Passive smoking and lung cancer in nonsmoking women.

OBJECTIVES. The causes of lung cancer among nonsmokers are not clearly understood. To further evaluate the relation between passive smoke exposure and lung cancer in nonsmoking women, we conducted a population-based, case-control study. METHODS. Case patients (n = 618), identified through the Missouri Cancer Registry for the period 1986 through 1991, included 432 lifetime nonsmokers and 186 ex-smokers who had stopped at least 15 years before diagnosis or who had smoked for less than 1 pack-year. Control subjects (n = 1402) were selected from driver's license and Medicare files. RESULTS. No increased risk of lung cancer was associated with childhood passive smoke exposure. Adulthood analyses showed an increased lung cancer risk for lifetime nonsmokers with exposure of more than 40 pack-years from all household members (odds ratio [OR] = 1.3; 95% confidence interval [CI] = 1.0, 1.8) or from spouses only (OR = 1.3; 95% CI = 1.0, 1.7). When the time-weighted product of pack-years and average hours exposed per day was considered, a 30% excess risk was shown at the highest quartile of exposure among lifetime nonsmokers. CONCLUSIONS. Ours and other recent studies suggest a small but consistent increased risk of lung cancer from passive smoking. Comprehensive actions to limit smoking in public places and worksites are well-advised.     

Lung Cancer in Chinese Women: Evidence for an Interaction between Tobacco Smoking and Exposure to Inhalants in the Indoor Environment

Background

Epidemiologic data suggest that Chinese women have a high incidence of lung cancer in relation to their smoking prevalence. In addition to active tobacco smoke exposure, other sources of fumes and airborne particles in the indoor environment, such as cooking and burning of incense and mosquito coils, have been considered potential risk factors for lung cancer.

Objectives

We used a case–control study to explore effects of inhalants from combustion sources common in the domestic environment on lung cancer and their modification by active tobacco smoking.

Methods

We analyzed 703 primary lung cancer cases and 1,578 controls. Data on demographic background and relevant exposures were obtained by face-to-face interviews in the hospital.

Results

We observed a positive relationship with daily exposure to incense or mosquito coils and to cooking fumes only among smokers, and no association among lifetime nonsmokers. Interactions between smoking and frequency of cooking, or exposure to incense or mosquito coils were statistically significant and consistent with synergistic effects on lung cancer. The odds ratio (OR) comparing smokers without daily incense or mosquito coil exposure with nonsmokers without daily exposure was 2.80 [95% confidence interval (CI), 1.86–4.21], whereas the OR comparing smokers with daily exposure to the same referent group was 4.61 (95% CI, 3.41–6.24). In contrast, daily exposure to incense or mosquito coils was not associated with lung cancer among nonsmokers (OR = 0.91; 95% CI, 0.72–1.16). We observed the same pattern of associations for smokers without (OR = 2.31; 95% CI, 1.52–3.51) and with (OR = 4.50; 95% CI, 3.21–6.30) daily cooking exposure compared with nonsmokers, with no evidence of an association with daily cooking exposure among nonsmokers.

Conclusion

Our results suggest that active tobacco smoking not only is an important risk factor for development of lung cancer, but also may cause smokers to be more susceptible to the risk-enhancing effects of other inhalants.     

Active and passive smoking in breast cancer: prospective results from the Nurses' Health Study

BACKGROUND: The role of active and passive smoking in breast cancer remains controversial. METHODS: Using data collected in the prospective Nurses' Health Study, we examined the influence of active and passive smoking on the incidence of invasive breast cancer. The analysis was based on women responding to the 1982 questionnaire, which included questions on passive smoking exposure. Information on active smoking was collected in biennial questionnaires. A total of 78,206 women were followed prospectively from 1982 until June 1996. RESULTS: Of these women, 3,140 reported a diagnosis of invasive breast cancer during follow-up. Compared with never active smoking, relative risks (RR) of breast cancer were 1.04 (95% CI = 0.94-1.15) for current active smoking and 1.09 (95% CI = 1.00-1.18) for past active smoking. The RR for regular passive exposure at work and at home was 0.90 (95% CI = 0.67-1.22). For active smoking, a modest increase in risk was confined to women who began smoking before the age of 17 (RR = 1.19; 95% CI = 1.03-1.37). CONCLUSION: Results suggest that passive smoking is unrelated to breast cancer. However, results for active smoking are compatible with a small increase in risk when smoking is initiated at young ages.     

