Cancer epidemiology of woodworking

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

The influence of sex and gender on the immune response

The immune system and its orchestrated response are affected by a multitude of endogenous and exogenous factors, modulators and challenges. One of the most frequent differences described in the immune response is its vigor and activity in females compared to males, leading to the consequent increase in autoimmune conditions seen in the female population as well as differences in the immune response to pathogens and viruses. The following review summarizes our present knowledge on sex differences in the immune response, detailing the hormonal and genetic effects that have been proposed as explanatory mechanisms. Sexual hormones, mostly estrogen but also progesterone and testosterone, affect immune cells quantitatively and qualitatively. Relevant research has focused on the impact of hormones on cytokine production by the different effector cells, as well as impact on immunoglobulin production by B lymphocytes and activity of granulocytes and NK cells. The biological aspects are complemented by research data on the possible modulatory role of the X chromosome. In addition to biological differences, the frequently neglected role of gender as an immunomodulator is introduced and explored. Gender affects all areas of human life and consequently affects the different steps of an immune response. Exposure to various types of antigens, access to health promotion programs and health care, as well as prioritization of health needs and household resource allocation all affect the different response of females and males to immunologic challenges.

Inflammatory response and genotoxicity of seven wood dusts in the human epithelial cell line A549

Exposure to wood dust is common in many workplaces. Epidemiological studies indicate that occupational exposure to hardwood dusts is more harmful than to softwood dusts. In this study, human epithelial cell line A549 was incubated with well-characterized dusts from six commonly used wood species and from medium density fibreboard (MDF), at concentrations between 10 and 300microg/ml. After 3 and 6h of incubation, genotoxicity was assessed by measurement of DNA damage with the single-cell gel electrophoresis (comet) assay and inflammation was measured by the expression of IL-6 and IL-8 mRNA and by the amount of IL-8 protein. There was a 1.2-1.4-fold increase in DNA strand breaks after incubation with beech, teak, pine and MDF dusts compared with the levels in untreated cells, but after 6h only the increase induced by the MDF dust remained. Increased expression of cellular IL-6 and IL-8 mRNA was induced by all of the wood dusts at both times. Similar to IL-8 mRNA expression, the amounts of secreted IL-8 protein were elevated, except after incubation with oak dust, where a marginal reduction was seen. On the basis of the effects on IL-8 mRNA expression, the wood dusts could be divided into three groups, with teak dust being the most potent, MDF, birch, spruce and pine being intermediate, and beech and oak being the least potent. The induction of DNA strand breaks did not correlate well with the interleukin response. In conclusion, all wood dusts induced cytokine responses, and some dusts induced detectable DNA damage. The inflammatory potency seemed intermediate for dusts from the typical softwoods spruce and pine, whereas the dusts from species linked to cancer, beech and oak, were the least inflammatory. The variation of the effects induced by different wood dusts over time indicates that the DNA damage was not secondary to the cytokine response. Although hardwoods are often considered more harmful than softwoods by regulatory agencies, the current experiments do not provide evidence for a clear-cut distinction between toxicities of hardwood and softwood dust.

Mechanisms of particle-induced pulmonary inflammation in a mouse model: exposure to wood dust

Repeated airway exposure to wood dust has long been known to cause adverse respiratory effects such as asthma and chronic bronchitis and impairment of lung function. However, the mechanisms underlying the inflammatory responses of the airways after wood dust exposure are poorly known. We used a mouse model to elucidate the mechanisms of particle-induced inflammatory responses to fine wood dust particles. BALB/c mice were exposed to intranasally administered fine (more than 99% of the particles had a particle size of < or = 5 microm, with virtually identical size distribution) birch or oak dusts twice a week for 3 weeks. PBS, LPS, and titanium dioxide were used as controls. Intranasal instillation of birch or oak dusts elicited influx of inflammatory cells to the lungs in mice. Enhancement of lymphocytes and neutrophils was seen after oak dust exposure, whereas eosinophil infiltration was higher after birch dust exposure. Infiltration of inflammatory cells was associated with an increase in the mRNA levels of several cytokines, chemokines, and chemokine receptors in lung tissue. Oak dust appeared to be a more potent inducer of these inflammatory mediators than birch dust. The results from our in vivo mouse model show that repeated airway exposure to wood dust can elicit lung inflammation, which is accompanied by induction of several proinflammatory cytokines and chemokines. Oak and birch dusts exhibited quantitative and qualitative differences in the elicitation of pulmonary inflammation, suggesting that the inflammatory responses induced by the wood species may rise via different cellular mechanisms.

