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Biomedical subjects

E Pukkala

Publications and source records attributed to E Pukkala.

At least 217 records · Page 12Linked to original sources

Evaluation of various treatments for carcinoma of the mandibular region.

Cancers of the mandibular region show the lowest survival rates of all oral cancers. In order to compare the effect of five different modes of treatment (including surgery and/or radiotherapy), a series of 159 patients was analysed. When adjustments were made for age, sex and tumour stage in a log-linear multivariate analysis, no differences between treatments in the 5-year relative survival rates (RSR) could be demonstrated for stage I and II tumours. In stage III and IV tumours, radiation treatment alone resulted in poor survival. Between the other four treatments, all including surgery, no statistically significant differences in the 5-year relative survival rates were found. Radiation therapy as an element in combination therapy may have postponed a recurrence but did not affect the 5-year survival rate. For advanced tumours, mostly responsible for the low overall 5-year RSR, higher survival rates can possibly be achieved by improving surgical treatment of the primary lesion and the neck. At present, however, only earlier diagnosis might significantly increase the survival rates.

Adult↗

Dietary cholesterol, fatty acids, and the risk of lung cancer among men.

The relation between dietary cholesterol and fatty acids and the incidence of lung cancer was studied among 4,538 Finnish men aged 20-69 years and initially free of cancer. During 20 years of follow-up, 117 lung cancer cases were diagnosed. Cholesterol intake was not associated with lung cancer risk, the age-, smoking-, and energy-adjusted relative risk between the lowest and highest tertiles being 1.0 [95% confidence interval (CI) = 0.6-1.9]. The intake of saturated fatty acids was nonsignificantly related with lung cancer incidence, the relative risk for the lowest compared with the highest tertile being 1.6 (CI = 0.8-3.2). The association was stronger among smokers than among nonsmokers, the relative risks being 2.1 (CI = 1.0-4.3) and 1.3 (CI = 0.4-4.1), respectively. The relative risk among smokers, however, decreased to 1.5 after adjustment for the amount they smoked. In the total cohort, there was a significantly elevated risk of lung cancer among men with a high intake of butter, one of the main sources of saturated fatty acids, the relative risk being 1.9 (CI = 1.1-3.2). The present data do not confirm previous results suggesting that dietary cholesterol predicts the occurrence of lung cancer among men. The association between intake of saturated fatty acids and lung cancer observed in the present study may be partly due to heavy smoking among high consumers of saturated fat.

Adult↗

Cancer incidence among pulp and paper workers exposed to organic chlorinated compounds formed during chlorine pulp bleaching.

The risk of cancer of 152 male workers exposed to organic chlorine compounds formed during chlorine pulp bleaching was assessed in a retrospective cohort study. The men had worked continuously for at least one year in selected job categories between 1 January 1945 and 31 December 1961. The cohort was followed for death and cancer incidence until 31 December 1987 with the use of the data of the National Population Register and the Finnish Cancer Registry. There were 12 observed cancers against 8.1 expected [standardized incidence ratio (SIR) 1.5, 95% confidence interval (95% CI) 0.8-2.6]. Among the stock preparation workers (N = 53), a significantly elevated risk of lung cancer was found (6 observed, 1.0 expected, SIR 6.3, 95% CI 2.3-14) that was especially prominent after a latency (time since first employment) of at least 15 years and in the age group of 35 to 59 years. Although all of the cases involved smokers, a part of the increased incidence may be associated with the workplace exposure to organic chlorinated compounds.

Adult↗

Social class as a prognostic factor in breast cancer survival.

