Case-control study of exposure to carbon black in the occupational setting and risk of lung cancer

Although it has been hypothesized that carbon black exposure may carry an excess risk of lung cancer, evidence to date is insufficient to assess the hypothesis properly. The relationship between workplace exposure to carbon black and lung cancer risk was examined in a population-based case-control study carried out in Montreal, Canada. Detailed job histories were elicited from 857 incident cases with histologically confirmed lung cancer as well as from 1,360 cancer controls and 533 population controls. Job histories were evaluated by a team of hygienists and chemists for evidence of exposure to a host of occupational substances, including carbon black. Logistic regression analyses adjusting for smoking and other nonoccupational and occupational potential confounders suggested no significant increase in risk with relatively low exposure to carbon black. Some increase in risk for all lung cancers was apparent with relatively high exposure using cancer controls (OR = 2.17; 95% CI = 0.95–4.91) and population controls (OR = 1.52; 95% CI = 0.58–3.97). Individuals with relatively high exposure had a significantly greater risk of oat-cell carcinoma using either control series (OR = 5.05; 95% CI = 1.72–14.87 using cancer controls and OR = 4.82; 95% CI = 1.36–17.02 using population controls). These results provide some evidence for an association between exposure to carbon black and lung cancer. © 1996 Wiley-Liss, Inc.     

Effects of work related confounders on the association between silica exposure and lung cancer: a nested case-control study among Chinese miners and pottery workers

Objective The role of silica in the causation of lung cancer is an ongoing debate. In order to explore whether observed association between silica exposure and lung cancer is confounded by exposure to other occupational carcinogens, we updated a previously nested case-control study among a cohort of male workers in 29 Chinese mines and factories on the basis of an extended follow-up. Methods Five hundred and eleven lung cancer cases and 1,879 matched controls were selected. Exposure to respirable silica as well as relevant occupational confounders were quantitatively assessed based on historical industrial hygiene data. The relationship between exposure to silica and lung cancer was analyzed by conditional logistic regression analysis adjusted for exposure to arsenic, polycyclic aromatic hydrocarbons (PAHs), radon, and smoking. Results In a crude analysis adjusted for smoking only, a significant trend of increasing risk of lung cancer with exposure to silica was found for tin, iron/copper miners, and pottery workers. But after adjustment for relevant occupational confounders, no relationship between silica and lung cancer can be observed. Instead, there is a significant association between lung cancer mortality and cumulative exposure to inorganic arsenic (OR = 1.86, 95% CI: 1.14, 3.04 for each mg/m³-year increase) and carcinogenic PAHs (OR = 1.35, 95% CI: 1.08, 1.69 for each 100 μg/m³-year increase). Conclusion This analysis does not provide any evidence to show that exposure to silica causes lung cancer in the absence of confounding factors.     

A case-control study of lung cancer at a dye and resin manufacturing plant.

This case-control study evaluated the relationship between lung cancer and occupational factors among employees at a dye and resin manufacturing plant. The study included 51 lung cancer cases and 102 controls who were members of a cohort of workers investigated in a previous retrospective follow-up study. Information on area of employment and on potential exposure to certain chemicals was obtained from plant personnel and medical records and from interviews with long-term employees. Information on potential confounders, including cigarette smoking, was obtained by interviewing study subjects or their next-of-kin. The odds ratio (OR) for heavy smokers compared with light or nonsmokers was 5.9 (95% confidence interval (CI) = 2.4-15). An elevated OR for lung cancer was observed for subjects who worked in the anthraquinone dye and epichlorohydrin manufacturing area of the plant (OR = 2.4; 95% CI = 1.1-5.2) and for employees who were seen at the plant infirmary for acute exposure to chlorine (OR, adjusted for smoking = 27; 95% CI = 3.5-205). Pipefitters employed at the plant for five or more years also had an elevated OR (3.3; 95% CI = 0.8-14).     

