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Biomedical subjects

L Teppo

Publications and source records attributed to L Teppo.

At least 37 records · Page 2Linked to original sources

Cancer incidence among European man-made vitreous fiber production workers.

OBJECTIVES: This study analyzed cancer incidence among man-made vitreous fiber workers. METHODS: A cancer incidence follow-up was conducted among 3685 rock-slag wool (RSW) and 2611 glass wool (GW) production workers employed for > or =1 year in Denmark, Finland, Norway, or Sweden, and the standardized incidence ratios (SIR) were calculated on the basis of national incidence rates. RESULTS: Overall cancer incidence was close to expectation. Lung cancer incidence was increased among the RSW [SIR 1.08, 95% confidence interval (95% CI) 0.85-1.36] and GW (SIR 1.28, 95% CI 0.91-1.74) workers. For both subcohorts, a trend was suggested for time since first employment (P-value for linear trend 0.1 and 0.2, respectively). Neither subcohort showed an association with employment during the early technological phase, when fiber exposure was high. The incidence of oral, pharyngeal, and laryngeal cancer was increased among the RSW (SIR 1.46, 95% CI 0.99-2.07) and the GW (SIR 1.41, 95% CI 0.80-2.28) subcohorts. Despite a trend in risk for these neoplasms among the GW workers with time since first employment, the lack of a positive relation with other indirect indicators of fiber exposure points against a causal interpretation. No association between RSW or GW exposure and the risk of other neoplasms was suggested. CONCLUSIONS: These lung cancer results are similar to those of a mortality study that included a larger number of factories. For other cancers there was no suggestion of an association with RSW or GW exposure.

Humans↗

Is low selenium status a risk factor for lung cancer?

The hypothesis that low selenium may in some circumstances be a risk factor for lung cancer was investigated in a case-control study nested within a longitudinal study. Serum samples from 9,101 cancer-free individuals were collected and stored at -20 degrees C by the Finnish Mobile Clinic in 1968-1971 and 1973-1976. During follow-up until the end of 1991, 95 cases of lung cancer were diagnosed. Selenium concentrations were determined from the serum samples of the cases and 190 controls, individually matched for sex, age, and place of residence. Mean levels of serum selenium in cases and controls were 53.2 microg/liter and 57.8 microg/liter, respectively. The relative risk of lung cancer between the highest and lowest tertiles of serum selenium, adjusted for smoking, serum alpha-tocopherol, serum cholesterol, serum copper, serum orosomucoid, and body mass index (kg/m2), was 0.41 (95% confidence interval (CI) 0.17-0.94). The association was stronger at lower levels (<5.9 mg/liter) of alpha-tocopherol (relative risk=0.24, 95% CI 0.07-0.85). The association was also pronounced among current smokers and at higher levels of serum orosomucoid and serum copper. The relative risk for smokers who were twice ranked in higher selenium tertiles, at an interval of 4-7 years, in comparison with smokers who remained in the lowest tertile was 0.16 (95% CI 0.04-0.74). In accordance with the hypothesis, the findings suggest that very low selenium status may contribute to the risk of lung cancer.

Adult↗

Variation in survival of adult patients with thyroid cancer in Europe. EUROCARE Working Group.

The survival of patients with thyroid cancer was analysed using population-based EUROCARE II data from 1978-1989 (trends in survival) and 1985-1989 (cross-sectional comparisons between areas). The data consisted of 7504 patients and covered 37 cancer registration areas in 17 European countries. In 90% of the patients the diagnosis was histologically confirmed. The prognosis of patients with thyroid cancer was relatively favourable. The overall 5-year relative survival rate was 72% for men and 80% for women. Substantial variation in this 5-year rate was observed between countries ranging from 59 to 83% in men and from 72 to 84% in women. Higher than average survival rates were observed in Finland, Iceland, The Netherlands and Sweden. Countries with lower than average rates were Denmark, England, Estonia, Slovakia, Slovenia and Poland (women). Elderly patients had lower survival rates than the younger ones. Time trends in survival (which could be analysed only in selected countries with sufficient numbers of cases) were irregular but generally showed slight increases compared with rates in 1978-1980. Different distributions in the histological subtypes of thyroid cancer is one plausible explanation for the variation in the survival rate. Other likely factors contributing to this are differences in the stage distribution and varying efficacy of treatment. The EUROCARE II data did not permit specific analyses of the roles of various prognostic factors.

