Dietary habits and lung cancer risk among non-smoking women

Anticarcinogenic potentials of tea catechins

Catechins are a cluster of polyphenolic bioactive components in green tea. Anticarcinogenic effects of tea catechins have been reported since the 1980s, but it has been controversial. The present paper reviews the advances in studies on the anticarcinogenic activities of tea and catechins, including epidemiological evidence and anticarcinogenic mechanism. Tea catechins showed antagonistic effects on many cancers, such as gynecological cancers, digestive tract cancers, incident glioma, liver and gallbladder cancers, lung cancer, etc. The mechanism underlying the anticarcinogenic effects of catechins involves in inhibiting the proliferation and growth of cancer cells, scavenging free radicals, suppressing metastasis of cancer cells, improving immunity, interacting with other anticancer drugs, and regulating signaling pathways. The inconsistent results and their causes are also discussed in this paper.

Etiology of lung cancer: Evidence from epidemiologic studies

Lung cancer is one of the leading causes of cancer incidence and mortality worldwide. While smoking, radon, air pollution, as well as occupational exposure to asbestos, diesel fumes, arsenic, beryllium, cadmium, chromium, nickel, and silica are well-established risk factors, many lung cancer cases cannot be explained by these known risk factors. Over the last two decades the incidence of adenocarcinoma has risen, and it now surpasses squamous cell carcinoma as the most common histologic subtype. This increase warrants new efforts to identify additional risk factors for specific lung cancer subtypes as well as a comprehensive review of current evidence from epidemiologic studies to inform future studies. Given the myriad exposures individuals experience in real-world settings, it is essential to investigate mixture effects from complex exposures and gene-environment interactions in relation to lung cancer and its subtypes.

Fruits and Vegetables and Lung Cancer Risk in Never Smokers. A Multicentric and Pooled Case-Control Study

BACKGROUND

The etiology of lung cancer in never smokers is partly unknown. We aimed to assess the effect of fruits and vegetables consumption on lung cancer risk in never smokers.

METHODS

We pooled five multicenter case-control studies performed in Northwestern Spain. Cases and controls were all never smokers. All lung cancer cases had anatomopathological confirmed diagnoses. We performed a multivariate logistic regression to analyze the effect of different types of fruits and vegetables consumption on lung cancer risk.

RESULTS

A total of 438 cases and 781 controls were included. We observed that a consumption from one to six times per week shows a negative association with lung cancer risk for: kiwis (OR 0.67; 95%CI 0.46-0.95), oranges (OR 0.55; 95%CI 0.37-0.80), turnip tops (OR 0.48; 95%CI 0.34-0.66), "berza gallega" (OR 0.70; 95%CI 0.51-0.97) and broccoli (OR 0.55; 95%CI 0.35-0.83) compared to less than once a week consumption. On the other hand, we found an increased risk for lung cancer with a daily consumption of tomatoes, carrots and potatoes.

CONCLUSIONS

Oranges, kiwis, turnip tops, berza gallega and broccoli may play a protective role on lung cancer development in never smokers while tomatoes, carrots and potatoes might have some association with this disease.

Risk of lung cancer among women in relation to lifetime history of tobacco smoking: a population-based case-control study in France (the WELCA study)

Background

This study aims to provide new insights on the role of smoking patterns and cigarette dependence in female lung cancer, and to examine differences by histological subtype.

Methods

We conducted a population-based case-control study in the great Paris area among women including 716 incident cases diagnosed between 2014 and 2017 and 757 age-matched controls. Detailed data on smoking history was collected during in-person interviews to assess intensity and duration of tobacco smoking, time since cessation, smoking habits (depth of smoke inhalation, use of filter, type of tobacco, and type of cigarettes) and Fagerström test for cigarette dependence. The comprehensive smoking index (CSI), a score modelling the combined effects of intensity, duration and time since quitting smoking was determined for each subject. Multivariable logistic regression models were fitted to calculate odds ratios (ORs) and their confidence intervals (95%CI) of lung cancer associated with smoking variables.

Results

Lung cancer risk increased linearly with intensity and duration of tobacco smoking while it decreased with time since cessation, to reach the risk in never-smokers after 20 years of abstinence. The combined effect of intensity and duration of tobacco smoking was more than multiplicative (p-interaction 0.012). The OR in the highest vs the lowest quartile of CSI was 12.64 (95%CI 8.50; 18.80) (p-trend < 0.001). The risk of small cell or squamous cell carcinomas increased with the CSI more sharply than the risk of adenocarcinomas. Deep smoke inhalation, dark vs blond tobacco, conventional vs light cigarettes, and unfiltered vs filtered cigarettes, as well as having mixed smoking habits, were found to be independent risk factors. Having high cigarette addiction behaviours also increased the risk after adjusting for CSI.

Conclusion

This study provides additional insights on the effects of tobacco smoking patterns on lung cancer risk among women.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08433-z.

Food, Nutrition, Physical Activity and Microbiota: Which Impact on Lung Cancer?

Lung cancer still represents the leading cause of cancer-related death, globally. Likewise, malnutrition and inactivity represent a major risk for loss of functional pulmonary capacities influencing overall lung cancer severity. Therefore, the adhesion to an appropriate health lifestyle is crucial in the management of lung cancer patients despite the subtype of cancer. This review aims to summarize the available knowledge about dietary approaches as well as physical activity as the major factors that decrease the risk towards lung cancer, and improve the response to therapies. We discuss the most significant dietary schemes positively associated to body composition and prognosis of lung cancer and the main molecular processes regulated by specific diet schemes, functional foods and physical activity, i.e., inflammation and oxidative stress. Finally, we report evidence demonstrating that dysbiosis of lung and/or gut microbiome, as well as their interconnection (the gut–lung axis), are strictly related to dietary patterns and regular physical activity playing a key role in lung cancer formation and progression, opening to the avenue of modulating the microbiome as coadjuvant therapy. Altogether, the evidence reported in this review highlights the necessity to consider non-pharmacological interventions (nutrition and physical activity) as effective adjunctive strategies in the management of lung cancer.

Citrus fruit intake and lung cancer risk: A meta-analysis of observational studies

OBJECTIVE

To explore the hypothesis that Citrus intake may reduce the risk of lung cancer.

DESIGN

Meta-analyses of Dichotomy and dose-response relationship.

DATA SOURCES

We searched online literature databases including PubMed, Embase, and Cochrane Library to screen relevant articles available up to 27 July 2020. Search terms included (i) Citrus, Fruit, Diet, Dietary; (ii) cancer, neoplasm, tumor (iii)lung; (iv)case-control, cohort, prospective.