Lung cancer in motor exhaust-related occupations

The association between employment in motor exhaust-related occupations and the risk for lung cancer was examined in 2,291 male cases of lung cancer and 2,570 controls in data pooled from three U.S. case control studies carried out by the National Cancer Institute between 1976 and 1983. Most analyses were limited to subjects providing direct, in-person interviews, including 1,444 cases and 1,893 controls. For those providing direct interviews and employed 10 years or more in motor exhaust-related (MER) occupations, the age, smoking, and study area adjusted odds ratio (OR) for lung cancer was 1.5 (95% CI = 1.2-1.9). Risk was elevated for truck drivers (OR = 1.5; 95% CI = 1.1-1.9) and for other MER occupations (OR = 1.4; 95% CI = 1.1-2.0). The odds ratios associated with MER employment of 10+ years were 1.6 (95% CI = 1.2-2.1) for whites and 1.4 (95% CI = 0.9-2.1) for nonwhites; 1.2 (95% CI = 0.7-2.0) [corrected] for those with possible exposure to other recognized or reported lung carcinogens; and 1.6 (95% CI 1.2-2.1) for those without such exposure. The 50% excess risk for lung cancer associated with employment in motor exhaust-related occupations could not be explained by greater use of cigarettes or by other occupational exposures among these workers.     

Association between asbestos exposure,cigarette smoking,myeloperoxidase (MPO) genotypes,and lung cancer risk

BACKGROUND: As observed in tobacco-associated carcinogenesis, genetic factors such as the polymorphic metabolic/oxidative enzyme myeloperoxidase (MPO) could modulate individual susceptibility to asbestos-associated carcinogenesis. METHODS: RFLP-PCR analysis identified the MPO genotypes in 375 Caucasian lung cancer cases and 378 matched controls. An epidemiological interview elicited detailed information regarding smoking history and occupational history and exposures. RESULTS: Asbestos exposure was associated with a significantly elevated risk estimate (OR = 1.45; 95% CI 1.04-2.02). On stratified analysis, we found the MPO genotypes modified the effect of asbestos exposure on lung cancer risk. Specifically, G/G carriers who were exposed to asbestos had an odds ratio (OR) of 1.72 (95% CI; 1.09-2.66), while A-allele carriers (G/A + A/A) exposed to asbestos exhibited a reduced OR of 0.89 (95% CI; 0.56-1.44). The OR was further reduced to 0.73 (0.49-1.06) for A-allele carriers not exposed to asbestos. A similar trend was observed for the joint effects between the MPO genotypes and pack-years smoking. Next, all three risk factors (MPO genotypes, asbestos exposure, and smoking) were analyzed simultaneously for joint effects. Heavy smokers with the G/G genotype and a history of asbestos exposure demonstrated a statistically significant elevated risk estimate (OR = 2.19; 95% CI 1.16-4.11), while the A-allele carriers with the same exposure profile were at a lower risk for lung cancer (OR = 1.18; 95% CI 0.58-2.38). The A-allele genotypes demonstrated similar protective effects for the other three exposure profiles. CONCLUSIONS: For a similar level of exposure to established carcinogens, individuals with the MPO A-allele genotypes appear to have a reduced risk of lung cancer.     

Diesel exhaust exposure and bladder cancer risk

A total of 136 cases of men with urinary bladder cancer and 272 matched hospital controls were examined for potential exposure to diesel exhaust. A lifetime occupational history was obtained for all subjects in the study and assessment of exposure to diesel exhaust was based on the job titles of the subject and self-reported exposure. The risk was assessed by odds ratios, with adjustment for confounding variables, in particular cigarette smoking. There was no evidence of elevated risk in occupations with possible or probable exposure (the ORs adjusted for smoking were 1.1. and 0.9 respectively). Truck driving alone was also not associated with elevated risk (adjusted OR=0.5). There was a weak positive crude association with any exposure, including self-reports (OR=1.4); however after adjustment for smoking, the estimate did not retain statistical significance (OR=1.2, 95% CI=0.8-2.0). This study provides little to support the hypothesis of an excess of bladder cancer risk from occupational exposure to diesel exhaust.Corresponding author.     