Adenocarcinoma, Follicular↗

Hereditary factors in basal cell carcinoma of the skin: a population-based cohort study in twins.

The contribution of hereditary factors in basal cell carcinoma of the skin has not been well defined at the population level. We aimed to assess the hereditary component in basal cell carcinoma by comparing its occurrence in monozygotic and dizygotic twin pairs. The Finnish Twin Cohort, comprising 12,941 adult, like-sex twin pairs with established zygosity and resident in Finland in 1975, was linked with the Finnish Cancer Registry. We identified 335 twin pairs in which at least one twin had basal cell carcinoma diagnosed between 1953 and 1996. Standardized incidence ratios, concordances, tetrachoric correlations and pairwise relative risks were computed by standard methods. Components of variance in liability were estimated by structural equation modelling. There was an elevated risk of basal cell carcinoma for the co-twin of a diseased twin, but no difference in risk by zygosity. During the prospective follow-up in 1976-96, the probandwise concordance was 7.7% in monozygotic and 7.0% in dizygotic pairs. Model fitting indicated that genetic factors were not needed to account for the distribution of basal cell carcinoma in twin pairs. These results confirm the major role of environmental factors in the aetiology of basal cell carcinoma.

Adult↗

Mortality of short-term workers in two international cohorts.

The purpose of this study was to compare the pattern of mortality of blue-collar workers employed less and more than 1 year in the man-made vitreous fiber (MMVF) and the reinforced plastic industries, the latter group being exposed to styrene. We conducted an analysis among 21,784 workers with less than 1 year of employment (short-term workers) and 19,117 workers with 1 or more years of employment (long-term workers) employed in eight European countries. We conducted analyses based on external as well as internal comparisons. In both cohorts, the standardized mortality ratio for all causes among short-term workers was approximately 40% higher, compared with that for longer-term workers. In internal comparisons, the difference was reduced to 9% in the MMVF cohort and 11% in the styrene cohort. Workers with less than 1 month of employment displayed an increased mortality in both cohorts and in most countries. The increased mortality among short-term workers was not concentrated shortly after they quit employment. In both cohorts, short-term workers had a higher mortality from external causes, while little difference was seen in mortality from ischemic heart disease and malignant neoplasms. Although extra-occupational factors may contribute to increase the mortality of short-term workers and, in particular, of those employed for less than 1 month, the difference observed in analyses adjusted for characteristics of employment suggested a relatively small difference in mortality from most causes.

Adult↗

[Incidence of cancer in Scandinavia].

The Nordic Cancer Registries have completed a long-term project designed to evaluate developments in cancer up to the year 2010. On the basis of trends hitherto discernible, the development of cancer morbidy and mortality in the Nordic countries was projected. Another aim was to investigate the manner in which the trend of increasing cancer incidence might be modified by preventive measures, early diagnosis and optimised treatment.

Finland↗

Dietary flavonoids and the risk of lung cancer and other malignant neoplasms.

Flavonoids are effective antioxidants and, in theory, may provide protection against cancer, although direct human evidence of this is scarce. The relation between the intake of antioxidant flavonoids and subsequent risk of cancer was studied among 9,959 Finnish men and women aged 15-99 years and initially cancer free. Food consumption was estimated by the dietary history method, covering the total habitual diet during the previous year. During a follow-up in 1967-1991, 997 cancer cases and 151 lung cancer cases were diagnosed. An inverse association was observed between the intake of flavonoids and incidence of all sites of cancer combined. The sex- and age-adjusted relative risk of all sites of cancer combined between the highest and lowest quartiles of flavonoid intake was 0.80 (95% confidence interval 0.67-0.96). This association was mainly a result of lung cancer, which presented a corresponding relative risk of 0.54 (95% confidence interval 0.34-0.87). The association between flavonoid intake and lung cancer incidence was not due to the intake of antioxidant vitamins or other potential confounding factors, as adjustment for factors such as smoking and intakes of energy, vitamin E, vitamin C, and beta-carotene did not materially alter the results. The association was strongest in persons under 50 years of age and in nonsmokers with relative risks of 0.33 (95% confidence interval 0.15-0.77) and 0.13 (95% confidence interval 0.03-0.58), respectively. Of the major dietary flavonoid sources, the consumption of apples showed an inverse association with lung cancer incidence, with a relative risk of 0.42 (95% confidence interval 0.23-0.76) after adjustment for the intake of other fruits and vegetables. The results are in line with the hypothesis that flavonoid intake in some circumstances may be involved in the cancer process, resulting in lowered risks.

