobe. Squamous cell carcinoma and small cell carcinoma were the major proliferative types (80.15% and 76.16% respectively). AFB is efficient in the detection of pre-invasive and invasive lung lesions. The morphological presentation is associated to the histological type. There is variation in the presentation and histology of cancerous lung lesions between genders.
    03/2012; 7(1):21-5. DOI:10.4103/1817-1737.91559
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    • "This apparently lower risk associated with smoking among Chinese has been attributed to lighter dose of smoking and the relatively late age of starting to smoke in China (Chen et al, 1997). There are disturbing observations that the mean cigarette consumption by Chinese men is increasing rapidly (Liu et al, 1998) and that smoking is starting at an earlier age (Yang, 1997). Lung cancer mortality attributed to smoking in China can therefore be expected to rapidly increase from the current 63% (Chen et al, 1997) to the above 90% levels noted in certain industrialised countries (Ezzati and Lopez, 2003). "
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    ABSTRACT: Smokers with low body mass index (BMI) may be more susceptible to lung cancer. We prospectively examined the association between baseline BMI and lung cancer risk in the Singapore Chinese Health Study, a cohort of 63 257 Chinese enrolled between 1993 and 1998. After adjustment for smoking intensity and duration, BMI was inversely associated with risk of lung cancer among current smokers (P for trend=0.0004). Current smokers at different dosage of smoking with low BMI had significantly higher risk for lung cancer than those with high BMI. Hazard ratios (95% confidence intervals) of lung cancer for heavy smokers with BMI of > or =28, 24-<28, 20-<24, and <20 kg m(-2) were 6.37 (2.10-19.30), 9.01 (5.04-16.10), 8.53 (6.35-11.5), and 11.12 (6.60-18.70), respectively, as compared with nonsmokers. BMI had no modifying effects on lung cancer risk among nonsmokers and former smokers. Smokers with lower BMI may experience an enhanced risk of lung cancer. The findings have significant public-health implication given the increase in smoking prevalence in developing countries, where people still have relatively low BMI.
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