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STUDY QUESTION Are genetic disorders and congenital malformations associated with premature ovarian insufficiency (POI)? SUMMARY ANSWER A wide range of genetic disorder and congenital malformation diagnoses are associated with POI, especially early onset POI. WHAT IS KNOWN ALREADY POI is known to be associated with some genetic disorders, such as Turner syndrome and Fragile X premutation. Multiple genetic syndromes, such as ataxia teleangiectasia and galactosemia, have also been associated with an increased risk of POI, and many of these genetic syndromes manifest with various congenital malformations. In previous studies, a genetic aetiology has been found for 7–15% of POI cases. STUDY DESIGN, SIZE, DURATION This population-based study included 5011 women diagnosed with POI in 1988–2017. The data were collected from various national registries and covers women with POI nationwide. PARTICIPANTS/MATERIALS, SETTING, METHODS We identified 5011 women diagnosed with POI from 1988 to 2017 from the drug reimbursement registry of the Social Insurance Institution of Finland. Women with surgical POI (bilateral oophorectomy for benign indications) were not included. We selected four population controls per woman with POI matched by month and year of birth and municipality of residence. Diagnostic codes for genetic disorders and congenital malformations (GD/CM) for the cases and controls were searched from the Hospital Discharge Register. Binary logistic regression was used to compare the odds for GD/CM among cases and controls. To minimize bias, for the statistical analyses, we excluded diagnoses which were reported MAIN RESULTS AND THE ROLE OF CHANCE Of the women with POI, 15.9% (n = 797) had at least one diagnostic code for GD or CM. The odds ratio (OR) for Turner syndrome was 275 (95% CI 68.1–1110), and for other sex chromosome abnormalities, it was 12.7 (95% CI 4.1–39.1). For autosomal single gene disorders, the OR was 16.5 (95% CI 6.2–43.7). Women with POI had a higher odds of having a GD/CM diagnosis in all categories. The OR for GD/CM diagnoses was highest among the youngest POI patients (10–14 years old, OR 24.1, 95% CI 15.1–38.2). The odds of having POI were higher the more GD or CM diagnoses a woman had. LIMITATIONS, REASONS FOR CAUTION Some women with POI might not have sought help for their symptoms and therefore remain undiagnosed. Due to the register-based nature of our study, we did not have access to more specific genetic diagnoses than international classification of diseases offers. WIDER IMPLICATIONS OF THE FINDINGS GD/CM diagnoses were strongly associated with POI, especially when POI was diagnosed at a young age. The risk of POI was highest in women with multiple GD/CM diagnoses. Early onset POI can be a sign of underlying genetic disorder or congenital anomaly, and this should serve as a reminder for clinicians to consider further examinations. To avoid unnecessary delay in the diagnosis of POI and starting relevant hormone replacement therapy treatment, clinicians should be aware of these associations. STUDY FUNDING/COMPETING INTEREST(S) Oulu University Hospital financially supported this work. H.S. has received personal grants from the Finnish Menopause Society, Oulu Medical Research Foundation, and Finnish Research Foundation of Gynaecology and Obstetrics. S.S. has received grants from the Finnish Menopause Society, the Finnish Medical Foundation, and the Juho Vainio Foundation. None of the authors have any competing interests to declare. TRIAL REGISTRATION NUMBER N/A.

