A multi-environmental source approach to explore associations between metals exposure and olfactory identification among school-age children residing in northern Italy.

BACKGROUND: Metal exposures can adversely impact olfactory function. Few studies have examined this association in children. Further, metal exposure occurs as a mixture, yet previous studies of metal-associated olfactory dysfunction only examined individual metals. Preventing olfactory dysfunctions can improve quality of life and prevent neurodegenerative diseases with long-term health implications. OBJECTIVE: We aimed to test the association between exposure to a mixture of 12 metals measured in environmental sources and olfactory function among children and adolescents residing in the industrialized province of Brescia, Italy. METHODS: We enrolled 130 children between 6 and 13 years old (51.5% females) and used the "Sniffin' Sticks" test to measure olfactory performance in identifying smells. We used a portable X-ray fluorescence instrument to determine concentrations of metals (arsenic (As), calcium, cadmium (Cd), chromium, copper, iron, manganese, lead (Pb), antimony, titanium, vanadium and zinc) in outdoor and indoor deposited dust and soil samples collected from participants' households. We used an extension of weighted quantile sum (WQS) regression to test the association between exposure to metal mixtures in multiple environmental media and olfactory function adjusting for age, sex, socio-economic status, intelligence quotient and parents' smoking status. RESULTS: A higher multi-source mixture was significantly associated with a reduced Sniffin' Sticks identification score (ß = -0.228; 95% CI -0.433, -0.020). Indoor dust concentrations of Pb, Cd and As provided the strongest contributions to this association (13.8%, 13.3% and 10.1%, respectively). The metal mixture in indoor dust contributed more (for 8 metals out of 12) to the association between metals and olfactory function compared to soil or outdoor dust. IMPACT STATEMENT: Among a mixture of 12 metals measured in three different environmental sources (soil, outdoor and indoor dust), we identified Pb, Cd and As measured in indoor dust as the main contributors to reduced olfactory function in children and adolescents residing in an industrialized area. Exposure to indoor pollution can be effectively reduced through individual and public health interventions allowing to prevent the deterioration of olfactory functions. Moreover, the identification of the factors that can deteriorate olfactory functions can be a helpful instrument to improve quality of life and prevent neurodegenerative diseases as long-term health implications.

Mesothelioma among seamen: a systematic review and meta-analysis.

OBJECTIVES: Navy personnel and seafarers live and work 24 h per day in the shipboard environment and they are exposed to asbestos fibers released into the confined spaces aboard ships. We conducted a systematic review and meta-analysis to quantify the mesothelioma risk of seamen working aboard ships, either commercial or naval vessels, as compared to that of the general population. METHODS: We carried out a literature search in MEDLINE through PubMed and EMBASE, from inception to 31 December 2021, of all studies on seamen working aboard ships, either commercial or naval vessels, characterized by exposure to asbestos and providing mesothelioma risk estimates. The Newcastle-Ottawa Scale was used to assess the quality of the studies included. The pooled standardized mortality ratio (SMR) was computed across eligible studies. The study protocol was registered on PROSPERO and reporting followed the preferred reporting items for systematic reviews and meta-analyses guidelines. RESULTS: A total of 10 studies published from 1990 to 2020 were considered eligible and included in the systematic review and meta-analysis. All the included studies were of good quality, with a median score of seven out of nine. Overall, there were 235 mesothelioma cases/deaths in the included studies versus 115.6 expected, with a pooled SMR of 2.11 (95% confidence intervals, 1.70-2.62), in the absence of a significant between-study heterogeneity ( I2  = 39%, P  = 0.11). CONCLUSION: A more than double excess risk for mesothelioma among seamen working aboard ships emerged from our meta-analysis.

An Industry-Relevant Metal Mixture, Iron Status, and Reported Attention-Related Behaviors in Italian Adolescents.