Adolescent↗

Diet and breast cancer risk in a cohort of Finnish women.

The associations between dietary antioxidant vitamins, dietary fiber, and selected foods and risk of breast cancer were studied in 4697 initially cancer-free women, aged 15 years or older. At baseline (1967-1972) the women were interviewed for total habitual diet over the preceding year. During a 25-year follow-up period 88 breast cancer cases were diagnosed. There was a significant inverse gradient between milk consumption and occurrence of breast cancer, whereas higher consumption of fried meat was associated with increased risk of breast cancer. No significant relationships were found between the intakes of vitamin E, vitamin C, beta-carotene, lycopene, lutein or dietary fiber and the occurrence of breast cancer.

Adolescent↗

Cancer mortality among man-made vitreous fiber production workers.

We have updated the follow-up of cancer mortality for a cohort study of man-made vitreous fiber production workers from Denmark, Finland, Norway, Sweden, United Kingdom, Germany, and Italy, from 1982 to 1990. In the mortality analysis, 22,002 production workers contributed 489,551 person-years, during which there were 4,521 deaths. Workers with less than 1 year of employment had an increased mortality [standardized mortality ratio (SMR) = 1.45; 95% confidence interval (CI) = 1.37-1.53]. Workers with 1 year or more of employment, contributing 65% of person-years, had an SMR of 1.05 (95% CI = 1.02-1.09). The SMR for lung cancer was 1.34 (95% CI = 1.08-1.63, 97 deaths) among rock/slag wool workers and 1.27 (95% CI = 1.07-1.50, 140 deaths) among glass wool workers. In the latter group, no increase was present when local mortality rates were used. Among rock/slag wool workers, the risk of lung cancer increased with time-since-first-employment and duration of employment. The trend in lung cancer mortality according to technologic phase at first employment was less marked than in the previous follow-up. We obtained similar results from a Poisson regression analysis limited to rock/slag wool workers. Five deaths from pleural mesothelioma were reported, which may not represent an excess. There was no apparent excess for other categories of neoplasm. Tobacco smoking and other factors linked to social class, as well as exposures in other industries, appear unlikely to explain the whole increase in lung cancer mortality among rock/slag wool workers. Limited data on other agents do not indicate an important role of asbestos, slag, or bitumen. These results are not sufficient to conclude that the increased lung cancer risk is the result of exposure to rock/slag wool; however, insofar as respirable fibers were an important component of the ambient pollution of the working environment, they may have contributed to the increased risk.

Aged↗

Elevated lung cancer risk among persons with depressed mood.

Although it has been hypothesized that depressive persons have an excess risk of cancer, few prospective data are available. The association between depressiveness and subsequent incidence of lung cancer was studied in the nationally representative Mini-Finland Health Survey. The study population comprised 7,018 adult men and women, free from cancer at the baseline, carried out in 1978-1980. During a 14-year follow-up, 605 cancer cases occurred, of which 70 were male lung cancer patients. Mental problems and disorders were assessed at the baseline examination using standard interview techniques (General Health Questionnaire and Present State Examination). The relative risk of lung cancer between depressive persons and individuals with a normal depressiveness score was 3.32 (95% confidence interval 1.53-7.20). Neither adjustment for the potential confounding factors of age, education, geographic area, smoking, alcohol consumption, body mass index, serum cholesterol, leisure-time exercise, general health, and use of antidepressant medication nor exclusion of cancer cases occurring during the first 4 years of follow-up notably altered the results. There was a strong interaction between depressiveness and smoking. The relative risks of lung cancer between smokers and nonsmokers were 3.38 (95% confidence interval 1.09-10.52) at normal depressiveness score levels and 19.67 (95% confidence interval 2.57-150.7) at strongly elevated levels, respectively. It is possible that depressiveness modifies the effect of smoking on lung cancer risk either by biologic mechanisms or by affecting smoking behavior.