STUDY QUESTION What is the incidence of premature ovarian insufficiency (POI), has the incidence of POI changed over time, and what is the risk of POI among relatives of POI women? SUMMARY ANSWER The incidence of POI increased among females aged 15–19 years from 2007 onwards and decreased in older age groups, and among relatives of women with POI the risk of POI is significantly increased. WHAT IS KNOWN ALREADY So far, there has been no good quality, nationwide studies of the incidence of POI. Early menopause has been associated with the elevated risk of early menopause among relatives, but the knowledge of the familial risk of POI is scarce. Lower socioeconomic status has been associated with lower age at natural menopause. STUDY DESIGN, SIZE, DURATION Population-based study with 5011 women diagnosed with POI in 1988–2017. The data were collected from national registries and covers POI subjects in entire Finland. PARTICIPANTS/MATERIALS, SETTING, METHODS Women with hormone replacement therapy reimbursement for POI were identified from Social Insurance Institution (SII). We calculated POI incidence in different age groups and studied the changes in the incidence rate over time in 5-year segments. Four population-based controls were selected from the Digital and Population Data Services Agency (DVV) for each POI woman. Family members of the POI cases and controls were identified from the DVV and linked to SII reimbursement data to identify POI diagnoses among them. The familial risk of POI was estimated with a logistical regression model. MAIN RESULTS AND THE ROLE OF CHANCE The incidence was highest in the 35–39 age group, ranging from 73.8/100 000 women-years in 1993–1997 to 39.9/100 000 women-years in 2013–2017. From 2007, the incidence among 15- to 19-year-olds rose from 7.0 to 10.0/100 000 women-years in 2015–2017. Cumulative incidence of POI for women under 40 years in 1988–2017 was 478/100 000 women. The relative risk of POI among relatives of women with POI was 4.6 (95% CI 3.3–6.5) compared to relatives of women without POI. POI women tended to have slightly lower socioeconomic status and level of education compared to controls. LIMITATIONS, REASONS FOR CAUTION For some women with POI, diagnosis or reimbursement may be lacking. However, we presume that these women represent a minority due to the nature of the disease and the economic benefits of reimbursement. Some changes in the incidence of POI can reflect changes in clinical practice and changing treatments and reimbursement criteria. WIDER IMPLICATIONS OF THE FINDINGS The risk of developing POI is significantly higher in women who have first-degree relatives diagnosed with POI. Raising awareness of the increased risk might lead to earlier diagnosis and initiation of hormonal replacement therapy, possibly preventing adverse effects of low oestrogen levels, such as osteoporosis. STUDY FUNDING/COMPETING INTEREST(S) This work was financially supported by the Oulu University Hospital. H.S. received a grant from Finnish Menopause Society. S.M.S. received a grant from the Finnish Menopause Society, the Finnish Medical Foundation and the Juho Vainio Foundation. The authors do not have any competing interests to declare. TRIAL REGISTRATION NUMBER N/A.

The Nordic Occupational Cancer (NOCCA) project was the largest and in many aspects, also qualitatively, the most unique research study ever done on occupation and cancer incidence. It consisted of a follow-up study on the entire working populations of Denmark, Island, Finland, Norway and Sweden with three million cancer cases diagnosed 1961–2005. It described risks of 84 cancer types in 54 occupational categories (astra.cancer.fi/NOCCA) and developed a Nordic Job Exposure Matrix (NOCCA-JEM) that converts the individual job histories of all Nordic people to quantitative estimates of exposure to potentially cancer-related factors. Many of the results on dose-response associations between exposures and cancers have been novel findings or have confirmed (or not) findings from earlier smaller studies. The NOCCA network still produces about one new publication each month from the old data. Still, not only the NOCCA researcher team but also institutions such as Nordic Minister Council and occupational health professionals have stressed that it would be important to continue NOCCA research work with updated data. New features in the work life, such as effects of sedentary work, could not be fully studied in the original NOCCA data. There is also an urgent need to follow effects of work safety regulations and operations that were started after the harmful effect of work carcinogens were recognised. For example, restaurant workers who had the highest risk of many cancers are no longer exposed to tobacco smoke in their work environment; this should be seen as a rapid decrease in their cancer risk. It has been proven that combining five entire national populations as a study cohort about 10 years ago was feasible and produced important results. The researchers of the NOCCA network are eager to continue and update the activity, provided that challenges related to funding and data access issues can be won.

Breast cancer (BC) and diabetes mellitus (DM) are major health problems. We examined the association between DM and BC stage at diagnosis and subsequent survival in a Finnish cohort of female BC patients. All BC cases (N = 73,170) diagnosed in 1995-2013 with dates and causes of death were identified from the Finnish Cancer Registry. Participation in organized mammography screening was obtained from Mass Inspection Registry. Information on DM diagnoses and background conditions recorded during 1995-2013 were obtained from national Care Register for Health Care and merged to data on medication use from the national Prescription Register. Logistic regression with adjustment for mammography screening and age at BC diagnosis was used to evaluate the risk of advanced stage BC at diagnosis. Cox regression was used to evaluate overall and BC survival. Analyses were adjusted for age, background conditions and mammography screening. Survival analyses were further adjusted for tumor extent, histology and primary treatment. Of the cohort 11,676 (16.0%) had DM. Screening participation did not differ by diabetes. Compared to non-diabetic women, diabetics had more often locally advanced (odds ratio, OR 1.26; 95% CI 1.18-1.35) or metastatic BC (OR 1.59; 95% CI 1.44-1.75) at diagnosis. During a median follow-up of 5.8 years after BC diagnosis 10,900 (14.9%) women died of BC. Risk of BC death was higher among diabetic compared to non-diabetic women (HR 1.36; 95% CI 1.27-1.46). Risk of BC death increased with duration of DM. This supports DM as a risk factor for fatal BC.

