Wood dust and nasal cancer risk. A review of the evidence from North America

Next-generation sequencing reveals remarkable genetic stability in primary and corresponding recurrent intestinal-type sinonasal adenocarcinoma

BACKGROUND

Recurrent intestinal-type sinonasal adenocarcinoma (ITAC) can occur several years after primary treatment and with different histology. We aimed to clarify if such recurrences could be second primary tumors and to identify actionable mutations as targets for personalized treatment of recurrent ITAC.

METHODS

Twelve pairs of primary and recurrent ITAC were histologically examined and analyzed by next-generation sequencing.

RESULTS

Histological differences between primary and recurrent tumor pairs were observed in five cases. Frequent mutations included TP53, APC, TSC2, ATM, EPHA2, BRCA2, LRP1B, KRAS, and KMT2B. There was 86% concordance of somatic mutations between the tumor pairs, while four cases carried additional mutations in the recurrence.

CONCLUSIONS

We found all cases to be clonal recurrences and not second primary tumors. Moreover, tumor pairs showed a remarkable genomic stability, suggesting that personalized treatment of a recurrence may be based on actionable molecular genetic targets observed in the primary tumor.

Gender Differences in Sinonasal Cancer Incidence: Data from the Italian Registry

BACKGROUND

Although rare, sinonasal cancers (SNCs) have a high occupational attributable fraction.

METHODS

We applied gender-based approaches to descriptive analyses, incidence, and patterns of exposures using the Italian National Sinonasal Cancer Registry (ReNaTuNS: Registro Nazionale Tumori Naso-Sinusali).

RESULTS

The study included 2851 SNC patients. SNC was diagnosed more often in men (73%) than in women (27%). The most frequent morphology in men was intestinal-type adenocarcinoma (33%), whereas in women, it was squamous cell carcinoma (49%). Nasal cavities were predominant in both genders (50%), ethmoidal sinus in men (24%), and maxillary in women (24%). Incidence rates were 0.76 (per 100,000 person-years) in men and 0.24 in women and increased by age, more evidently in men, peaking over 75 years in both. Occupational exposures to wood and leather dusts were the most frequent (41% for men, 33% for women). Few exposures were extra-occupational or domestic. Unlikely exposure was relevant in women (57%).

CONCLUSIONS

The surveillance of SNC cases through a registry that allows for the identification of and compensation for this occupational disease is important in Italy, where numerous workers are exposed to carcinogens for SNC, without even being aware. Considering the rarity of the disease, particularly among women, the ReNaTuNS can provide a method to analyze gender differences.

Sinonasal intestinal- and non-intestinal-type adenocarcinoma in China: a retrospective study of 14 cases

BACKGROUND

In China, reports on the epidemiology of adenocarcinomas of the nasal cavity and paranasal sinuses are limited.

AIM

This study aimed to describe the experience of a single institution in China in treating these malignant tumours.

MATERIALS AND METHODS

We conducted a retrospective chart review of patients with adenocarcinoma of the nasal cavity and paranasal sinuses admitted between January 2019 and December 2021. Tumour staging was based on the American Joint Committee on Cancer, 8th edition, for sinonasal malignancies.

RESULTS

The series included 10 men and 4 women (mean age, 54.5 [range, 14-80] years). Epistaxis and nasal obstruction were the most common clinical manifestations in 10 (71.4%) patients. Ten (71.4%) had stage T4 disease at diagnosis, but no patient had lymph node or distant metastasis. The posterosuperior septum (100.0%) and middle turbinate (92.8%) were the two sites most vulnerable to tumour invasion. All patients underwent endoscopic resection as the initial treatment; one patient died.

CONCLUSIONS AND SIGNIFICANCE

In China, these malignancies are related to exposure to certain substances; however, diagnosis can be delayed. Endoscopic resection is a suitable treatment option for adenocarcinomas of the nasal cavity and paranasal sinuses.

Occurrence of Sinonasal Intestinal-Type Adenocarcinoma and Non-Intestinal-Type Adenocarcinoma in Two Countries with Different Patterns of Wood Dust Exposure

