Passive smoking and breast cancer risk among non-smoking Chinese women

Our purpose was to evaluate whether passive exposure to cigarette smoke may be related to breast cancer risk. Data from the Shanghai Breast Cancer Study, a large population-based study of 1459 breast cancer cases and 1556 controls aged 25-64 years, were analyzed. Respective response rates were 91.1% and 90.3%. Passive smoking questions were added to all face-to-face interviews 7 months into the study. Women were asked about exposure to their husbands' smoke at home as well as exposure in the workplace. Analyses were restricted to the 1013 cases and 1117 controls with passive tobacco smoke exposure data who had never actively smoked. Over 60% of controls reported some exposure to a husband's smoke and over 40% reported exposure to passive smoke in the workplace. Overall, there was no apparent association between any passive smoke exposure or exposure to a husband's smoke and breast cancer risk. There was some evidence of an elevated breast cancer risk associated with passive smoking exposure of 5 hr or more per day in the workplace (OR = 1.6, 95% confidence interval 1.0-2.4; p for trend = 0.02). This association warrants further investigation.     

Incidence and mortality of female breast cancer in the AsiaPacific region

Objective： To provide an overview of the incidence and mortality of female breast cancer for countries in the Asia-Pacific region.Methods： Statistical information about breast cancer was obtained from publicly available cancer registry and mortality databases（such as GLOBOCAN）, and supplemented with data requested from individual cancer registries. Rates were directly age-standardised to the Segi World Standard population and trends were analysed using joinpoint models.Results： Breast cancer was the most common type of cancer among females in the region, accounting for 18% of all cases in 2012, and was the fourth most common cause of cancer-related deaths（9%）. Although incidence rates remain much higher in New Zealand and Australia, rapid rises in recent years were observed in several Asian countries. Large increases in breast cancer mortality rates also occurred in many areas, particularly Malaysia and Thailand, in contrast to stabilising trends in Hong Kong and Singapore, while decreases have been recorded in Australia and New Zealand. Mortality trends tended to be more favourable for women aged under 50 compared to those who were 50 years or older. Conclusion： It is anticipated that incidence rates of breast cancer in developing countries throughout the Asia-Pacific region will continue to increase. Early detection and access to optimal treatment are the keys to reducing breast cancerrelated mortality, but cultural and economic obstacles persist. Consequently, the challenge is to customise breast cancer control initiatives to the particular needs of each country to ensure the best possible outcomes.     

Relationship of cigarette smoking and radiation exposure to cancer mortality in Hiroshima and Nagasaki

Cancer mortality among 40,498 Hiroshima and Nagasaki residents was examined in relation to cigarette smoking habits and estimated atomic bomb radiation exposure level. Relative risk (RR) models that are either multiplicative or additive in the two exposures were emphasized. Most analyses were directed toward all nonhematologic (ANH) cancer, stomach cancer, lung cancer, or digestive tract cancer other than stomach cancer, for which there were, respectively, 1,725, 658, 281, and 338 deaths in the follow-up period for this study. Persons heavily exposed to both cigarette smoke and radiation were found to have significantly lower cancer mortality than multiplicative RR models would suggest for ANH cancer, stomach cancer, and digestive tract cancer other than stomach cancer. Surprisingly, the RR function appeared not only to be submultiplicative for some of these cancer site categories but also may be subadditive. The lung cancer RR function could not be distinguished from either a multiplicative or an additive form. The number of deaths was sufficient to permit some more detailed study of ANH cancer mortality: RR functions appeared to be consistent between males and females, though a paucity of heavy smoking females limits the precision of this comparison. The submultiplicative nature of the RR function mentioned above was particularly pronounced among persons who were relatively young (less than or equal to 30 yr of age) at the time of radiation exposure. The RR function for these younger subjects depends strongly on both radiation and cigarette smoke exposure levels. Even light smoking (approximately 5 cigarettes/day) for an extended period of time was associated with a large estimated RR. Implications of these findings are discussed in relation to human carcinogenesis models. As a byproduct, cancer mortality of several sites is significantly related to radiation exposure in this population, after accommodation for the possible confounding effects of cigarette smoking.     

Passive smoking and lung cancer among Japanese women

A case-control study conducted in Hiroshima and Nagasaki, Japan, revealed a 50% increased risk of lung cancer among nonsmoking women whose husbands smoked. The risks tended to increase with amount smoked by the husband, being highest among women who worked outside the home and whose husbands were heavy smokers, and to decrease with cessation of exposure. The findings provide incentive for further evaluation of the relationship between passive smoking and cancer among nonsmokers.     