STUDY SELECTION

The selection of studies and the meta-analysis were carried out by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The following inclusion criteria were chosen: (i) epidemiological studies with case-control or cohort design; (ii) human participants; (iii) studies investigated the relationship between Citrus fruit intake and lung cancer risk; (iv) if data were duplicated in more than two studies, we brought the most recent or all-sided study into this analysis. We collected all full-text articles that met the inclusion criteria. We applied the following exclusion criteria to the full-text articles, including possible articles listed by manual search: (i) there was no represented odds ratio (OR) or relative risk (RR) estimate and its corresponding 95 % confidence interval (95 % CI) (or data to calculate them) for the highest versus lowest levels of Citrus fruit consumption (ii) reviews, systematic reviews and meta-analyses; (iii) there was no data of Citrus fruit intake at the individual level.

DATA EXTRACTION

Two reviewers independently performed the extraction of data from eligible studies.

STATISTICAL METHODS

Adjusted odds ratios (ORs) and 95 % CIs were combined and weighted by the method of "Dersimonian and Laird" to produce pooled ORs using a random-effects model. Moreover, we utilized the method reported by "Longnecker and Greenland" to evaluate linear trends and 95 % CIs by the ORs' natural logs and corresponding CIs from categories of Citrus intake. Finally, we evaluated the risk of publication bias and selection bias by inspecting for asymmetry in the pre-specified funnel plots of the study OR against the standard error of the OR's logarithm and by "Egger's test".

RESULTS

We included twenty-one studies in the final review. Pooled analyses suggested that those with the highest Citrus fruit intake compared to the lowest intake had a 9% reduction in lung cancer risk [OR 0.91 (95 % CI 0.84-0.98)]. We found a nonlinear association between Citrus intake and lung cancer risk in the dose-response analysis (p = 0.0054) and that the risk reached the minimum (OR = 0.91) around 60 g/d. However, no obvious dose-response association was observed with intakes above 80 g/d.

CONCLUSION

We found that Citrus fruit intake was negatively associated with the risk of lung cancer. Besides, there was a nonlinear dose-response relationship between Citrus intake and lung cancer risk within a certain range.

Green tea (Camellia sinensis) for the prevention of cancer

BACKGROUND

This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (2009, Issue 3).Tea is one of the most commonly consumed beverages worldwide. Teas from the plant Camellia sinensis can be grouped into green, black and oolong tea, and drinking habits vary cross-culturally. C sinensis contains polyphenols, one subgroup being catechins. Catechins are powerful antioxidants, and laboratory studies have suggested that these compounds may inhibit cancer cell proliferation. Some experimental and nonexperimental epidemiological studies have suggested that green tea may have cancer-preventative effects.

OBJECTIVES

To assess possible associations between green tea consumption and the risk of cancer incidence and mortality as primary outcomes, and safety data and quality of life as secondary outcomes.

SEARCH METHODS

We searched eligible studies up to January 2019 in CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and reference lists of previous reviews and included studies.

SELECTION CRITERIA

We included all epidemiological studies, experimental (i.e. randomised controlled trials (RCTs)) and nonexperimental (non-randomised studies, i.e. observational studies with both cohort and case-control design) that investigated the association of green tea consumption with cancer risk or quality of life, or both.

DATA COLLECTION AND ANALYSIS

Two or more review authors independently applied the study criteria, extracted data and assessed methodological quality of studies. We summarised the results according to diagnosis of cancer type.

MAIN RESULTS

In this review update, we included in total 142 completed studies (11 experimental and 131 nonexperimental) and two ongoing studies. This is an additional 10 experimental and 85 nonexperimental studies from those included in the previous version of the review. Eleven experimental studies allocated a total of 1795 participants to either green tea extract or placebo, all demonstrating an overall high methodological quality based on 'Risk of bias' assessment. For incident prostate cancer, the summary risk ratio (RR) in the green tea-supplemented participants was 0.50 (95% confidence interval (CI) 0.18 to 1.36), based on three studies and involving 201 participants (low-certainty evidence). The summary RR for gynaecological cancer was 1.50 (95% CI 0.41 to 5.48; 2 studies, 1157 participants; low-certainty evidence). No evidence of effect of non-melanoma skin cancer emerged (summary RR 1.00, 95% CI 0.06 to 15.92; 1 study, 1075 participants; low-certainty evidence). In addition, adverse effects of green tea extract intake were reported, including gastrointestinal disorders, elevation of liver enzymes, and, more rarely, insomnia, raised blood pressure and skin/subcutaneous reactions. Consumption of green tea extracts induced a slight improvement in quality of life, compared with placebo, based on three experimental studies. In nonexperimental studies, we included over 1,100,000 participants from 46 cohort studies and 85 case-control studies, which were on average of intermediate to high methodological quality based on Newcastle-Ottawa Scale 'Risk of bias' assessment. When comparing the highest intake of green tea with the lowest, we found a lower overall cancer incidence (summary RR 0.83, 95% CI 0.65 to 1.07), based on three studies, involving 52,479 participants (low-certainty evidence). Conversely, we found no association between green tea consumption and cancer-related mortality (summary RR 0.99, 95% CI 0.91 to 1.07), based on eight studies and 504,366 participants (low-certainty evidence). For most of the site-specific cancers we observed a decreased RR in the highest category of green tea consumption compared with the lowest one. After stratifying the analysis according to study design, we found strongly conflicting results for some cancer sites: oesophageal, prostate and urinary tract cancer, and leukaemia showed an increased RR in cohort studies and a decreased RR or no difference in case-control studies.

AUTHORS' CONCLUSIONS

Overall, findings from experimental and nonexperimental epidemiological studies yielded inconsistent results, thus providing limited evidence for the beneficial effect of green tea consumption on the overall risk of cancer or on specific cancer sites. Some evidence of a beneficial effect of green tea at some cancer sites emerged from the RCTs and from case-control studies, but their methodological limitations, such as the low number and size of the studies, and the inconsistencies with the results of cohort studies, limit the interpretability of the RR estimates. The studies also indicated the occurrence of several side effects associated with high intakes of green tea. In addition, the majority of included studies were carried out in Asian populations characterised by a high intake of green tea, thus limiting the generalisability of the findings to other populations. Well conducted and adequately powered RCTs would be needed to draw conclusions on the possible beneficial effects of green tea consumption on cancer risk.

Perioperative outcome of lung cancer surgery in women: results from a Spanish nationwide prospective cohort study

Background

To assess possible differences in the perioperative profile between men and women in lung cancer surgery.

Methods

A prospective cohort multicenter study was design, in which consecutive patients undergoing curative intent surgery for lung cancer in 24 Thoracic Services throughout Spain were included. Clinical features, tumor- and surgery-related data, postoperative complications, and mortality were recorded.