Sinonasal intestinal-type adenocarcinoma is strongly associated with hardwood dust exposure. Non-intestinal-type adenocarcinoma is a rarer and less well-known subtype considered not to be related with wood dust exposure. We determined the relative numbers of these two tumor types in 56 sinonasal adenocarcinoma patients in France and Finland, relating them with carefully assessed wood dust exposure histories. Diagnostic workup including immunohistochemistry for the intestinal markers CDX2 and CK20 indicated that the proportions of the two tumors differed significantly between France and Finland. In Finnish samples non-intestinal adenocarcinomas were more common than intestinal-type adenocarcinomas (12 non-intestinal vs. nine intestinal), while in the French samples the reverse was true (six non-intestinal vs. 29 intestinal). Such remarkably dissimilar occurrence of these tumors in France and Finland presumably reflects different pathogenetic circumstances in the two countries, and perhaps their different patterns of wood dust exposure. In France the main source of wood dust is from hardwoods. In Finland it is derived from softwoods. This is the first systematic comparison of the occurrence of intestinal-type adenocarcinoma and non-intestinal-type adenocarcinoma in two countries with different wood usage. It appears to be the first systematic study on differences in wood dust exposure between intestinal-type adenocarcinoma and non-intestinal-type adenocarcinoma.

Occupational exposure to wood dust and risk of nasal and nasopharyngeal cancer: A case-control study among men in four nordic countries-With an emphasis on nasal adenocarcinoma

The current study aims to provide stronger evidence to aid in our understanding of the role of cumulative occupational exposure to (softwood-dominated) mixed wood dust in aetiology of nasal cancer. We included broad exposure occurred in a range of wood-processing occupation across varied industries in four Nordic countries. A population-based case-control study was conducted on all male cases with nasal adenocarcinoma (393 cases), other types of nasal cancer (2,446) and nasopharyngeal cancer (1,747) diagnosed in Finland, Sweden, Norway and Iceland between 1961 and 2005. For each case, five male controls, who were alive at the time of diagnosis of the case (index date), were randomly selected, matched by birth-year and country. Cumulative exposures (CE)s to wood dust and formaldehyde before the index date were quantified based on a job-exposure matrix linked to occupational titles derived from population censuses. Hazard ratios (HRs) for the CE of wood dust were estimated by conditional logistic regression, adjusted for CE to formaldehyde and 95% confidence intervals (CIs) were calculated. There was an increasing risk of nasal adenocarcinoma related to wood dust exposure. The HR in the highest CE category of wood dust (≥ 28.82 mg/m³ -years) was 16.5 (95% CI 5.05-54.1). Neither nonadenocarcinoma of the nose nor nasopharyngeal cancer could be linked to wood dust exposure. CE to softwood-dominated mixed wood dusts is strongly linked with elevated risk in nasal adenocarcinoma but not with other types of nasal or nasopharyngeal cancer.

Potential Occupational Exposures and Health Risks Associated with Biomass-Based Power Generation

Biomass is increasingly being used for power generation; however, assessment of potential occupational health and safety (OH&S) concerns related to usage of biomass fuels in combustion-based generation remains limited. We reviewed the available literature on known and potential OH&S issues associated with biomass-based fuel usage for electricity generation at the utility scale. We considered three potential exposure scenarios--pre-combustion exposure to material associated with the fuel, exposure to combustion products, and post-combustion exposure to ash and residues. Testing of dust, fungal and bacterial levels at two power stations was also undertaken. Results indicated that dust concentrations within biomass plants can be extremely variable, with peak levels in some areas exceeding occupational exposure limits for wood dust and general inhalable dust. Fungal spore types, identified as common environmental species, were higher than in outdoor air. Our review suggests that pre-combustion risks, including bioaerosols and biogenic organics, should be considered further. Combustion and post-combustion risks appear similar to current fossil-based combustion. In light of limited available information, additional studies at power plants utilizing a variety of technologies and biomass fuels are recommended.

Association between Occupational Exposure to Wood Dust and Cancer: A Systematic Review and Meta-Analysis

Objective

To perform a systematic review to analyze the association between occupational exposure to wood dust and cancer.

Methods

A systematic literature search of entries made in the MEDLINE-PubMed database between 1957 and 2013 was conducted to identify studies that had assessed the relationship between occupational exposure to wood dust and different types of cancer. A meta-analysis of selected case-control and cohort studies was subsequently performed.

Results

A total of 114 studies were identified and 70 were selected for review. Of these, 42 studies focused on the relationship between wood dust and nasal cancer (n = 22), lung cancer (n = 11), and other types of cancer (n = 9). Low-to-moderate quality evidence that wood dust acts as a carcinogen was obtained, and a stronger association between wood dust and nasal adenocarcinoma was observed. A lesser association between wood dust exposure and lung cancer was also observed. Several studies suggested that there is a relationship between wood dust and the onset of other cancers, although there was no evidence to establish an association. A meta-analysis that included four case-controls studies showed that workers exposed to wood dust exhibited higher rates of nasal adenocarcinoma than other workers (odds ratio = 10.28; 95% confidence interval: 5.92 and 17.85; P<0,0001), although a large degree of heterogeneity was found.