The objective of this study was to determine the site-specific cancer incidence of hypertensive patients and examine the effect of blood pressure-related variables on the risk of cancers with elevated incidence among the hypertensive patients. A record linkage study of Hypertension Register of the North Karelia Project and the Finnish Cancer Registry was conducted. The mean follow-up time was 16 years. A total of 20 529 hypertensive patients were studied. Main outcome measures were standardised incidence ratios and hazard ratios. The overall cancer incidence was close to that of the general population for both men and women. The incidence rate for the kidney cancer was significantly increased in hypertensive patients (standardised incidence ratio 1.34, 95% confidence interval (CI) 1.11-1.60), as well as incidence rates for cancers of pancreas (1.26, 1.02-1.54), and endometrium (1.22, 1.01-1.44) in hypertensive women. The incidence of lung cancer was significantly decreased (0.86, 0.77-0.95). The incidence of liver cancer was elevated with borderline significance (1.36, 0.99-1.82). In Cox regression models, the use of antihypertensive drugs at baseline was a significant predictor of kidney (hazard ratio for use of antihypertensive drugs 1.89, 95% CI 0.96-3.75) and pancreatic cancer (1.78, 0.99-3.22) in women but not in men. The incidence of endometrial cancer or liver cancer was not related to blood pressure levels or the use of antihypertensive drugs. In women, obesity was a significant predictor of cancers of the endometrium, kidney and liver. In conclusion, increased occurrence of some cancer types among hypertensive patients seem to be partly explained by obesity and the use of antihypertensive drugs.

A study on cancer incidence after kidney transplantation was performed using data of national transplant and cancer registries. Since 1964 up to 30 June 1997, 3440 kidney transplantations were performed on 2890 patients. From 1967 to 1997, 230 posttransplantation malignancies were found in 20 817 patient-years of follow up. The standardised incidence ratio (SIR) was 3.33 compared to the general population. The SIR was highest in skin cancer (39.2). The SIRs were high in cancers of the lip (23.0), thyroid (8.08), kidney (8.0), lower urinary tract (3.2), non-Hodgkin lymphoma (4.8), ovary (3.9) and colon (3.9). Skin cancer and lymphomas had much higher SIRs in men than in women whereas lower urinary tract cancer had a higher SIR in women. During the first 10 follow up years, life-table analysis indicates a higher cancer risk in cyclosporine-treated patients, but this may be biased by their shorter follow up as the overall SIR was equal in both groups. This population study shows the increased incidence of cancer in the transplant population and points out the importance of cancer surveillance in the years following kidney transplantation.

The purpose of the study was to estimate subsequent incidence of cervical cancer among women with positive cytology followed by negative histology.This was a longitudinal cohort study involving about 80,000 women with class II, III, IV or V cytology at the organized mass screening in Finland in 1971 1990. Follow-up through the Finnish Cancer Registry started from the fifth month following the initial screening and ended on December 31, 1995.Standardized incidence ratios (SIR) of invasive cervical cancer varied from 2.2 (class II) to 19 (class V), and SIRs of preinvasive lesion varied from 3.0 (class II) to 20 (class V) compared to the risk among the total Finnish female population of same age and calendar period. The relative risk was greatest during first years of follow-up for both preinvasive and invasive cervical lesions, and it remained significantly high over 5 years of follow-up. For women with class II cytology there were peaks in relative risk in the years of subsequent rescreenings.Women with positive cytology have a high relative risk of cervical cancer even when excluding the cancers found at screening; the high relative risk is persistent for more than 5 years, and therefore these women should be kept under close surveillance and repeated smears should be taken with relatively short intervals.