Results

There were 2,566 men and 741 women. Women were younger than men [mean (SD) age, 61.8 (10.8) vs. 66.5 (9.1) years, P<0.0001] and showed a more favorable preoperative characteristics, with significantly higher percentages of ECOG grade 0 and lower percentages of active smokers (28.4% vs. 33.9%; pack-years 18.8 vs. 26.9) and comorbidities [chronic obstructive pulmonary disease (COPD), diabetes, hypertension, cardiac disorders]. There were significant differences (P<0.001) in histological types and TNM stages with adenocarcinoma (70.1% vs. 46.4%) and IA stage (41.5% vs. 33.6%) more frequent in women. The use of VATS or thoracotomy was similar. The rate of pneumonectomy was higher in men (10.9%) than in women (5.1%) (P<0.001) but the distributions of other procedures were similar. Postoperative complications (pneumonitis, atelectasis, air leak, hemorrhage, fistula, empyema, wound dehiscence, and need of reintubation) were lower in women. Significant differences (P<0.0001) in the severity of postoperative complications (Clavien-Dindo classification) were also found, with higher percentages of grades I (51.6% vs. 43%) and II (37.5% vs. 33%) and lower percentages of grades III and IV among women. The mean length of hospital stay was 7.8 (7.1) days in men versus 6.3 (5.0) days in women, and the 30-day mortality rate 0.3% in women versus 2.9% in men (P<0.0001). The percentage of readmissions within 30 days after surgery was also higher in men (8.6% vs. 2.8%).

Conclusions

This multicenter nationwide study of lung cancer surgery with curative intent shows that the perioperative profile is better in women than in men.

Pharmacological values and therapeutic properties of black tea (Camellia sinensis): A comprehensive overview

Medicinal plants are essential parts of traditional medicine due to their phytochemical constituents having pharmacological values and therapeutic applications. Black tea have thousands of various biological compounds such as flavonoids (Thearubigins (TRs) and theaflavins (TFs) and catechins), amino acids (L.theanine), vitamins (A, C, K), phenolic acids (caffeic acid (CA), gallic acid (GA), chlorogenic acids (CGA) and cauramic acid), lipids, proteins, volatile compounds carbohydrates, β-carotene and fluoride that illustrated many promising pharmacological effects regarded as growth promoter, cardioprotector, potent cholesterol-lowering effect, antioxidant and antimicrobial, etc inhuman. Although there is an exponential growth in molecular evidence of cholesterol-lowering and antioxidant effect in human, there is still a lack of information of the pharmacological effects of black tea. To fill this information gap, therefore, this review article underscores broadening the new insight pertaining to black tea that could be used as safe food additive. This article also illuminates the interesting role of black tea as an herbal medicine that is the future demand to get rid of synthetic health promoters in the human health practice. Moreover, this information would be useful in terms of the low-cost practice of natural medicines with no residual effects, and a natural protection of the human being. In addition, further studies at a molecular level are needed to reveal its mechanism of action particularly for the hypocholesterolemic effect of black tea to overcome the heart-related diseases, fewer side effects and being a natural safeguard of human health.

[Clinical Epidemiology and Histological Characteristics of 3,663 Lung Cancer Patients in Sichuan Province from 2008 to 2013]

背景与目的

肺癌作为全球男女性中致死率最高的肿瘤之一，严重威胁着人类的健康。近些年来，各个地区肺癌的发病率及死亡率也有逐年上升的趋势。本研究旨在分析四川地区肺癌患者的临床病理特征与流行趋势，了解肺癌地区与时间分布特点及差异。

方法

收集2008年-2013年四川大学华西医院就诊的四川地区肺癌患者，分析川中、川南、川北、川西的患者临床病理特征及流行趋势。

结果

纳入患者3, 663例（川中2, 378例，川南469例，川北584例，川西232例）。患者平均年龄59.6岁，各个地区患者平均年龄不同（P < 0.001），以川中最大，为61.0岁。患者以男性为主（68.4%），不同地区患者男性构成比存在差异（P=0.014），以川北最高，为73.3%。此外，各个地区的病理类型构成比也存在差异（P=0.014），腺癌和鳞癌都在川西构成比最高，分别为57.8%和30.2%，小细胞癌则在川北构成比最高（19.9%）。2013年腺癌与鳞癌构成比较2008年均有所降低，早期肺癌及淋巴结转移构成比有所上升。此外，不同地区肺癌患者3年生存率不同（P=0.021），以川西最低，仅为13.6%，可能与该地区采用姑息治疗患者比率高相关。

结论

近六年于我院就诊的四川地区肺癌患者以川中为主，男性多见，中老年为甚，腺癌居多，且腺癌和鳞癌的构成比与六年前相比均有下降，早期肺癌及淋巴结转移构成比上升。不同地区肺癌患者的平均年龄、男性构成比、病理类型及3年生存率均有差异。

Does smoking influence the physical activity and lung cancer relation? A systematic review and meta-analysis

Research suggests an inverse association between physical activity and lung cancer. However, whether the relation is modified by degree of smoking adjustment has not been summarized. We conducted a meta-analysis of physical activity and lung cancer focusing on evaluating whether smoking status and the degree of smoking adjustment influenced the association. Comparing high versus low physical activity levels from 25 observational studies yielded a lung cancer summary relative risk (RR) of 0.79 [95 % confidence interval (CI) = 0.72-0.87], with RRs of 0.87 (95 % CI = 0.80-0.94) for cohort studies and 0.57 (95 % CI = 0.46-0.71) for case-control studies. In further analyses restricted to cohort studies, physical activity was inversely related to lung cancer among former smokers (RR = 0.68, 95 % CI = 0.51-0.90) and current smokers (RR = 0.80, 95 % CI = 0.70-0.90), whereas the association was null among never smokers (RR = 1.05, 95 % CI = 0.78-1.40, p interaction = 0.26). The degree of smoking adjustment did not modify the association (p interaction = 0.73). Physical activity was unrelated to lung cancer among never smokers but it was inversely associated with lung cancer among former and current smokers. Although the physical activity and lung cancer relation was not modified by smoking status or degree of smoking adjustment, residual confounding by smoking remains a possible explanation for the relations observed.

Physical Activity and Risk of Lung Cancer: A Meta-analysis

OBJECTIVE

Previous studies concerning the association between physical activity (PA) and risk of lung cancer yielded mixed results. We investigated the association by performing a meta-analysis.

DATA SOURCES

Relevant studies were identified by searching PubMed and EMBASE to January 2014. Twelve cohort studies and 6 case-control studies involving 2 468 470 participants and 26 453 cases of lung cancer were selected for meta-analysis.

MAIN RESULTS

We calculated the summary relative risk (RR) and 95% confidence intervals (CIs) using random-effects models. The analyses showed that individuals who participated in any amount of PA had an RR of 0.79 (95% CI, 0.73-0.86) for risk of lung cancer. Those who participated in high PA (vs low PA) had an RR of 0.75 (95% CI, 0.68-0.84). Stratifying by study design (case-control and cohort studies), smoking status (current, former, and never smokers), and gender, similar inverse associations were found for all the subgroups except for never smokers subgroup.

CONCLUSIONS

Pooled results from observational studies support a protective effect of PA against lung cancer.

