Relative Risk Of Lung Cancer Research Articles

Lung cancer mortality and radon exposure in Russia

Abstract The association between the lung cancer and indoor radon exposure in Russian population was investigated. The average indoor radon concentration for each region was estimated using the annual reports issued by the Saint-Petersburg Ramzaev Research Institute of Radiation Hygiene for the period 2008–2013. The average standardized lung cancer mortalities among males and females were estimated using the reports of the Moscow Hertzen Cancer Research Institute for the period 2008–2012. The relative risk (RR) was estimated as a ratio between the average mortality within seven exposure intervals and background mortality. The slope factors of linear dependence between the indoor radon exposure and lung cancer RR are 0.026 (−0.11÷0.17) and 0.83 (0.52–1.12) per radon concentration 100 Bq/m3 for males and females, respectively (with 90% confidence interval). The obtained results can be explained by the confounding effect of tobacco smoking. Significant excess risk of lung cancer in female population can be associated with radon exposure and low prevalence of smoking.

Secondhand smoke exposure and risk of lung cancer in Japan: a systematic review and meta-analysis of epidemiologic studies.

Systematic evaluation of the association between secondhand smoke exposure and lung cancer in Japan has yet to be conducted. Here, we performed a systematic review and meta-analysis of the relationship between secondhand smoke and lung cancer in Japanese non-smokers. Relevant studies were collected from the MEDLINE and Ichushi Web databases using a combination of search terms and Medical Subject Headings. Eligible studies were identified, and relative risks or odds ratios were extracted to calculate pooled risk estimates. This procedure was performed independently by at least two authors. Stratified analyses were carried out according to study design, publication year, and whether or not potential confounding variables were accounted for. The presence of publication bias was assessed via funnel plots. We identified four cohort studies and five case-control studies. Quantitative synthesis was conducted only for secondhand smoke exposure in the home during adulthood. Of the 12 populations included in meta-analysis, positive secondhand smoke exposure-lung cancer associations were observed in 11, whereas an inverse association was found in the remaining 1. The pooled relative risk of lung cancer associated with secondhand smoke exposure was 1.28 (95% confidence interval: 1.10-1.48). We found no evidence of publication bias, and a significant association remained even when potentially missing studies were included (pooled relative risk: 1.26; 95% confidence interval: 1.09-1.46). The results were stable across different subgroup analyses, including by study design, publication year, and when adjusting for confounding variables. Secondhand smoke exposure in the home during adulthood results in a statistically significant increase in the risk of lung cancer.

Burden of cancer attributable to tobacco smoking in member countries of the Association of Southeast Asian Nations (ASEAN), 2012

BackgroundCancer is an increasing problem in ASEAN (Association of Southeast Asian Nations). Tobacco use is a well-established risk factor for many types of cancers. Evidence on burden of cancer attributable to tobacco is essential to raise public and political awareness of the negative effects of tobacco on cancer and to be used to stimulate political action aims at reducing smoking prevalence in ASEAN member countries. The objective of this study was to estimate burden of cancer attributable to tobacco smoking in ASEAN, 2012. MethodsIn this study, smoking prevalence was combined with Relative Risks (RRs) of cancer to obtain Smoking Attributable Fractions (SAFs). Cancer incidence and mortality data among individuals aged 15 years and older were derived from GLOBOCAN 2012. Fourteen types of cancer were included in the analysis. Sensitivity analyses were conducted to examine the impact of the use of alternative RRs and the use of alternative prevalence of smoking in some countries. ResultsThe findings showed that tobacco smoking was responsible for 131,502 cancer incidence and 105,830 cancer mortality in ASEAN countries in 2012. In other words, tobacco smoking was accounted for 28.4% (43.3% in male and 8.5% in female) of cancer incidence and 30.5% (44.2% in male and 9.4% in female) of cancer mortality in ASEAN. When looking at the types of cancer, lung cancer showed the strongest association with tobacco smoking. Incidence of cancer and cancer mortality attributable to tobacco smoking varied by countries due to the differences in size of population, background risk of cancer, and prevalence of smoking in each country. According to the sensitivity analyses, RRs of lung cancer, pharynx cancer, and larynx cancer used in the estimates have significant impact on the estimates. ConclusionsAs about one-third of cancer incidence and mortality in ASEAN are attributable to tobacco smoking ASEAN member countries are strongly encouraged to put in place stronger tobacco control policies and to strengthen the existing tobacco control measure in order to effectively control cancer.

