Small-cell lung cancer in never-smokers.

BACKGROUND: Lung cancer is a public health problem worldwide. Small-cell lung cancer (SCLC) is the most aggressive histologic type, with a 5-year survival <10%. SCLC is closely associated with tobacco consumption and infrequent in never-smokers. We aim to describe SCLC characteristics in never-smokers recruited in a radon-prone area. PATIENTS AND METHODS: We designed a multicentric case series where SCLC cases were recruited consecutively following histologic confirmation. Detailed information was obtained for indoor radon exposure, occupation and environmental tobacco smoke. We also collected different clinical characteristics such as extended or limited disease at diagnosis. RESULTS: We recruited 32 never-smoking SCLC cases. Median age was 75 years and 87.5% were women; 47% had extended disease. Median radon concentration was 182 Bq/m3. There were no statistically significant differences in residential radon concentration neither regarding age at diagnosis nor regarding sex. The most frequent symptoms were constitutional syndrome (23.1%) and coughing (23.1%). As much as 63% of cases had an Eastern Cooperative Oncology Group Study (ECOG) status of 0-2. The 1- and 2-year survival rates were 34.4% and 21.9%, respectively. The 2-year survival rate with a localized tumor was 26.7%, compared with 18.8% for extended disease. CONCLUSIONS: These results show, for the first time, that indoor radon might not be associated with SCLC characteristics at diagnosis in never-smokers, and also confirms the low survival of this aggressive type of lung cancer also for never-smokers.

Exposure to environmental tobacco smoke in Chaves after the implementation of the law 37/2007. A cross-sectional study in two healthcare settings.

INTRODUCTION: Environmental tobacco smoke (ETS) is currently the main indoor pollutant and causes a high morbility and mortality. A partial restriction came into force in Portugal, in 2008, law 37/2007, trying to control, define and regulate smoke-free environments. OBJECTIVE: To assess exposure and perceived impact of the law 37/2007 on exposure to ETS among adults attending to the two health care facilities of Chaves (Portugal). METHOD: A cross-sectional survey on tobacco consumption and exposure to ETS was undertaken in Chaves (Northern Portugal) between November 2009 and February 2010. All the patients, over 17, attending to any of the Chaves Primary Care Facilities were interviewed. Patient enrolment was done on a rolling basis covering all days of the week. A face to face interview was carried out and a carbon monoxide was measured. Prevalence and means are shown with 95% confidence intervals. RESULTS: 287 patients participated in the survey, 56% were males and the mean age was 54 years. Smoking prevalence was 23,6%, significantly higher in males (31% vs 17%). 46,2% reported exposure tobacco smoke elsewhere (53% in males vs. 40% in females). Smokers declared to be more exposed to ETS than non-smokers. 16.2% of the population declared to be exposed at home, 14% at work and 33% at leisure places. The highest decrease in perception of passive exposure was found for restaurants (95%). In nightclubs 68% of the participants stated that exposure has remained unchanged. CONCLUSION: The tobacco control law offered protection against tobacco smoke in several closed public spaces. However, a significant proportion of the population remains exposed. This study highlights the ineffectiveness of a partial ban. A comprehensive law is, therefore, required in Portugal.

Tobacco consumption and oral and pharyngeal cancer in a Spanish male population.

The incidence of oral and pharyngeal cancer in Spain is among the highest in Europe. A hospital-based case-control study was carried out in NW Spain to investigate the role of tobacco. The study included 92 incident male cases and 230 male controls. Tobacco smoking was strongly associated with oral and pharyngeal cancer (OR(ever smokers)=27.7). The risk for black tobacco (OR=33.1) was approximately double that of blond tobacco (OR=15.4). Alcohol drinking increased the risk posed by tobacco consumption. Risks were significantly lower for subjects that started smoking later and was significantly reduced after 10 years of leaving the habit.

Analysis of the relationship between p53 immunohistochemical expression and risk factors for lung cancer, with special emphasis on residential radon exposure.

