Occupation and cancer of the oral cavity or oropharynx in Turin, Italy

In a population-based case-referent study, the occupational experience of 86 men with oral or oropharyngeal cancer and 373 referents was analyzed with respect to employment in 41 occupations and 40 industries, as well as to exposure to 16 chemicals, as estimated via a job-exposure matrix. Among the occupations and industries at higher risk were machinery operator (odds ratio [OR] 2.0; 95% confidence interval [95% CI] 1.0-4.0), plumber (OR 5.0, 95% CI 1.2-21.5), building industry (OR 2.5; 95% CI 1.3-4.5), textile industry (OR 2.5; 95% CI 0.6-4.6), and electricity production (OR 2.8; 95% CI 0.7-12.1). All the OR estimates were adjusted for age, education, area of birth, tobacco smoking, and alcohol consumption. An association between formaldehyde exposure and oral cancer was suggested (OR for any exposure 1.6, 95% CI 0.9-2.8; OR for probable or definite exposure 1.8, 95% CI 0.6-5.5). No other chemical included in the matrix showed any risk pattern. The evidence of an association between formaldehyde exposure and oral or oropharyngeal cancer is strengthened by the results of this study.     

Dietary patterns and risk of cancer of the oral cavity and pharynx in Uruguay

From 1995 to 2002, a case-control study on food groups and risk of cancer of the oral cavity and pharynx was conducted in Montevideo, Uruguay. Two hundred thirty cases were frequency-matched to 460 controls on age, residence, and urban/rural status. The study was restricted to men. The relationship between foods and risk of oral and pharyngeal squamous cell carcinoma was examined through: 1) individual food group analysis, 2) factor analysis, and 3) determination of empirical scores. The results were similar. Factor analysis generated 2 patterns, which were labeled as "stew" and "vegetables and fruits." The stew pattern loaded positively on boiled meat, cooked vegetables, potato, and sweet potato. This pattern was directly associated with risk of oral and pharyngeal cancer [odds ratio (OR), 3.75; 95% confidence interval (CI), 1.99-7.06; P value for trend=0.0002]. The vegetables and fruits factor loaded positively on raw vegetables, citrus fruits, other fruits, liver, fish, and desserts. This pattern was inversely associated with risk of oropharyngeal carcinoma (OR, 0.34; 95% CI, 0.18-0.64; P value for trend=0.0008). Joint effects of high intake of risk foods and low intake of protective foods were associated with a risk of 12.0 (95% CI, 4.1-34.6). Our study confirms the important role of dietary factors in oral and pharyngeal cancer risk and suggests that the analysis of dietary patterns is a powerful tool to investigate the links between nutrition and cancer.     

The relation of socioeconomic status to oral and pharyngeal cancer

We assessed the relation between socioeconomic status and risk of oropharyngeal cancer in a population-based interview study of 762 male cases and 837 male controls in four areas of the United States. Three primary indicators of socioeconomic status were evaluated: education, occupational status, and percentage of potential working life spent in employment. With adjustment for the effects of established risk factors, such as use of tobacco products, alcohol consumption, and poor dentition, a relatively low percentage of years worked was also a risk factor. Educational attainment and occupational status were not independently related to risk of oropharyngeal cancer. These results are consistent with the hypothesis that behaviors that lead to social instability, and/or social instability itself, are linked to an increased risk of oral and pharyngeal cancers.     

Delayed diagnosis of cancer with emphasis on oral cavity cancers.