BACKGROUND: Exposure to environmental metals has been consistently associated with attention and behavioral deficits in children, and these associations may be modified by coexposure to other metals or iron (Fe) status. However, few studies have investigated Fe status as a modifier of a metal mixture, particularly with respect to attention-related behaviors. METHODS: We used cross-sectional data from the Public Health Impact of Metals Exposure study, which included 707 adolescents (10-14 years of age) from Brescia, Italy. Manganese, chromium, and copper were quantified in hair samples, and lead was quantified in whole blood, using inductively coupled plasma mass spectrometry. Concentrations of Fe status markers (ferritin, hemoglobin, transferrin) were measured using immunoassays or luminescence assays. Attention-related behaviors were assessed using the Conners Rating Scales Self-Report Scale-Long Form, Parent Rating Scales Revised-Short Form, and Teacher Rating Scales Revised-Short Form. We employed Bayesian kernel machine regression to examine associations of the metal mixture with these outcomes and evaluate Fe status as a modifier. RESULTS: Higher concentrations of the metals and ferritin were jointly associated with worse self-reported attention-related behaviors: metals and ferritin set to their 90th percentiles were associated with 3.0% [ß=0.03; 95% credible interval (CrI): -0.01, 0.06], 4.1% (ß=0.04; 95% CrI: 0.00, 0.08), and 4.1% (ß=0.04; 95% CrI: 0.00, 0.08) higher T-scores for self-reported attention deficit/hyperactivity disorder (ADHD) index, inattention, and hyperactivity, respectively, compared with when metals and ferritin were set to their 50th percentiles. These associations were driven by hair manganese, which exhibited nonlinear associations with all self-reported scales. There was no evidence that Fe status modified the neurotoxicity of the metal mixture. The metal mixture was not materially associated with any parent-reported or teacher-reported scale. CONCLUSIONS: The overall metal mixture, driven by manganese, was adversely associated with self-reported attention-related behavior. These findings suggest that exposure to multiple environmental metals impacts adolescent neurodevelopment, which has significant public health implications. https://doi.org/10.1289/EHP12988.

Assessing the mediating role of iron status on associations between an industry-relevant metal mixture and verbal learning and memory in Italian adolescents.

BACKGROUND: Metals, including lead (Pb), manganese (Mn), chromium (Cr) and copper (Cu), have been associated with neurodevelopment; iron (Fe) plays a role in the metabolism and neurotoxicity of metals, suggesting Fe may mediate metal-neurodevelopment associations. However, no study to date has examined Fe as a mediator of the association between metal mixtures and neurodevelopment. OBJECTIVE: We assessed Fe status as a mediator of a mixture of Pb, Mn, Cr and Cu in relation to verbal learning and memory in a cohort of Italian adolescents. METHODS: We used cross-sectional data from 383 adolescents (10-14 years) in the Public Health Impact of Metals Exposure Study. Metals were quantified in blood (Pb) or hair (Mn, Cr, Cu) using ICP-MS, and three markers of Fe status (blood hemoglobin, serum ferritin and transferrin) were quantified using luminescence assays or immunoassays. Verbal learning and memory were assessed using the California Verbal Learning Test for Children (CVLT-C). We used Bayesian Kernel Machine Regression Causal Mediation Analysis to estimate four mediation effects: the natural direct effect (NDE), natural indirect effect (NIE), controlled direct effect (CDE) and total effect (TE). Beta (ß) coefficients and 95 % credible intervals (CIs) were estimated for all effects. RESULTS: The metal mixture was jointly associated with a greater number of words recalled on the CVLT-C, but these associations were not mediated by Fe status. For example, when ferritin was considered as the mediator, the NIE for long delay free recall was null (ß = 0.00; 95 % CI = -0.22, 0.23). Conversely, the NDE (ß = 0.23; 95 % CI = 0.01, 0.44) indicated a beneficial association of the mixture with recall that operated independently of Fe status. CONCLUSION: An industry-relevant metal mixture was associated with learning and memory, but there was no evidence of mediation by Fe status. Further studies in populations with Fe deficiency and greater variation in metal exposure are warranted.

Associations of an industry-relevant metal mixture with verbal learning and memory in Italian adolescents: The modifying role of iron status.