Active and passive smoking and risk of breast cancer by age 50 years among German women

Recent studies suggest that both active and passive smokers have an increased risk of breast cancer compared with women who have never been either actively or passively exposed. Data on lifetime active and passive smoking were collected in 1999-2000 from 468 predominantly premenopausal breast cancer patients diagnosed by age 50 years and 1,093 controls who had previously participated in a German case-control study conducted in 1992-1995. Compared with never active/passive smokers, former smokers and current smokers had odds ratios of 1.2 (95% confidence interval (CI): 0.8, 1.7) and 1.5 (95% CI: 1.0, 2.2), respectively, and ever active smokers had an odds ratio of 1.3 (95% CI: 0.9, 1.9). The risk increased with duration of smoking and decreased after cessation of smoking. Among never active smokers, ever passive smoking was associated with an odds ratio of 1.6 (95% CI: 1.1, 2.4). Exposure to environmental tobacco smoke during childhood or before the first pregnancy did not appear to increase breast cancer risk. At greatest risk were women who had a high level of exposure to both passive and active smoking (odds ratio = 1.8, 95% CI: 1.2, 2.7). This study strengthens the hypothesis of a causal relation between active and passive smoke exposures and breast cancer risk.     

Cigarette smoking and breast cancer.

An epidemiological case-control study was conducted in New York State, with 1617 primary breast cancer patients and an equal number of controls, to examine the relationship between cigarette smoking and breast cancer. Results showed no overall association between ever smokers versus never smokers and breast cancer risk (odds ratio [OR] = 1.03, 95% confidence interval [CI]: 0.90-1.19), nor was there any dose response trend observed with increased levels of smoking. In addition, no association was found with risk and age started smoking, age stopped smoking, amount smoked or total years smoked. Controlling for previously identified risk factors for breast cancer in the analysis did not significantly alter these relationships. Previous studies have found a difference in menopausal age among smokers compared to nonsmokers. The mean menopausal age was only slightly lower in smokers than in never smokers for both cases and controls. Breast cancer risk was observed to be close to unity for premenopausal women (OR = 0.97, 95% CI: 0.74-1.34) and postmenopausal women (OR = 1.06, 95% CI: 0.91-1.26). A recent study suggested breast cancer risk was more strongly related to starting smoking at a young age among women who smoked at least 25 or more cigarettes per day in the most recent year of smoking. This hypothesis was not supported by these data.     

Exposure to environmental tobacco smoke in the nonsmoking population of Cambodia

OBJECTIVE: To estimate the extent of environmental tobacco smoke (ETS) exposure among nonsmokers in the adult population of Cambodia. METHODS: A cross-sectional survey was conducted on a nationally representative sample of 13,988 Cambodian adults in 2005. Information on smoking and exposure to ETS was obtained by trained interviewers using a standard questionnaire. RESULTS: Overall, 37.4% of the 10,263 nonsmoking responders, or an estimated 1,629,700 nonsmoking Cambodians, were exposed to ETS. One third of pregnant women (31.4%) were exposed to ETS at home. In both unadjusted and adjusted models, men were less likely to be exposed to ETS at home (OR=0.34; 95% CI=0.29-0.41) and more likely to be exposed to ETS at work and in public places (OR=3.08; 95% CI=2.14-4.43 and OR=2.17; 95% CI=1.82-2.59, respectively). Education was inversely related to ETS exposure at home (OR=0.51; 95% CI=0.27-0.96 for 10 years of education vs 5 years or less). Legislators, senior officials, and managers were less likely to be exposed to ETS at home than professionals (OR=0.13; 95% CI=0.04-0.46), but more likely to be exposed at work or in public places. Rural residence was associated with higher ETS exposure in the home (OR=2.52; 95% CI=1.71-3.71) and lower ETS exposure at work (OR=0.42; 95% CI=0.24-0.76) compared to urban residence. CONCLUSIONS: The high prevalence of ETS exposure among adult Cambodians indicates an urgent need for specific measures such as public awareness campaigns, policies, and regulations to protect nonsmokers in Cambodia.     