Mendelian randomisation study of smoking exposure in relation to breast cancer risk

Background Despite a modest association between tobacco smoking and breast cancer risk reported by recent epidemiological studies, it is still equivocal whether smoking is causally related to breast cancer risk.Methods We applied Mendelian randomisation (MR) to evaluate a potential causal effect of cigarette smoking on breast cancer risk. Both individual-level data as well as summary statistics for 164 single-nucleotide polymorphisms (SNPs) reported in genome-wide association studies of lifetime smoking index (LSI) or cigarette per day (CPD) were used to obtain MR effect estimates. Data from 108,420 invasive breast cancer cases and 87,681 controls were used for the LSI analysis and for the CPD analysis conducted among ever-smokers from 26,147 cancer cases and 26,072 controls. Sensitivity analyses were conducted to address pleiotropy.Results Genetically predicted LSI was associated with increased breast cancer risk (OR 1.18 per SD, 95% CI: 1.07–1.30, P = 0.11 × 10^–2), but there was no evidence of association for genetically predicted CPD (OR 1.02, 95% CI: 0.78–1.19, P = 0.85). The sensitivity analyses yielded similar results and showed no strong evidence of pleiotropic effect.Conclusion Our MR study provides supportive evidence for a potential causal association with breast cancer risk for lifetime smoking exposure but not cigarettes per day among smokers.Subject terms: Breast cancer, Risk factors     

天津市女性乳腺癌发病率死亡率和生存率分析

目的：观察天津市乳腺癌发病率和死亡率的变化趋势,评价乳腺癌的防治效果。方法：用描述流行病学的方法研究天津市乳腺癌的流行情况。结果：1981－1997年间,天津市乳腺癌总发病率有增加的趋势（增加了39．7％）,年龄别发病率高峰有下降的趋势,死亡率有下降的趋势（下降了31．0％）。同时,通过对1970－1995年天津市肿瘤医院确诊的所有女性乳腺癌随访发现,天津市乳腺癌3,5年生存率均有不同程度的提高。结论：天津市乳腺癌发病率增长较快,但同时死亡率在下降,生存率在提高。     

Burden of disease from breast cancer attributable to smoking and second-hand smoke exposure in Europe

Smoking and second-hand smoke (SHS) exposure have been recently linked to a higher risk of breast cancer in women. The aim of this work is to estimate the number of deaths and disability-adjusted life years (DALYs) from breast cancer attributable to these two risk factors in the European Union (EU-28) in 2017. The comparative risk assessment method was used. Data on prevalence of smoking and SHS exposure were extracted from the Eurobarometer surveys, relative risks from a recent meta-analysis, and data on mortality and DALYs from breast cancer were estimated from the Global Burden of Disease, Injuries and Risk Factors Study. In 2017, 82 239 DALYs and 3354 deaths from breast cancer in the EU-28 could have been avoided by removing exposure to these two risk factors (smoking and SHS exposure). The proportion of DALYs from breast cancer lost respectively from smoking and SHS exposure was 2.6% and 1.0%, although geographically distributed with significant heterogeneity. These results represent the first estimates of breast cancer burden in women attributable to smoking and SHS exposure for the EU-28. It is important to increase awareness among women, health professionals and wider society of the association between smoking, SHS exposure and breast cancer, a relationship that is not widely recognised or discussed.     

Passive smoking and lung cancer in Chandigarh, India.

The aim of this study is to assess the relationship between exposure to environmental tobacco smoke (ETS) and lung cancer in non-smokers, a case-control study among lifetime non-smokers was conducted in Chandigarh, India. Cases consisted of 58 non-smoking histologically confirmed lung cancer patients; two controls for each case were selected, one among other patients admitted to the wards and one among the visitors to hospital patients. Subjects were asked about ETS exposure from different tobacco products in childhood and in adulthood at home, at the work place and in vehicles. Multivariate logistic regression analysis was used to assess the effects of the ETS exposure variables on lung cancer. Exposure to ETS during childhood was strongly associated with lung cancer (odds ratio (OR) = 3.9; 95% confidence interval (CI) = 1.9-8.2), the effect mostly arising from exposure to cigarettes smoke. The excess risk was observed with either a smoking father or mother. An increasing risk was found with increasing number of smokers and duration of exposure. Restricting the analysis to women produced higher estimates of the risk. No increased risk was found with exposure to a smoking spouse, except for those exposed only to cigarette smoke (OR = 5.1; 95% CI = 1.5-17). A weak association was seen between lung cancer and ETS exposure at the workplace, which increased with the number of years of exposure. Exposure in vehicles also was detected as a risk factor for lung cancer in non-smokers. This study suggests that ETS exposure may be a strong risk factor for lung cancer also in India, a country with low prevalence of smoking and, therefore, low rates of lung cancer. Other studies need to be conducted in similar settings to confirm the role played by ETS exposure early in life in the causation of lung cancer.     