BACKGROUND: Biomarker concentrations of metals are associated with neurodevelopment, and these associations may be modified by nutritional status (e.g., iron deficiency). No prior study on associations of metal mixtures with neurodevelopment has assessed effect modification by iron status. OBJECTIVES: We aimed to quantify associations of an industry-relevant metal mixture with verbal learning and memory among adolescents, and to investigate the modifying role of iron status on those associations. METHODS: We used cross-sectional data from 383 Italian adolescents (10-14 years) living in proximity to ferroalloy industry. Verbal learning and memory was assessed using the California Verbal Learning Test for Children (CVLT-C), and metals were quantified in hair (manganese, copper, chromium) or blood (lead) using inductively coupled plasma mass spectrometry. Serum ferritin, a proxy for iron status, was measured using immunoassays. Covariate-adjusted associations of the metal mixture with CVLT subtests were estimated using Bayesian Kernel Machine Regression, and modification of the mixture associations by ferritin was examined. RESULTS: Compared to the 50th percentile of the metal mixture, the 90th percentile was associated with a 0.12 standard deviation [SD] (95% CI = -0.27, 0.50), 0.16 SD (95% CI = -0.11, 0.44), and 0.11 SD (95% CI = -0.20, 0.43) increase in the number of words recalled for trial 5, long delay free, and long delay cued recall, respectively. For an increase from its 25th to 75th percentiles, copper was beneficially associated the recall trials when other metals were fixed at their 50th percentiles (for example, trial 5 recall: ß = 0.31, 95% CI = 0.14, 0.48). The association between copper and trial 5 recall was stronger at the 75th percentile of ferritin, compared to the 25th or 50th percentiles. CONCLUSIONS: In this metal mixture, copper was beneficially associated with neurodevelopment, which was more apparent at higher ferritin concentrations. These findings suggest that metal associations with neurodevelopment may depend on iron status, which has important public health implications.

Relationships of Nutritional Factors and Agrochemical Exposure with Parkinson's Disease in the Province of Brescia, Italy.

Environmental exposures to agrochemicals and nutritional factors may be associated with Parkinson's Disease (PD). None of the studies to date has examined the combined effects of diet and agricultural chemical exposure together. To address these research gaps, we aimed to assess the association of nutritional factors and agrochemical exposure with the risk of PD. A hospital-based case-control study was conducted. Multivariable logistic regressions were used to estimate the association of nutritional and agrochemical exposures with PD, adjusting for gender, age, socio-economic status, head injury, family history, smoking, metals exposure, and α-synuclein gene polymorphism. Weighted Quantile Sum (WQS) regression was applied to examine the effect of dietary components as a mixture. We recruited 347 cases and 389 controls. Parent history of PD (OR = 4.15, 95%CI: 2.10, 8.20), metals exposure (OR = 2.50, 95%CI: 1.61-3.89), SNCA rs356219 polymorphism (OR = 1.39, 95%CI: 1.04-1.87 for TC vs. TT; OR = 2.17, 95%CI: 1.43-3.28 for CC vs. TT), agrochemical exposures (OR = 2.11, 95%CI: 1.41-3.16), and being born in the Brescia province (OR = 1.83, 95%CI: 1.17-2.90) were significantly associated with PD. Conversely, fish intake and coffee consumption had a protective effect. The study confirmed the role of environmental exposures in the genesis of PD. Fish intake and coffee consumption are protective factors even when agricultural chemical exposures exist. Genetic factors and metals exposure were confirmed as risk factors for PD.

Critical windows of susceptibility in the association between manganese and neurocognition in Italian adolescents living near ferro-manganese industry.