BACKGROUND: Indoor radon exposure has been postulated as the second risk factor of lung cancer after tobacco. The objective of this work is to analyze if there exists any effect on p53 immunohistochemical expression mainly due to radon exposure and other risk factors for lung cancer. PATIENTS AND METHODS: The tumor samples of a case series of 163 lung cancer cases were analyzed to know the p53 staining. The staining was classified into four categories from no staining to intense staining (>60%). This staining was correlated with radon exposure, tobacco consumption, having worked in risk occupations for lung cancer and alcohol consumption. RESULTS: Only 72 samples could be analyzed for immunohistochemistry and some of these samples were sequenced from exons 4-8. No association was observed for staining intensity and radon exposure and also for tobacco and occupation. A slight association with a more intense staining was observed for high alcohol intake. In the four samples with a staining >60% that could be sequenced from exons 4 to 8, no mutation was observed in the p53 gene. CONCLUSION: There is no association between radon exposure and p53 expression, indicating that maybe the effect of radon is not mediated through p53 alterations.

CYP1A1, mEH, and GSTM1 Polymophisms and Risk of Oral and Pharyngeal Cancer: A Spanish Case-Control Study.

Background. Genetic polymorphisms of drug metabolizing enzymes involved in the detoxification pathways of carcinogenic substances may influence cancer risk. Methods. Case-control study that investigates the relationship between CYP1A1 Ile/Val, exon 4 mEH, and GSTM1 null genetic polymorphism and the risk of oral and pharyngeal cancer examining the interaction between these genes, tobacco, and alcohol. 92 incident cases and 130 consecutive hospital-based controls have been included. Results. No significant associations were found for any of the genotypes assessed. The estimated risk was slightly elevated in subjects with the wild type of the mEH gene and the null GSTM1 genotype. For exon 4 mEH heterozygous polymorphism, the risk was slightly lower for heavy smokers than for light smokers. The inverse association was observed for the GSTM1 null genotype. Conclusions. The results suggest that exon 4 mEH and GSTM1 null polymorphisms might influence oral and pharyngeal cancer.

Meat and fish consumption and risk of lung cancer: A case-control study in Galicia, Spain.

Diet is one of the elements that may influence the development of lung cancer. To ascertain the relationship between meat and fish consumption and the appearance of this disease, a case-control study was conducted on a population in Galicia (NW Spain), with a sample of 295 cases and 322 controls. All cases had histologic confirmation, and controls were individuals who were attending the hospital to undergo trivial surgery. All subjects were over 35, and sampling was based on sex frequency. Frequent consumption of meat seemed to have a protective effect, with an OR of 0.24 (95% CI 0.11-0.50), an effect that was maintained for pork consumption (OR 0.35; 95% CI 0.18-0.67). In contrast, consumption of fish showed an association with lung cancer, with an OR of 1.67 (95% CI 0.99-2.81), an association that extended to both white (OR 1.61 95% CI 0.93-2.79) and blue fish (OR 2.03 95% CI 1.23-3.34). Consumption of meat seems to reduce the risk of lung cancer, whereas consumption of fish could exert an influence by increasing the risk of this disease.

Factors underlying residential radon concentration: results from Galicia, Spain.

Radon causes lung cancer when inhaled for prolonged periods of time. A range of factors influence residential radon concentration and this study therefore sought to ascertain which dwelling-related factors exert an influence on radon levels. A cross-sectional study was conducted from 2001 to 2003 which analyzed 983 homes of as many subjects randomly selected from the 1991 census. Sampling was carried out by district and stratified by population density to ensure that more detectors were placed in the most heavily populated areas. Radon concentration and different dwelling characteristics were measured in each of the homes selected. Bivariate and multivariate analyses were performed to ascertain which factors influenced radon concentration. The geometric mean of radon concentration was 69.5 Bq/m3, and 21.3% of homes had concentrations above 148 Bq/m3. Factors shown to influence radon concentration in the bivariate analysis were: age of dwelling; interior building material; exterior building material; and storey on which the detector was placed. Explanatory variables in the multivariate analysis were: age of dwelling; number of storeys; distance off floor; and interior building material. The model was significant, but the variability explained was around 10%. These results highlight the fact that the study area is an area of high radon emission and that factors other than those directly related with the characteristics of the dwelling also influence radon concentration.

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

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

Antioxidant vitamins and risk of lung cancer.