Previous job-exposure matrices (JEM) have usually cross-tabulated classified exposure information by chemical agent and occupational class. A new Finnish job-exposure matrix (FINJEM) was constructed for exposure assessment in large register-based studies. Unlike most other JEMs, FINJEM was designed to contain definitions, inferences, exposure data, and references. This documentation enables FINJEM to be applied also as a general exposure information system for hazard control, risk quantification and hazard surveillance. The system includes, e.g., workforce data, and it provides information on the numbers of exposed workers in Finland by agent, occupation, and level of exposure. The exposures of FINJEM cover major physical, chemical, microbiological, ergonomic, and psychosocial factors. The assessment period is 1945–1997, divided into several subperiods. Exposure is described by the prevalence of exposure and the level of exposure among the exposed, both estimated mainly on continuous scales. The user may also define the final criteria of exposure, and thereby influence the magnitude of misclassification. Am. J. Ind. Med. 33:409–417, 1998. © 1998 Wiley-Liss, Inc.

The purpose of our study was to find out whether bleeding symptoms are predictive factors of subsequent gynecological or urinary cancers among women screened negative.The data stemmed from the Finnish Mass Screening Registry, and were linked to the National Cancer Registry: 37,596 screening negative women in the nationwide population-based mass screening program for cervical cancer were classified by their bleeding symptom (bloody discharge, coital bleeding, irregular bleeding, postmenopausal bleeding) at the time of screening (1985-1990) and followed up (1985-1994) in order to assess the subsequent risk of cancer.Bleeding symptoms with prevalence of 5.9% were more likely to be signs of preinvasive than invasive cervical cancer with the exception of coital bleeding, nevertheless relative risk of cervical cancer (SIR 1.1, 95% CI 0.8-1.4) was not significantly increased during the total follow-up of maximum 10 years. Women with any bleeding symptom had increased risk of cancer of the corpus uteri (SIR 2.1, 95% CI 1.6-2.6), postmenopausal bleeding was the strongest symptom (RR 3.6, 95% CI 2.0-6.0). None of the bleeding symptoms increased subsequent risk of ovarian, vaginal or vulvar carcinoma. The risk of kidney cancer was increased (SIR 1.7, 95% CI 1.0-2.6).The prevalence of bleeding symptoms was small and relative risks for cancers were low for them to be suitable as predictive factors of cancer neither in clinical practice nor for public health purposes, e.g. in developing selective screening based on this high risk group. Only 34 gynecological cancers during 220,000 person-years in women with bleeding symptoms were attributable to bleeding. Relative risks remained increased only for a short time after screening. Therefore, short term surveillance is important, but due to the fact that relative risks approached unity during the follow-up, reassurance of a woman that she is cancer-free should be emphasized more in the long term after the bleeding symptoms.

This project (KoL 12-08) was performed for the Climate and Air Quality Group (KlimaogLuftgruppen, KoL), Nordic Council of Ministers by atmospheric emission, exposureand epidemiology experts from Denmark, Finland, Norway and Sweden. Emission inventory methods and exposure models were presented. A list of carcinogenic andco-carcinogenic pollutants (particles, heavy metals and organic compounds) emittedfrom energy production, industrial activities, road transport, navigation, agriculture, residential heating and product use was compiled. Pollutant emissions levels for 2010and trends for 1990 to 2010 were compiled and discussed, and modelled andmeasured atmospheric concentrations for 2010 were compiled on regional, urbanand local scales. Nordic maps of emissions and air concentrations of PM2.5, PM10, NOx,NMVOC, benzene, BaP, dioxin, cadmium and nickel were compiled for allaggregated main sources, traffic and residential wood combustion. An overview of local studies on exposure for cities or communities with emphasis on wood combustion and traffic and a discussion of existing epidemiological studies on cancer and environment were given.