INTRODUCTION: Understanding the neurodevelopmental effects of manganese (Mn) is complicated due to its essentiality for growth and development. While evidence exists for the harmful effects of excess Mn, pediatric epidemiologic studies have observed inconsistent associations between Mn and child cognition. OBJECTIVE: We sought to estimate prospective associations between Mn measured in three different early-life time windows with adolescent cognition using deciduous teeth biomarkers. METHODS: Deciduous teeth were collected from 195 participants (ages 10-14 years) of the Public Health Impact of Manganese Exposure (PHIME) study in Brescia, Italy. Measurements of tooth Mn represented prenatal (∼14 weeks gestation - birth), early postnatal (birth - 1.5 years) and childhood (∼1.5 - 6 years) time windows. Neuropsychologists administered the Wechsler Intelligence Scale for Children, 3rd edition (WISC-III), to obtain composite IQ and subtest scores. Associations between tooth Mn at each time window and adolescent WISC-III scores were estimated using multivariable linear regression. We tested differences in associations between Mn and outcomes across time windows using multiple informant models. Sex-specific associations were explored in stratified models. RESULTS: Adjusted associations between tooth Mn and composite IQ scores were positive in the prenatal period and negative in the childhood period. Associations were strongest for subtest scores that reflect working memory, problem solving, visuospatial ability and attention: prenatal Mn was positively associated with Digits backward [SD change in score per interquartile range increase in Mn: ß = 0.20 (95 % CI: 0.02, 0.38)] and Block design [ß = 0.21 (0.01, 0.41)] and early postnatal Mn was positively associated with Digits forward [ß = 0.24 (0.09, 0.40)], while childhood Mn was negatively associated with Coding [ß = -0.14 (-0.28, -0.001)]. Sex-stratified analyses suggested different Mn-cognition associations for boys and girls and was also dependent on the time window of exposure. CONCLUSION: Our results suggest that exposure timing is critical when evaluating Mn associations between Mn and cognition. Higher prenatal Mn was beneficial for adolescent cognition; however, these beneficial associations shifted towards harmful effects in later time windows. Cognitive domains most sensitive to Mn across time windows included visuospatial ability, working memory, attention and problem-solving.

CYP1A2 polymorphisms, occupational and environmental exposures and risk of bladder cancer.

Cytochrome P4501A2 (CYP1A2) is a key enzyme for activation of bladder carcinogens. Polymorphisms in the 5'-noncoding promoter region of CYP1A2 gene [mainly -2467T/delT(rs35694136) and -163C/A(rs762551)], are crucial in modifying CYP1A2 activity in smokers. Within the framework of a hospital-based case/control study, we investigated the relationship between CYP1A2 polymorphisms, occupational/environmental exposures and bladder cancer (BC) risk. The study population included 185 BC cases and 180 non-cancer controls, all Caucasian males. Data were collected on lifetime smoking, coffee drinking, dietary habits and lifetime occupation, with particular reference to exposure to aromatic amines (AAs) and polycyclic aromatic hydrocarbons (PAHs). A case-only design was applied to study the interaction between CYP1A2 -2467T/delT (or -163C/A) and occupational and environmental factors. Multiple logistic regression showed a significantly increased risk among heavy smokers (> or =50 packyears; OR 5.6, 95% CI: 2.5-12.5) and heavy coffee drinkers (>5 cups/day; OR 3.1, 95% CI: 1.2-7.9). Exposure to AAs showed a significant trend of BC risk with increasing cumulative exposure (CE) (P = 0.04), with heavy smoking as possible confounder. A decreased risk was noted for large leaf vegetable consumption, with significant trend from <1/month to >3 times/week (P = 0.008). The case-only analysis showed an interaction between -2467T/delT and tobacco smoking >25 packyears (P = 0.04); no interaction was detected between such polymorphisms and coffee consumption, dietary habits and occupational exposure to AAs. No effects were shown with -163C/A genotype as well as no overall effect of CYP1A2 by itself on BC risk. This is the first study suggesting that CYP1A2 -2467T/delT modifies the effect of cigarette smoking on BC risk.

A sequence variant at 4p16.3 confers susceptibility to urinary bladder cancer.

Previously, we reported germline DNA variants associated with risk of urinary bladder cancer (UBC) in Dutch and Icelandic subjects. Here we expanded the Icelandic sample set and tested the top 20 markers from the combined analysis in several European case-control sample sets, with a total of 4,739 cases and 45,549 controls. The T allele of rs798766 on 4p16.3 was found to associate with UBC (odds ratio = 1.24, P = 9.9 x 10(-12)). rs798766 is located in an intron of TACC3, 70 kb from FGFR3, which often harbors activating somatic mutations in low-grade, noninvasive UBC. Notably, rs798766[T] shows stronger association with low-grade and low-stage UBC than with more aggressive forms of the disease and is associated with higher risk of recurrence in low-grade stage Ta tumors. The frequency of rs798766[T] is higher in Ta tumors that carry an activating mutation in FGFR3 than in Ta tumors with wild-type FGFR3. Our results show a link between germline variants, somatic mutations of FGFR3 and risk of UBC.