PTU-053 Metachronous Extra-Colonic Malignancy in Collagenous Colitis

Introduction Collagenous colitis (CC) is a syndrome of chronic, watery, non-bloody diarrhoea.1 Its worldwide incidence is increasing; emerging evidence suggests a possible association between CC and malignancy.2 However, studies thus far have been inconclusive and data on the incidence of metachronous extra-colonic malignancy (MEcM) in CC is scarce.3 This study aimed to determine the occurrence of MEcM in patients with CC. Methods Retrospective study; data on MEcM in patients previously diagnosed with CC was collected within NHS Lothian (Scotland) over a 14 year period (Jan 2000 – Nov 2013). Person-years at risk were calculated according to age-specific categories. The standard error (Se) was calculated using the Poisson approximation. Relative risk (RR) and confidence interval (CI) of the age-standardised rate (ASR) were compared to publicly available population data for Lothian, Scotland.4 Results are reported as average ± standard deviation or RR with confidence interval (CI). P values Results In the aforementioned period, 394 patients were diagnosed with CC and included for analysis. Thirty-three (21 F/12 M) developed MEcM, Table 1. The average age of the group with MEcM was 71.6 ±7.4 years compared to 65.9 ±13.6 years for the remainder of the patients (P Conclusion The RR of MEcM, including lung cancer, is higher in patients with CC.The increased RR for lung cancer may be explained by the association between CC and smoking.5 Further collective data will be useful to clarify other associations. References 1 Munch A, et al. Microscopic colitis: current status, present and future challenges: statements of the European Microscopic Colitis Group. J Crohn’s Colitis 2012;6:932–945. 2 Freeman HJ. Complications of collagenous colitis. World J gastroenterol 2008;14:1643. 3 Chan JL, et al. Cancer risk in collagenous colitis. Inflamm Bowel Dis 1999;5:40–43. 4 http://www.ncin.org.uk/cancer_information_tools/eatlas/guide 5 Vigren L, et al. Is smoking a risk factor for collagenous colitis? Scand J Gastroenterol 2011;46:1334–1339. Disclosure of Interest None Declared

Lung cancer in never smokers in the UK Million Women Study.

To assess directly the effects of various risk factors on lung cancer incidence among never smokers, large prospective studies are needed. In a cohort of 1.2 million UK women without prior cancer, half (634,039) reported that they had never smoked. Mean age at recruitment was 55 (SD5) years, and during 14 (SD3) years of follow‐up, 0.2% (1,469) of these never smokers developed lung cancer. Cox regression was used to estimate relative risks (RRs) of lung cancer for 34 potential risk factors, of which 31 were nonsignificant (p > 0.05). The remaining three risk factors were associated with a significantly increased incidence of lung cancer in never smokers: non‐white vs. white ethnicity (RR = 2.34, 95% CI 1.55–3.52, p < 0.001), asthma requiring treatment vs. not (RR = 1.32, 1.10–1.58, p = 0.003) and taller stature (height ≥ 165 cm vs. <160 cm: RR = 1.16, 1.03–1.32, p = 0.02). There was little association with other sociodemographic, anthropometric or hormonal factors, or with dietary intakes of meat, fish, fruit, vegetables and fiber. The findings were not materially affected by restricting the analyses to adenocarcinomas, the most common histological type among never smokers.