Meta- and pooled analysis of GSTT1 and lung cancer: a HuGE-GSEC review

Lung cancer is the most common malignancy in the Western world, and the main risk factor is tobacco smoking. Polymorphisms in metabolic genes may modulate the risk associated with environmental factors. The glutathione S-transferase theta 1 gene (GSTT1) is a particularly attractive candidate for lung cancer susceptibility because of its involvement in the metabolism of polycyclic aromatic hydrocarbons found in tobacco smoke and of other chemicals, pesticides, and industrial solvents. The frequency of the GSTT1 null genotype is lower among Caucasians (10-20%) than among Asians (50-60%). The authors present a meta- and a pooled analysis of case-control, genotype-based studies that examined the association between GSTT1 and lung cancer (34 studies, 7,629 cases and 10,087 controls for the meta-analysis; 34 studies, 7,044 cases and 10,000 controls for the pooled analysis). No association was observed between GSTT1 deletion and lung cancer for Caucasians (odds ratio (OR) = 0.99, 95% confidence interval (CI): 0.87, 1.12); for Asians, a positive association was found (OR = 1.28, 95% CI: 1.10, 1.49). In the pooled analysis, the odds ratios were not significant for either Asians (OR = 0.97, 95% CI: 0.83, 1.13) or Caucasians (OR = 1.09, 95% CI: 0.99, 1.21). No significant interaction was observed between GSTT1 and smoking on lung cancer, whereas GSTT1 appeared to modulate occupational-related lung cancer.     

鞍钢工人的肿瘤危险度——肺癌病例-对照研究

对鞍钢男工中６１０例肺癌新发病例及９５９例对照进行了访问调查。经吸烟、其他肺疾患、家族肿瘤史、食用水果等非职业因素调整后，岗位工龄等于或超过１５年的下列工人的肺癌危险度显著增高：冶炼工和轧钢工（ＱＲ＝１．５，９５％ＣＩ＝１．１～２．２），耐火砖厂工（ＯＲ＝２．９，９５％ＣＩ＝１．４～５．９），装卸工（ＯＲ＝２．５，９５％ＣＩ＝１．０～６．１），焦炉工（ＯＲ＝３．４，９５％ＣＩ＝１．４～８．５）。各种粉尘和Ｂ［ａ］Ｐ暴露与肺癌危险性呈显著的剂量－反应关系，但与粉尘的特殊成分未见此种关联。长期暴露于污染物的钢铁工人的肺癌的危险度增加４０％。     

Study of lung cancer histologic types, occupation, and smoking in Missouri

A case-control study of lung cancer was conducted to evaluate the relationship between lung cancer histologic types and occupation, adjusted for smoking. A total of 4,431 white male cases and 11,326 cancer controls, diagnosed between 1980 and 1985, were identified through the Missouri Cancer Registry. For all histologic types combined, excess risk was observed among many a priori suspected high-risk occupations. Lung cancer was elevated among men employed as insulators (odds ratio [OR] = 6.0; 95% confidence interval [CI] = 0.7, 137.8), carpenters (OR = 1.3; 95% CI = 1.0, 1.7), painters, plasterers, and wallpaper hangers (OR = 2.0; 95% CI = 1.2,3.3), structural metal workers (OR = 1.9; 95% CI = 0.6,6.0), mechanics and repairers (OR = 1.3; 95% CI = 1.0,1.7), motor vehicle drivers (OR = 1.5; 95% CI = 1.2,1.8), police and firefighters (OR = 1.6; 95% CI = 1.1,2.3), and food service personnel (OR = 1.8; 95% CI = 1.0,3.5). A deficit of lung cancer was observed among farmers (OR = 0.9; 95% CI = 0.7,1.0). Adenocarcinoma of the lung was elevated among carpenters (OR = 1.6; 95% CI = 1.0,2.5) and cabinet and furniture makers (OR = 2.0; 95% CI = 0.4,8.1), which is interesting because of the previous reports of excess adenocarcinoma of the nasal cavity associated with wood dust exposure. Adenocarcinomas were also elevated among plumbers (OR = 2.0; 95% CI = 1.0,3.8) and printers (OR = 1.8; 95% CI = 0.7,4.2). Electricians were at slightly increased risk for adenocarcinoma (OR = 1.5; 95% CI = 0.7,2.8) and "other" or mixed cell types of lung cancer (OR = 1.5; 95% CI = 0.8,2.9) but at decreased risk for small cell (OR = 0.8; 95% CI = 0.3,2.0) and squamous cell (OR = 0.8; 95% CI = 0.4,1.6) tumors. Among welders, adenocarcinoma (OR = 1.7; 95% CI = 0.7,3.8) and squamous cell (OR = 1.7; 95% CI = 0.9,3.3) cancers were elevated, but small cell and "other" lung cancers were not. Despite the limitations of the Cancer Registry data, some interesting associations were observed that merit further study, particularly the association between lung adenocarcinoma and occupational exposure to wood and wood dust.     