Polymorphisms in DNA repair genes, smoking, and bladder cancer risk: findings from the international consortium of bladder cancer.

Tobacco smoking is the most important and well-established bladder cancer risk factor and a rich source of chemical carcinogens and reactive oxygen species that can induce damage to DNA in urothelial cells. Therefore, common variation in DNA repair genes might modify bladder cancer risk. In this study, we present results from meta-analyses and pooled analyses conducted as part of the International Consortium of Bladder Cancer. We included data on 10 single nucleotide polymorphisms corresponding to seven DNA repair genes from 13 studies. Pooled analyses and meta-analyses included 5,282 cases and 5,954 controls of non-Latino white origin. We found evidence for weak but consistent associations with ERCC2 D312N [rs1799793; per-allele odds ratio (OR), 1.10; 95% confidence interval (95% CI), 1.01-1.19; P = 0.021], NBN E185Q (rs1805794; per-allele OR, 1.09; 95% CI, 1.01-1.18; P = 0.028), and XPC A499V (rs2228000; per-allele OR, 1.10; 95% CI, 1.00-1.21; P = 0.044). The association with NBN E185Q was limited to ever smokers (interaction P = 0.002) and was strongest for the highest levels of smoking dose and smoking duration. Overall, our study provides the strongest evidence to date for a role of common variants in DNA repair genes in bladder carcinogenesis.

Sequence variant on 8q24 confers susceptibility to urinary bladder cancer.

We conducted a genome-wide SNP association study on 1,803 urinary bladder cancer (UBC) cases and 34,336 controls from Iceland and The Netherlands and follow up studies in seven additional case-control groups (2,165 cases and 3,800 controls). The strongest association was observed with allele T of rs9642880 on chromosome 8q24, 30 kb upstream of MYC (allele-specific odds ratio (OR) = 1.22; P = 9.34 x 10(-12)). Approximately 20% of individuals of European ancestry are homozygous for rs9642880[T], and their estimated risk of developing UBC is 1.49 times that of noncarriers. No association was observed between UBC and the four 8q24 variants previously associated with prostate, colorectal and breast cancers, nor did rs9642880 associate with any of these three cancers. A weaker signal, but nonetheless of genome-wide significance, was captured by rs710521[A] located near TP63 on chromosome 3q28 (allele-specific OR = 1.19; P = 1. 15 x 10(-7)).

Bladder cancer, GSTs, NAT1, NAT2, SULT1A1, XRCC1, XRCC3, XPD genetic polymorphisms and coffee consumption: a case-control study.

The aim of the study was to investigate NAT1, NAT2, GSTM1, GSTT1, GSTP1, SULT1A1, XRCC1, XRCC3 and XPD genetic polymorphisms, coffee consumption and risk of bladder cancer (BC) through a hospital-based case-control study. The study population included 197 incident BC cases and 211 controls. The association between genetic polymorphisms, coffee drinking and BC risk was assessed by logistic regression taking into account age, education, tobacco smoking and occupational exposures to polycyclic aromatic hydrocarbons and aromatic amines. No association was found between the genetic polymorphisms investigated and BC risk according to coffee consumption apart of a significant increased BC risk among GSTP1 105-114 Val carriers heavy coffee drinkers (>3 cups/day) (OR 3.18, 95% CI 1.06-9.55). In conclusion our findings suggest a very limited role, if any, of genetic polymorphisms investigated in modulating the BC risk in coffee drinkers.

From clinical activities to didactics and research in occupational medicine.