Chromosomal imbalances in wood dust-related adenocarcinomas of the inner nose and their associations with pathological parameters

Comparative genomic hybridization (CGH) was used to screen 42 wood dust-related sinonasal adenocarcinomas for chromosomal alterations. The tumour collection comprised 39 papillary-tubular cylinder cell adenocarcinomas (PTCCs; six cases G1, 23 G2, and ten G3), two alveolar goblet cell adenocarcinomas (AGCs), and one signet ring cell adenocarcinoma (SRC), according to the Kleinsasser and Schroeder classification. Copy number changes were detected in 41 tumours (97.6%). The one carcinoma without imbalances was a PTCC-G1. DNA gains were most frequently seen on chromosomes 12p (83%), 7q (74%), 8q (71%), and 20q (71%), 11q (61%), 22 (59%), and 1q (52%). Pronounced overrepresentations suggestive of high copy amplifications were detected on 8q (15 cases, 36%), 7q (six cases, 14%), 20q (five cases, 12%), 13q14 (three cases, 7%), 1q22, 5p, 12p and 20 (two cases, 5% each), and 2q24, 3q13, 3q22, 7p, 14q12, and 16q13 (one case, each 2%). Frequent chromosomal losses occurred at 5q (81%), 18q (76%), 4 (74%), 8p (61%), 9p (60%), 6q and 17p (52% each), and 3p, 13q, and 21 (50% each). There was a quantitative as well as a qualitative increase of alterations from PTCC-G1 to PTCC-G2 and finally PTCC-G3, confirming the usefulness of histopathological grading. While PTCC-G1 carried only a few alterations, namely gains on chromosomes 17 and 7 as well as losses of 4q and 13q, PTCC-G2 already carried many of the above-mentioned alterations, while PTCC-G3 showed significantly more gains of 7q, 8q, and 12p, and losses of 8p and 17p. Additionally, the latter subgroup was particularly prone to carry pronounced DNA gains. These data provide further evidence for a recurrent pattern of chromosomal imbalances in sinonasal adenocarcinomas and highlight distinct aberrations that are associated with tumour differentiation and progression.

Characterization of oak and birch dust-induced expression of cytokines and chemokines in mouse macrophage RAW 264.7 cells

Occupational exposure to wood dust is related to several respiratory diseases, such as allergic rhinitis, chronic bronchitis, and asthma. However, virtually nothing is known about molecular mechanisms behind wood dust-induced pulmonary inflammation. To elucidate the effects of wood dust exposure on cytokine and chemokine expression in murine macrophage cell line cells, mouse RAW 264.7 cells were exposed to two selected hardwood dusts, oak and birch. TiO2 and LPS were used as controls. Expression patterns of several cytokines, chemokines, and chemokine receptors were assessed by real-time quantitative PCR system and by ELISA. Exposure to birch dust caused a major increase in TNF-alpha and IL-6 protein levels whereas a weaker induction of TNF-alpha protein was found after exposure to oak dust. Inorganic TiO2 dust did not induce significant cytokine expression. With respect to the chemokines, a dose-dependent, about 10-fold induction of CCL2 mRNA and protein was found after exposure to birch dust. Oak dust induced weakly CCL2 protein. Similarly, birch dust induced a strong expression of CCL3, CCL4, and CXCL2/3 mRNA whereas only moderate levels of these chemokine mRNAs were detected after oak dust exposure. In contrast, expression of CCL24 mRNA was inhibited by more than 40-fold by both oak and birch dusts. TiO2 dust induced about five-fold expression of CCL3 and CCL4 mRNA but did not affect significantly other chemokines. These results suggest that exposure to birch or oak dusts may influence the development of the inflammatory process in the airways by modulating the expression of macrophage-derived cytokines and chemokines.

Schneiderian papillomas and nonsalivary glandular neoplasms of the head and neck

Schneiderian papillomas and nonsalivary glandular neoplasms of the head and neck continue to be a source of confusion for both the clinician and pathologist. An update on these lesions is provided.

Cancer, cigarette smoking and premature death in Europe: a review including the Recommendations of European Cancer Experts Consensus Meeting, Helsinki, October 1996