The effect of social class on survival of female breast cancer patients was studied by linking the patient files of the Finnish Cancer Registry (FCR) with the information on patient's social status, obtained from the 1970 Population Census of Finland. The material consisted of 10,181 patients 25 to 69 years of age at diagnosis, whose cancer was diagnosed between 1971 and 1980. The classification of social class was based on occupation. The effects of social class, age, period of diagnosis, and stage of disease on survival were evaluated using the Cox proportional hazards model; mortality from causes of death other than breast cancer was taken into account using the exact causes of death. Those in the lowest social class had about 1.3 times higher relative excess risk of dying than those in the highest social class. The older the patients, the greater was the difference in survival by social class. Differences in stage distribution explained only a minor proportion of the variation in survival by social class. The Finnish legislation guarantees everyone fairly equal accessibility to health care. The results suggest that more determined efforts should be undertaken to reduce inequity in survival.

Adult↗

Risk for cancer of the urinary bladder among hairdressers in the Nordic countries.

Several studies have indicated an increased risk for cancer of the urinary bladder among hairdressers. In a Danish linkage between census data and cancer register data both male and female hairdressers have an elevated risk for bladder cancer. The risk for lung cancer is close to unity, indicating that occupational factors rather than smoking, may be responsible for the increased risk for bladder cancer among hairdressers. To evaluate this hypothesis we conducted a collaborative analysis of data from similar linkages in Finland, Norway, and Sweden. The combination of high risk for bladder cancer and low or no risk for lung cancer was not found in the other Nordic countries; however, statistically significant increased risks for both bladder and lung cancer were found among male hairdressers in both Norway and Sweden. The relative risks for bladder cancer were of the same magnitude as the relative risks for lung cancer.

Adolescent↗

Incidence of leukaemia and brain tumours in Finnish workers exposed to ELF magnetic fields.

The relative incidence of leukaemia, acute myeloid leukaemia (AML) and central nervous system (CNS) tumours among workers presumably exposed to extremely low frequency (ELF) magnetic fields (MFs) was studied. The study population consisted of all male industrial workers in Finland aged 25 to 64 years during 1971-1980 according to the Population Census in 1970. The occupations were grouped into three exposure categories according to the probability of exposure. The category of "probable" exposure included electrical occupations and the category of "possible" exposure included occupations where electric motors or welding are common. All other occupations were included to the category of "no exposure". Cancer incidence rates in different occupational groups during 1971-1980 were obtained after linking the census records with the national death certificates and the files of the Finnish Cancer Registry. The adjusted relative risks (with 95% confidence limits) in the categories of "probable" and "possible" exposure were for all leukaemia 1.9 (1.0-3.5) and 1.4 (1.1-1.8), for AML 1.5 (0.5-4.7) and 1.4 (0.9-2.1), and for CNS tumours 1.3 (0.7-2.3) and 1.3 (1.0-1.6), respectively. The results are concordant with earlier studies suggesting elevated risk among workers exposed to ELF magnetic fields.

Adult↗

Dietary fat and risk of breast cancer.

The relationship between dietary fat and subsequent risk of breast cancer was studied in 3988 initially cancer-free Finnish women aged 20-69 y. During a follow-up period of 20 y, 54 breast-cancer cases were diagnosed. Risk of breast cancer was significantly inversely related to energy intake and nonsignificantly inversely related to absolute fat intake. A positive association between energy-adjusted total fat intake and occurrence of breast cancer was also observed. The relative risk in the highest tertile as compared with the lowest tertile was 1.7 (95% confidence limits 0.6-4.8). The corresponding relative risks were 1.4 (0.5-3.7) for saturated fatty acids, 2.7 (1.0-7.4) for monounsaturated fatty acids, 1.2 (0.6-2.8) for polyunsaturated fatty acids, and 2.2 (1.0-5.0) for cholesterol intake. Adjustment for different potential confounding factors did not alter the results. The present data suggest that breast cancer is associated inversely with energy intake and weakly positively with energy-adjusted fat intake.

Adult↗

Cancer risk among glass factory workers: an excess of lung cancer?