Trends in research on indoor radon exposure and lung cancer in South Korea.

Editorial Radon is recognized by the World Health Organization as a lung cancer-causing carcinogen in humans, and is the second most common cause of lung cancer after smoking [1]. A causal relationship between radon and lung cancer was first described in epidemiological studies on underground mine workers. Thereafter, case–control studies further demonstrated that exposure to low concentrations of radon carries a risk for lung cancer. Recently, pooling studies have set out to investigate lung cancer risk in relation to exposure to radon indoors. In South Korea, a total of 47,869 men died from cancer in 2014, comprising 32.5 % of all male deaths that year. Among these Korean men, lung cancer had the highest mortality rate, compared to all other cancer types, and accounted for 12,785 deaths, corresponding to 26.7 % of all deaths from cancer. Meanwhile, in the same year, a total of 28,742 women died from cancer in South Korea, comprising 23.9 % of all deaths among women. As in men, lung cancer exhibited the highest mortality rate, accounting for 4655 deaths (16.2 % of all deaths from cancer) [2]. As the incidence of lung cancer has continued to increase, studies have been undertaken to outline the etiology thereof. Histologically, lung cancer is primarily classified into small cell lung cancers (about 20 % of all lung cancers) and non-small cell lung cancers (80 %); non-small cell lung cancer is further subdivided into adenocarcinoma (40 %), squamous cell carcinoma (30 %), and large cell carcinoma (15 %). Small cell lung cancer is typically malignant, and in most cases, metastasizes to other organs before it is detected. Generally, smoking is considered to be the main cause of lung cancer: small cell lung cancers and squamous cell carcinoma are positively associated with smoking, whereas adenocarcinoma exhibits relatively lower correlation with smoking [2–4]. Meanwhile, however, 10–25 % of all cases of lung cancer are not directly related to smoking [5]. Reports suggest that passive smoking increases the risk of lung cancer by 35 % in men and 25 % in women [6]. Lung cancer has also been found to be related with radon exposure, exposure to potential lung carcinogens (asbestos, polycyclic hydrocarbons, silica, heavy metals, etc.), oil vapor when cooking, coal combustion, hormonal factors, and air pollution [7]. Despite awareness of radon’s association with lung cancer, Koreans are less aware of the potential risks of indoor radon exposure. This paper aimed to review trends in studies on indoor radon exposure and lung cancer in South Korea, to suggest the need to establish reference levels for indoor radon levels specific to South Korea, and to highlight the necessity of continuous indoor radon exposure-related research. In this article, we outline eight papers published on indoor radon exposure and lung cancer with respect to Korea, covering topics related to epidemiological studies, mathematical-statistical modeling, environmental burden of disease, genetics biomarkers, and radon measurement methods. The following summarizes our findings from reviewing research on indoor radon exposure:

A Healthy Dietary Pattern Reduces Lung Cancer Risk: A Systematic Review and Meta-Analysis.

Background: Diet and nutrients play an important role in cancer development and progress; a healthy dietary pattern has been found to be associated with several types of cancer. However, the association between a healthy eating pattern and lung cancer risk is still unclear. Objective: Therefore, we conducted a systematic review with meta-analysis to evaluate whether a healthy eating pattern might reduce lung cancer risk. Methods: We identified relevant studies from the PubMed and Embase databases up to October 2015, and the relative risks were extracted and combined by the fixed-effects model when no substantial heterogeneity was observed; otherwise, the random-effects model was employed. Subgroup and publication bias analyses were also performed. Results: Finally, eight observational studies were included in the meta-analysis. The pooled relative risk of lung cancer for the highest vs. lowest category of healthy dietary pattern was 0.81 (95% confidence interval, CI: 0.75–0.86), and no significant heterogeneity was detected. The relative risks (RRs) for non-smokers, former smokers and current smokers were 0.89 (95% CI: 0.63–1.27), 0.74 (95% CI: 0.62–0.89) and 0.86 (95% CI: 0.79–0.93), respectively. The results remained stable in subgroup analyses by other confounders and sensitivity analysis. Conclusions: The results of our meta-analysis suggest that a healthy dietary pattern is associated with a lower lung cancer risk, and they provide more beneficial evidence for changing the diet pattern in the general population.

