Environmental tobacco smoke and lung cancer risk in nonsmoking women.

BACKGROUND: Exposure to environmental tobacco smoke (passive smoking) has been suggested to be a cause of lung cancer, although early epidemiologic studies have produced inconsistent results. PURPOSE: We conducted an epidemiologic case-control study to assess the relationship between exposure to environmental tobacco smoke and lung cancer risk among women who have never smoked (i.e., having smoked for a total of less than 6 months or having smoked less than 100 cigarettes in their lifetimes). METHODS: Case patients (n = 210) were women with histologically confirmed primary carcinomas of the lung who were lifetime nonsmokers. They were identified through hospital tumor registries and the Florida Cancer Data System of the Statewide Cancer Registry. Community-based control women (n = 301) were also lifetime nonsmokers and were identified through random-digit dialing. Details on childhood and adulthood exposures to environmental tobacco smoke were ascertained through interviews with the study participants themselves or with surrogate respondents. Risks were calculated in terms of smoke-years, defined as the sum of the reported years of exposure to cigarette smoke from each smoker in the household. RESULTS: The risk of lung cancer more than doubled for women who reported 40 or more smoke-years of household exposure during adulthood (odds ratio [OR] = 2.4; 95% confidence interval [CI] = 1.1-5.3) or 22 or more smoke-years of exposure during childhood and adolescence (OR = 2.4; 95% CI = 1.1-5.4). Risks were highest for non-adenocarcinoma lung cancers, although modest elevations in risk were also observed for adenocarcinomas. When a surrogate respondent other than the patient's husband provided information on exposure, the risk estimates were considerably lower. CONCLUSION: These findings suggest that long-term exposure to environmental tobacco smoke increases the risk of lung cancer in women who have never smoked.

Histopathology of lung cancers among smokers and nonsmokers in Florida.

A study was undertaken of the relationship between lung cancer cell type and age, race, sex and smoking characteristics. The study population consisted of 35 183 cases of microscopically confirmed carcinoma of the lung, first diagnosed between 1981 and 1985, among residents of the state of Florida. The data suggested that the histological types of lung cancer observed varied by age, sex and the use of cigarettes. The number of cigarettes smoked per day did not appear to influence the cell types observed. The study indicated that adenocarcinomas occurred more frequently in lung cancer cases diagnosed at earlier ages, among both men and women. Among women who smoked, there was an increased proportion of small cell carcinomas compared to nonsmoking women, while in male smokers, the increase appeared primarily in squamous cell carcinomas.

Impact of smoking and smokeless tobacco on the risk of cancer of the head and neck.

A case-control epidemiologic study was conducted to determine the relationship between quantities and types of tobacco and the risk of cancers of individual sites within the head and neck. Substantial variations were found to exist in the tobacco-associated risk for each site. The use of cigarettes was associated with an increased risk of cancers of all sites, except the salivary glands. Cancers of the floor of the mouth and larynx exhibited the highest cigarette-related risks. Cigar smokers experienced excess risks of cancers of the tongue, pharynx, and larynx. Pipe smokers experienced elevated risks of cancer of the tongue, mouth, pharynx, and larynx. Among users of smokeless tobacco, increased risks of cancer of the mouth and gum, pharynx, and salivary glands were observed.

A cohort mortality study of painters and allied tradesmen.

A cohort study was conducted of the membership of a large international union of painters and allied tradesmen. The union membership consisted of both painters and associated trades such as glaziers and tile and carpet layers. The study examined the mortality experience of 57 175 current and former union members in four states (California, Missouri, New York, and Texas) in the United States (US) from 1975 through 1979. No excess mortality was observed for the total union membership when compared to that of all US white males. When the study population was subdivided by the trade affiliation, members of locals comprised primarily of painters exhibited a significant elevation in mortality from all malignant neoplasms, lung cancer, and stomach cancer, compared to all US white males. To reduce the impact of potential nonoccupational differences between the study population and all US white males, the data were also analyzed using the entire cohort as the standardization population. Significant elevations continued to be observed for all malignant neoplasms and lung cancer among the membership of painting locals compared to other locals. In addition there was a statistically significant difference in mortality from leukemia and cancer of the bladder observed between the groups.

Descriptive study of deaths from cancer associated with residential proximity to the site of underground nuclear detonations.