A total of 3749 workers employed for at least three months in two Finnish glass factories (cohorts A and B) were followed up for cancer in 1953-86 through the Finnish Cancer Registry. In cohort A (1353 men, 1261 women), 106 primary cancers were diagnosed among men, and their standardised incidence ratio (SIR) for all cancers was 99. Among women the risk was low (65 cases, SIR 64). In cohort B (450 men, 685 women), the relative risk of cancer was close to unity for both men (57 cases) and women (75 cases). The risk of cancer was analysed by primary site, type of work, years since first exposure, and age at diagnosis. The only significantly increased risks were those of lung cancer among men (SIR 130, 95% CI 100-167, cohorts A and B combined), and skin cancer among glass blowers (SIR 625, 95% CI 129-1827). An increased risk of lung, stomach, and colon cancer as well as of brain tumours has been reported in previous studies. It is postulated that the excess risk of lung cancer, detected in this study, can also be accounted for by lifestyle, and not only by possible occupational exposures, because a similar excess risk of lung cancer has been found previously for all industrial workers in Finland. Although the risk of stomach cancer in this study was increased among glass blowers, it was not high in the largest groups of plain glass workers. The risks of tumours of the central nervous system and colon were not increased either.

Chemical Industry↗

Formaldehyde exposure and respiratory cancer among woodworkers--an update.

Respiratory cancer was examined in relation to occupational formaldehyde exposure in a case-referent study (136 cases, 408 referents) nested in a woodworker cohort. Plant- and time-specific job-exposure matrices were constructed for formaldehyde exposure. Over 3 ppm-months of formaldehyde exposure was associated with an odds ratio of 1.4 [90% confidence interval (90% CI) 0.5-4.1]. The odds ratios for lung cancer were near unity, the excess risk concentrating on the upper respiratory tract. That for combined exposure to formaldehyde-phenol exposure (all respiratory cancers) was 1.6 (90% CI 0.6-4.4) but 1.0 for formaldehyde only. No consistent exposure-response patterns emerged for the level, duration, or cumulative exposure. The results are hardly more than debatable support for the hypothesis concerning formaldehyde as a carcinogen in humans, the possible risk seemingly concentrating on the upper respiratory tract rather than the lung.

Case-Control Studies↗

Cancer risk among health care personnel in Finland, 1971-1980.

Standardized incidence ratios were calculated for the assessment of cancer risk among Finnish health care personnel in 1971-1980. The overall relative cancer risk among the men was low when compared with that of all economically active men, mainly due to the low relative risk of lung cancer. The cancer risk of female health care personnel was increased when compared with that of all economically active women. The relative risk of breast cancer among registered nurses was high, being twice that of practical nurses, who had an average risk. In contrast, the risk of lymphomas, leukemia, and primary liver carcinoma was low among registered nurses and high among practical nurses. Although specific occupational exposures could not be assessed, the results did not imply any alarming major hazards related to health care work itself.

Adult↗

Cancer maps of Finland: an example of small area-based mapping.

The first cancer maps of Finland based on small geographical areas, municipalities (mean population 5000 inhabitants), were drawn by the Finnish Cancer Registry in late 1950s. Since then several cancer maps based on larger administrative units, such as counties or central hospital districts, have been produced. Because of the heterogeneity of large administrative areas in terms of way of life and possible cancer risk determinants, different methods were tried to portray the geographical pattern of cancer incidence by municipality. Two major problems were encountered: (1) because of the small numbers of cases per municipality the random variation was disturbingly large when single municipality-specific rates were presented and (2) the areas of municipalities with largest populations (cities) were so small that these most important points were hardly visible on the map. After the development of computerized mapping programs, a method based on smoothed averages of municipality-based cancer incidences was selected for the Atlas of Cancer Incidence in Finland 1953-82. These maps are combinations of municipality-specific observation and the background illustrating the average cancer incidence in different parts of the country. Because of the weighting by population, a large town whose rate deviates from the level of the surrounding areas is more visible on the map than a small municipality which differs from its background in the same way. The maps show the present situation for total cancer and for the 20 most interesting specific cancer sites using a 21-color scale. In addition some comparisons are illustrated, for example geographical time trends, male/female differences, and urban/rural variations.(ABSTRACT TRUNCATED AT 250 WORDS)

Cluster Analysis↗

Survival of female breast cancer patients in Finland and in Estonia: stage at diagnosis important determinant of the difference between countries.