Measurements of Indoor Radon Levels and Dose Estimation and Lung Cancer Risk Determination for Workers in Health Centres of Some Towns in the Sudan

The indoor radon concentration level and radon effective dose rate were carried out in the health centers of Khartoum, Behri(Khartoum North), Medani and Kassala towns – Sudan, in 222 measurements, using passive integrated solid-state nuclear track devices containing allyl diglycol carbonate plastic detectors. The radon concentration in the corresponding health centers was found to vary from 60 ± 12 Bq.m-3, in Kassala town health centers, and 34 ± 9 Bq.m-3 in Wad Medani town health centers, while Khartoum and Behri (Khartoum North) health centers are recording an average values of 49 ± 12 Bq.m-3 to 46 ± 11 Bq.m-3, respectively. The overall average of radon concentration for health centers in our study was found to be 47 ± 11 Bq.m-3. These values are noticed to be far below than the radon action level 200- 600 Bq.m-3 as recommended by ICRP. Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, we found that the annual effective dose rate from radon was estimated to be 1.19 ± 0.28 mSv.y-1, and the relative lung cancer risk for radon exposure was found to be 1.042%. From our study, it is clear that the annual effective dose rate is lower than both the “normal” back ground level as quoted by UNSCEAR and the recommended action level of ICRP, and less than the maximum permissible dose defined by the International Atomic Energy Agency.

Should Never-Smokers at Increased Risk for Lung Cancer Be Screened?

Lung cancer in never-smokers ranks among the 10 most common causes of death due to cancer worldwide and in the United States. However, it is unknown whether never-smokers at elevated risk for developing lung cancer may benefit from lung cancer screening. The MIcrosimulation SCreening ANalysis (MISCAN)-Lung microsimulation model was used to assess the effects of lung cancer screening for simulated cohorts of never-smokers at different levels of relative risk (RR) for lung cancer compared with never-smokers at average risk. The benefits and harms of screening were estimated for each cohort and compared with those of a cohort of ever-smokers eligible for lung cancer screening according to the United States Preventive Services Task Force (USPSTF) criteria. The relative lung cancer mortality reduction in never-smokers was higher than the USPSTF eligible cohort (37% compared with 32%). However, the number of life-years gained per lung cancer death averted was lower (10.4 compared with 11.9) and the proportion of overdiagnosed cancers was higher (9.6% compared with 8.4%) for never-smokers compared with the USPSTF eligible cohort, as never-smokers are diagnosed at a later age. The estimated number of screens per lung cancer death averted ranged from 6162 for never-smokers at average risk to 151 for never-smokers with an RR of 35 compared with 353 for the USPSTF eligible cohort. Never-smokers with RRs of 15 to 35 have similar to better trade-offs between benefits and harms compared with ever-smokers recommended for lung cancer screening by the USPSTF guidelines. For most never-smokers, lung cancer screening is not beneficial.

Secular trend analysis of lung cancer incidence in Sihui city, China between 1987 and 2011.