BACKGROUND: The daily practice of Occupational Physicians in the mot industrialized countries suggests that the frequency of traditional occupational diseases is progressively lowering, their gravity is decreasing, and the etiological factors are changing. This trend should be quantitatively and qualitatively verified with ad hoc studies. The information is particularly relevant for Academic Institutions where medical students and residents in occupational medicine are trained. OBJECTIVES: To analyse the trends of clinical diagnoses and health surveillance activities conducted in the last 15 years by an Italian Institute of Occupational Health, and to gain information on the most relevant topics to be taught in academic program and to be addressed with future research. METHODS: Data sources were represented by the computerised registration of a) diagnostic activities and b) health surveillance programs, conducted by the Institute of Occupational Medicine of the University of Brescia, a highly industrialized area in Northern Italy. The observation period was from 1990 to 2005. The health surveillance programs regarded workers pulled from an iron foundry, a veterinary institute, a health departments for the assistance of elderly subjects, a nursery schools and a municipal department for road maintenance. RESULTS: Diagnostic activities were conducted on 9080 subjects, who had been referred for suspected occupational disease. The diagnosis of occupational disease was confirmed for 3759 cases. Multiple diseases were diagnosed in 1554 subjects, yielding the total number of 5721 occupational diseases. The most frequent diagnoses accounted for allergic skin disease (23.4%), followed by pneumoconiosis (20.4%), chronic obstructive pulmonary disease (15.9%), noise hearing loss (7.1%), musculoskeletal disorders (6.9%), respiratory allergies (6.9%), cancer (5.9%), miscellaneous (6.4%). When limited to the last quinquennium, the analysis showed a definite increase of muskuloskeltal disorders, cancer, and, although at a lesser extent, diseases due to psychosocial factors. The analysis of the health surveillance programs regarded 1207 workers, and showed that various non occupational diseases caused limitation to individual work fitness. The most frequent conditions were musculoskeletal disorders (65%) and skin diseases (14%). CONCLUSIONS: The results from these two investigations are important not only for the didactic program run by the Institute, but also because they indicate the most relevant topics to be addressed with future research, at least at a local level.

[Occupational cancer. The role of the occupational physician in systematic search and aetiological diagnosis of lung cancer. Analysis of a case list]. / I tumori occupazionali "ritrovati". Considerazioni sul ruolo del Medico del Lavoro nella ricerca sistematica e nella diagnosi eziologica dei tumori polmonari, alla luce di una casistica.

BACKGROUND: About 15% of lung cancers (LC) might be attributable to occupation. However, clinical practice shows that LC percentage for which occupational aetiology is recognized is lower than expected. OBJECTIVES: To address the role of Occupational Physicians (OP) in systematic search and aetiological diagnosis of LC. METHODS: The search was carried out at a university hospital in Brescia, northern Italy, a highly industrialized area with many workers potentially exposed to occupational lung carcinogens. Through short occupational history forms, physicians of various departments refer all new cases of primary LC to OP When occupational exposure to lung carcinogens is presumed, the OP evaluates the case at the occupational health clinic and sends clinical reports to notifying physicians, containing aetiological diagnosis and indications for medico-legal obligations. RESULTS: Before 1998, few cases were referred to the OP and even less were compensated. The search yielded 1502 LC; after screening, full occupational health evaluation was performed in 693 cases: occupational aetiology was recognized in 182 (26%). Risk factors were silica, asbestos, polycyclic aromatic hydrocarbons, truck driving, painting, road paving; many workers were exposed to multiple carcinogens. 48 cases were compensated, many others are under litigation. CONCLUSIONS: A systematic LC search made it possible to: reach an aetiological diagnosis and reduce the gap between expected LC and those reported/compensated; inform health authorities and undertake preventive action in workplaces; detect sentinel events; provide epidemiological data at community level; promote cooperation among health professionals (oncologists, surgeons, pneumologists, general practitioners, plant OP); increase teaching opportunities for medical students, those taking a specialisation course in occupational health; provide counselling and expert opinions for individual subjects, trade unions, employers, law courts.

Malignant mesothelioma and the working environment: the viewpoint of the occupational physician.