Risk factors for exposure to environmental tobacco smoke among ethnically diverse women in the United States

The likelihood of exposure to environmental tobacco smoke (ETS) has been shown to vary across sociodemographic characteristics, health behaviors, and the type of smoking restrictions at work. Women may be particularly at risk. The purpose of our study was to assess differences in the likelihood of exposure to ETS at home and at work among an ethnically diverse sample of women age 40 and older in the United States. We used data from the U.S. Women's Determinants Study and restricted the sample to include only nonsmoking women (n = 2326). Unadjusted and adjusted odds ratios (aOR) for exposure to ETS by sociodemographic characteristics, health risk behaviors, and the type of workplace smoking policy were calculated using logistic regression. Exposure to ETS at home was associated with being American Indian/Alaska Native (aOR 1.5, 95% CI 1.0, 2.6), age 40-44 (aOR 1.6, 95% CI 1.0, 2.6) and 45-54 (aOR 1.8, 95% CI 1.2, 2.6), having eighth grade (aOR 2.1, 95% CI 1.3, 3.6) or high school education (aOR 2.2, 95% CI 1.4, 3.3), inadequate fruit and vegetable consumption (aOR 1.5, 95% CI 1.0, 2.1), and not getting screened for breast cancer (aOR 1.5, 95% CI 1.1, 2.0). Women who did not have regular breast (aOR 1.3, 95% CI 1.9, 1.9) and cervical (aOR 2.0, 95% CI 1.5, 5.3) cancer screening were more likely to be exposed to ETS at work. Exposure to ETS at work was higher among women with some high school education (aOR 2.8, 95% CI 1.5, 5.3) and high school graduates (aOR 3.1, 95% CI 1.9, 5.1) and substantially higher for women who worked where smoking was allowed in some (aOR 15.1, 95% CI 10.2, 22.4) or all (aOR 44.8, 95% CI 19.6, 102.4) work areas. Larger effect sizes were observed for the relationship between selected risk factors and ETS exposure at work than for ETS exposure at home. Among individual risk factors, lower education level was most strongly related to ETS exposure at work. The likelihood of being exposed to ETS at work was highest for women whose workplace smoking policies allowed smoking in some or all work areas.     

孕妇被动吸烟与低出生体重关系的Meta分析

目的分析孕妇孕早期和不同孕期被动吸烟对新生儿低出生体重的影响。方法通过Meta分析方法分析孕妇被动吸烟与新生儿低出生体重之间的关系。对NCBI、OVID-MEDLINE、CNKI、VIP以及CBM数据库进行检索(截止日期为2008年4月),结果报告合并OR值及95%CI。结果共获得26篇文献,其中队列研究20篇,病例对照研究6篇。总体分析,孕妇被动吸烟的合并效应值OR=1.65(95%CI:1.39～1.97);调整合并效应值OR=1.60(95%CI:1.25～2.05);最低和最高暴露量的合并效应值分别为OR=1.53(95%CI:1.14～2.04)和OR=2.53(95%CI:1.46～4.36);孕早期暴露的合并效应值OR=1.12(95%CI:0.82～1.55),没有统计学意义。结论孕妇被动吸烟增加新生儿低出生体重的危险性;孕中晚期可能是被动吸烟效应的敏感期;被动吸烟的阈值是否存在尚不明确。     

南方女性复发性流产环境因素分析

目的:探讨南方女性不明原因复发性流产(undentifiedrecurrentspontaneousabortion,URSA)流行病学因素。方法:对326例URSA及400例正常对照育龄妇女进行健康问卷调查,用Logistic回归模型,纳入体重指数(BMI)、自然流产家族史、吸烟史、被动吸烟史、饮酒史、饮咖啡史,找出有独立意义的环境危险因素,并对自然流产次数3次及≥4次者进行分层分析。结果:吸烟史、饮酒史和饮咖啡史不是URSA的危险因素,短时间被动吸烟(1h/天)及长时间被动吸烟(≥1h/天)是URSA的危险因素,OR及95%CI分别是2.30,1.50～3.52及4.76,3.24～6.99。家族史及BMI≥24.0kg/m2是URSA危险因素,OR及95%CI分别是2.12,1.28～3.49及1.55,1.12～2.14。结论:被动吸烟史、BMI≥24.0kg/m2、自然流产家族史是中国南方女性URSA独立危险因素。     