Tobacco use is the leading risk factor for lung cancer, yet in addition to smoking habit, diet may also play a role in the disease's appearance. While there are reports to indicate that antioxidant vitamins and carotenoids may decrease the risk of lung cancer, results to date have been somewhat ambiguous. This review aimed to describe the results yielded by different studies, which have addressed antioxidant vitamin intake and lung cancer, and to indicate the mechanisms whereby these nutrients might be exercising their activity. Antioxidant vitamins were observed to have no clear protective effect, though there was some evidence pointing to a protective role for vitamins C and E. Vitamin A, in contrast, evinced no clear effect. Insofar as provitamin A carotenoids were concerned, lutein/zeaxanthin, lycopene and alpha-carotene displayed a certain protective trend, yet beta-carotene exhibited no protective effect whatsoever; and indeed, there was speculation as to whether it might even be pernicious in smokers. Beta-criptoxanthin, on the other hand, showed a more consistent protective effect. The study highlighted the need to conduct further research on smokers and non-smokers alike, and in particular, to investigate the effect, if any, on lung cancer of carotenoids or vitamins when ingested in differing dosages.

Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies.

OBJECTIVE: To determine the risk of lung cancer associated with exposure at home to the radioactive disintegration products of naturally occurring radon gas. DESIGN: Collaborative analysis of individual data from 13 case-control studies of residential radon and lung cancer. SETTING: Nine European countries. SUBJECTS: 7148 cases of lung cancer and 14,208 controls. MAIN OUTCOME MEASURES: Relative risks of lung cancer and radon gas concentrations in homes inhabited during the previous 5-34 years measured in becquerels (radon disintegrations per second) per cubic metre (Bq/m3) of household air. RESULTS: The mean measured radon concentration in homes of people in the control group was 97 Bq/m3, with 11% measuring > 200 and 4% measuring > 400 Bq/m3. For cases of lung cancer the mean concentration was 104 Bq/m3. The risk of lung cancer increased by 8.4% (95% confidence interval 3.0% to 15.8%) per 100 Bq/m3 increase in measured radon (P = 0.0007). This corresponds to an increase of 16% (5% to 31%) per 100 Bq/m3 increase in usual radon--that is, after correction for the dilution caused by random uncertainties in measuring radon concentrations. The dose-response relation seemed to be linear with no threshold and remained significant (P = 0.04) in analyses limited to individuals from homes with measured radon < 200 Bq/m3. The proportionate excess risk did not differ significantly with study, age, sex, or smoking. In the absence of other causes of death, the absolute risks of lung cancer by age 75 years at usual radon concentrations of 0, 100, and 400 Bq/m3 would be about 0.4%, 0.5%, and 0.7%, respectively, for lifelong non-smokers, and about 25 times greater (10%, 12%, and 16%) for cigarette smokers. CONCLUSIONS: Collectively, though not separately, these studies show appreciable hazards from residential radon, particularly for smokers and recent ex-smokers, and indicate that it is responsible for about 2% of all deaths from cancer in Europe.

Type of wine and risk of lung cancer: a case-control study in Spain.

BACKGROUND: Few epidemiological studies have examined the effect of wine on the risk of lung cancer. A study was therefore undertaken to estimate the effect of wine consumption, both overall and by type of wine, on the risk of developing lung cancer. METHODS: A hospital based case-control study was conducted on 319 subjects (132 cases, 187 controls) in 1999-2000. All subjects were interviewed about their lifestyles with particular reference to alcohol consumption and tobacco use. The results were analysed using non-parametric logistic regression. The main outcome measure was the risk of lung cancer associated with consumption of wine and its individual types. RESULTS: A very slight but significant association was observed between the risk of lung cancer and white wine consumption (odds ratio (OR) 1.20 for each daily glass). Red wine consumption, on the other hand, had an OR of 0.43 (95% CI 0.19 to 0.96), with each daily glass of red wine having an inverse association with the development of lung cancer (OR 0.87 (95% CI 0.77 to 0.99)). There was no apparent association between lung cancer and consumption of beer or spirits. CONCLUSIONS: These results suggest that the consumption of red wine is negatively associated with the development of lung cancer. Further studies are needed to test this finding in cancer induced laboratory animals.

GSTM1 and GSTT1 polymorphisms, tobacco and risk of lung cancer: a case-control study from Galicia, Spain.