Delayed diagnosis of cancer and, of oral cavity cancers in particular, is of crucial importance for the clinical management, costs of care and unfavourable outcome. Many scientists have studied the causes of delayed diagnosis to find solution of the problem. However, only few studies of this kind have been performed in Bulgaria, especially for oral cavity cancers. The aim of this overview was to summarize and analyze publications on problems and causes of delayed diagnosis of cancer in general and, of oral cavity cancers in particular. The literature search was made in different databases such as MEDLINE, BIOSIS, INTERNET, etc. More than 100 relevant items of information were extracted but only 22 of them were found suitable and further analyzed. The analysis of the literature has revealed the importance of recognizing the warning signals and causes of delayed diagnosis in cancer in general and in oral cavity cancers in particular. For instance, survival of patients with squamous cell carcinoma of the tongue (Dx:141) was related to delayed diagnosis (20% of patients survive more than 5 years and 71%--only 2 years after diagnosis). The problems of delayed diagnosis in patients with multiple neoplasm of the oral cavity (Dx:143-145) and with nasopharyngeal carcinoma (Dx:146-149) were also discussed (96.6% of patients were in stage III at diagnosis). This overview has summarized problems in and stressed the main aspects of delayed diagnosis of cancer in general. It has also denoted hints in delayed diagnosis of cancer of the oral cavity and their relevance to the clinical management, outcome and costs of care for such patients. The latter has been considered of primary importance for general practitioners, dentists and specialists in public health medicine.     

Occupational cadmium exposure and renal status

With chronic low-level exposure to cadium (Cd) the kidney is considered to be the organ at risk. Thus, permissible exposure levels (PEL) should be established to protect against the risk of renal dysfunction for a working lifetime. In this study, the prevalence of renal dysfunction among 33 male subjects exposed to Cd fumes at and below the current PEL of 100 μgCd/m³ for at least 21 years, was 21 % (adjusted for confounding factors). The average cumulative time-weighted exposure in subjects with abnormal renal function was 1137 μg/m³ years, which was significantly different (p = .02) from subjects with normal renal function. These findings are consistent with those of other investigators and suggest that the current PEL does not protect against the risk of renal dysfunction, secondary to Cd fume exposure, for a working lifetime (? 40 years).     

Occupational exposures and squamous cell carcinoma of the oral cavity, pharynx, larynx, and oesophagus: a case-control study in Sweden

OBJECTIVES: This community based case-referent study was initiated to investigate aetiological factors for squamous cell carcinoma of the upper gastrointestinal tract. METHODS: The study was based on all Swedish men aged 40-79 living in two regions of Sweden during 1988-90. Within that base, efforts were made to identify all incident cases of squamous cell carcinoma of the oral cavity, oropharynx and hypopharynx, larynx, and oesophagus. Referents were selected as a stratified (age, region) random sample of the base. The response was 90% among cases and 85% among referents. There were 545 cases and 641 referents in the final study group. The study subjects were interviewed about several lifestyle factors and a life history of occupations and work tasks. The exposure to 17 specific agents were coded by an occupational hygienist. The relative risk (RR) of cancer was calculated by logistic regression, standardising for age, geographical region, and alcohol and tobacco consumption. RESULTS: Exposure to asbestos was associated with an increased risk of laryngeal cancer, and a dose-response relation was present. The RR was 1.8 (95% confidence interval (95% CI) 1.1 to 3.0) in the highest exposure group. More than eight years of exposure to welding fumes was associated with an increased risk of pharyngeal cancer (RR 2.3 (1.1 to 4.7)), and laryngeal cancer (RR 2.0 (1.0 to 3.7)). There were indications of a dose-response for duration of exposure. Associations were also found for high exposure to polycyclic aromatic hydrocarbons (PAHs) and oesophageal cancer, RR 1.9 (1.1 to 3.2). Exposure to wood dust was associated with a decreased risk of cancer at the studied sites. CONCLUSIONS: Some of the present findings confirm known or suspected associations--such as asbestos and laryngeal cancer. The study indicates that welding may cause an increased risk of pharyngeal as well as laryngeal cancer. The findings corroborate an association between exposure to PAHs and oesophageal cancer.

 

     

Work in dry cleaning and the incidence of cancer of the oral cavity, larynx, and oesophagus.