Environmental tobacco smoke and lung cancer: a case-control study in Germany

To assess the association between exposure to environmental tobacco smoke (ETS) and lung cancer, the authors personally interviewed 292 lifelong nonsmoking lung cancer cases (recruited from 15 hospitals in the study area) and 1,338 nonsmoking controls (randomly selected by population registries) between 1990 and 1996 in Germany. Subjects were asked by a standardized questionnaire about exposure to ETS in childhood, by spouse, at work, and in transportation and social settings. Several indicators of these different sources of exposure were investigated, using not or low exposed subjects as the reference category. The most informative quantification index was weighted duration of exposure (hours x level of smokiness). No effect of ETS exposure during childhood and no clear effect of spousal ETS were observed. However, for the highest category of exposure, clear effects of ETS at the workplace (odds ratio (OR) = 1.93; 95% confidence interval (CI): 1.04, 3.58), in vehicles (OR = 2.64; 95% CI: 1.30, 5.36), and from all sources combined (OR = 1.39; 95% CI: 0.96, 2.01) were found. Adjustment for occupational carcinogens, radon, and diet did not appreciably change the results. These findings suggest that exposures to high levels of ETS at the workplace and in other public indoor settings appear to be important risk factors for lung cancer risk in nonsmokers.     

Influence of Asthma on the Validity of Reported Lifelong Environmental Tobacco Smoke in the EGEA Study

The aim of this study was to assess the short-term reproducibility and the validity of reported ETS (environmental tobacco smoke) exposure, with a special emphasis on the potential misclassification related to personal or family history of asthma. Analyses were based on the data on the Epidemiological study on the Genetics and Environment of Asthma, bronchial hyperresponsiveness and atopy (EGEA), a case-control study of asthma that included first degree relatives of asthmatic cases. The study was comprised of 348 families of asthmatics recruited in six chest clinics throughout France and 416 population-based controls. For studying the validity of ETS reports, personal active smoking histories reported by family members were taken as reference. The reproducibility of ETS exposure report was good, and independent of asthma. The validity of the report of maternal and paternal smoking in childhood and spouse smoking during life was high (overall agreement > or = 84%). Mothers of asthmatic children significantly underreported their smoking habits when questioned on their children's passive tobacco exposure. Offspring of parents who had stopped smoking underestimated their ETS exposure in childhood. In conclusion, interviews with mothers on their personal active smoking habits may provide a more accurate estimate of their asthmatic child's passive exposure than asking mothers specifically about their children's passive exposure. There was no indication that asthma status (either of the parent/spouse or of the respondent) by itself influences the report of ETS exposure during childhood or adulthood.     

Active smoking, passive smoking, and breast cancer risk: findings from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk

Background

Evidence is lacking regarding the relationship between cigarette smoking and breast cancer in Japanese women. We examined the association between breast cancer incidence and active and passive smoking in the Japan Collaborative Cohort Study for Evaluation of Cancer Risk.

Methods

Our study comprised 34,401 women aged 40-79 years who had not been diagnosed previously with breast cancer and who provided information on smoking status at baseline (1988-1990). The subjects were followed from enrollment until December 31, 2001. Cox proportional-hazards models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for the association between breast cancer incidence and tobacco smoke.

Results

During 271,412 person-years of follow-up, we identified 208 incident cases of breast cancer. Active smoking did not increase the risk of breast cancer, with a HR for current smokers of 0.67 (95% CI: 0.32-1.38). Furthermore, an increased risk of breast cancer was not observed in current smokers who smoked a greater number of cigarettes each day. Overall, passive smoking at home or in public spaces was also not associated with an increased risk of breast cancer among nonsmokers. Women who reported passive smoking during childhood had a statistically insignificant increase in risk (HR: 1.24; 95% CI: 0.84-1.85), compared with those who had not been exposed during this time.