Conclusions

Low-to-moderate quality evidence supports a causal association between cancer and occupational exposure to wood dust, and this association was stronger for nasal adenocarcinoma than for lung cancer. There was no evidence of an association between wood dust exposure and the other cancers examined.

Assessment of exposure to oak wood dust using gallic acid as a chemical marker

OBJECTIVES

The American Conference of Governmental Industrial Hygienists (ACGIH) has classified oak dust as a human carcinogen (A1), based on increased sinus and nasal cancer rates among exposed workers. The aims of this study were to investigate the use of gallic acid (GA) as a chemical marker of occupational exposure to oak dusts, to develop a high-performance liquid chromatography-diode array detector method to quantify GA and to apply the method in the analysis of oak dust samples collected in several factories.

METHODS

A high-performance liquid chromatography method was developed to detect GA in oak wood dust. The method was tested in the field, and GA was extracted from inhalable oak wood dust collected using the Institute of Occupational Medicine inhalable dust sampler in the air of five woodworking plants where only oak wood is used.

RESULTS

A total of 57 samples with dust concentrations in the range of 0.27-11.14 mg/m(3) were collected. Five of these samples exceeded the Italian threshold limit value of 5 mg/m(3), and 30 samples exceeded the ACGIH TLV of 1 mg/m(3). The GA concentrations were in the range 0.02-4.18 µg/m(3). The total oak dust sampled was correlated with the GA content with a correlation coefficient (r) of 0.95.

CONCLUSIONS

The GA in the tannic extracts of oak wood may be considered a good marker for this type of wood, and its concentration in wood dust sampled in the work environment is useful in assessing the true exposure to carcinogenic oak dust.

A survey of occupational exposure to inhalable wood dust among workers in small- and medium-scale wood-processing enterprises in Ethiopia

A study of wood dust exposure in 20 small- and medium-scale wood-processing enterprises was performed in Ethiopia. Sampling was conducted daily from January to June, 2013 and a total of 360 samples from 113 workers were collected with Institute of Occupational Medicine (IOM) personal samplers. Eight-hour time-weighted average exposure to wood dust ranged from 0.24 to 23.3mg m(-3) with a geometric mean (GM) of 6.82mg m(-3) and a geometric standard deviation of 1.82. Although Ethiopia did not have any defined standard of Occupational Exposure Limit for wood dust exposure, 71% of the measurements exceeded the limit of 5mg m(-3) set by the European Union (EU). Higher than the EU exposure limit was measured while workers perform sanding and sawing activities with a GM of 9.72 and 7.60mg m(-3), respectively. In conclusion, wood workers in the small- and medium-scale enterprises are at a higher risk of developing different respiratory health problems with continuous exposure trends.

Sinonasal carcinoma: clinical, pathological, genetic and therapeutic advances

The sinonasal cavities represent an anatomical region affected by a variety of tumours with clinical, aetiological, pathological, and genetic features distinct from tumours at the main head and neck cancer localizations. Together, squamous-cell carcinoma and adenocarcinoma account for 80% of all sinonasal tumours, and are aetiologically associated with professional exposure to wood and leather dust particles and other industrial compounds, and therefore, are officially recognized as an occupational disease. Owing to their distinctive characteristics, sinonasal tumours should be considered as separate entities, not to be included in the miscellany of head and neck cancers. Sinonasal tumours are rare, with an annual incidence of approximately 1 case per 100,000 inhabitants worldwide, a fact that has hampered molecular-genetic studies of the tumorigenic pathways and the testing of alternative treatment strategies. Nevertheless, the clinical management of sinonasal cancer has improved owing to advances in imaging techniques, endoscopic surgical approaches, and radiotherapy. Genetic profiling and the development of in vitro cell lines and animal models currently form the basis for future targeted anticancer therapies. We review these advances in our understanding and treatment of sinonasal tumours.

Occupational health outcomes for workers in the agriculture, forestry and fishing sector: implications for immigrant workers in the southeastern US

BACKGROUND

Workers in the Agriculture, Forestry, and Fisheries (AgFF) sector experience exposures directly related to the work itself, as well as the physical environment in which the work occurs. Health outcomes vary from immediate to delayed, and from acute to chronic.

METHODS

We reviewed existing literature on the health outcomes of work in the AgFF sector and identified areas where further research is needed to understand the impact of these exposures on immigrant Latino workers in the southeastern US.