Adult↗

Alpha-Tocopherol and beta-carotene supplements and lung cancer incidence in the alpha-tocopherol, beta-carotene cancer prevention study: effects of base-line characteristics and study compliance.

BACKGROUND: Experimental and epidemiologic investigations suggest that alpha-tocopherol (the most prevalent chemical form of vitamin E found in vegetable oils, seeds, grains, nuts, and other foods) and beta-carotene (a plant pigment and major precursor of vitamin A found in many yellow, orange, and dark-green, leafy vegetables and some fruit) might reduce the risk of cancer, particularly lung cancer. The initial findings of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC Study) indicated, however, that lung cancer incidence was increased among participants who received beta-carotene as a supplement. Similar results were recently reported by the Beta-Carotene and Retinol Efficacy Trial (CARET), which tested a combination of beta-carotene and vitamin A. PURPOSE: We examined the effects of alpha-tocopherol and beta-carotene supplementation on the incidence of lung cancer across subgroups of participants in the ATBC Study defined by base-line characteristics (e.g., age, number of cigarettes smoked, dietary or serum vitamin status, and alcohol consumption), by study compliance, and in relation to clinical factors, such as disease stage and histologic type. Our primary purpose was to determine whether the pattern of intervention effects across subgroups could facilitate further interpretation of the main ATBC Study results and shed light on potential mechanisms of action and relevance to other populations. METHODS: A total of 29,133 men aged 50-69 years who smoked five or more cigarettes daily were randomly assigned to receive alpha-tocopherol (50 mg), beta-carotene (20 mg), alpha-tocopherol and beta-carotene, or a placebo daily for 5-8 years (median, 6.1 years). Data regarding smoking and other risk factors for lung cancer and dietary factors were obtained at study entry, along with measurements of serum levels of alpha-tocopherol and beta-carotene. Incident cases of lung cancer (n = 894) were identified through the Finnish Cancer Registry and death certificates. Each lung cancer diagnosis was independently confirmed, and histology or cytology was available for 94% of the cases. Intervention effects were evaluated by use of survival analysis and proportional hazards models. All P values were derived from two-sided statistical tests. RESULTS: No overall effect was observed for lung cancer from alpha-tocopherol supplementation (relative risk [RR] = 0.99; 95% confidence interval [CI] = 0.87-1.13; P = .86, logrank test). beta-Carotene supplementation was associated with increased lung cancer risk (RR = 1.16; 95% CI = 1.02-1.33; P = .02, logrank test). The beta-carotene effect appeared stronger, but not substantially different, in participants who smoked at least 20 cigarettes daily (RR = 1.25; 95% CI = 1.07-1.46) compared with those who smoked five to 19 cigarettes daily (RR = 0.97; 95% CI = 0.76-1.23) and in those with a higher alcohol intake (> or = 11 g of ethanol/day [just under one drink per day]; RR = 1.35; 95% CI = 1.01-1.81) compared with those with a lower intake (RR = 1.03; 95% CI = 0.85-1.24). CONCLUSIONS: Supplementation with alpha-tocopherol or beta-carotene does not prevent lung cancer in older men who smoke. beta-Carotene supplementation at pharmacologic levels may modestly increase lung cancer incidence in cigarette smokers, and this effect may be associated with heavier smoking and higher alcohol intake. IMPLICATIONS: While the most direct way to reduce lung cancer risk is not to smoke tobacco, smokers should avoid high-dose beta-carotene supplementation.

Age Factors↗

Trends in non-epithelial cancer incidence in Denmark, Finland, and Sweden, 1961-1990.

Trends in the incidence of non-epithelial cancers are particularly likely to reflect environmental carcinogens, since these malignancies are not commonly the targets of screening efforts, and have generally not been closely associated with life style factors such as cigarette smoking and diet. We used data from nation-wide cancer registries in Denmark, Finland, and Sweden to examine trends in non-epithelial cancers over the period 1961-1990. Linear regression analysis of age-standardized rates, and age-period-cohort models were fit to assess the temporal patterns within each country. Within each of the 3 countries, there was a similarly increasing incidence of both hematological malignancies and nervous system/bone/soft-tissue neoplasms. The increases were smallest in children and adolescents (ages 0-14), moderate among young and middle aged adults (ages 15-64), and most pronounced among the elderly (ages 65+). Age-period-cohort modeling suggested that the dominant factor in the increases were birth cohort effects. It is not clear what factors underlie this increase in incidence; it seems most likely that increases both in diagnostic efficiency and in exposure to environmental carcinogens play a role.