OBJECTIVES: To investigate whether employment in dry cleaning, and potential exposure to perchloroethylene (PCE), were associated with increased risk of carcinoma of the oral cavity and pharynx, larynx, oesophagus, and gastric cardia. METHODS: Two population based case-control studies were carried out. There were 491 cases of carcinoma of the oral cavity and pharynx, 235 of the larynx, and 404 of the oesophagus and gastric cardia. 724 controls were selected by random digit dialing. Personal interviews ascertained information on lifetime job histories, cigarette use, alcohol consumption, and other potential risk factors. The probability and level of exposure to PCE were estimated from the scientific literature. RESULTS: People who worked in dry cleaning tended to consume less alcohol and cigarettes than the general population. The adjusted odds ratio (OR) associated with ever having worked in dry cleaning was 1.6 (95% confidence interval (95% CI) = 0.6 to 4.4) for all cancer types together. The strongest associations were with laryngeal (OR 2.7; 95% CI 0.6 to 10.9) and oesophageal squamous cell carcinomas (OR 3.6; 95% CI 0.5 to 27.0). For laryngeal cancer, the relative risk increased with number of years employed in the dry cleaning industry (P = 0.14. The two cases of oesophageal squamous cell carcinomas had worked in dry cleaning for only a short time. Analyses of subsites showed higher risks for supraglottic laryngeal cancer (OR 5.7; 95% CI 1.0 to 32.1) and cancer of the tongue (OR 2.3; 95% CI 0.4 to 12.6). Analyses of exposure to PCE yielded similar results. CONCLUSIONS: These findings could easily be explained by chance; nevertheless, they are consistent with previous reports of excess risk of oesophageal, laryngeal, and tongue cancer, and suggest that previous studies of dry cleaners that could not control for alcohol and cigarette use may have underestimated the relative risks of such cancers.     

Occupational exposures to asbestos,polycyclic aromatic hydrocarbons and solvents,and cancers of the oral cavity and pharynx: a quantitative literature review

Purpose  

The role of occupational risk factors in oral and pharyngeal cancer is not well known and is possibly underestimated. This quantitative review summarizes epidemiological findings on exposure to asbestos, polycyclic aromatic hydrocarbons and solvents, and cancers of the oral cavity and pharynx.     

Primary malignant melanoma of oral cavity

Primary oral malignant melanomas (POMM) are very rare. Definitive identification is usually possible only after they develop metastases. So every new case is instructive. P.P., a 76-year-old woman presented with a painless exophytic mass (measuring 3 x 3.5 cm) on a pedicle in the right alveolar crest of the upper jaw (teeth 6, 7 and 8) and the palate. The mass was dark red with lobate and ulcerated surface and dense and elastic consistency. Electroresection was performed until healthy tissue was reached. One year later there were enlarged lymph nodes submandibularly on the right: a metastasis arising from an achromatic melanoma of the upper jaw. Fontana-Masson staining, expression of S-100 protein in the melanocytes. The patient was in good condition two years after the administered telegamma and immunotherapy. POMM affects mainly men at advanced age. It is four times as frequent in the upper jaw and palate as it is on the surfaces. The tongue is not affected by POMM but is targeted by the melanoma metastases. Only one third of all cases of POMM are pigmented. They arise on the basis of premelanotic changes. Every equivocal pigmented lesion in the oral cavity should be obligatorily subjected to biopsy. Primary lymph dissection is not used routinely. The therapy of choice is a radical resection combined with chemical, radio and immunotherapy. Prognosis remains grave in spite of treatment.     

The practice guideline 'Carcinoma of the oral cavity and oropharynx'

With a total incidence of ca. 800 per year, oral cavity or oropharyngeal carcinoma represents only a small fraction of the total number of cases of cancer in The Netherlands. In order to achieve as much nationwide uniformity as possible in its diagnosis, treatment, after-care and follow-up, a practice guideline has now been developed. The diagnosis of the primary tumour and the neck, careful clinical examination is complemented by echography, often combined with a biopsy, MRI and CT, while technetium scintigraphy in combination with an orthopantomogram is used to detect invasion of the mandible. The smaller oropharyngeal carcinomas (T1 and T2), surgery and radiotherapy (external therapy or brachytherapy) are equally useful, but for the larger carcinomas (T3 and T4) in patients in good general condition, surgery in combination with radiotherapy is preferred. When radiotherapy is chosen, then brachytherapy is preferred for the smaller tumours of the tongue and the floor of the mouth. In patients without demonstrable metastases to the lymph nodes, just as in the case oforopharyngeal carcinomas, the decision whether or not to treat the neck depends on the chances that cervical lymph node metastases are present: when the risk is smaller than 20% (as with smaller tumours), then a wait-and-see policy is justified, but if the risk is greater than 20% (as with larger tumours or very thick rumours), then the neck should be treated, either surgically or by radiotherapy. The practice guideline also contains information regarding decision making, information and communication, palliative therapy and symptomatic treatment, psychosocial assistance, prosthetic reconstruction, physiotherapy, oral hygiene, nutrition and dietetics, swallowing and speech rehabilitation, and the policy with regard to smoking and alcohol consumption.     