BackgroundWith industrial and econom ic development in recent decades in South China, cancer incidence may have changed due to the changing lifestyle and environment. However, the trends of lung cancer and the roles of smoking and other environmental risk factors in the development of lung cancer in rural areas of South China remain unclear. The purpose of this study was to explore the lung cancer incidence trends and the possible causes of these trends.MethodsJoinpoint regression analysis and the age–period–cohort (APC) model were used to analyze the lung cancer incidence trends in Sihui, Guangdong province, China between 1987 and 2011, and explore the possible causes of these trends.ResultsA total of 2,397 lung cancer patients were involved in this study. A 3-fold increase in the incidence of lung cancer in both sexes was observed over the 25-year period. Joinpoint regression analysis showed that while the incidence continued to increase steadily in females during the entire period, a sharp acceleration was observed in males starting in 2005. The full APC model was selected to describe age, period, and birth cohort effects on lung cancer incidence trends in Sihui. The age cohorts in both sexes showed a continuously significant increase in the relative risk (RR) of lung cancer, with a peak in the eldest age group (80–84 years). The RR of lung cancer showed a fluctuating curve in both sexes. The birth cohorts identified an increased trend in both males and females; however, males had a plateau in the youngest cohorts who were born during 1955–1969.ConclusionsIncreasing trends of the incidence of lung cancer in Sihui were dominated by the effects of age and birth cohorts. Social aging, smoking, and environmental changes may play important roles in such trends.

Evidence for a genetical contribution to non-smoking-related lung cancer

BackgroundThe majority of lung cancers are smoking-related, with environmental and genetical factors contributing. The interplay between environmental and genetical contributions in non-smoking-related lung cancers is less clear.MethodsWe analysed a population-based...

Eligibility for low-dose computerized tomography screening among asbestos-exposed individuals.

The study aimed to incorporate an estimate of risk for asbestos exposure in the Canadian Cancer Risk Management Lung Cancer (CRMM-LC) microsimulation model. In CRMM-LC, a 3-year probability of developing lung cancer can be derived from different risk profiles. An asbestos-exposed cohort was simulated and different scenarios of low-dose computerized tomography (LDCT) screening were simulated. As annual LDCT screening among non-asbestos-exposed individuals is less cost-effective than biennial screening, all the scenarios modeled for an asbestos-exposed cohort were biennial. For individuals with a two-fold risk of asbestos-induced lung cancer to be eligible for biennial LDCT screening, a smoking history of ≥15 pack-years would be necessary. For non-smokers with asbestos exposure resulting in a relative risk (RR) for lung cancer, it is not cost-effective to screen those with a RR of 5, but it is cost-effective to screen those with a RR of 10 (the heavily exposed). Asbestos-exposed individuals with an estimated two-fold or more risk of lung cancer from asbestos-exposure are eligible for LDCT screening at all ages from 55-74 years if they have a cigarette smoking history of ≥15 pack-years. Asbestos-exposed individuals who are lifelong non-smokers are eligible for LDCT screening at all ages from 55-74 years if they have accumulated a degree of asbestos exposure resulting in an estimated risk of lung cancer of ≥10.

Diet and health. What can you believe: or does bacon kill you?

Diet and health. What can you believe: or does bacon kill you?

Vitamin D and Lung Cancer Risk: A Comprehensive Review and Meta-Analysis

Background/Aim: Vitamin D has been suggested to have important roles against cancer development. There were several published studies on the association between vitamin D and lung cancer risk, but not conclusive results were available. Methods: To clarify the role of vitamin D in lung carcinogenesis, we performed a comprehensive review of the literature and a meta-analysis to evaluate the association of serum vitamin D levels and dietary vitamin D intake with lung cancer risk. Twelve studies (9 prospective cohort and 3 nested case-control studies) with a total of 288,778 individuals were included. The summary relative risk (RR) with 95% confidence interval (CI) was used to assess lung cancer risk. Results: Meta-analysis of total 12 studies showed that RR for the association of high vitamin D status with lung cancer was 0.84 (95%CI 0.78-0.90, P < 0.001). The RR of lung cancer for the highest versus lowest quintile of serum vitamin D levels was 0.83 (95%CI 0.77-0.90, P < 0.001). The RR of lung cancer for the highest versus lowest quintile of vitamin D intake was 0.89 (95%CI 0.74-1.06, P = 0.184). Conclusion: Current data suggest an inverse association between serum vitamin D and lung cancer risk. Further studies are needed to investigate the effect of vitamin D intake on lung cancer risk and to evaluate whether vitamin D supplementation can prevent lung cancer.