BACKGROUND: Firm scientific evidence supports the causal association between malignant mesothelioma (MM) and occupational exposure to asbestos. Risk attributable to occupation varies from 30 to 80% across different populations. The existence of a threshold level below which there is no risk of MM is still debated. A prompt and thorough assessment of exposure is essential to evaluate and manage MM cases, from diagnostic and epidemiological points of view. OBJECTIVES AND METHODS: To highlight the multiple areas of intervention by Occupational Physicians (OP) in MM evaluation and management, to describe an experience of OP in the province of Brescia. RESULTS: The main areas of interest of the OP are exposure assessment, diagnosis (clinical, etiological), medico-legal issues, social consequences, preventive strategies, risk communication, scientific dispute/uncertainties. By means of an active search, the Brescia MM registry, managed by OP belonging to the local health authority observed 309 MM from 1977 to 2003; the local Institute of Occupational Health, hosted in a hospital of national relevance, evaluated about 200 MM in the last decade. The main outcomes of OP activity are the high percentage of direct interviews, individual case management, expert exposure assessment, etiological diagnosis, counselling, medico-legal assistance, better knowledge of occupational risks, enhanced cooperation among health professionals (oncologists, pathologists, surgeons, pneumologists, general practitioners and OP), important contribution to Registries and to epidemiology (estimates of attributable risks, incidence, survival rates), with positive social and scientific consequences (insurance agencies, trade union organizations, public events, teaching opportunities). CONCLUSIONS: This experience highlights the multifaceted role of OP in active research and evaluation of MM cases, in the context of a multidisciplinary approach.

GST, NAT, SULT1A1, CYP1B1 genetic polymorphisms, interactions with environmental exposures and bladder cancer risk in a high-risk population.

Tobacco smoking and occupation are major risk factors of bladder cancer via exposure to polycyclic aromatic hydrocarbons (PAHs) and aromatic amines. Glutathione S-transferase (GST) M1, T1 and P1 are involved in the detoxification of PAH reactive metabolites. Two N-acetyltransferase isozymes, NAT2 and NAT1, have major roles in catalyzing the N-acetylation and O-acetylation of aromatic amines. Cytochrome p450 1B1 (CYP1B1) and sulfotransferase 1A1 (SULT1A1) are also involved in the metabolism of PAHs and aromatic amines. It is hypothesized that the genetic polymorphisms of these metabolic enzymes have an effect on the individual susceptibility to bladder cancer in particular by interacting with relevant environmental exposures. A hospital-based case-control study among men in Brescia, Northern Italy recruited 201 incidence cases and 214 controls from 1997-2000. Occupational exposures were blindly coded by occupational physicians. Genotyping of polymorphisms were carried out with PCR-RFLP method. Unconditional multivariate logistic regression was applied to model the association between genetic polymorphisms and bladder cancer risk. Effect modifications by age of onset, smoking and occupational exposures to PAHs and aromatic amines were evaluated. We also conducted an analysis of interaction between genetic factors. GSTM1 and GSTT1 null genotype were associated with an increased risk of bladder cancer with an odds ratio (OR) of 1.69 (95% confidence interval [CI] = 1.11-2.56) and 1.74 (95% CI = 1.02-2.95), respectively. The effect of GSTM1 null was seen particularly in heavy smokers, and there was a combined effect with occupational exposure of aromatic amines (OR = 2.77, 95% CI = 1.08-7.10). We observed a trend (p-value < 0.01) of increasing cancer risk comparing subjects with normal GSTM1 and T1 activity to subjects with one (OR = 1.82, 95% CI = 1.16-2.85) or both null genotypes (OR = 2.58, 95% CI = 1.27-5.23). NAT2 slow acetylator was associated with marginally increased risk of bladder cancer (OR = 1.50, 95% CI = 0.99-2.27), and the OR for the joint effect with occupational exposure of aromatic amines was 3.26 (95% CI = 1.06-9.95). SULT1A1 Arg213His polymorphism showed a marginal protective effect. These findings suggest that individual susceptibility to bladder cancer may be modulated by GSTM1, GSTT1 and NAT2 polymorphisms.

Genetic polymorphisms of MPO, COMT, MnSOD, NQO1, interactions with environmental exposures and bladder cancer risk.