Lung cancer in relation to residence in census tracts with toxic-waste disposal sites: a case-control study in Niagara County, New York

Nine selected census tracts containing 12 toxic-waste disposal sites with known or suspected lung carcinogens were identified in Niagara County, New York. Analysis of death certificates of 339 lung cancer cases (decedents) and 676 controls who died of other causes excluding respiratory diseases in 1978-1981 showed no association between death from lung cancer and residence in the selected census tracts (odds ratio = 0.95; 95% confidence interval = 0.65-1.38). Analysis of mail questionnaires from surrogate respondents for 209 lung cancer decedents and 417 controls showed no significant association between lung cancer and a history of ever having resided in the selected census tracts (age-adjusted odds ratio = 1.17; 95% CI = 0.78-1.76) and no significant interaction between such residence and cigarette smoking. Duration of residence in the selected census tracts did not differ between cases and controls. The limitations of this low-cost study design, in terms of response rates and potential misclassification of exposure, were discussed along with its value in interim studies of potentially hazardous dumpsites (prior to more intensive case-control or other studies using better exposure data).     

Lung cancer and occupation: results of a multicentre case-control study.

The objective of the current study was to estimate the risk of lung cancer attributable to occupational factors and not due to tobacco. At 24 hospitals in nine metropolitan areas in the United States, 1793 male lung cancer cases were matched for race, age, hospital, year of interview, and cigarette smoking (never smoker, ex-smoker, smoker (1-19 and > or = 20 cigarettes per day)) to two types of controls (cancer and non-cancer hospital patients). Information on usual occupation, exposure to specific potential carcinogens, and cigarette smoking was obtained by interview. Risk of lung cancer was increased significantly for electricians; sheetmetal workers and tinsmiths; bookbinders and related printing trade workers; cranemen, derrickmen, and hoistmen; moulders, heat treaters, annealers and other heated metal workers; and construction labourers. All of these occupations are potentially exposed to known carcinogens. Odds ratios (ORs) were increased for exposure to coal dust (adjusted OR = 1.5; 95% confidence interval (95% CI) 1.1-2.1). After stratification, this association was statistically significant only after 10 or more years of exposure. Lung cancer was also related to exposure to asbestos (adjusted OR = 1.8; 95% CI 1.5-2.2). The ORs increased with increasing duration of exposure to asbestos for all smoking categories except for current smokers of 1-19 cigarettes per day. The statistical power to detect ORs among occupations that were previously reported to be at increased risk of lung cancer but that failed to show an OR of at least 1.5 in the current study was small. The cumulative population attributable risk (PAR) of lung cancer due to occupation was 9.2%. It is concluded that occupational factors play an important part in the development of lung cancer independently of cigarette smoking. Because occupations at high risk of lung cancer were under-represented, the cumulative PAR of the present study is likely to be an underestimate of the true contribution of occupation to risk of lung cancer.     

Occupational exposure to lead compounds and risk of cancer among men: a population-based case-control study