The risk of lung cancer after cessation of asbestos exposure in construction workers using pleural malignant mesothelioma as a marker of exposure.

Objective:To study the risk of lung cancer in heavily asbestos-exposed workers after the exposure to asbestos has ended.Methods:Lung cancer was studied in a cohort of 189,896 Swedish construction workers through a linkage with the Swedish Cancer Registry. Asbestos exposure was estimated by the incidence of malignant mesothelioma in the occupational group.Results:There were in total 2835 cases of lung cancer. Workers with heavy exposure to asbestos had an increased risk of lung cancer (relative risks = 1.74; 95% confidence interval, 1.25 to 2.41) before exposure ended and a similar risk to those with low exposure 20 years after the exposure had ceased (relative risks = 0.94; 95% confidence interval, 0.77 to 1.15).Conclusions:Workers with heavy exposure to asbestos have a similar risk of lung cancer as persons with low or no exposure 20 years after the exposure has ended.

Risk of Leukemia in Uranium Miners

Epidemiological studies among uranium miners have evidenced lung cancer risk in relation to radon exposure. Although leukemia is especially sensitive to induction by radiation, the assessment of le...

Time series analysis and risk assessment of domestic radon: Data collected in dwellings along fault lines

Indoor radon-in-air (IR) concentrations in dwellings situated on a fault line passing underneath Muzaffarabad City were measured with a continuous radon monitor. Measurements were taken at half an hour intervals at 11 sites for 48 h. The values ranged from 14 ± 1 to 155 ± 4 Bq.m− 3 with an average value of 42 ± 2 Bq.m−3. The geometric mean (GM), standard deviation (STD) and geometric standard deviation (GSD) were 32 ± 2, 40.2 ± 0.8 and 1.5 Bq.m−3, respectively. Annual mean effective doses ranged between 0.35 ± 0.03 and 3.9 ± 0.1 mSv.y−1 with an overall mean value 1.05 ± 0.05 mSv.y−1. The experimental data were analysed by comparing algorithms to extract phase space dynamical information in the radon time series. Such approaches are potentially useful for deriving methods of extrapolation of short-term measurements to annualized average predictions and for earthquake detection. The computed values for Hurst exponent (H) from the rescaled range analysis and the Lyapunov exponent (L) provided estimates of the degree of chaotic regime. The Hurst exponent (0.877) for the radon time series indicates that the radon time series is a persistent time series. The value of Lyapunov exponent (0.0021) shows deterministic chaos in the data. The permutation entropy value was 0.6894 reflecting the irregularity in IR time series. The value of entropy obtained confirmed that the predictability of the IR time series is restricted to approximately one time step into the future. The mean value of IR concentrations corresponds to excess relative risks (ERR) of radon-induced lung cancer for 35- and 55-year-olds at all sites of 0.25 ± 0.01 and 0.205 ± 0.01, respectively. The observed 48-h average level (42 ± 2 Bq.m−3) was less than those recommended by the World Health Organization (WHO) (100 Bq.m−3), US Environmental Protection Agency (148 Bq.m−3) and Health Protection Agency, UK (200 Bq.m−3).

Diabetes mellitus: influences on cancer risk.