RESULTS

Outcomes related to specific body systems (e.g., musculoskeletal, respiratory) as well as particular exposure sources (e.g., pesticides, noise) were reviewed. The most extensive evidence exists for agriculture, with a particular focus on chemical exposures. Little research in the southeastern US has examined health outcomes of exposures of immigrant workers in forestry or fisheries.

CONCLUSION

As the AgFF labor force includes a growing number of Latino immigrants, more research is needed to characterize a broad range of exposures and health outcomes experienced by this population, particularly in forestry and fisheries.

Risk factors for nasal malignancies in German men: the South-German Nasal cancer study

BACKGROUND

There are few studies of the effects of nasal snuff and environmental factors on the risk of nasal cancer. This study aimed to investigate the impact of using nasal snuff and of other risk factors on the risk of nasal cancer in German men.

METHODS

A population-based case-control study was conducted in the German Federal States of Bavaria and Baden-Württemberg. Tumor registries and ear, nose and throat departments provided access to patients born in 1926 or later.

RESULTS

Telephone interviews were conducted with 427 cases (mean age 62.1 years) and 2.401 population-based controls (mean age 60.8 years). Ever-use of nasal snuff was associated with an odds ratio (OR) for nasal cancer of 1.45 (95% confidence interval [CI] 0.88-2.38) in the total study population, whereas OR in smokers was 2.01 (95% CI 1.00-4.02) and in never smokers was 1.10 (95% CI 0.43-2.80). The OR in ever-smokers vs. never-smokers was 1.60 (95% CI 1.24-2.07), with an OR of 1.06 (95% CI 1.05-1.07) per pack-year smoked, and the risk was significantly decreased after quitting smoking. Exposure to hardwood dust for at least 1 year resulted in an OR of 2.33 (95% CI 1.40-3.91) in the total population, which was further increased in never-smokers (OR 4.89, 95% CI 1.92-12.49) in analyses stratified by smoking status. The OR for nasal cancer after exposure to organic solvents for at least 1 year was 1.53 (1.17-2.01). Ever-use of nasal sprays/nasal lavage for at least 1 month rendered an OR of 1.59 (1.04-2.44). The OR after use of insecticides in homes was 1.48 (95% CI 1.04-2.11).

CONCLUSIONS

Smoking and exposure to hardwood dust were confirmed as risk factors for nasal carcinoma. There is evidence that exposure to organic solvents, and in-house use of insecticides could represent novel risk factors. Exposure to asbestos and use of nasal snuff were risk factors in smokers only.

Occupational exposure to wood dust and formaldehyde and risk of nasal, nasopharyngeal, and lung cancer among Finnish men

Controversy exists over whether or not occupational inhalation exposure to wood dust and/or formaldehyde increases risk for respiratory cancers. The objective of this study was to examine the risk of nasal, nasopharyngeal, and lung cancer in relation to occupational exposure to wood dust and formaldehyde among Finnish men. The cohort of all Finnish men born between the years 1906 and 1945 and in employment during 1970 was followed up through the Finnish Cancer Registry for cases of cancers of the nose (n = 292), nasopharynx (n = 149), and lung (n = 30,137) during the period 1971–1995. The subjects’ occupations, as recorded in the population census in 1970, were converted to estimates of exposure to wood dust, formaldehyde, asbestos, and silica dust through the Finnish job-exposure matrix. Cumulative exposure (CE) was calculated based on the prevalence, average level, and estimated duration of exposure. The relative risk (RR) estimates for the CE categories of wood dust and formaldehyde were defined by Poisson regression, with adjustments made for smoking, socioeconomic status, and exposure to asbestos and/or silica dust. Men exposed to wood dust had a significant excess risk of nasal cancer overall (RR, 1.59; 95% confidence interval [CI], 1.06–2.38), and specifically nasal squamous cell carcinoma (RR, 1.98; 95% CI, 1.19–3.31). Workers exposed to formaldehyde had an RR of 1.18 (95% CI, 1.12–1.25) for lung cancer. There was no indication that CE to wood dust or formaldehyde would increase the risk of nasopharyngeal cancer. Occupational exposure to wood dust appeared to increase the risk of nasal cancer but not of nasopharyngeal or lung cancer. The slight excess risk of lung cancer observed for exposure to formaldehyde may be the result of residual confounding from smoking. In summary, this study provides further evidence that exposure to wood dust in a variety of occupations may increase the risk of nasal cancer.