Occupational bladder cancer

4-Aminobiphenyl, 2-naphthylamine, benzidine, 1-naphthylamine and 4-nitrobiphenyl are responsible for occupational bladder cancer in man. Bladder tumors are found in workers who make or use these substances and possibly in those who purify them. The manufacture of auramine and magenta is also associated with the disease. Direct evidence that these chemicals are occupational bladder carcinogens has been obtained from the chemical and rubber industries. Occupational bladder cancer is also a problem in other industries, but in such cases, etiological agents have not been defined. Animal experiments have confirmed that aromatic amines, such as 2-naphthylamine, are carcinogenic and have helped to elucidate their mechanism of action. The problems in protecting workers already exposed to occupational bladder carcinogens and methods which may be used to control the disease are discussed.     

Occupational lung cancer

Bronchopulmonary carcinoma is the first cause of death by cancer in males, its principal cause being tobacco consumption. Nonetheless, different studies have attributed a certain, by no means negligible percent of its aetiology to the occupational exposure to agents considered carcinogenic such as asbestos, with which half of the cases of occupational lung cancer are related. Given the low survival rate of this pathology, preventive measures directed at identifying carcinogenic agents and reducing exposure to them are extremely important. Given that the clinical presentation does not differ from tobacco-related carcinoma, a high level of suspicion, based on a meticulous occupational history, is fundamental to its diagnosis. Due to the synergic effect of tobacco, measures aimed at reducing its consumption continue to be extremely important in the exposed population.     

Occupational mortality and cancer analysis

The 1970-census populations have been followed up for deaths and emigrations in the ten-year period 1970-80 in all the Nordic countries. The data show more than a 2-fold difference in overall mortality between the low-risk group of men with pedagogical work and the high-risk group of deck and engine crew workers. These data files have also been supplemented with cancer register records. In Denmark this combined data set has been used in four different ways. First, in order to check the validity of the register, classic associations known from in-depth epidemiological studies were tabulated. Examples are cancer of the lip in farmers and fishermen, where the standardized incidence ratio (SIR) values were 1.85 and 3.17, respectively, and cancer of the nasal cavities and sinuses in skilled furniture makers, SIR = 12.25. Second, a social cancer map was produced by tabulating the cancer incidence by 20 socioeconomic groups. The social gradient was steepest for certain rare cancers related to specific etiologic factors. The social gradient also varied across cancer sites. Third, the register was used as a library for elucidation of newly reported associations. An association confirmed in the Danish data is an excess risk of bladder cancer in hairdressers, SIR = 2.05. An unconfirmed example is an excess risk of malignant melanoma in the printing industry, where Danish data show an SIR of 0.95. Fourth, a systematic tabulation of each cancer diagnosis across detailed occupational groups may lead to identification of previously unknown associations. This procedure is illustrated using cancer of the larynx as an example. Smiths, mechanics, foremen, and shop owners of engineering works and workshops all have an excess risk of laryngeal cancer, SIR = 1.63.     

Occupational factors and pancreatic cancer

The relation between occupational factors and pancreatic cancer has been studied by two different approaches: a population based case-control study with two series of controls and a retrospective cohort study based on register data. With both approaches, some support was found for an association with occupational exposure to petroleum products. Associations were also indicated with exposure to paint thinner (case-control study) and work in painting and in paint and varnish factories (cohort study), for exposure to detergents, floor cleaning agents, or polish (case-control study) and with floor polishing or window cleaning (cohort study), and for exposure to refuse (case-control study) and work in refuse disposal plants (cohort study).