Dairy Product, Calcium Intake and Lung Cancer Risk: A Systematic Review with Meta-Analysis

The effects of dairy products on human health have been studied for years. However, the relationship between dairy products as well as calcium intake and the risk of lung cancer is still inconclusive. A total of 32 studies regarding this association were identified from the PubMed and Web of Science databases through April 1, 2015, including 12 cohort studies and 20 case-control studies. After pooling the results of individual studies, the summary RRs (relative risks) of lung cancer for the highest versus lowest intake were 1.05 (95%CI: 0.84–1.31) and 1.08 (95%CI: 0.80–1.46) for total dairy products and milk, respectively. The results on the consumption of cheese, yogurt and low-fat milk were also negative, and the RRs for total and dietary calcium intakes were 0.99 (95%CI: 0.70–1.38) and 0.85 (95%CI: 0.63–1.13), respectively. After stratifying by potential confounders, the results remained consistent in most subgroup analyses. Our study indicates that intake of dairy products or calcium was not statistically associated with the risk of lung cancer. This negative finding provides a conclusive answer to the disease association issue based on current evidence, and suggests that further efforts should be made to find other nutritional risk factors for lung cancer.

Lactose intolerance and risk of lung, breast and ovarian cancers: aetiological clues from a population-based study in Sweden

Background:

Individuals with lactose intolerance are recommended to avoid milk or dairy products, which may affect the development of cancer.

Methods:

We identified individuals with lactose intolerance from several Swedish Registers linked to the Swedish Cancer Registry to calculate standardised incidence ratios (SIRs) for cancers in the breast, lung, and ovary.

Results:

A total of 22 788 individuals with lactose intolerance were identified, and their risks of lung (SIR=0.55), breast (SIR=0.79), and ovarian (SIR=0.61) cancers were significantly decreased. Cancer incidences in the siblings and parents of individuals with lactose intolerance were similar to those in the general population.

Conclusions:

In this large cohort study, people with lactose intolerance, characterised by low consumption of milk and other dairy products, had decreased risks of lung, breast, and ovarian cancers, but the decreased risks were not found in their family members, suggesting that the protective effects against these cancers may be related to their specific dietary pattern.

Fruit and vegetable consumption and lung cancer risk: a case-control study in Galicia, Spain

Lung cancer has multiple risk factors and tobacco is the main one. Diet plays a role, but no clear effect has been consistently observed for different fruit and vegetable consumption. We aim to assess the association between fruit and vegetable consumption and lung cancer risk through a hospital-based case-control study in Spanish population. We recruited incident lung cancer cases in 2 Spanish hospitals from 2004 to 2008. Controls were individuals attending hospital for trivial surgery. Cases and controls were older than 30 and did not have a neoplasic history. We collected information on lifestyle with special emphases on tobacco and dietary habits. We included 371 cases and 496 controls. We found no protective effect for overall fruit consumption. For green leafy vegetables, the odds ratio (OR) was 0.92 [95% confidence interval (CI) = 0.32-2.69), and for other vegetables the OR was 0.77 (95% CI = 0.40-1.48) for the categories compared. We observed a reduced risk for broccoli and pumpkin intake. Although fruit consumption does not seem to be associated with a lower lung cancer risk, only the frequent consumption of specific green leafy vegetables and other vegetables might be associated with a reduced risk of lung cancer.

Body mass index, cholesterol level and risk of lung cancer in Lithuanian men

OBJECTIVE

Our objective was to investigate the association between body mass index (BMI), total serum cholesterol (TSC) level and risk of lung cancer in a Lithuanian population-based cohort study.

MATERIALS AND METHODS

The study included 6729 men initially free from cancer. During the follow-up (1978-2008), 358 lung cancer cases were identified. Cox proportional hazards models were used to estimate hazard ratios (HR) and corresponding 95% confidence intervals (95% CI).

RESULTS

Following adjustment for age, smoking, alcohol consumption, and education, BMI 25-29.9 and ≥30.0kg/m(2) hazard ratios (HR) were significantly associated with decreasing risk for lung cancer, HR=0.73; 95% CI: 0.59, 0.91 and 0.62; 95% CI: 0.45, 0.87, respectively (ptrend=0.001) compared to BMI<25 kg/m(2). Inverse association between BMI and lung cancer was observed among current smokers. We found no evidence that BMI was associated with decreased lung cancer risk in never smokers, although small sample size precluded meaningful analysis. Not significantly lower risk of lung cancer among participants in the 5th quintile compared with the 1st quintile of TSC concentrations was observed. HR per 1 mmol/l increase of TSC was 0.90; 95% CI: 0.82, 1.00. Findings suggest consistent effects of BMI and TSC when follow-up was 1993-2008.

CONCLUSION

Our results show an inverse dose-dependent association between lung cancer risk and BMI in Lithuanian men, especially among current smokers. The inverse association could not be attributed to preclinical cancer effect hypothesis. TSC level was not statistically significantly related to a lung cancer incidence.

Tea and health: studies in humans

Tea, next to water is the cheapest beverage humans consume. Drinking the beverage tea has been considered a healthpromoting habit since ancient times. The modern medicinal research is providing a scientific basis for this belief. The evidence supporting the health benefits of tea drinking grows stronger with each new study that is published in the scientific literature. Tea plant Camellia sinensis has been cultivated for thousands of years and its leaves have been used for medicinal purposes. Tea is used as a popular beverage worldwide and its ingredients are now finding medicinal benefits. Encouraging data showing cancer-preventive effects of green tea from cell-culture, animal and human studies have emerged. Evidence is accumulating that black tea may have similar beneficial effects. Tea consumption has also been shown to be useful for prevention of many debilitating human diseases that include maintenance of cardiovascular and metabolic health. Various studies suggest that polyphenolic compounds present in green and black tea are associated with beneficial effects in prevention of cardiovascular diseases, particularly of atherosclerosis and coronary heart disease. In addition, anti-aging, antidiabetic and many other health beneficial effects associated with tea consumption are described. Evidence is accumulating that catechins and theaflavins, which are the main polyphenolic compounds of green and black tea, respectively, are responsible for most of the physiological effects of tea. This article describes the evidences from clinical and epidemiological studies in the prevention of chronic diseases like cancer and cardiovascular diseases and general health promotion associated with tea consumption.

Tea consumption and lung cancer risk: a meta-analysis of case-control and cohort studies

OBJECTIVE

Recent epidemiologic studies, especially cohort and case-control studies, have yielded inconsistent findings regarding the association between tea consumption and risk for lung cancer. The aim of this study was to assess a potential relationship between tea consumption and the incidence of lung cancer worldwide.

METHODS

A systematic literature search of PubMed, Web of Science, the Cochrane Library, Google Scholar, the Chinese Biomedical Database, and Wanfang Database was conducted from 1966 to January 2014 by two investigators. All cohort studies and case-control studies that evaluated the association of tea and lung cancer were included. Summary relative risks (RR) and the corresponding 95% confidence intervals (CIs) were calculated using a random-effects model. Quality assessments were performed using the Newcastle-Ottawa Scale. Heterogeneity was assessed using the Q and I(2) tests, and the source of heterogeneity was detected by meta-regression analysis. Publication bias was evaluated with Egger's regression symmetry test. Subgroup analyses and sensitivity analysis were performed.