Molecular characterisation of sinonasal carcinomas and their clinical implications

Sinonasal carcinomas are rare tumours with an unfavourable prognosis whose management is difficult and complex, leading to high morbidity and mortality despite improvements in the field of surgery and radiotherapy. An elevated number of these tumours can be attributed to occupational exposure. In comparison with other head and neck malignancies, studies of molecular changes in these tumours are infrequent. This review was focused on findings about the epidemiology and molecular and phenotypic characterisation of sinonasal carcinomas, which can potentially be useful for diagnosis and treatment. The increasing knowledge about the molecular biology that underlies their carcinogenesis may help to identify precursor lesions, prognostic markers and markers that predict chemoradiotherapy response and, finally, to identify potential molecular targets that will expand treatment options.

Intestinal type adenocarcinoma of the ethmoid sinus in wood and leather workers: a retrospective study of 153 cases

BACKGROUND

The purpose of our study was to identify the role of work exposure to organic dusts in patients with malignant paranasal sinus tumors.

METHODS

We analyzed all patients surgically treated for a malignant paranasal sinus tumor at our institution between 1987 and 2006. All patients were specifically asked about their occupational history. The tumor site was classified as maxillary or ethmoid sinus. Adenocarcinomas were divided into intestinal type (ITAC) and non-ITAC.

RESULTS

The sample included 345 patients with ethmoid sinus and 301 maxillary sinus. Regarding the ethmoid sinus, we found an exposure to organic dusts in 148 of 153 patients with ITAC, in 3 of 16 patients with non-ITAC adenocarcinoma, and in 10 of 176 patients with other tumors. Regarding the maxillary sinus, we found an exposure in 1 of 20 patients with non-ITAC adenocarcinoma and in 4 of 281 patients with other histologies.

CONCLUSION

Our study demonstrates that only ethmoid ITACs have an indisputable relationship with the exposure to organic dusts.

Sinonasal carcinomas: recent advances in molecular and phenotypic characterization and their clinical implications

Sinonasal carcinomas are rare tumors with an aggressive clinical behaviour which frequently pose a number of problems regarding the interpretation of diagnostic findings and the treatment. In addition, in comparison with other malignancies of the head and neck region, an elevated fraction of sinonasal carcinomas can be attributed to occupational exposure. This review is focused on the recent advances in the molecular and phenotypic characterization of sinonasal carcinomas, and their possible implications for the interpretation of epidemiological data, as well as for the diagnosis and treatment of these rare malignancies. The increasing knowledge on their phenotypic and genotypic features is progressively leading to a refinement in diagnosis, especially for poorly differentiated and undifferentiated lesions, as well as to the identification of markers which can be potentially useful to identify the early phases of carcinogenesis, to detect subclinical disease, to predict the response to therapy, and finally, that may represent potential targets for alternative treatments.

Occupational wood dust exposure and the risk of laryngeal cancer: a population based case-control study in Germany

BACKGROUND

To investigate the effect of exposure to wood dust on the risk of laryngeal cancer.

METHODS

A population-based case-control study on laryngeal cancer was conducted in South-West Germany between 1st of May 1998 to 31st of December 2000 with 257 histologically confirmed cases (236 males, 21 females), age 37 to 80 years, and 769 population controls (702 males, 67 females), 1:3 frequency matched by age and sex. Occupational exposures and other risk factors were obtained with face-to-face interviews using a detailed standardized questionnaire. The complete individual work history was assessed. Work conditions were obtained by job-specific questionnaires for selected jobs known to be associated with exposure to potential carcinogens. Additionally, a specific substance check-list was used as a method for exposure assessment.

RESULTS

43 (16.7%) cases (41 males, 2 females) and 107 (13.9%) controls (105 males, 2 females) reported wood dust exposure. Numbers were almost identical for two different methods of exposure assessment; however, the agreement of these methods was around 95%. A strong effect on laryngeal cancer risk after adjustment for smoking, alcohol and education was observed for high exposure to hardwood dust (OR = 2.6, 95% CI 1.3-5.2) and to softwood dust (OR = 2.2, 95% CI 1.1-4.2), as assessed by substance list.

CONCLUSIONS

Our findings for higher exposure to hardwood and softwood dust contribute to the evidence that wood dust, in particular from hardwood is an independent risk factor.