Tobacco smoking and occupational exposure are major risk factors of bladder cancer via exposure to polycyclic aromatic hydrocarbons (PAHs) and aromatic amines, which lead to oxidative stress and DNA damage. Several enzymes, which play key roles in oxidative stress are polymorphic in humans. Myeloperoxidase (MPO) produces a strong oxidant for microbicidal activity, and activates carcinogens in tobacco smoke. Catechol-O-methyltransferase (COMT) catalyzes the methylation of endo- and xenobiotics and prevents redox cycling. NAD(P)H:quinone oxidoreductase (NQO1) catalyzes the two-electron reduction of quinoid compounds, which also protects cells from redox cycling. Manganese superoxide dismutase (MnSOD) protects cells from free radical injury. To test the hypothesis that the risk of bladder cancer can be influenced by polymorphisms in the genes that modulate oxidative stress, in particular by interacting with environmental carcinogens, we conducted a hospital-based case-control study among men in Brescia, Northern Italy. We recruited and interviewed 201 incident cases and 214 controls from 1997 to 2000. Occupational exposures to PAHs and aromatic amines were coded blindly by occupational physicians. Unconditional multivariate logistic regression was applied to model the association between genetic polymorphisms and bladder cancer risk and the effect of modifications of smoking and occupational exposures were evaluated. MPO G-463A homozygous variant was associated with a reduced risk of bladder cancer with an OR of 0.31 (95% CI = 0.12-0.80). MnSOD Val/Val genotype increased the risk of bladder cancer with OR of 1.91 (95% CI = 1.20-3.04), and there was a combined effect with smoking (OR = 7.20, 95% CI = 3.23-16.1) and PAH (OR = 3.02, 95% CI = 1.35-6.74). We did not observe an effect of COMT Val108Met polymorphism. These findings suggest that individual susceptibility of bladder cancer may be modulated by MPO and MnSOD polymorphisms, and that the combination of genetic factors involved in oxidative stress response with environmental carcinogens may play an important role in bladder carcinogenesis.

Polymorphisms of the DNA repair genes XRCC1, XRCC3, XPD, interaction with environmental exposures, and bladder cancer risk in a case-control study in northern Italy.

Tobacco smoking and occupational exposures are the main known risk factors for bladder cancer, causing direct and indirect damage to DNA. Repair of DNA damage is under genetic control, and DNA repair genes may play a key role in maintaining genome integrity and preventing cancer development. Polymorphisms in DNA repair genes resulting in variation of DNA repair efficiency may therefore be associated with bladder cancer risk. A hospital-based case-control study was conducted in Brescia, Italy, to assess the relationship between polymorphisms in DNA repair genes XRCC1 (Arg(399)Gln), XRCC3 (Thr(241)Met), and XPD (Lys(751)Gln) and bladder cancer risk. A total of 201 male incident bladder cancer cases and 214 male controls with urological nonneoplastic diseases were recruited and frequency-matched on age, period, and hospital of recruitment. Detailed information was collected using a semistructured questionnaire on demographic, dietary, environmental, and occupational factors. Genotypes were determined by PCR-RFLP analysis. The XRCC3 codon 241 variant genotype exhibited a protective effect against bladder cancer [odds ratio (OR), 0.63; 95% confidence interval (CI), 0.42-0.93], which was prominent among heavy smokers (OR, 0.49; 95% CI, 0.28-0.88) but not among never and light smokers. No overall impact of the XRCC1 codon 399 polymorphism was found (OR, 0.86; 95% CI, 0.59-1.28), but a protective influence of the homozygous variant was suggested among heavy smokers (OR, 0.38; 95% CI, 0.14-1.02). XPD polymorphisms did not show an association with bladder cancer (OR, 0.92; 95% CI, 0.62-1.37). There was no statistical evidence of an interaction between these three genetic polymorphisms and either tobacco smoking or occupational exposure to polycyclic aromatic hydrocarbons and aromatic amines. The XRCC3 codon 241 polymorphism had an overall protective effect against bladder cancer that was most apparent among heavy smokers. Similarly, the XRCC1 codon 399 polymorphism also had a protective effect on bladder cancer among heavy smokers. The XPD polymorphism was not, however, associated with bladder cancer risk.