RESULTS

Thirty-eight lung cancer studies (26 case-control studies and 12 cohort studies) with 59,041 cases and 396,664 controls were included. Overall tea consumption was significantly associated with decreased risk for lung cancer (RR, 0.78; 95% CI, 0.70-0.87). Subgroup analyses showed that tea consumption was associated with reduced risk for lung cancer in women (RR, 0.76; 95% CI, 0.62-0.93), case-control studies (RR 0.72; 95% CI 0.63-0.83), Western studies (RR, 0.85; 95% CI, 0.75-0.97), and studies in China and Japan (RR, 0.74; 95% CI, 0.62-0.88). Both green tea (RR, 0.75; 95% CI, 0.62-0.91) and black tea (RR, 0.82; 95% CI, 0.71-0.94) were significantly associated with reduced lung cancer risk. No significant association was found in men or in cohort studies.

CONCLUSION

Tea consumption may offer some protection against lung cancer.

Meat consumption and risk of lung cancer: evidence from observational studies

BACKGROUND

A number of epidemiological studies have reported inconsistent findings on the association between meat consumption and lung cancer.

DESIGN

We therefore conducted a systematic review and meta-analysis to investigate the relationship between meat consumption and lung cancer risk in epidemiological studies.

RESULTS

Twenty-three case-control and 11 cohort studies were included. All studies adjusted for smoking or conducted in never smokers. The summary relative risks (RRs) of lung cancer for the highest versus lowest intake categories were 1.35 (95% confidence interval (CI) 1.08-1.69) for total meat, 1.34 (95% CI 1.18-1.52) for red meat, and 1.06 (95% CI 0.90-1.25) for processed meat. An inverse association was found between poultry intake and lung cancer (RR = 0.91, 95% CI 0.85-0.97), but not for total white meat (RR = 1.06, 95% CI 0.82-1.37) or fish (RR = 1.01, 95% CI 0.96-1.07).

CONCLUSIONS

The relationship between meat intake and lung cancer risk appears to depend on the types of meat consumed. A high intake of red meat may increase the risk of lung cancer by about 35%, while a high intake of poultry decreases the risk by about 10%. More well-designed cohort studies on meat mutagens or heme iron, meat cooking preferences, and doneness level are needed to fully characterize this meat-lung cancer association.

Body mass index and lung cancer risk: results from the ICARE study, a large, population-based case-control study

BACKGROUND

The association between body mass index (BMI) and lung cancer is still disputed because of possible residual confounding by smoking and preclinical weight loss in case-control studies. We examined this association using data from the multicenter ICARE study in France, a large, population-based case-control study.

METHODS

A total of 2,625 incident lung cancer cases and 3,381 controls were included. Weight was collected at interview, 2 years before the interview, and at age 30. Lifetime smoking exposure was calculated using the comprehensive smoking index (CSI). Adjusted odds ratios (aORs) and 95 % confidence intervals were estimated by unconditional logistic regression and controlled for age, area, education, CSI, occupational exposure, previous chronic bronchitis, and parental history of lung cancer. We also examined the role of weight change. Analyses were stratified by smoking status and sex.

RESULTS

When compared with that of men with normal BMI 2 years before the interview, lung cancer aORs (95 % CI) among men with BMIs of <18.5, 25-29.9, 30-32.4, and ≥32.5 kg/m(2) were 2.7 (95 % CI 1.2-6.2), 0.9 (95 % CI 0.7-1.1), 0.8 (95 % CI 0.6-1.1), and 0.8 (95 % CI 0.6-1.0), respectively (p(trend) = 0.02). Results were more pronounced among current smokers and were similar in men and women. Weight gain over time was associated with a significant decreased risk of lung cancer.

CONCLUSIONS

We found an inverse dose-dependent association between lung cancer risk and BMI 2 years prior to interview in current smokers. IMPACT STATEMENT: BMI might be an individual factor impacting the risk of lung cancer related to smoking's carcinogen-induced DNA damage.

Dietary patterns affect lung cancer risk in never smokers

A number of studies suggest a role of dietary factors as risk predictors of lung cancer in never smokers. However, it is difficult to interpret the observed associations of lung cancer risk with any particular dietary item due to high correlation among different dietary items. In this study, we derived uncorrelated patterns of dietary items in the never smokers and evaluated the association of these patterns with lung cancer risk, using food frequency data from 299 never-smoker lung cancer patients and 317 controls enrolled in an ongoing case-control lung cancer study. We identified 2 major dietary patterns in never smokers: a "healthy eating" pattern including vegetables, fruits, and low-fat food items, and a "mixed dishes" pattern including most foods with positive loadings. Using multivariable regression analysis, we show that the healthy eating pattern is associated with a significant reduction of lung cancer risk among never smokers. The effect of the healthy eating pattern remained significant after adjustment for age, gender, education, caloric intake, secondhand smoke exposure, and family history of cancer. This finding, if confirmed in a prospective study, has a clear preventive significance, by promoting interventions encouraging healthier diets.

Outcome and treatment strategy in female lung cancer: a single institution experience

PURPOSE

To assess the survival rate of female lung cancer treated at the Institute of Oncology of the Vilnius University, Lithuania during the period between 1996-2005.

MATERIALS AND METHODS

During the period between 1996-2005, 471 women diagnosed with lung cancer were treated at the Department of Thoracic Surgery and Oncology of the Institute of Oncology, Vilnius University. Data on morphology, stage and treatment was collected from the medical records. All lung cancer cases by histology were classified in two groups: non-small cell lung cancer (includes squamous cell carcinoma, large cell carcinoma, adenocarcinoma and other less common types) and small cell lung cancer. The vital status of the study group was assessed as of December 31, 2007, by passive follow-up, using data from the population registry. It was found that 411 (87.3%) of the patients had died. Survival was estimated according to the Kaplan-Meier method.

RESULTS

The median survival of female lung cancer diagnosed during 1996-2005 in Lithuania show to be 8.7 months (8.4 (95% CI 7.2-10.8) months with non-small cell lung cancer and 9.3 (95% CI 6.3-13.0) months with small-cell lung cancer). Survival was more than 20 months in resectable non-small cell lung cancer (stages I, II, IIIA). Non-small cell lung cancer survival in advanced stages was less than 7 months. Small-cell lung cancer patients median survival at limited and extended stages of the disease were 9.5 (95% CI 2.9-18.4) compared to 9.2 (95% CI 6.2-13.7) months. Non-small cell lung cancer patients most frequently were treated by surgery (27.0%), surgery and chemotherapy or radiotherapy (19.6%). Small cell lung cancer patient treatment included chemo and radiotherapy (27.0%), chemotherapy (19.0%), radiotherapy (17.5%), surgery (27.9%).