The International Agency for Research on Cancer recently classified inorganic lead as a probable carcinogen, while organic lead remained unclassifiable. Uncertainty persists because of limited epidemiologic evidence. The authors addressed the relation between occupational exposure to lead and the risk of 11 types of cancer among men in a case-control study conducted in Montreal, Quebec, Canada, in the 1980s. Incident cases (n = 3,730) and general population controls (n = 533) were interviewed to elicit information on job history and potential confounders. Expert chemists translated each job into a list of substances to which the subject had potentially been exposed. Exposure to lead was classified into three categories: organic lead (3% of subjects ever exposed), inorganic lead (17%), and lead in gasoline emissions (39%). Odds ratios and 95% confidence intervals were estimated by logistic regression using two control groups: general population controls and cancer controls. Stomach cancer was associated with organic lead when the authors used population controls (odds ratio (OR) = 3.0, 95% confidence interval (CI): 1.2, 7.3) and cancer controls (OR = 2.0, 95% CI: 1.1, 3.8) and with substantial exposure to lead in gasoline emissions when they used cancer controls (OR = 2.9, 95% CI: 1.4, 5.9). There was no association with inorganic lead and little evidence for associations with other cancer types.     

Breastfeeding,Other Early Life Exposures and Childhood Leukemia and Lymphoma

Childhood cancer incidence increases and although rare, it is a leading cause of mortality. Leukemia and lymphoma comprise 40% of all cancers in children but little is known of their etiology. In this study, we examined the associations of breastfeeding and other early life exposures with childhood leukemia and lymphoma. A population-based case–control study carried out in 2011–2013 comprised mothers of 190 incidents (2005–2013) of leukemia/lymphoma cases aged 1–19 yr at diagnosis and 384 population-based controls. Interviews based on a computerized structured questionnaire were conducted with the mothers. Multivariate logistic regression models adjusted for potential confounders assessed the association between breastfeeding patterns and childhood leukemia/lymphoma. Ever breastfeeding category was associated with a 64% decreased risk for childhood leukemia/lymphoma lsqb;odds ratio (OR) = 0.36, 95% confidence interval (CI): 0.22, 0.60lrqb; and similar trends, with a dose–response effect, were observed for any breastfeeding (exclusive and/or partial) category for 6, 12, and 18+ mo. Other infant exposures associated with cancer risk were child iron supplementation (OR = 0.39, 95% CI: 0.26, 0.59), pet ownership (OR = 0.50, 95% CI: 0.33, 0.78), paternal smoking (OR = 1.93, 95% CI: 1.18, 3.15), and having older siblings (OR = 1.18, 95% CI: 1.05, 1.33). Breastfeeding—a controllable and modifiable exposure—is inversely associated with risk for childhood leukemia and lymphoma with a dose–response effect.     

Risk of lung cancer from exposure to dusts and fibers in Leningrad Province, Russia

BACKGROUND: Exposures to several dusts and fibers (DFs) have been established or suggested as etiologic factors for lung cancer. METHODS: To investigate lung cancer risk in relation to exposure to DFs, we identified 540 pathologically-diagnosed lung cancer cases and 582 controls from the 1993-1998 autopsy records of the 88 hospitals of Leningrad Province, Russia. Lifetime job-specific exposure measurements were available for 15 organic, 15 man-made and 28 natural-inorganic agents. RESULTS: In male workers, increased risks were found for linen dust (OR = 3.68, 95% CI 1.00-13.6, adjusted for age, smoking and residence), and unspecified DFs (OR = 1.44, 95% CI 1.07-1.94). Small non-significant excess risks were observed for quartz dust (OR = 1.27; 95% CI 0.83-1.93) and man-made vitreous fibers (MMVFs) (OR = 1.82, 95% CI 0.88-3.75). In female subjects, risks were non-significantly associated with paper dust (OR = 1.77, 95% CI 0.74-4.20), and unspecified DFs (OR = 1.52, 95% CI 0.77-3.03). CONCLUSIONS: The study showed increased lung cancer risk for selected categories of DFs.     

Occupational lung cancer risk for men in Germany: results from a pooled case-control study