Cigarette smoking has been clearly and unambiguously identified as a direct cause of cancers of the oral cavity, oesophagus, stomach, pancreas, larynx, lung, bladder, kidney and leukaemia, especially acute myeloid leukaemia. Additionally, cigarette smoking is a direct cause of ischaemic heart disease (the commonest cause of death in western countries), respiratory heart disease, aortic aneurysm, chronic obstructive lung disease, stroke, pneumonia and cirrhosis and cancer of the liver. Cigarette smoking can kill in 24 different ways and, although smoking protects against several fatal and non-fatal conditions, the adverse effect of smoking on health is largely negative. In developed countries as a whole, tobacco is responsible for 24% of all male deaths and 7% of all female deaths: these figures rise to over 40% in men in some countries of central and eastern Europe and to 17% in women in the United States. The average loss of life of smokers is 8 years. Among United Kingdom doctors followed for 40 years, overall death rates in middle age were about three times higher among doctors who smoked cigarettes as among doctors who had never smoked regularly. About half of all regular cigarette smokers will eventually be killed by their habit. The important information is that it is never too late to stop smoking: among United Kingdom doctors who stopped smoking, even in middle age, there was a substantial improvement in life expectancy. World-wide, smoking is killing three million people each year and this figure is increasing. In most countries the worst is yet to come, since by the time the young smokers of today reach middle or old age there will be about 10 million deaths/year from tobacco. Approximately 500 million individuals alive today can expect to be killed by tobacco, 250 million of these deaths will occur in middle age. Tobacco is already the biggest cause of adult death in developed countries. Over the next few decades tobacco could well become the biggest cause of adult death in the world. For men in developed countries, the full effects of smoking can already be seen. Tobacco now causes one-third of all male deaths in middle age (plus one fifth in old age). Tobacco is a cause of about half of all male cancer deaths in middle age (plus one-third in old age). Of those who start smoking in their teenage years and keep on smoking, about half will be killed by tobacco. Half of these deaths will be in middle age (35-69) and each will lose an average of 20-25 years of non-smoker life expectancy. In non-smokers in many countries, cancer mortality is decreasing slowly and total mortality rapidly. The war against cancer is being won slowly: the effects of cigarette smoking are holding back this victory. Lung cancer now kills more women in the United States each year than breast cancer. For women in developed countries, the peak of the tobacco epidemic has not yet arrived. Tobacco now causes almost one-third of all deaths in women in middle age in the United States. Although it has only 5% of the world's female population, the United States has 50% of the world's deaths from smoking in women. Tobacco smoking is a major cause of premature death. Throughout Europe, in 1990 tobacco smoking caused three quarters of a million deaths in middle age (between 35 and 69). In the Member States of the European Union in 1990 there were over one quarter of a million deaths in middle age directly caused by tobacco smoking: there were 219700 in men and 31900 in women. There were many more deaths caused by tobacco at older ages. In countries of central and eastern Europe, including the former USSR, there were 441200 deaths in middle age in men and 42100 deaths in women. There is a need for urgent action to help contain this important and unnecessary loss of life. In formulating Recommendations, the European Cancer Experts Consensus Committee recognised that Tobacco Control depends on various parts of society and not only on the individual.

Genotoxicity of wood dust in a human embryonic lung cell line

Wood dust exposure has been found to be an occupational hazard, being linked to an enhanced incidence of various neoplasias. Here we performed an experiment to evaluate the ability of solvent extracts of natural woods to induce chromosome aberrations in respiratory cells in culture. Human embryonic lung cells, MRC-5, grown in Dulbecco's medium were exposed to various concentrations of the dust extracts of pesticide-free (untreated) beech, oak and pine woods. Three concentrations per extract with and without metabolic activation (S9) and 100 metaphase cells per dose were examined for possible structural aberrations. Although no dose-dependent activity could be found with any extract in the presence of S9, most aberrations observed were of the chromatid type caused by oak wood. Dose-dependent chromosomal breaks caused by oak and chromatid breaks caused by both beech and oak were observed in the absence of S9. These data might support the early hypothesis that hard wood dust per se contains some in vivo genotoxic and thus possibly carcinogenic components.

Formaldehyde and cancer morbidity among male employees in Denmark

Formaldehyde, a genotoxic and potent animal carcinogen, is widespread in the working environment as well as in private homes. The risk for cancer morbidity in Denmark during 1970-84 was estimated from standardized proportionate incidence ratios (SPIR) among men whose longest employment had been held since 1964, at least 10 years before diagnosis, in 265 companies in which exposure to formaldehyde was identified. The results do not support the hypothesis that formaldehyde is associated with lung cancer (SPIR = 1.0, 410 cases). Significantly elevated risks were found for cancers of the colon (SPIR = 1.2, 166 cases), kidney (SPIR = 1.3, 60 cases), and sino-nasal cavities (SPIR = 2.3, 13 cases). For sino-nasal cancer, a relative risk of 3.0 (95 percent confidence interval = 1.4-5.7) was found among blue-collar workers with no probable exposure to wood dust, the major confounder. This study provides further evidence that occupational exposure to formaldehyde increases the risk for sino-nasal cancer.