CONCLUSIONS

The single center study of female lung cancer diagnosed during 1996-2005 in Lithuania show a significantly better chance of survival in resectable non-small cell lung cancer. Advanced stages of the disease at the time of diagnosis and choice of treatment options of female lung cancer in the country still remains an issue.

Coffee consumption and risk of lung cancer: a meta-analysis

Epidemiologic studies have evaluated the potential association between coffee consumption and lung cancer risk. However, results were inconsistent. To clarify the role of coffee in lung cancer, we conducted a meta-analysis on this topic. We searched PubMed and EMBASE databases (from 1966 to January 2009) and the reference lists of retrieved articles. Study-specific risk estimates were pooled using random-effects model. Five prospective studies and 8 case-control studies involving 5347 lung cancer cases and 104,911 non-cases were included in this meta-analysis. The combined results indicated a significant positive association between highest coffee intake and lung cancer [relative risk (RR)=1.27, 95% confidence interval (CI)=1.04-1.54). Furthermore, an increase in coffee consumption of 2 cups/day was associated with a 14% increased risk of developing lung cancer (RR=1.14, 95% CI=1.04-1.26). In stratified analyses, the highest coffee consumption was significantly associated with increased risk of lung cancer in prospective studies, studies conducted in America and Japan, but borderline significantly associated with decreased risk of lung cancer in non-smokers. In addition, decaffeinated coffee drinking was associated with decreased lung cancer risk, although the number of studies on this topic was relative small. In conclusion, results from this meta-analysis indicate that high or an increased consumption of coffee may increase the risk of lung cancer. Because the residual confounding effects of smoking or other factors may still exist, these results should be interpreted with caution.

Green tea, black tea consumption and risk of lung cancer: a meta-analysis

Studies investigating the association of green tea and black tea consumption with lung cancer risk have reported inconsistent findings. To provide a quantitative assessment of this association, we conducted a meta-analysis on the topic. Studies were identified by a literature search in PubMed from 1966 to November 2008 and by searching the reference lists of relevant studies. Summary relative risk (RR) estimates and their corresponding 95% confidence intervals (CIs) were calculated based on random-effects model. Our meta-analysis included 22 studies provided data on consumption of green tea or black tea, or both related to lung cancer risk. For green tea, the summary RR indicated a borderline significant association between highest green tea consumption and reduced risk of lung cancer (RR=0.78, 95% CI=0.61-1.00). Furthermore, an increase in green tea consumption of two cups/day was associated with an 18% decreased risk of developing lung cancer (RR=0.82, 95% CI=0.71-0.96). For black tea, no statistically significant association was observe through the meta-analysis (highest versus non/lowest, RR=0.86, 95% CI=0.70-1.05; an increment of two cups/day, RR=0.82, 95% CI=0.65-1.03). In conclusion, our data suggest that high or an increase in consumption of green tea but not black tea may be related to the reduction of lung cancer risk.

A review of the epidemiological evidence on tea, flavonoids, and lung cancer

Tea and its main bioactive ingredients, the flavonoids, have been associated with human cancer for several decades. In this article, an overview is provided of observational epidemiological studies of lung cancer incidence in relation to intake of green tea, black tea, flavonols/flavones, and catechins. A PubMed search was conducted in September 2007. Articles were selected if they provided risk ratios (relative risk or odds ratio) for lung cancer and were of observational design (cohort, case-control, or case-cohort). Three of 12 studies reported a significantly lower risk of lung cancer with a high intake of flavonoids, whereas 1 study reported a significantly increased risk. After stratification by type of flavonoid, catechin intake was no longer associated with lung cancer risk in 3 of 4 studies available. For tea, 4 of 20 studies reported significantly reduced risks with high intake. Two studies found significantly increased risk ratios, but both were older studies. Findings were similar for green and black tea but became more significant when only methodologically sounder cohort studies were considered. When tea intake and lung cancer were studied among never- or former smokers to eliminate the confounding effect of smoking, 4 of 7 reported associations were significantly protective. In general, the studies on tea, flavonoids, and lung cancer risk indicate a small beneficial association, particularly among never-smokers. More well-designed cohort studies, in particular for catechins, are needed to strengthen the evidence on effects of long-term exposure to physiological doses of dietary flavonoids.

Body mass index and waist circumference in relation to lung cancer risk in the Women's Health Initiative

Investigators in several epidemiologic studies have observed an inverse association between body mass index (BMI) and lung cancer risk, while others have not. The authors used data from the Women's Health Initiative to study the association of anthropometric factors with lung cancer risk. Over 8 years of follow-up (1998-2006), 1,365 incident lung cancer cases were ascertained among 161,809 women. Cox proportional hazards models were used to estimate hazard ratios adjusted for covariates. Baseline BMI was inversely associated with lung cancer in current smokers (highest quintile vs. lowest: hazard ratio (HR) = 0.62, 95% confidence interval (CI): 0.42, 0.92). When BMI and waist circumference were mutually adjusted, BMI was inversely associated with lung cancer risk in both current smokers and former smokers (HR = 0.40 (95% CI: 0.22, 0.72) and HR = 0.61 (95% CI: 0.40, 0.94), respectively), and waist circumference was positively associated with risk (HR = 1.56 (95% CI: 0.91, 2.69) and HR = 1.50 (95% CI: 0.98, 2.31), respectively). In never smokers, height showed a borderline positive association with lung cancer. These findings suggest that in smokers, BMI is inversely associated with lung cancer risk and that waist circumference is positively associated with risk.

Associations between beer, wine, and liquor consumption and lung cancer risk: a meta-analysis

OBJECTIVE

Epidemiologic studies suggest that the effect on lung cancer risk may be different for beer, wine, and liquor. We conducted dose-specific meta-analyses and dose-response meta-regression to summarize findings from the current literature on the association between consumption of beer, wine, or liquor and lung cancer risk.

RESULTS

Average beer consumption of one drink or greater per day was associated with an increased risk of lung cancer [relative risk (RR), 1.23; 95% confidence interval (95% CI), 1.06-1.41]. This association was observed in both men and women, although it was only significant in men. A J-shaped dose-response curve was suggested for beer intake. An inverse association was observed for both average wine consumption of less than one drink per day (RR, 0.77; 95% CI, 0.59-1.00) and one drink or greater per day (RR, 0.78; 95% CI, 0.60-1.02) in the drinking range incurred in the source studies. Average liquor consumption of one drink or greater per day was found to be associated with increased risk in men (RR, 1.33; 95% CI, 1.10-1.62). No association was observed for liquor drinking in women. The presence of heterogeneity between studies was detected. Study design, country, gender, adjustment factors, and lung cancer histologic type were not significant predictors of the heterogeneity.

