Faculty Bibliography

A case-control study of prostatic cancer which consisted of 100 patients with prostatic cancer, matched for hospital, age (+/- 3 yr) and hospital admission date (+/- 3 months) to patients with benign prostatic hyperplasia (BPH) and hospital controls, was conducted from 1981 to 1984. Low daily intake of beta-carotene (RR = 2.13: 95% confidence interval, 1.20-3.77) and of vitamin A (RR = 1.94: 1.10-3.43), as compared to the intake of those substances by BPH controls, were factors significantly correlated with the development of prostatic cancer. Low daily intake of beta-carotene (RR = 2.13: 1.20-3.77), as compared with hospital controls, were significantly correlated with prostatic cancer development. Infrequent intake of bread (RR = 2.40: 1.31-4.38), intended to represent a westernized diet, and of spinach (RR = 1.96: 1.01-7.73), a typical green and yellow vegetable, as compared to BPH controls and infrequent intake of spinach (RR = 4.55: 1.82-11.11) as compared to by hospital controls, were significant risk factors for prostatic cancer. Intake of carbohydrates, protein, fat, total calories, fibers, vitamin B and vitamin C were not correlated with the development of prostatic cancer

The risk for sinonasal cancer associated with tobacco use was examined in a case-control study in males diagnosed between 1978 and 1981 in the Netherlands. Of the 116 cases of sinonasal cancer and 259 controls identified, interviews were completed for 92 (79%) of the cases and 195 (75%) of the controls. Ever-users of cigarettes had a moderately elevated risk for sinonasal cancer. The association was strongest for squamous cell carcinoma among recent users of tobacco (RR = 3.1, P less than 0.05, one-sided). For recent tobacco users, there was also a trend in risk associated with the amount of cigarette use (P less than 0.05, one-sided). Associations between tobacco use and adenocarcinoma were inconsistent, and no positive associations were found for the other histologic types, largely undifferentiated tumours. The study findings indicate that tobacco use, and in particular recent tobacco use, is associated with the development of squamous cell sinonasal cancer

The cancer mortality experience of 2649 Swedish grain millers was followed during the period from 1961 to 1979. Although the overall cancer incidence was not elevated, the risk of primary liver cancer was significantly elevated for this group (standard incidence ratio = 238). The Swedish data is compared to the cancer mortality experience of workers in the Netherlands and the United States who are also involved in the bulk handling and storage of agricultural foodstuffs (e.g., peanuts, grains). The varying occupational exposures in this international comparison help establish etiologic hypotheses in the absence of comprehensive exposure information. Agents of potential concern include metabolic products of fungal contaminants (e.g., aflatoxins) and pesticides used to protect grain from insect infestation

A case-control study was conducted to examine the relations between type of woodworking and the extent of wood dust exposure to the risks for specific histologic types of sinonasal cancer. In cooperation with the major treatment centers in the Netherlands, 116 male patients newly diagnosed between 1978 and 1981 with primary malignancies of epithelial origin of this site were identified for study. Living controls were selected from the municipal registries, and deceased controls were selected from the national death registry. Interviews were completed for 91 (78%) cases and 195 (75%) controls. Job histories were coded by industry and occupation. An index of exposure was developed to classify the extent of occupational exposure to wood dust. When necessary, adjustment was made for age and usual cigarette use. The risk for nasal adenocarcinoma was elevated by industry for the wood and paper industry (odds ratio (OR) = 11.9) and by occupation for those employed in furniture and cabinet making (OR = 139.8), in factory joinery and carpentry work (OR = 16.3), and in association with high-level wood dust exposure (OR = 26.3). Other types of nasal cancer were not found to be associated with wood-related industries or occupations. A moderate excess in risk for squamous cell cancer (OR = 2.5) was associated with low-level wood dust exposure; however, no dose-response relation was evident. The association between wood dust and adenocarcinoma was strongest for those employed in wood dust-related occupations between 1930 and 1941. The risk of adenocarcinoma did not appear to decrease for at least 15 years after termination of exposure to wood dust. No cases of nasal adenocarcinoma were observed in men whose first exposure to wood dust occurred after 1941