Background We have quantified the site-specific risk of second malignant neoplasms among nearly 29,000 survivors (> or = 1 year) of testicular cancer, taking into account the histologic type of initial cancer and the primary therapy used to treat it. Methods The study cohort consisted of 28,843 men identified within 16 population-based tumor registries in North America and Europe; over 3300 men had survived more than 20 years. New invasive cancers were identified through a search of registry files. Results Second cancers were reported in 1406 men (observed-to-expected ratio [O/E] = 1.43; 95% confidence interval = 1.36-1.51), with statistically significant excesses noted for acute lymphoblastic leukemia (O/E = 5.20), acute nonlymphocytic leukemia (O/E = 3.07), melanoma (O/E = 1.69), non-Hodgkin's lymphoma (O/E = 1.88), and cancers of the stomach (O/E = 1.95), colon (O/E = 1.27), rectum (O/E = 1.41), pancreas (O/E = 2.21), prostate (O/E = 1.26), kidney (O/E = 1.50), bladder (O/E = 2.02), thyroid (O/E = 2.92), and connective tissue (O/E = 3.16). Overall risk was similar after seminomas (O/E = 1.42) or nonseminomatous tumors (O/E = 1.50). Risk of solid tumors increased with time since the diagnosis of testicular cancer, yielding an O/E = 1.54 (O = 369) among 20-year survivors (two-sided P for trend = .00002). Secondary leukemia was associated with both radiotherapy and chemotherapy, whereas excess cancers of the stomach, bladder, and, possibly, pancreas were associated mainly with radiotherapy. Conclusions Men with testicular cancer continue to be at significantly elevated risk of second malignant neoplasms for more than two decades following initial diagnosis. Patterns of excess second cancers suggest that many factors may be involved, although the precise roles of treatment, natural history, diagnostic surveillance, and other influences are yet to be clarified.

The European Childhood Leukaemia - Lymphoma Incidence Study (ECLIS) is designed to address concerns about a possible increase in the risk of cancer in Europe following the nuclear accident in Chernobyle in 1986. This paper reports results of surveillance of childhood leukaemia in cancer registry populations from 1980 up to the end of 1991. There was a slight increase in the incidence of childhood leukaemia in Europe during this period, but the overall geographical pattern of change bears no relation to estimated exposure to radiation resulting from the accident. We conclude that at this stage of follow-up any changes in incidence consequent upon the Chernobyl accident remain undetectable against the usual background rates. Our results are consistent with current estimates of the leukaemogenic risk of radiation exposure, which, outside the immediate vicinity of the accident, was small.

To study the long term risk of cancer in patients with rheumatoid arthritis (RA) who have been treated with yttrium.The medical record numbers of 1228 patients with RA who were admitted to hospital in 1979-85 were identified in the database of Jyväskylä Central Hospital. Radiosynovectomy of the knee joint was performed in a total of 143 patients using yttrium-90 silicate during the years 1970-85, while 1075 did not receive yttrium radiosynovectomy; 10 received yttrium treatment later than 1985 and were excluded from the analysis. The Finnish Cancer Registry database was used to examine whether the subjects had cancer during the follow up from 1979 until the end of 1999.Nine cases of cancer were found among the patients who had received yttrium, whereas the expected number based on the incidence among the population in the region was 14.9. The standardised incidence ratio of cancer was 0.6 (95% confidence interval (CI) 0.3 to 1.1) for the patients who received yttrium, and 1.1 (95% CI 0.9 to 1.3) for the patients who did not receive yttrium.Yttrium treatment did not increase the risk of cancer.

The risk of smoking-related secondary cancers developing in bladder cancer patients was studied. The study population consisted of 10,014 bladder cancer patients reported to the Finnish Cancer Registry between 1953 and 1989. The risk of contracting a new primary cancer was estimated as a standardized incidence ratio, defined as the ratio of the observed and expected numbers of cases. Of 660 secondary cancers (6.6%) observed (standardized incidence ratio 0.96) 44% were considered to be smoking-related. Lung cancer was the most common secondary cancer (30% overall), and it occurred significantly more often than expected (standardized incidence ratio 1.31, 95% confidence interval 1.13 to 1.50). Also, larynx cancer among men (standardized incidence ratio 1.67, 95% confidence interval 0.95 to 2.79) and kidney cancer among women (standardized incidence ratio 3.55, 95% confidence interval 1.84 to 6.20) were found more often than expected. These excess risks were observed up to 20 years after diagnosis of bladder cancer. Therefore, bladder cancer patients experience an excess risk of smoking-related new tumors, which must be acknowledged during the initial evaluation and regular followup of such patients.