Diabetes mellitus and cancer are common conditions, and their co-diagnosis in the same individual is not infrequent. The relative risks associated with type 2 diabetes are greater than twofold for hepatic, pancreatic, and endometrial cancers. The relative risk is somewhat lower, at 1.2-1.5-fold for colorectal, breast, and bladder cancers. In comparison, the relative risk of lung cancer is less than 1. The evidence for other malignancies (e.g. kidney, non-Hodgkin lymphoma) is inconclusive, whereas prostatic cancer occurs less frequently in male patients with diabetes. The potential biologic links between the two diseases are incompletely understood. Evidence from observational studies suggests that some medications used to treat hyperglycemia are associated with either increased or reduced risk of cancer. Whereas anti-diabetic drugs have a minor influence on cancer risk, drugs used to treat cancer may either cause diabetes or worsen pre-existing diabetes. If hyperinsulinemia acts as a critical link between the observed increased cancer risk and type 2 diabetes, one would predict that patients with type 1 diabetes would have a different cancer risk pattern than patients with type 2 diabetes because the former patients are exposed to lower levels of exogenous administered insulin. Obtained results showed that patients with type 1 diabetes had elevated risks of cancers of the stomach, cervix, and endometrium. Type 1 diabetes is associated with a modest excess cancer risk overall and risks of specific cancers that differ from those associated with type 2 diabetes.

Lung cancer risk in relation to TP53 codon 47 and codon 72 polymorphism in Bangladeshi population.

The objective of this study was to determine whether p53 codon 47 and codon 72 polymorphisms are associated with increased risk of lung cancer in Bangladeshi population. We carried out a case-control study and examined the genotype distribution Pro47Ser and Arg72Pro single-nucleotide polymorphisms along with tobacco smoking in the predisposition of lung cancer by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach. The study included 106 lung cancer patients and 116 control subjects from Bangladesh. Lung cancer risk was estimated as odds ratio (OR) and 95 % confidence interval (CI) using conditional logistic regression models adjusting for age, sex, and smoking. No significant association was found between Pro47Ser SNP and lung cancer. The frequencies of p53 codon 72 polymorphisms (Arg/Arg, Arg/Pro, and Pro/Pro) in lung cancer were 25.5, 37.7, and 36.8 %, respectively; frequencies in the controls were 53.4, 30.2, and 16.4 %, respectively (p < 0.01). The Arg/Pro and Pro/Pro genotype were significantly associated with increased risk of lung cancer (OR = 2.51, 95 % CI = 1.38-4.82 and OR = 4.62, 95 % CI = 2.31-9.52, respectively) compared with the Arg/Arg genotype. The combined frequency of Arg/pro and Pro/Pro genotype was also found to be associated with elevated risk of lung cancer (OR = 3.36, 95 % CI = 1.90-5.94, p < 0.01). However, no significant relationship was found between age, sex, and histological subtypes of lung cancer with p53 codon 72 genotype distributions. When classified by smoking status, the effects of Arg72Pro polymorphism on lung cancer risk was only found to be significant (χ (2) = 33.94, p = 0.00000004) in case of heavy smokers (40 packs per year or more). We conclude that not Pro47Ser SNP but Arg72Pro SNP is involved in susceptibility to developing lung cancer, at least in Bangladeshi population.

Reconstruction of historical exposures at a Welsh nickel refinery (1953-2000).

Past epidemiological studies of workers in a nickel refinery in Clydach, Wales, have shown evidence of large excess respiratory cancer mortality risks [lung cancer relative risk (RR) ≈ 3; nasal cancer RR ≈ 140] in those employed prior to 1930, with risks dropping dramatically in workers hired subsequently. The pre-1930 risks have generally been attributed to high exposures to mixtures of nickel compounds. More recent studies of this refinery's workers have focused on those first hired in 1953, when many of the operations that presumably gave rise to the high exposures were no longer in operation. While these studies have shown greatly decreased lung cancer risks overall (RR ≈ 1.4), and no substantive evidence of increased nasal cancer risk, the absence of reliable exposure estimates have made it difficult to ascertain whether the increased lung cancer risks are nickel related or due to other factors. This study uses nickel measurements from the 1970s to the present, documentation of process changes, and dust measurements taken around the 1950s to construct an exposure matrix for the recent cohort. It provides evidence of at least 30-fold decreases in levels of nickel exposure from the 1950s to the present, with estimated inhalable nickel concentrations in the 1950s in excess of 5mg Ni m(-3).