Lifestyle-related factors and environmental agents causing cancer: an overview

The increasing incidence of a variety of cancers after the Second World War confronts scientists with the question of their origin. In Western countries, expansion and ageing of the population as well as progress in cancer detection using new diagnostic and screening tests cannot fully account for the observed growing incidence of cancer. Our hypothesis is that environmental factors play a more important role in cancer genesis than it is usually agreed. (1) Over the last 2-3 decades, alcohol consumption and tobacco smoking in men have significantly decreased in Western Europe and North America. (2) Obesity is increasing in many countries, but the growing incidence of cancer also concerns cancers not related to obesity nor to other known lifestyle-related factors. (3) There is evidence that the environment has changed over the time period preceding the recent rise in cancer incidence, and that this change, still continuing, included the accumulation of many new carcinogenic factors in the environment. (4) Genetic susceptibility to cancer due to genetic polymorphism cannot have changed over one generation and actually favours the role of exogenous factors through gene-environment interactions. (5) Age is not the unique factor to be considered since the rising incidence of cancers is seen across all age categories, including children, and adolescents. (6) The fetus is specifically vulnerable to exogenous factors. A fetal exposure during a critical time window may explain why current epidemiological studies may still be negative in adults. We therefore propose that the involuntary exposure to many carcinogens in the environment, including microorganisms (viruses, bacteria and parasites), radiations (radioactivity, UV and pulsed electromagnetic fields) and many xenochemicals, may account for the recent growing incidence of cancer and therefore that the risk attributable to environmental carcinogen may be far higher than it is usually agreed. Of major concern are: outdoor air pollution by carbon particles associated with polycyclic aromatic hydrocarbons; indoor air pollution by environmental tobacco smoke, formaldehyde and volatile organic compounds such as benzene and 1,3 butadiene, which may particularly affect children and food contamination by food additives and by carcinogenic contaminants such as nitrates, pesticides, dioxins and other organochlorines. In addition, carcinogenic metals and metalloids, pharmaceutical medicines and some ingredients and contaminants in cosmetics may be involved. Although the risk fraction attributable to environmental factors is still unknown, this long list of carcinogenic and especially mutagenic factors supports our working hypothesis according to which numerous cancers may in fact be caused by the recent modification of our environment.

The multitude and diversity of environmental carcinogens

We have recently proposed that lifestyle-related factors, screening and aging cannot fully account for the present overall growing incidence of cancer. In order to propose the concept that in addition to lifestyle related factors, exogenous environmental factors may play a more important role in carcinogenesis than it is expected, and may therefore account for the growing incidence of cancer, we overview herein environmental factors, rated as certainly or potentially carcinogenic by the International Agency for Research on Cancer (IARC). We thus analyze the carcinogenic effect of microorganisms (including viruses), radiations (including radioactivity, UV and pulsed electromagnetic fields) and xenochemicals. Chemicals related to environmental pollution appear to be of critical importance, since they can induce occupational cancers as well as other cancers. Of major concerns are: outdoor air pollution by carbon particles associated with polycyclic aromatic hydrocarbons; indoor air pollution by environmental tobacco smoke, formaldehyde and volatile organic compounds such as benzene and 1,3 butadiene, which may particularly affect children, and food pollution by food additives and by carcinogenic contaminants such as nitrates, pesticides, dioxins and other organochlorines. In addition, carcinogenic metals and metalloids, pharmaceutical medicines and cosmetics may be involved. Although the risk fraction attributable to environmental factors is still unknown, this long list of carcinogenic and especially mutagenic factors supports our working hypothesis according to which numerous cancers may in fact be caused by the recent modification of our environment.

Wood dust exposure and the association with lung cancer risk

BACKGROUND

Wood dust was designated as a human carcinogen based on increased sinus and nasal cancer rates among exposed workers. However, data on an association with lung cancer have been inconclusive.

METHODS

Self-reported wood dust exposure was compared between 1,368 lung cancer patients and 1,192 cancer-free adults, in a lung cancer case-control study. Epidemiological information was collected through a detailed personal interview.

RESULTS

Using several definitions of wood dust exposure we consistently observed statistically significant elevated adjusted risk estimates; for example, the adjusted odds ratio (OR) for combined wood dust related occupations and industries was 3.15 (95% confidence intervals (CI) 1.45-6.86) and for an overall summary exposure measure it was 1.60 (95% CI 1.19-2.14). The association was maintained when stratified by histopathological type. Among those exposed to cigarette smoke and wood dust, 21% of the cases were attributable to biologic interaction.

CONCLUSIONS

Wood dust exposure is a potential risk factor for lung cancer.

Occupational risks for nasal cancer in Sweden

An elevated risk of nasal cancer (NC) has been associated with numerous occupations but with contradicting results. We sought to address recent and current risks of NC in a nationwide study. The nationwide Swedish Family-Cancer Database was used to calculate standardized incidence ratios (SIRs) for 52 occupational groups. SIRs were adjusted for age and socioeconomic status. Among 739 male cases, significantly elevated SIRs for nasal adenocarcinoma were observed in woodworkers, teachers, and fishermen. In woodworkers, the risk increased with a longer occupational history in exposure to softwood in combination with hardwood. Electrical workers had a significant elevated risk for squamous cell carcinoma. Among 182 female cases, significantly elevated SIRs were observed in glass, ceramic, and tile workers. The study identified some known risk occupations and suggested some new ones.