BACKGROUND: Only 15% of heavy smokers go on to develop lung cancer, indicating the existence of individual predisposition. PATIENTS AND METHODS: Using a case-control study, we ascertained whether there were differences between cases and controls in the frequency of GSTM1 and GSTT1 gene polymorphisms, and whether their effect might be linked to smoking habit. RESULTS: While a risk of lung cancer of 1.7 (1.0-3.0) was observed for GSTM1 gene deficiency, there appeared to be no such association for absence of the GSTT1 gene. The interaction observed with tobacco use indicated an excess risk of 24.5% (IC 95%-59.8-109.0) for the GSTM1 gene, with no such interaction in evidence for the GSTT1 gene. The highest risk for a combination of the different haplotypes was for subjects with the GSTT1 gene present and the GSTM1 gene deleted, with an Odds Ratio of 2.19 (1.18-4.07). CONCLUSION: The absence of the GSTM1 gene is, while that of the GSTT1 gene is seemingly not, implicated in susceptibility to lung cancer.

Dose-response relationship between tobacco and lung cancer: new findings.

The purpose of this work is to model the relationship between smoking-related variables and the risk of lung cancer by using parametric and non-parametric models. A hospital-based case-control study was conducted to ascertain the influence of smoking on risk of lung cancer. We used parametric logistic regression with a series of categorized independent variables and non-parametric logistic regression models. Such models allow for variables to be treated as continuous, since they avoid arbitrariness in the selection of cut-offs and furnish information on the dose-risk relationship. The results point to the possible existence of a saturation effect for a lifetime tobacco consumption of around 25 000-30 000 packets. Duration of habit and years of abstinence show a linear relationship marked by opposite, though similar, slopes, which would seem to indicate that for every year of smoking, risk rises by an amount (8.00%, 95% confidence interval (CI) 5.94-10.06) equal to the decline in risk for every year of abstinence (6.98%, 95% CI 2.53-11.84). Lastly, a lower age of smoking initiation appears to have an influence, although non-significant, on the appearance of the disease. The risk of lung cancer due to duration of the habit would seem to be proportional to years of abstinence, and there could be a saturation effect with respect to lifetime tobacco consumption.

Lung cancer and related risk factors: an update of the literature.

At the present time, lung cancer is the leading cause of cancer-related death in males. Diagnostic difficulty makes detection complicated and this, in conjunction with the low survival rate, renders the disease a serious health problem. In-depth knowledge of associated risk factors is therefore called for, in order to prevent or at least reduce the appearance of lung cancer and to open new avenues of research. Although the disease has a multicausal aetiology, tobacco accounts for 85-90% of all cases. This paper reviews the current situation, dividing the risk factors, for study purposes, into two groups; intrinsic (non-modifiable) and extrinsic (modifiable).

Diet and lung cancer: a new approach.

Lung cancer is one of major public health problems facing the world today, owing to the high incidence of the disease and its poor prognosis. Although the principal cause of lung cancer is tobacco use, smokers find it extremely difficult to quit the habit. Hence, there is a need to take action targeted at other risk factors for this disease. One such factor is diet, which is known to be able to raise or lower the risk of lung cancer. This paper seeks to complement other reviews in the field and to shed more light both on the influence that dietary factors may have upon the occurrence of this neoplasm and on the causes of this possible effect.

[Mortality by cause of death in the province of A Coruña: geographic distribution of age-adjusted rates, from 1961 to 1970 and 1971 to 1980]. / La mortalidad causal en la provincia de A Coruña: una distribución geográfica de las tasas ajustadas por edad, durante los decenios 1961-1970 y 1971-1980.

We have studied mortality due to general causes and to eight groups of causes (CIE-WHO) in 28 Basic Areas or parishes of the province of A Coruña (Galicia, Spain). We have calculated the direct adjusted rates for men and women, in 1961-1970 and 1971-1980, and we have compared them with the respective provincial rates, thereby identifying areas with excess or infra-mortality. We have found a decrease of general mortality between the two decades, larger in the case of women (4.5%) than in the case of men (0.9%), as well as an increase in the cardiovascular mortality (12% in men and 6% in women) and in mortality due to accidents (41.77% and 45.11% respectively). The rate of neoplasias in men has increased (7.62%) but decreased in women (2.32%). We have examined the geographical distribution criteria for tumoral rates and for accidents in areas which are mainly urban (men and women) and for cardiovascular rates in rural areas (for women, especially).