The survival experiences of female breast cancer patients diagnosed in 1968-81 in Finland and in Estonia were compared. The series consisted of 18,729 patients in Finland and 4100 in Estonia. The overall estimated 5-year relative survival rate was 67.3% in Finland and 55.9% in Estonia. The stage-adjusted 5-year relative survival rate in Estonia was 63.4% (the Finnish rates used as a standard). Older patients in Finland had much higher survival rates than older patients in Estonia. There was a clear difference in the stage distribution in Estonia between older and younger age groups, with non-localized cases occurring in older age groups. No such difference was noticed in Finland. It seems that the diagnostic lag for older women is longer in Estonia than in Finland. In Estonia older patients seek medical assistance later, or symptoms and signs of younger patients are more effectively studied.

Adult↗

Cancer incidence of workers in a Finnish sawmill.

The cancer incidence of 1,223 sawmill workers with continuous employment of at least one year between 1 January 1945 and 31 December 1961 was followed until 31 December 1980. Separate analyses were made for the 801 workers hired after 1 January 1945, and smoking habits were surveyed. Among the men, 90 cases of primary cancer were detected versus 83.5 expected and among the women 55 cancer cases versus 44.5 expected. Skin cancer was in excess among the men, especially among those employed after 1 January 1945. Lip, mouth, and pharynx cancer and lymphomas were also slightly in excess among the men, as was leukemia among both sexes. Workplace exposure, especially to chlorophenols, may be associated with the excess skin cancer and the slight excess of lymphomas, but this finding should be further evaluated with special emphasis on well-defined exposure data.

Adolescent↗

Incidence of cancer among welders, platers, machinists, and pipe fitters in shipyards and machine shops.

The incidence of cancer in 12,693 shipyard and machine shop male workers (1689 welders, 4308 platers, 6003 machinists, 693 pipe fitters) employed for at least one year between 1945 and 1960 was investigated in a retrospective cohort study. The welders had welded only mild steel and had not been exposed to hexavalent chromium containing fume. The follow up was 99.7% complete and the total number of person-years was 304,682. The incidence of cancer in 1953-81 was ascertained through the Finnish Cancer Registry. The observed numbers of cases of cancer were compared with the expected numbers based on regional urban rates. The smoking habits of the cohort were surveyed with a postal questionnaire sent to a sample of 961 workers. The smoking habits of the cohorts were similar and smoking was not more common than among the general population. The total number of cases of cancer was 611 (exp 629) among the shipyard workers and 376 (exp 388) among the machine shop workers. The incidence of lung cancer was increased among the shipyard workers (obs 227, exp 192). This excess was observed in all the worker groups and was most evident for the pipe fitters and platers. Among the machine shop workers, the incidence of lung cancer was lower than expected with the exception of the welders who had a slightly raised risk of lung cancer (obs 14, exp 10). The incidence of laryngeal cancer was slightly raised among the shipyard workers (obs 24, exp 20) but not in the machine shop workers. No excess risk was observed among the welders. The incidence of cancer of the prostate was increased among the machine shop workers (obs 39, exp 31) but not in the shipyard workers. The excess was statistically significant for the welders. No pronounced excess could be found for other types of cancer. Analysis by the duration or exposure showed that the excess of lung cancer in the shipyard workers was most evident during the last period of observation (1972-81). No other trends were obvious and the slight excess of lung cancer observed among the welders did not increase with increasing follow up time. No excess risk for mesothelioma was found. The small excess of lung cancer in welders could be due to chance. The fact that only a small and statistically insignificant excess of lung cancer could be found among this group of heavily exposed welders suggest that if the risk of lung cancer was associated with welding this risk must nowadays be low and probably too low to be unequivocally detected in most epidemiological studies.

Finland↗