Carcinogenic effects of wood dust: review and discussion

Occupational exposure to wood dust (alone or chemically treated) is associated with an increased risk of developing adenocarcinoma of the nasal cavity. The specific causative agents, i.e., wood dust alone (natural products), wood dust with additives used in the processing or manufacturing of wood products, and/or physical determinants of wood dust and the associated risk factors, are not known or understood. The strongest association of exposure to wood dust and development of nasal cancer is observed in those occupations where workers are exposed to hard wood dust and chemical additives are not used. The time between first occupational exposure to wood dust and the development of adenocarcinoma of the nasal cavity averages 40 years (range 7-70 years). The epidemiological data available are not sufficient to make a definitive assessment between wood dust exposure and increased risk for cancer other than nasal cancer. The toxicity, mutagenicity, and carcinogenicity of wood dust to laboratory animals or in vitro with animal or microbial cells have not been thoroughly studied. Thus there is no direct experimental evidence on the potential hazards of wood dust. Data are insufficient or lacking on 1) wood dust exposure levels in ambient air and worker's breathing zone, and the deposition in the nasal cavity; 2) hard vs. soft wood dusts; 3) particle size and shape; 4) chemical composition of wood dust and the extent of contamination with chemical additives; and 5) interaction between inhaled wood dust, chronic irritation, and tobacco smoking. These data are required so that one can understand the association between wood dust exposure and nasal cavity tumors, along with demographic differences in cancer rates, and to develop strategies for intervention and reduction of disease causing agents in order to reduce risk to wood industry workers.

Genotoxic effects of subacute treatments with wood dust extracts on the nasal epithelium of rats: assessment by the micronucleus and 32P-postlabelling

Human exposure to wood dust has been epidemiologically linked to a number of enhanced incidences of various neoplasias, including those of the nose. Among different suspected woods, long-term exposure to the dust of beech (Fagus silvatica) is strongly associated with development of these tumors. Experimentally, it has been shown that a simple alcoholic extract of beech wood dust is mutagenic toward some bacteria and tumorigenic on mouse skin. For the present study, different groups of male Wistar rats were treated with aqueous, ethanol, or methanol extract of untreated beech wood dust via nasal drip at three concentrations for 48 h. Animals were killed 24 h after the last treatment and the nasal tissues were isolated to be examined for possible induction of micronuclei and DNA adducts. A clear dose-dependent increase in the number of micronuclei (P < 0.01) was observed after treatment of rats with each alcoholic extract of wood dust. In contrast, no DNA adducts could be detected with these extracts using the 32P-postlabelling technique. No increased number of micronucleated cells was found with solvents alone or with aqueous extract of dust. These data might support the early hypothesis that wood dust per se contains some in vivo genotoxic and thus possibly carcinogenic components extractable by an alcohol.

Salivary-type neoplasms of the sinonasal tract

Salivary-type neoplasms of the nasal cavity and paranasal sinuses are numerically dominated by adenoid cystic carcinomas and pleomorphic adenomas. All others, benign or malignant, are rarely encountered and are usually biologically and histologically low-grade. Sites of origin in the sinonasal tract conform to the density and distribution of the seromucous glands and hence are most often nasal (septum and turbinates) or ostial.

Release of mutagens after chemical or microbial degradation of beech wood lignin

The microbial or chemical degradation of lignin from untreated samples of beech wood dusts (Fagus silvatica) resulted in the release of different mutagenic responses in the Salmonella/mammalian plate incorporation assay. In the first experiment using chemical degradation of lignin, dust samples were pre-extracted using acetone-water; the lignin portions were degraded into simpler compounds which were further fractionated on a Sephadex-LH20 column. The compounds isolated from the second phase of Sephadex, representing substances with a 3-4 ring structure and/or those of the same molecular weight, were highly mutagenic towards Salmonella typhimurium TA100 in the presence of metabolic activation. These substances were also active to some extent in strain TA1537 both in the presence and absence of Aroclor-induced rat liver homogenates. In contrast, no direct- or indirect-acting mutagenicity was found when testing with strains TA97 and TA98. Strain TA1535 responded positively only to direct-acting mutagens in the fraction tested. The mutagenic fraction was found to be toxic to the cells when tested in a histidine-rich medium. Repurification of this mutagenic fraction, using silica-gel column chromatography, revealed much higher mutagenic activity than the test material towards strain TA100. In the second pilot experiment, Phanerochaete chrysosporium and Chaetomium globosum, which are known for their ability to degrade lignin, were each incubated with wood dusts in a mixture of physiological saline and nutrient broth for either 3 or 30 days. Significant mutagenic activity was observed with the dust extract after incubation with Ph. chrysosporium but not with Ch. globosum which is a known degrader of beech lignin. These results are discussed regarding hypotheses on the carcinogenicity of beech wood dusts.