CONCLUSIONS

The results from this meta-analysis suggest that high consumption of beer and liquors may be associated with increased lung cancer risk, whereas modest wine consumption may be inversely associated with risk. More research with improved control of confounding is needed to confirm these findings and to establish the dose-response relationship, particularly risk at high consumption levels.

Unpasteurized milk consumption and subsequent risk of cancer

Concerns have been raised regarding the possible adverse health effects of consumption of unpasteurized milk and risk of cancer. We examined the association of self-reported intake of unpasteurized milk with subsequent risk of cancer in a large population-based cohort study. The Iowa Women's Health Study is a prospective cohort study of 55-69 year old women at baseline in 1986. Of the 41,836 women in the cohort at baseline, 22,808 cancer-free women completed the fourth follow-up questionnaire in 1997. Risk ratios (RR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards regression analysis. Reported intake of unpasteurized milk was high: 59.2% consumed only as a child, 2.5% consumed only as an adult, and 16.5% consumed as a child and an adult. A total of 2,379 cancers were identified in the cohort at risk. Overall, the age-adjusted risk of cancer was lower among women who reported consumption of unpasteurized milk only as a child (RR = 0.90, 95% CI: 0.82-0.99) or as a child and an adult (RR = 0.85; 95% CI: 0.75-0.97). Adjustment for confounding factors attenuated these associations (RR = 0.92, 95% CI: 0.83-1.02 for consumption only as a child, and RR = 0.91; 95% CI: 0.79-1.04 for consumption as a child and an adult). These data suggest that consumption of unpasteurized milk does not increase risk of cancer.

Body Mass Index and Lung Cancer Risk in Women

BACKGROUND

Studies have suggested that leanness in adulthood may be a risk factor for lung cancer; however, there is justifiable concern that the observed association may be due to residual confounding by smoking, preclinical weight loss, competing causes of death, or some combination of these.

METHODS

To examine this association we used data from the Canadian National Breast Screening Study, which included 89,835 women ages 40-59 years at recruitment between 1980 and 1985. During a mean of 16 years of follow-up, we observed 750 incident lung cancer cases. We used Cox proportional hazards models to estimate hazard ratios and 95% confidence intervals for the association between body mass index (BMI) and lung cancer.

RESULTS

After adjustment for pack-years of smoking and other covariates, there was some evidence for inverse associations in current smokers (hazard ratio for highest BMI quintile relative to the lowest = 0.63; 95% confidence interval = 0.48-0.83) and in former smokers (0.69; 0.39-1.23), whereas in never-smokers, BMI was positively associated with lung cancer (2.19; 1.00-4.80). The results for current and former smokers were not altered by exclusion of cases diagnosed within the first 5 years of follow-up; however, in never-smokers the strength of the association was reduced.

CONCLUSIONS

The present study contributes to the aggregate evidence suggesting that there may be an inverse association between BMI and lung cancer among smokers. However, the contrasting pattern of associations between BMI and lung cancer seen in ever-smokers and never-smokers in this study requires explanation.

Inhibition of carcinogenesis by tea constituents

The possible cancer preventive activity of tea has received much attention in recent years. The inhibitory activities of tea and tea constituents against carcinogenesis at different organ sites have been demonstrated in many animal models. The effect of tea consumption on human cancers, however, remains inconclusive. The mechanisms of action of tea polyphenols, especially EGCG, the most abundant and active catechin, have been extensively investigated. Most of the studies, however, were based on cell culture systems, and these mechanisms need to be evaluated and verified in animal models or humans in order to gain more understanding on the effect of tea consumption on human cancer. Human intervention trials are warranted to determine the possible prevention of cancer of specific sites by preparation of tea constituents.

Tea polyphenols for health promotion

People have been consuming brewed tea from the leaves of the Camellia sinensis plant for almost 50 centuries. Although health benefits have been attributed to tea, especially green tea consumption since the beginning of its history, scientific investigations of this beverage and its constituents have been underway for less than three decades. Currently, tea, in the form of green or black tea, next to water, is the most widely consumed beverage in the world. In vitro and animal studies provide strong evidence that polyphenols derived from tea may possess the bioactivity to affect the pathogenesis of several chronic diseases. Among all tea polyphenols, epigallocatechin-3-gallate has been shown to be responsible for much of the health promoting ability of green tea. Tea and tea preparations have been shown to inhibit tumorigenesis in a variety of animal models of carcinogenesis. However, with increasing interest in the health promoting properties of tea and a significant rise in scientific investigation, this review covers recent findings on the medicinal properties and health benefits of tea with special reference to cancer and cardiovascular diseases.

Gender differences in non-small cell lung cancer: a population-based study

BACKGROUND

A retrospective study including all patients with non-small cell lung cancer carcinoma in a population-based registry was performed to characterize gender differences in lung cancer and to analyze the factors influencing prognosis in women.

METHODS

We retrieved through the Tuscan Cancer Registry (RTT) archive 2,523 lung tumor cases diagnosed during the period 1996-1998 in the provinces of Florence and Prato, central Italy. We compared the prognosis within 464 non-small lung cancer women and 1,798 men in a population-based case series. The influence of the following variables on postoperative survival were analyzed: age, cell type, pathologic T and N status, site of tumor and type of surgical resection.

RESULTS

The age at diagnosis was similar in women and in men. Women were significantly more likely to have adenocarcinoma but less likely to have squamous cell carcinoma compared with men. Fewer pneumonectomies were performed in women than in men. Nevertheless, prognosis was similar in both sexes and type of surgical resection was significant prognostic factor.

CONCLUSIONS

Lung cancer was more frequent in men than in women, but overall survival is similar. Differences in lung cancer histology and rate of pneumonectomies were found between men and women.

Fruit and vegetable consumption and lung cancer risk: Updated information from the European Prospective Investigation into Cancer and Nutrition (EPIC)

The association of fruit and vegetable consumption and lung cancer incidence was evaluated using the most recent data from the European Prospective Investigation into Cancer and Nutrition (EPIC), applying a refined statistical approach (calibration) to account for measurement error potentially introduced by using food frequency questionnaire data. Between 1992 and 2000, detailed information on diet and life-style of 478,590 individuals participating in EPIC was collected. During a median follow-up of 6.4 years, 1,126 lung cancer cases were observed. Multivariate Cox proportional hazard models were applied for statistical evaluation. In the whole study population, fruit consumption was significantly inversely associated with lung cancer risk while no association was found for vegetable consumption. In current smokers, however, lung cancer risk significantly decreased with higher vegetable consumption; this association became more pronounced after calibration, the hazard ratio (HR) being 0.78 (95% CI 0.62-0.98) per 100 g increase in daily vegetable consumption. In comparison, the HR per 100 g fruit was 0.92 (0.85-0.99) in the entire cohort and 0.90 (0.81-0.99) in smokers. Exclusion of cases diagnosed during the first 2 years of follow-up strengthened these associations, the HR being 0.71 (0.55-0.94) for vegetables (smokers) and 0.86 (0.78-0.95) for fruit (entire cohort). Cancer incidence decreased with higher consumption of apples and pears (entire cohort) as well as root vegetables (smokers). In addition to an overall inverse association with fruit intake, the results of this evaluation add evidence for a significant inverse association of vegetable consumption and lung cancer incidence in smokers.