In 1983 the relative validity of a retrospective dietary history method was assessed against a current dietary history taken seven years previously in 1976 and a second current dietary history taken in 1983. In total, 44 men and 58 women, aged 38 to 62 years, participated in the study. For energy intake and for most nutrients, the relative difference between the results obtained with the retrospective dietary history and the current dietary history in 1976 was below 15% and for six of the 11 nutrients below 10%. When the three macronutrients (protein, fat, and carbohydrate) were expressed as a proportion of energy intake, the relative difference was also below 10%. Similar results were found for food groups. The data obtained retrospectively correlate rather well with the results of the current dietary history taken in 1983, suggesting an effect of contemporaneous food habits on retrospective reporting

This case-control study of nasal and paranasal sinus tumors, in males diagnosed between 1978 and 1981 in the Netherlands, was designed to identify environmental risk factors. Special attention was given to assessing any association between nasal cancer and an occupational history of possible formaldehyde exposure while taking into account histologic type of tumor, history of tobacco use, and occupational exposure to wood dust. Of the 116 cases and 259 controls identified, interviews were completed for 91 (78%) of the cases and 195 (75%) of the controls. Adenocarcinoma was strongly associated with a history of high wood dust exposure (RR = 27.0). Two independent assessments of the association between possible formaldehyde exposure and the risk for nasal cancer were carried out (Assessments A and B). By Assessment A the relative risk for nasal cancer associated with possible formaldehyde exposure was 2.5 and by Assessment B it was 1.9. The risk appeared to be most strongly associated with squamous-cell carcinoma and could not be attributed to differences between cases and controls in age, smoking habits, or wood dust exposure. By its retrospective nature, the classification of formaldehyde exposure in this study is not based on known exposures to formaldehyde but on assessment of employment in jobs where formaldehyde exposure is thought possible. Given the limitations of the study, the authors do not consider that it provides conclusive evidence of a carcinogenic effect for formaldehyde, but that it indicates a need for further research--particularly into formaldehyde and squamous carcinoma of the nose

Mortality occurring between 1963 and 1980 in a small cohort (N = 71) of Dutch oil-press workers exposed between 1961 and 1969 to aflatoxins primarily via the respiratory route, was assessed and compared to that of a similar group of unexposed workers (N = 67). For the entire period of study, the observed mortalities for total-cancer and respiratory cancer were higher than expected in the aflatoxin-exposed group. Mortality observed in the comparison group was within the expected range. While two deaths in the exposed group were attributed to non-malignant liver disease, no primary liver tumours were observed. The greatest difference between observed and expected mortality was in the period between 1963 and 1968

The relative validity of a method for determining dietary intake four years previously was assessed. In May 1981, 79 people (46 women and 33 men, aged 29-69 years) were interviewed by use of the dietary history method concerning dietary intake in 1977. These results were compared with those obtained in this same group by means of a seven-day record in February 1977. For daily intake of energy and selected nutrients, the differences in mean intake were generally below 10%, while for six examined food groups, larger differences in the median estimates were noted. The results provide evidence that retrospectively collected dietary data have some meaningfulness, although questions remain concerning whether the retrospective dietary history method is sufficiently valid for use in a particular epidemiologic study

Mortality among male employees was studied in a chromium chemical production plant, part of which was rebuilt in 1950-51 and the remainder in 1960, to reduce exposure to chromium bearing dusts. Of 2 101 employees initially employed between 1945 and 1974 and having worked at least 90 days, the vital status of 88% was ascertained, as of mid-1977. Lung cancer mortality for hourly workers initially employed between 1945 and 1959 was significantly higher than in the comparison Baltimore City population (SMR = 2.0), yet it was lower than that reported in previous studies of this industry. A dose response effect was evident from the relationship between duration of employment and mortality. The lung cancer mortality among those employed for three or more years exclusively in the new facility was similar to that observed for such long-term workers in other parts of the plant. Specific job positions were examined. A history of employment in the Bichromate and Special Products Department (production of chromic acid and other products), known as the 'wet end', was associated with the increased lung cancer mortality in contrast to the Mill and Roast Department, known as the 'dry end'. Because of the long latency period associated with chromium exposure and cancer, it was not possible to adequately assess the risk of cancer for workers initially employed after 1960. Methodological issues related to these findings are discussed