[Nasal sinus carcinoma after wood dust exposure. Morphological spectrum of 100 cases]

Sinonasal carcinomas are usually of the squamous cell or transitional cell type. Adenocarcinomas of the inner nose and the paranasal sinus correlate with exposure to wood dust. However, this is only true for adenocarcinomas of the intestinal type and not for salivary gland carcinomas or polymorphous low-grade adenocarcinomas. Of 160 cases with a history of wood dust exposure and malignant tumors of the inner nose, 134 were sinonasal adenocarcinomas of the intestinal type (SNAIT). In addition, there were 24 other carcinomas as well as 1 malignant melanoma and 1 malignant synovial tumor. The SNAIT showed various subtypes with great morphological similarities to colorectal adenocarcinomas (papillary tubular cylinder cell: 72.4%; alveolar goblet cell: 5.2%; signet ring cell: 3.7%; transitional type: 18.7%). Highly differentiated adenocarcinomas (G1) and mucinous adenocarcinomas were relatively frequent: they accounted for 23.1% and 29.1% of the 134 SNAIT, respectively. Apart from wood dust, wood additives are discussed as a carcinogenic factor. With the development of SNAIT, a metaplasia-dysplasia-carcinoma in situ sequence is probable. If the clinical course shows few symptoms, the first manifestation of such a tumor often occurs in an advanced stage.

Spatial epidemiology: current approaches and future challenges

Spatial epidemiology is the description and analysis of geographic variations in disease with respect to demographic, environmental, behavioral, socioeconomic, genetic, and infectious risk factors. We focus on small-area analyses, encompassing disease mapping, geographic correlation studies, disease clusters, and clustering. Advances in geographic information systems, statistical methodology, and availability of high-resolution, geographically referenced health and environmental quality data have created unprecedented new opportunities to investigate environmental and other factors in explaining local geographic variations in disease. They also present new challenges. Problems include the large random component that may predominate disease rates across small areas. Though this can be dealt with appropriately using Bayesian statistics to provide smooth estimates of disease risks, sensitivity to detect areas at high risk is limited when expected numbers of cases are small. Potential biases and confounding, particularly due to socioeconomic factors, and a detailed understanding of data quality are important. Data errors can result in large apparent disease excess in a locality. Disease cluster reports often arise nonsystematically because of media, physician, or public concern. One ready means of investigating such concerns is the replication of analyses in different areas based on routine data, as is done in the United Kingdom through the Small Area Health Statistics Unit (and increasingly in other European countries, e.g., through the European Health and Environment Information System collaboration). In the future, developments in exposure modeling and mapping, enhanced study designs, and new methods of surveillance of large health databases promise to improve our ability to understand the complex relationships of environment to health.

Cancer incidence among union carpenters in New Jersey

A cohort of 13,354 male union carpenters in New Jersey was linked to cancer registry data to investigate cancer incidence during 1979 through 2000. Surveillance, Epidemiology and End Results data were used to calculate standardized incidence ratios (SIRs). A total of 592 incident cancers were observed among this cohort (SIR=1.07), which was not statistically in excess. However, significant excesses were observed for cancers of the digestive system and peritoneum (SIR=1.24) and the respiratory system (SIR=1.52). Workers in the union more than 30 years were at significant risk for cancers of the digestive organs and peritoneum (SIR=3.98), rectum (SIR=4.85), trachea, bronchus, and lung (SIR=4.56), and other parts of the respiratory system (SIR=11.00). Testicular cancer was significantly in excess (SIR=2.48) in analyses that lagged results 15 years from initial union membership. Additional etiologic research is needed to evaluate possible occupational and nonoccupational risk factors for testicular cancer.