Tea and cancer prevention: molecular mechanisms and human relevance

Tea made from the leaves of the plant Camellia sinensis is a popular beverage. The possible cancer-preventive activity of tea and tea polyphenols has been studied extensively. This article briefly reviews studies in animal models, cell lines, and possible relevance of these studies to the prevention of human cancer. The cancer-preventive activity of tea constituents have been demonstrated in many animal models including cancer of the skin, lung, oral cavity, esophagus, stomach, liver, pancreas, small intestine, colon, bladder, prostate, and mammary gland. The major active constituents are polyphenols, of which (-)-epigallocatechin-3-gallate (EGCG) is most abundant, most active, and most studied, and caffeine. The molecular mechanisms of the cancer-preventive action, however, are just beginning to be understood. Studies in cell lines led to the proposal of many mechanisms on the action of EGCG. However, mechanisms based on studies with very high concentrations of EGCG may not be relevant to cancer prevention in vivo. The autooxidation of EGCG in cell culture may also produce activities that do not occur in many internal organs. In contrast to the cancer prevention activity demonstrated in different animal models, no such conclusion can be convincingly drawn from epidemiological studies on tea consumption and human cancers. Even though the human data are inconclusive, tea constituents may still be used for the prevention of cancer at selected organ sites if sufficient concentrations of the agent can be delivered to these organs. Some interesting examples in this area are discussed.

Consumption of Alcoholic Beverages and Risk of Lung Cancer: Results from Two Case–control Studies in Montreal, Canada

OBJECTIVE

To investigate the association between consumption of alcoholic beverages and lung cancer risk.

METHODS

Data were collected in two population-based case-control studies, conducted in Montreal (Study I--mid-1980s and Study II--mid-1990s). Study I included 699 cases and 507 controls, all males; Study II included 1094 cases and 1468 controls, males and females. In each study group (Study I men, Study II men and Study II women) odds ratios (OR) were estimated for the associations between beer, wine or spirits consumption and lung cancer, while carefully adjusting for smoking and other covariates. The reference category included abstainers and occasional drinkers.

RESULTS

For Study I men, lung cancer risk increased with the average number of beers/week consumed (for 1-6 beers/week: OR=1.2, 95% confidence interval (CI): 0.9-1.7; for >or=7 beers/week: OR=1.5, 95% CI: 1.1-2.1). For Study II men, beer consumption appeared harmful only among subjects with low fruit and vegetable consumption. In Study II, wine consumers had low lung cancer risk, particularly those reporting 1-6 glasses/week (women: OR=0.3, 95% CI: 0.2-0.4; men: OR=0.6, 95% CI: 0.4-0.8).

CONCLUSIONS

Beer consumption increased lung cancer risk, particularly so among men who had relatively low fruit and vegetable consumption. Moderate wine drinkers had decreased lung cancer risk.

Chemoprevention of lung cancer by tea

Tea is the second only to water as the most consumed beverage in the world. Both green and black teas have been studied for their health benefits for a variety of diseases, particularly cancer. Lung cancer is the predominant cause of cancer mortality in developed countries. Smokers' risk of lung cancer is 20 times that of persons who have never smoked. Epidemiological studies on the cancer-preventive effects of tea produce inconsistent results, which could in part be attributed to the lack of a universal standard for tea preparations. However, most animal studies indicate that tea has strong chemopreventive effects against lung tumorigenesis. The reported mechanisms for chemopreventive activity of green tea are antioxidation, induction of phase II enzymes, inhibition of TNFalpha expression and release, inhibition of cell proliferation, and induction of apoptosis. Cell cycle arrest and apoptosis induced by green tea are probably the two most significant factors. Future studies are needed to determine how green tea affects the genes associated with cell cycle regulation and apoptosis during the mouse lung carcinogenesis process.

Lung cancer in women

Lung cancer is one of the most important avoidable causes of death around the world, it is the most widespread carcinoma with a very poor prognosis, and is the leading cause of cancer death in both developed and developing countries. At present more men than women die each year from lung cancer, but in recent years a rapid increase in lung cancer mortality has been observed among women in developed countries, contrasting with a levelling off or decrease among men. The rising trend in female lung cancer mortality has been observed to parallel with the past and current prevalence of cigarette smoking among women in the United States and elsewhere. An important role of other factors acting either as independent risk factors or interacting with the effect of smoking has been suggested by some studies among women, among them genetic, biologic and hormonal factors, and probably some factors related to the environment and lifestyle. There is a controversy concerning the claim that women have a different susceptibility to tobacco carcinogens, which might or might not be greater than men do. Since tobacco is far and away the strongest epidemiological risk factor for the development of lung cancer, comprehensive smoking control efforts are the priority in the prevention of lung cancer among women.

Modification of N‐Acetyltransferases and Glutathione S‐Transferases by Coffee Components: Possible Relevance for Cancer Risk

Enzymes of xenobiotic metabolism are involved in the activation and detoxification of carcinogens and can play a pivotal role in the susceptibility of individuals toward chemically induced cancer. Differences in such susceptibility are often related to genetically predetermined enzyme polymorphisms but may also be caused by enzyme induction or inhibition through environmental factors or in the frame of chemopreventive intervention. In this context, coffee consumption, as an important lifestyle factor, has been under thorough investigation. Whereas the data on a potential procarcinogenic effect in some organs remained inconclusive, epidemiology has clearly revealed coffee drinkers to be at a lower risk of developing cancers of the colon and the liver and possibly of several other organs. The underlying mechanisms of such chemoprotection, modifications of xenobiotic metabolism in particular, were further investigated in rodent and in vitro models, as a result of which several individual chemoprotectants out of the >1000 constituents of coffee were identified as well as some strongly metabolized individual carcinogens against which they specifically protected. This chapter discusses the chemoprotective effects of several coffee components and whole coffee in association with modifications of the usually protective glutathione-S-transferase (GST) and the more ambivalent N-acetyltransferase (NAT). A key role is played by kahweol and cafestol (K/C), two diterpenic constituents of the unfiltered beverage that were found to reduce mutagenesis/tumorigenesis by strongly metabolized compounds, such as 2-amino-1-methyl-6-phenylimidazo-[4,5-b]pyridine, 7,12-dimethylbenz[a]anthracene, and aflatoxin B(1), and to cause various modifications of xenobiotic metabolism that were overwhelmingly beneficial, including induction of GST and inhibition of NAT. Other coffee components such as polyphenols and K/C-free coffee are also capable of increasing GST and partially of inhibiting NAT, although to a somewhat lesser extent.