Conclusion

Smoking may not be associated with an increased risk of breast cancer in this cohort of Japanese women.Key words: Smoking, Breast Neoplasms, Risk, Cohort Studies     

Breast cancer and active and passive smoking: the role of the N-acetyltransferase 2 genotype

The association of breast cancer with passive and active smoking was investigated in slow and fast acetylators of aromatic amines in a Geneva, Switzerland, study in 1996-1997. A slow acetylator was homozygous for one, or heterozygous for two, of three N-acetyltransferase 2 (NAT2) polymorphisms determined on buccal cell DNA from 177 breast cancer cases and 170 age-matched, population controls. The reference group consisted of women never regularly exposed to active or passive smoke. Among premenopausal women, the odds ratios were homogeneous in slow and fast acetylators: 3.2 (95% confidence interval (CI): 1.2, 8.7) for passive smoking and 2.9 (95% CI: 1.1, 7.5) for active smoking. Among postmenopausal women, the odds ratios for fast acetylators were 11.6 (95% CI: 2.2, 62.2) for passive and 8.2 (95% CI: 1.4, 46.0) for active smoking; the corresponding effects were also apparent but less strong in slow acetylators. After the nonexposed and the passive smokers were grouped in a single reference category, active smoking was associated with postmenopausal breast cancer in slow acetylators (odds ratio (OR) = 2.5, 95% CI: 1.0, 6.2) but not in fast acetylators (OR = 1.3, 95% CI: 0.5, 3.3). Thus, the associations of both passive and active smoking with breast cancer appear stronger in fast than in slow NAT2 genotypes. Separating passive smokers from the nonexposed impacts on the inference about a possible NAT2-smoking interaction.     

孕期被动吸烟对妊娠并发症及妊娠结局的影响

目的了解孕期被动吸烟发生情况,并探讨其对妊娠并发症及结局的影响。方法选取2012年4月―2013年3月在我国15家医疗保健机构分娩的8926例单胎活产产妇作为研究对象,使用自制调查问卷收集孕期被动吸烟发生情况、妊娠并发症和结局等信息,采用单因素和多因素Logistic回归分析模型分析孕期被动吸烟对妊娠并发症及结局的影响。结果共1801例产妇在孕期经历被动吸烟。控制混杂因素后,孕期经历被动吸烟的产妇妊娠期糖尿病(gestational diabetes mellitus,GDM)的发生风险是非被动吸烟者的1.359倍(95%CI:1.146~1.612,P<0.001),胎膜早破的风险为1.290倍(95%CI:1.095~1.520,P=0.002),早产的风险为1.367倍(95%CI:1.155~1.619,P<0.001),娩出低出生体重儿的风险为1.341倍(95%CI:1.079~1.668,P=0.008)。与非被动吸烟者相比,平均每周被动吸烟天数≥4天者胎膜早破、早产和低出生体重儿的发生风险分别为非被动吸烟者的1.402倍(95%CI:1.104~1.780,P=0.006)、1.690倍(95%CI:1.339~2.132,P<0.001)和1.584倍(95%CI:1.172~2.141,P=0.023)。结论被调查产妇孕期被动吸烟率较高,孕期经历被动吸烟能够增加妊娠期糖尿病、胎膜早破、早产和低出生体重儿的发生风险。     

Preterm delivery and exposure to active and passive smoking during pregnancy: a case-control study from Italy

The aim of this study was to assess the relationship between preterm/early preterm delivery and active smoking as well as environmental tobacco smoke (ETS) exposure in a sample of pregnant Italian women. A case-control study was conducted in nine cities in Italy between October 1999 and September 2000. Cases of preterm birth were singleton babies born before the 37th gestational week; babies born before the 35th gestational week were considered early preterm births. Controls were babies with gestational ages >or= 37th week. A total of 299 preterm cases (including 105 early preterm) and 855 controls were analysed. A self-administered questionnaire was used to assess active smoking and ETS exposure, as well as potential confounders. Multivariable logistic regression analysis showed a relationship between active smoking during pregnancy and preterm/early preterm delivery [adjusted ORs: 1.53; 95% CI 1.05, 2.21 and 2.00; 95% CI 1.16, 3.45, respectively]. A dose-response relationship was found for the number of cigarettes smoked daily. The adjusted ORs were 1.54 and 1.69 for preterm babies and 1.90 and 2.46 for early preterm babies for 1-10 and >10 cigarettes/day respectively. ETS exposure was associated with early preterm delivery [adjusted OR 1.56; 95% CI 0.99, 2.46] with a dose-response relationship with the number of smokers in the home. Smoking during pregnancy was strongly associated with preterm delivery with a dose-response effect. ETS exposure in non-smoking women was associated only with early preterm delivery.     