During the 1960s, two nuclear detonations were exploded in an underground salt dome in Lamar County, Mississippi. Citizens in this rural area expressed concern about excess cancer among the residents as a result of exposure to tritium. Researchers initiated an epidemiologic investigation in response to these concerns. Investigators identified 2251 deaths, of which 562 (25.7%) were cancer related. Observed cancer rates for the area of Mississippi were no different than those expected for the state as a whole. Investigators found no association between cancer mortality and distance from the center of detonation.

A case-control study of lung cancer in painters.

A case-control study of lung cancer was conducted within a cohort of painters and allied tradesmen drawn from the New York State membership of a large international union. Lung cancer cases were identified through the New York State Cancer Registry. Controls were randomly selected from the same union population. Data collected by mailed questionnaire included lifetime work history, work environment, and life-style factors. An almost threefold excess risk (odds ratio, 2.75) of lung cancer was associated with a usual occupation of painting. When a logistic regression model was used to adjust for other risk factors such as cigarette smoking, a fivefold excess lung cancer risk was observed among painters who never wore a mask or respirator; no excess risk was observed among painters who wore a mask or respirator.

Cigarette smoking and the risk of female reproductive cancer.

An epidemiologic study was conducted to evaluate the relationship between cigarette smoking and the risk of breast, endometrial, and ovarian cancers. Results indicated a clear reduction of risk for endometrial cancer among women aged 50 years and older who smoke cigarettes. Risks were significantly reduced among moderate smokers (odds ratio = 0.6), heavy smokers (odds ratio = 0.4), and former smokers (odds ratio = 0.6). No association was observed among women under age 50 years. When the relationship between cigarette smoking and breast cancer was investigated, no statistically significant association between cigarette smoking and the risk of breast cancer was observed except among women greater than 50 years who were light smokers only. There was also a nonstatistically significant increase in risk among younger women smoking more than two packs of cigarettes a day (odds ratio = 2.0), but overall there was no evidence of any relationship. Similarly, no association between ovarian cancer and cigarette smoking was apparent, although there was a nonsignificant increase in risk among women under age 50 years who smoked 40 or more cigarettes a day or were exsmokers.

Lung cancer in Florida. Risks associated with residence in the central Florida phosphate mining region.

A case-control study that included 25,398 cases of lung cancer among Florida residents, first diagnosed in 1981-1983, was conducted to determine if residence in the central Florida phosphate mining region was associated with an increased risk of lung cancer. A twofold increase in lung cancer risk was observed among male nonsmokers who lived in the study area. Risks were elevated for all major lung cancer cell types, with the highest risks observed for small cell carcinoma of the lung. Among cigarette smokers, a slight, but not statistically significant, additional increase in risk was associated with residence in the study area. Among women, no significant elevations in risk were observed for persons who lived in the study area. The greatest increase in risk among women was for small cell carcinomas, but the elevations were not statistically significant.

Dietary intake and risk of lung cancer in women who never smoked.

A case-control study was conducted to examine the influence of dietary factors on the risk of developing lung cancer among women who have never smoked cigarettes. This study included 124 cases of histologically confirmed carcinoma of the lung and 263 community-based controls. Dietary data were collected utilizing the reduced version of the National Cancer Institute (Block) food frequency questionnaire. The results of this analysis, adjusted for age, education, and total calories, indicated a strong protective effect associated with total vegetable consumption and intake of carotene. Individuals in the highest quartile of vegetable consumption experienced the greatest decreased risk with an odds ratio (OR) of 0.2, [confidence interval (CI) 0.1-0.5]. The effect of all vegetables combined was greater than that of green and yellow vegetables alone (highest quartile OR 0.4, CI 0.2-0.7). Similarly, the protective effect of total carotene (highest quartile OR 0.3, CI 0.1-0.6) was somewhat greater than that of beta-carotene alone (highest quartile OR 0.4, CI 0.2-0.8). Retinol intake was not associated with a decreased risk of lung cancer in our population. There was an inverse association between lung cancer risk and vitamin C intake, which was not significant, although a statistically significant trend was noted.

Sugarcane exposure and the risk of lung cancer and mesothelioma.

A case-control study was conducted of the risk of lung cancer and mesothelioma from environmental and occupational exposures associated with sugarcane production. A slight, not statistically significant, excess risk of lung cancer was observed among participants who reported working in the sugarcane industry (odds ratio 1.8, 95% confidence interval 0.5-7.5). No increased risk was observed among our population, associated with living near sugarcane growing areas. Little difference was observed between cases and controls in years employed in the industry or jobs performed. Only one mesothelioma case and no controls reported working in the sugarcane industry.