Evidence of p53 immunohistochemical overexpression in ethmoidal mucosa of woodworkers

A high risk of neoplastic transformation of nasal and paranasal sinuses mucosa is related to the occupational exposure to wood dust, however no conclusive data have been reported up to now about morphological precursors of these tumors, mechanisms of carcinogenesis and role of p53 gene. Immunohistochemical overexpression of protein p53 (DO7 clone) by epithelial cells of ethmoidal mucosa was investigated on 60 woodworkers occupationally exposed for a minimum of 10 years, on 50 functional and/or esthetic nasal surgery patients (control group) and on 15 cases of intestinal-type adenocarcinoma, 10 of these involving subjects who had a longtime exposure to wood dust. In almost all the woodworkers (92%) the normal ciliated epithelium showed tracts of squamous metaplasia. The mean percentage of p53-positive cells in woodworkers and in controls was 28.6 and 7.97%, respectively, in metaplastic epithelium (P<0.001), 11.7 and 2.08% in ciliated epithelium (P<0.001), 12.46 and 1.03% (P<0.001) in the sero-mucous glands of the nasal stroma. Both in tracts of metaplastic epithelium and in those of ciliated epithelium, positive cells were distributed in basal and suprabasal layers. A high number of p53-positive cells was also observed in the normal ciliated epithelium close to the neoplastic cells, of intestinal-type adenocarcinomas affecting subjects with longtime exposure to wood dust. Moreover, a higher number of p53 positive neoplastic cells was showed by the cases occurring in occupationally exposed patients than by the others. The following conclusions can be drawn: (1) in the ethmoidal mucosa, a region at high risk of carcinogenesis in subjects exposed to wood dust, epithelial cells overexpress p53 protein, and this may be linked to the presence of p53 gene mutations; malignant transformation, as at other head and neck sites, may thus occur through this pathway; (2) the presence of p53 overexpression in sero-mucous glands is in keeping with the histogenesis of some tumors from these structures; (3) since tumors of nose and paranasal sinuses, mainly adenocarcinoma, are recognized as occupational neoplasias, immunohistochemical evaluation of p53, perhaps combined with molecular methods, could be the first step to detect subjects at high risk of carcinogenesis among woodworkers.

Epstein-Barr virus in squamous carcinoma of the anterior nasal cavity

Squamous carcinoma is the most common malignancy of the head and neck, but it rarely occurs in the nasal vestibule. Epstein-Barr virus (EBV) has been detected in and is causally linked to various head and neck tumors, particularly nasopharyngeal carcinoma. The possible role of EBV in squamous carcinoma of the anterior nasal cavity, particularly of the nasal vestibule, has not been previously investigated. Histologic sections from 17 patients with nasal vestibular squamous carcinoma were examined. Material for EBV detection by immunohistochemistry and by in situ hybridization was available in 15 of the 17 cases. The study group consisted of eight men and nine women ranging in age from 40 to 82 years (mean age, 64 years). None of the patients was of Asian descent. The squamous carcinomas were graded as well differentiated (one case), moderately differentiated (11 cases), and poorly differentiated (five cases). Fourteen patients were smokers; the history of smoking ranged from 20 to 60 pack-years. Treatment modalities included surgical resection, radiation, chemotherapy, or a combined approach. The clinical follow-up periods ranged from 7 months to 16 years. Three patients developed metastases, one of whom died of disease after 1 year. Epstein-Barr virus was not detected in any of the 15 of 17 cases tested by either immunohistochemistry or by in situ hybridization. Squamous carcinoma of the nasal vestibule is an uncommon cancer that is not causally related to EBV.

Pulmonary and intraperitoneal inflammation induced by cellulose fibres

The inflammatory effects of respirable cellulose fibres were studied in two short-term animal models: intraperitoneal injection in mice, and inhalation in rats. The mouse peritoneal cavity is particularly sensitive to fibrous compared to non-fibrous particles. Both cellulose fibres and the positive control fibre, crocidolite asbestos, were administered in doses ranging from 10(4) to 10(8) fibres and caused marked, dose-dependent recruitment of inflammatory cells to the mouse peritoneal cavity, which was highest 1 day following injection. Crocidolite was much more active than cellulose, despite the mass dose of cellulose being 66 times greater for an equivalent number of fibres. Crocidolite at the higher doses caused inflammation to persist through 7 days. For the inhalation study, rats were exposed daily, 5 days per week, to aerosols of cellulose dust for ca. 3 weeks at a concentration of 1000 fibres ml(-1). Inhalation exposure induced an early inflammatory response in rat lungs, as determined by bronchoalveolar lavage, which peaked at 1 day following the start of inhalation and thereafter declined, despite a further 13 days of exposure over a period of 18 calendar days. In vitro production of the pro-inflammatory cytokine tumour necrosis factor alpha (TNF-alpha) by lavaged alveolar macrophages was markedly depressed by the end of the exposure period in cellulose-exposed animals, compared to sham-exposed controls, and this effect was still present in rats that had been allowed to recover for 28 days beyond the end of exposure. We conclude that the cellulose material studied is less inflammogenic than crocidolite and that the extent of the inflammatory response within the lung appears to reduce with continued exposure over a 14-day period.