Adolescent↗

Circulating anti-Helicobacter pylori immunoglobulin A antibodies and low serum pepsinogen I level are associated with increased risk of gastric cancer.

Helicobacter pylori infection has been suggested to be associated with an increased risk of gastric cancer, and low levels of serum pepsinogen I (PG I) have been linked to atrophic gastritis, which is a risk factor for gastric cancer. In Finland, 39,268 persons from 25 cohorts participated during 1968-1972 in a health examination survey and were followed for up to 13 years. A nested case-control study was performed on 84 stomach cancer patients identified from the Finnish Cancer Registry and 146 controls matched for age, sex, and municipality. Serum samples drawn at the baseline study were analyzed. An elevated level of serum anti-H. pylori immunoglobulin A (IgA) antibodies (a titer > or = 70) and a low serum PG I level ( < 49 micrograms/liter) were associated with an increased risk of gastric cancer. The odds ratios were 2.52 (95% confidence interval (CI) 1.14-5.57) for high IgA and 2.68 (95% CI 1.35-5.30) for low PG I. For high immunoglobulin G (IgG) ( > or = 700), the odds ratio was only 1.50 (95% CI 0.70-3.22). When both high IgA and low PG I were present, the odds ratio was 5.96 (95% CI 2.02-17.57). The association of H. pylori infection with cancer became stronger with longer follow-up times, whereas that of low PG I was strongest at shorter follow-up times. Our findings support the hypothesis that H. pylori infection is a prevalent and potentially preventable cause of gastric cancer. They stress the value of IgA antibody determinations and provide new evidence for a pathogenesis leading from prolonged infection through atrophic gastritis to gastric cancer.

Aged↗

Increase in testicular cancer incidence in six European countries: a birth cohort phenomenon.

BACKGROUND: For unknown reasons, the age-standardized incidence of testicular cancer has shown a rapid increase in virtually all countries (mostly Western) studied. For populations with a sufficiently long period of cancer registration, this development can be traced back to the first half of this century. PURPOSE: By evaluating data from six countries with long periods of cancer registration (Denmark, Norway, Sweden, the former German Democratic Republic [East Germany], Finland, and Poland), we sought to determine whether the increase in testicular cancer risk follows a birth cohort pattern and, if so, to quantify and compare any birth cohort effects. METHODS: A total of 30,908 incident cases of testicular cancer, diagnosed from 1945 through 1989 in men who were 20-84 years of age, were identified in population-based cancer registries in the six countries. In addition to performing simple trend analyses, we fitted several Poisson regression models (with the explanatory variables age, time period [calendar time], and birth cohort) to the data. Individual models were estimated by the maximum likelihood method. RESULTS: The age-standardized incidence of testicular cancer was found to vary among the six populations and, on the basis of total registration data, increased annually at rates ranging from 2.3% (in Sweden) to 5.2% (in East Germany). A comparison of several regression models indicated that birth cohort was a stronger determinant of testicular cancer risk than was calendar time for all six populations. Within each population, little variation in testicular cancer risk was observed for men born between 1880 and 1920; thereafter, the risk began to increase. Among men born in Denmark, Norway, and Sweden between 1930 and 1945 (the period encompassing the Second World War), the increasing trend in risk was interrupted (i.e., a leveling in risk occurred). After 1945, an uninterrupted increase in risk was observed for all six populations. With men born around 1905 as the reference group, the relative risk of testicular cancer for those born around 1965 varied from 3.9 (95% confidence interval [CI] = 2.7-5.6) in Sweden to 11.4 (95% CI = 8.3-15.5) in East Germany. CONCLUSIONS AND IMPLICATIONS: The increasing trend in testicular cancer risk observed for these six populations follows a birth cohort pattern. This distinct risk pattern provides a framework for the identification of specific etiologic factors.

Adult↗