Occupational exposures such as crystalline silica, diesel engine exhaust, polycyclic aromatic hydrocarbons, and man-made mineral fibers are strongly suspected to increase lung cancer risk. Two case-control studies in Germany conducted between 1988 and 1996 were pooled for a joint analysis. A total of 3,498 male cases and 3,541 male population controls, frequency matched for age and region, were included in the study. The lifelong history of all jobs and industries was coded and occupational exposures were evaluated by expert rating. Odds ratios, crude and adjusted for smoking and asbestos exposure, were calculated by conditional logistic regression. Job-related evaluation showed a statistically significant increased odds ratio adjusted for smoking among farmers; forestry workers, fishermen, and livestock workers; miners and quarrymen; chemical processors; cabinet makers and related wood workers; metal producers and processors; bricklayers and carpenters; road construction workers, pipelayers and well diggers; plasterers, insulators, and upholsterers; painters and lacquerers; stationary engine and heavy equipment operators; transport workers and freight handlers; and service workers. With regard to specific occupational exposures, elevated odds ratios (OR) (95% confidence intervals (CI)) for lung cancer risk adjusted for smoking and asbestos exposure were observed for man-made mineral fibers (OR = 1.48, 95% CI 1.17, 1.88); crystalline silica (OR = 1.41, 95% CI 1.22, 1.62); diesel engine exhaust (OR = 1.43, 95% CI 1.23, 1.67); and polycyclic aromatic hydrocarbons (OR = 1.53, 95% CI 1.14, 2.04). The risk of asbestos exposure, adjusted for smoking was also increased (OR = 1.41, 95% CI 1.24, 1.60).     

基于倾向性评分法的藏族非吸烟人群被动吸烟暴露与失眠的关联研究

  目的  描述中国藏族非吸烟人群被动吸烟暴露与失眠症状的分布特征,探究被动吸烟暴露与失眠症状的关联程度。  方法  基于“西南区域自然人群队列”项目2018年5月―2019年8月在拉萨市调查的7 737名藏族居民数据,采用倾向性评分逆概率加权法和边际结构模型分析被动吸烟暴露与失眠症状的关联,并比较该关联在不同年龄、性别、BMI、负性生活事件、社会支持组别之间的差异。  结果  调查人群中被动吸烟暴露率为22.50%,失眠检出率为33.67%。利用倾向性评分均衡潜在混杂因素后,被动吸烟暴露组发生失眠症状的风险为非被动吸烟暴露组的1.24倍(OR=1.24, 95% CI: 1.14~1.34);年龄≥50岁(OR=1.25, 95% CI: 1.01~1.54)、男性(OR=1.60, 95% CI: 1.17~2.18)、超重(OR=1.24, 95% CI: 1.05~1.47)、有过1次负性生活事件(OR=1.46, 95% CI: 1.01~2.10)和中等社会支持(OR=1.46, 95% CI: 1.12~1.92)人群被动吸烟暴露与失眠有显著关联。  结论  在藏族非吸烟人群中被动吸烟暴露是失眠的危险因素,应该采取相关降低被动吸烟暴露的干预措施去促进人群睡眠健康。     

Lung cancer risk of workers in shoe manufacture and repair

BACKGROUND: The occupational lung cancer risk in manufacturing and repair of shoes was studied by pooling of two major case-control studies from Germany. METHODS: Some 4184 incident hospital-based cases of primary lung cancer and 4253 population controls, matched for sex, age, and region of residence were intensively interviewed with respect to their occupational and smoking history. Based on the occupational coding and a free text search, all individuals who had ever worked in shoe manufacturing or repair for at least half a year were identified. Shoemaker-years were calculated as the cumulated duration of working in shoe manufacturing or repair. Odds ratios (OR) and 95% confidence intervals (CI) were calculated via conditional logistic regression. Additional adjustment for smoking and occupational asbestos exposure was used. RESULTS: Seventy-six cases and 42 controls who had ever worked in shoe manufacture or repair (OR = 1.89, 95% CI: 1.29-2.78). After adjustment for smoking, this risk was lowered to 1.69 (95% CI: 1.09-2.62). Further adjustment for asbestos exposure only slightly changed the risk estimates upwards. The smoking adjusted OR in males was 1.50 (95% CI: 0.93-2.41) and 2.91 (95% CI: 0.90-9.44) in females. Logistic regression modeling showed a positive dose-effect relationship between duration of exposure in shoe manufacture and repair and lung cancer risk. The odds ratio for 30 years of exposure varied between 1.98 and 2.24 depending on the model specified. CONCLUSIONS: The study demonstrates an increased lung cancer risk for shoemakers and workers in shoe manufacturing. The risk seems to double after being 30 years in these occupations.     