Alcohol, cigarette smoking and breast cancer

The results of two case-control studies of breast cancer which included questions on exposure to tobacco and alcohol are reported. One study included 998 hospital cases and a like number of matched hospital controls while the other included 118 cases identified during mammographic screening and a like number of matched normal screenees. Both studies used the same questionnaires and the same methods to obtain information. The results with regard to cigarette smoking differed between the two studies. The hospital-based study showed a decreased risk of breast cancer with increasing amounts smoked (relative risk for 15 or more cigarettes per day was 0.82, 95% confidence interval 0.60-1.13) while the screening study showed an increased risk (relative risk for 15 or more cigarettes per day was 2.90, 95% confidence interval 1.16-7.25). Evidence is presented that both results may be attributable to bias in the selection of cases and controls. It is concluded that reliable results on the relationship between smoking and breast cancer are only likely to come from population-based studies. These studies, in general, have found no relationship. Neither study produced any hint of an association between alcohol consumption and breast cancer. From this, it appears that bias in subject selection may not be such a significant factor in interpretation of studies of alcohol and breast cancer as it is in studies of smoking and the disease. A number of other difficulties in the interpretation of studies of alcohol and breast cancer are considered, including the great variation in the amount of alcohol consumed. It is concluded that the assertion that alcohol is a risk factor for breast cancer remains unproven.     

山东省1970-2005年女性乳腺癌死亡率变化趋势

目的:分析山东省1970-2005年女性乳腺癌的死亡情况.方法:根据山东省1970-2005年全死因调查资料以及乳腺癌的死亡登记历史资料,计算女性乳腺癌的死亡率、中国1964年人口和世界1967年人口标化死亡率,采用游程检验和Cox-Stuart检验分析女性乳腺癌死亡率的变化趋势.结果:女性乳腺癌的死亡率随年龄增长呈上升趋势.山东省1970-2005年女性乳腺癌的死亡率总体无显著性上升,但2005年的世界人口标化死亡率(5.35/10万)仍然显著高于1970年(4.49/10万).按照城乡分布,城市女性乳腺癌的死亡率高于农村.城市女性乳腺癌死亡率1970-1992年呈上升趋势,1992年后则平稳略降;农村则是从1992年后呈上升趋势.结论:山东女性乳腺癌发病及死亡率仍处于低水平,但农村显示出明显的上升趋势.根据乳腺癌的相关危险性因素变化,预期今后城乡女性乳腺癌死亡率会缓慢上升.     

Cadmium exposure and breast cancer risk

Cadmium, a highly persistent heavy metal, has been categorized as a probable human carcinogen by the U.S. Environmental Protection Agency. Primary exposure sources include food and tobacco smoke. We carried out a population-based case-control study of 246 women, aged 20-69 years, with breast cancer and 254 age-matched control subjects. We measured cadmium levels in urine samples by inductively coupled plasma mass spectrometry and conducted interviews by telephone to obtain information on known breast cancer risk factors. Odds ratios (ORs) and 95% confidence intervals (CIs) for breast cancer by creatinine-adjusted cadmium levels were calculated by multivariable analysis. Statistical tests were two-sided. Women in the highest quartile of creatinine-adjusted cadmium level (> or = 0.58 microg/g) had twice the breast cancer risk of those in the lowest quartile (<0.26 microg/g; OR = 2.29, 95% CI = 1.3 to 4.2) after adjustment for established risk factors, and there was a statistically significant increase in risk with increasing cadmium level (P(trend) = .01). Based on this study, the absolute risk difference is 45 (95% CI = 0 to 77) per 100,000 given an overall breast cancer rate of 124 per 100,000. Whether increased cadmium is a causal factor for breast cancer or reflects the effects of treatment or disease remains to be determined.     

Oestrogen exposure and breast cancer risk

Epidemiological and experimental evidence implicates oestrogens in the aetiology of breast cancer. Most established risk factors for breast cancer in humans probably act through hormone-related pathways, and increased concentrations of circulating oestrogens have been found to be strongly associated with increased risk for breast cancer in postmenopausal women. This article explores the evidence for the hypothesis that oestrogen exposure is a major determinant of risk for breast cancer. We review recent data on oestrogens and breast cancer risk, consider oestrogen-related risk factors and examine possible mechanisms that might account for the effects of oestrogen. Finally, we discuss how these advances might influence strategies for reducing the incidence of breast cancer.