Marriage to a smoker and lung cancer risk.

As part of a population-based case-control study of lung cancer in New Mexico, we have collected data on spouses' tobacco smoking habits and on-the-job exposure to asbestos. The present analyses include 609 cases and 781 controls with known passive and personal smoking status, of whom 28 were lifelong nonsmokers with lung cancer. While no effect of spouse cigarette smoking was found among current or former smokers, never smokers married to smokers had about a two-fold increased risk of lung cancer. Lung cancer risk in never smokers also increased with duration of exposure to a smoking spouse, but not with increasing number of cigarettes smoked per day by the spouse. Our findings are consistent with previous reports of elevated risk for lung cancer among never smokers living with a spouse who smokes cigarettes.     

Lifetime environmental exposure to tobacco smoke and primary lung cancer of non-smoking Taiwanese women

BACKGROUND: For a female population with a high lung cancer mortality rate, such as Taiwanese women, who smoke relatively rarely, but live in an environment with high male smoking prevalence, the risk and population burden of lung cancer due to environmental tobacco smoke (ETS) are relatively important. METHODS: An age-matched case-control study was designed to investigate the effects of cumulative environmental exposure to tobacco smoke during childhood and adult life on lung cancer risk among non-smoking women in Taiwan. Information on passive smoking from all possible sources and life periods were obtained from interviews with 268 and 445 lifetime non-smoking cases and controls. Conditional logistic regression and synergism 'S' index were applied to the data to assess the independent and joint effects of passive smoking in different life stages while controlling for possible confounding variables. RESULTS: Risks of contracting lung cancer among women near-distantly exposed to the highest level of ETS in childhood (>20 smoker-years) and in adult life (>40 smoker-years) were 1.8-fold (95% CI: 1.2-2.9) and 2.2-fold (95% CI: 1.4-3.7) higher than that among women being never exposed to ETS, and the two variables accounted for about 37% of tumours in this non-smoking female population. Children were found to be more susceptible to ETS than adults and such early exposure was found to modify the effect of subsequent tobacco smoke exposure in adult life based on an additive interaction model. CONCLUSIONS: Environmental tobacco smoke exposure occurring in childhood potentiates the effect of high doses of exposure in adult life in determining the development of lung cancer. Smoking prohibition would be expected to protect about 37% of non-smoking Taiwanese women against lung cancer.     

Maternal active and passive smoking and fetal growth: A prospective study in Nagoya, Japan

In order to examine the effect of maternal active and passive smoking on fetal growth, we carried out a population-based cohort study. A self-administered questionnaire was distributed to 15,207 women who notified their pregnancy from April, 1989 to March, 1991. A total of 7,411 mother-singleton infant pairs were analyzed in this study. Paternal smoking status and maternal hours exposed to environmental tobacco smoke (ETS) were used as indicators of passive smoking. Infants born to active smoking mothers were 96 g lighter, on an average, at birth than those born to non-smokers, and the relative risk for intrauterine growth retardation was 1.79 (95% confidence interval (CI) = 1.05-3.04) among active smoking mothers. Infants with smoking fathers weighted 11 g lighter, on an average, than those with non-smoking fathers, and mean birth weight of infants was reduced by 19 g among mothers exposed to ETS. The relative risk for intrauterine growth retardation in non-smoking pregnants with a smoking husband and those exposed to ETS was 0.95 (95% CI = 0.72-1.26) and 0.95 (95% CI = 0.71-1.26), respectively. Our findings indicated an adverse effect of maternal active smoking on fetal growth in Japanese pregnant population, but with small influence of maternal passive smoking.     