Occupation and cancer of the oral cavity or oropharynx in Turin, Italy

In a population-based case-referent study, the occupational experience of 86 men with oral or oropharyngeal cancer and 373 referents was analyzed with respect to employment in 41 occupations and 40 industries, as well as to exposure to 16 chemicals, as estimated via a job-exposure matrix. Among the occupations and industries at higher risk were machinery operator (odds ratio [OR] 2.0; 95% confidence interval [95% CI] 1.0-4.0), plumber (OR 5.0, 95% CI 1.2-21.5), building industry (OR 2.5; 95% CI 1.3-4.5), textile industry (OR 2.5; 95% CI 0.6-4.6), and electricity production (OR 2.8; 95% CI 0.7-12.1). All the OR estimates were adjusted for age, education, area of birth, tobacco smoking, and alcohol consumption. An association between formaldehyde exposure and oral cancer was suggested (OR for any exposure 1.6, 95% CI 0.9-2.8; OR for probable or definite exposure 1.8, 95% CI 0.6-5.5). No other chemical included in the matrix showed any risk pattern. The evidence of an association between formaldehyde exposure and oral or oropharyngeal cancer is strengthened by the results of this study.     

Reevaluation of the confounding effect of cigarette smoking on the relationship between alcohol use and lung cancer risk, with larynx cancer used as a positive control

BACKGROUND: The effect of smoking on lung cancer risk has been well documented, while the effect of alcohol remains controversial. We examined the hypothesis that the apparent association between alcohol intake and lung cancer risk is fully due to the confounding effect of cigarette smoke. METHODS: Our sample of hospitalized patients included 2,953 male and 1,622 female lung cancer cases; 521 male and 159 female larynx cancers cases; and 8,169 male and 4,154 female controls, admitted to participating hospitals between 1981 and 1994. All controls had been diagnosed with non-smoking-related diseases. Larynx cancer was used as a positive control for lung cancer. Relative risks were estimated through odds ratios, adjusted through multiple logistic regression. RESULTS: Although the odds ratios for alcohol had been significantly elevated prior to adjustment for smoking (OR = 2.4, 95% CI = 2.0-2.8), alcohol had no effect on lung cancer following this adjustment (OR = 1.2, 95% CI = 1.0-1.4). By contrast, the effect of alcohol on larynx cancer remained high even after adjustment for smoking (OR = 5.6, 95% CI = 3.7-8.6). CONCLUSION: The often-reported association between alcohol and lung cancer risk can be fully explained by the confounding effect of cigarette use.     

Cigarette smoking and risk of bladder, pancreas, kidney, and colorectal cancers in Iowa

PURPOSE: Although there are numerous reports on the effects of cigarette smoking and cancer, they have infrequently compared risks at more than one cancer site after multivariate adjustment. We analyzed data from a population-based case-control study that included five anatomic sites to evaluate the association between cigarette smoking and each cancer site and to rank the associations by site. METHODS: Study respondents included 1452 bladder, 406 kidney, 376 pancreatic, 685 colon, and 655 rectal cancer cases, as well as 2434 population controls. A self-administered questionnaire was used to collect information on cigarette smoking and other potential confounders including occupation, drinking water source, and dietary practices. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), after adjustment for age, total energy intake, and other site- and sex-specific confounders. RESULTS: In both sexes, cigarette smoking (ever vs. never) was associated with risk of bladder cancer (OR = 2.5; 95% CI, 2.0-3.1 for males; OR = 2.7; 2.0-3.6 for females) and pancreatic cancer (OR = 1.8; 1.2-2.8 for males; OR = 2.1; 1.4-3.1 for females). Cigarette smoking also increased the risk of kidney cancer among males (OR = 1.8; 1.3-2.7), and to a lesser degree, among females (OR = 1.2; 0.8-1.8). No association was found for colon or rectal cancer in either sex. CONCLUSIONS: Cigarette smoking increased the risk of bladder, kidney, and pancreatic cancer in men and women. The rankings of multivariate-adjusted ORs from highest to lowest were bladder, pancreas, kidney, and colorectum, with little difference between men and women.