Lifetime exposure to environmental tobacco smoke and cervical intraepithelial neoplasms among nonsmoking Taiwanese women

Cigarette smoke is one of the most important environmental risk factors for the development of cervical intraepithelial neoplasms (CINs). Given that the prevalence of cigarette smoking in Taiwanese women is very low, compared with Caucasian women (3-4% vs. approximately 28%, respectively), direct smoking is likely a minimal risk factor in the Taiwanese group. However, the evaluation of the association between indirect tobacco exposure, or exposure to environmental tobacco smoke (ETS), and CIN risk in Taiwanese women may be enlightening. The authors designed a community-based nested case-control study to examine the association between ETS exposure and CIN risk among Taiwanese women who were nonsmokers. The study was conducted in Chia-Yi, a city in southwestern Taiwan. The test population comprised adult females (n = 32,466) who had undergone Pap smear screening during the 14-mo period that preceded this study. Potential cases were chosen from individuals who demonstrated positive Pap smear results, which were indicative of at least a level II cervical intraepithelial neoplasm (i.e., > or = CIN2), as confirmed by cervical biopsy (n = 116). The authors chose 2 matched controls for each case; criteria used were (a) the 2 controls for each case had to be approximately the same age (+/- 2 yr) as the case; (b) each case and respective control lived in the same residential area; and (c) each control had a negative Pap smear, determined during the same time frame (+/- 6 mo) that the matched study subject was tested. A total of 100 study subjects and 197 control females (3 cases had only 1 control) underwent interviews by public health nurses, who obtained information about the participants' active and passive smoking histories and other potential risk factors. The incidence of cigarette smoking was low (5.0% [n = 5]) in study subjects and lower in controls (3.1% [n = 6]). The authors' final analysis was restricted to 89 nonsmoking pairs (89 subjects and 175 controls). Of the affected subjects, 85.4% reported exposure to passive smoke at home during their adulthood, vs. 61.1% of controls. The authors found that, after adjusting for other covariates, there was a 2.73-fold increased risk of contracting CIN (95% confidence interval [CI] = 1.31, 5.67) among ETS-exposed individuals. The authors assessed cumulative dose in terms of pack-years (i.e., average daily exposure [number of packs smoked] multiplied by the number of years the same exposure continued). Compared with nonsmokers, women exposed to 1-20 pack-yr and more than 20 pack-yr had 1.90-fold (95% CI = 0.72, 5.03) and 2.99-fold (95% CI = 1.10, 8.09) increased risks, respectively, of developing CIN. The authors concluded that lifetime ETS exposure is a major determinant for contracting cervical neoplasms among nonsmoking women in Taiwan.     

Environmental Tobacco Smoke and Lung Cancer Among Chinese Nonsmoking Males: Might Adenocarcinoma Be the Culprit?

No studies have specifically reported the association of lungadenocarcinoma with environmental tobacco smoke (ETS) exposureamong nonsmoking males. The objective of this study was to examinethe exposure-response relation between ETS exposure and lungcancer among nonsmoking males. In particular, the associationwith adenocarcinoma of the lung was studied. This is a population-based,case-referent study in Hong Kong during 2004–2006. A totalof 132 Chinese male nonsmokers with newly diagnosed primarylung cancer and 536 nonsmoking community referents were interviewedabout ETS exposures from the household and/or workplace, includingever ETS exposure, sources of exposure, number of smoking cohabitants/coworkers,and smoker-years. Univariate logistic regression analyses showeda weak association between all lung cancers and ever ETS exposurefrom the household and/or workplace (odds ratio (OR) = 1.11,95% confidence interval (CI): 0.74, 1.67), but an increasedrisk was restricted to adenocarcinoma (OR = 1.68, 95% CI: 1.00,2.38). After adjustment for family cancer history and otherconfounders, excess risk (OR = 1.62, 95% CI: 0.91, 2.88) stillpersisted for adenocarcinoma, although it was no longer statisticallysignificant. Exposure-response relations for adenocarcinomawere found with increasing levels of all ETS indices when exposuresfrom the household and workplaces were combined. The consistentexposure-response relations between ETS exposures and adenocarcinomasuggested a probable causal link, which would have to be confirmedby future larger studies. adenocarcinoma; lung neoplasms; tobacco smoke pollution