Impaired semen quality and testicular cancer may be linked through a testicular dysgenesis syndrome of foetal origin. The incidence of testis cancer has been shown to increase among Finnish men, whereas there is no recent publication describing temporal trends in semen quality. Therefore, we carried out a prospective semen quality study and a registry study of testis cancer incidence among Finnish men to explore recent trends. A total of 858 men were investigated in the semen quality study during 1998-2006. Median sperm concentrations were 67 (95% CI 57-80) million/mL, 60 (51-71) and 48 (39-60) for birth cohorts 1979-81, 1982-83 and 1987; total sperm counts 227 (189-272) million, 202 (170-240) and 165 (132-207); total number of morphologically normal spermatozoa 18 (14-23) million, 15 (12-19) and 11 (8-15). Men aged 10-59 years at the time of diagnosis with testicular cancer during 1954-2008 were included in the registry study, which confirmed the increasing incidence of testicular cancer in recent cohorts. These simultaneous and rapidly occurring adverse trends suggest that the underlying causes are environmental and, as such, preventable. Our findings necessitate not only further surveillance of male reproductive health but also research to detect and remove the underlying factors.

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.

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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.

Broad variations in the incidence of gestational trophoblastic diseases have been reported in different parts of the world. Recent time trends in the incidence of hydatidiform mole in Western countries have not been elucidated. We studied the epidemiology of hydatidiform mole in Finland over a period of 27 years.Women reported to have hydatidiform mole from 1975-2001 were identified from the National Research and Development Center for Welfare and Health. Women with choriocarcinoma were identified from the Finnish Cancer Registry.We identified 1659 cases of hydatidiform mole between 1975 and 2001. This gives an incidence of 73/10(6) women or 984/10(6) deliveries. The overall incidence remained fairly constant over the study period. The incidence was higher in women below 20 years and above 39 years than in women in the other age groups. Forty-nine percent of choriocarcinomas identified during the study period were associated with a preceding hydatidiform mole. The risk of choriocarcinoma after a hydatidiform mole was 2.2%.The incidence of hydatidiform mole in Finland follows the same patterns as in other Western countries. The incidence has not changed considerably in recent decades.

To compare the risk of cancer between BRCA1 or BRCA2 mutation-positive and -negative families.We assessed standardized incidence ratios (SIR) in 107 Finnish breast cancer families (12 BRCA1, 11 BRCA2, 84 non-BRCA1/2) with confirmed genealogy. The observed numbers of cancer cases were compared to the expected ones; both numbers were based on the population-based Finnish Cancer Registry.Risk of ovarian cancer for first-degree relatives was high in BRCA1 (SIR 29, 95% confidence interval 9.4-68) and in BRCA2 families (SIR 18. 8.3-35), but not increased for non-BRCA1/2 families (SIR 1.0, 0.2-2.9). The SIR for subsequent ovarian cancer among breast cancer patients was 61 (20-142), 38 (11-98), and 0 (0-4.2), respectively. The risk of subsequent new breast cancer among breast cancer patients was equally high in BRCA1 families (SIR 11, 3.6-26) and in BRCA2 families (SIR 10, 3.3-24) and somewhat lower in mutation-negative families (SIR 3.7, 2.1-6.1). The risk of breast cancer among relatives was markedly increased in all three groups. The only elevated SIR, besides breast and ovarian, was that for prostate cancer in BRCA2 families (SIR 4.9, 1.8-11).The excess risk of breast cancer in non-BRCA1/2 families suggests the existence of another predisposition gene which seems not to be linked with increased risk of ovarian cancer.

Five to ten percent of prostate cancers may be caused by inherited genetic defects. In order to explore the nature of inherited cancer risks in the genetically homogeneous Finnish population, we investigated the incidence of prostate cancer and other cancers in first-degree relatives of prostate cancer patients by linking the population-based parish records on relatives with the Finnish Cancer Registry (FCR) data.The study population was composed of first-degree relatives of two groups of prostate cancer patients diagnosed in Finland during 1988-1993: (1) all early-onset (60 years) patients (n = 557) from the entire country, (2) a sample (n = 989) of prostate cancer patients diagnosed at an age of60 years. A total of 11,427 first-degree relatives were identified through parish records, and their cancer incidence was determined based on a total of 299,970 person-years. Standardized incidence ratios (SIR) were calculated based on expected cancer rates in the general population.The SIR of prostate cancer was increased in both Cohort 1 (2.5, 95% CI 1.9-3.2) and Cohort 2 (1.7, 95% CI 1.4 2.1). The risk of prostate cancer was high for relatives of patients diagnosed at an early age, and then leveled off for patients in the median age of prostate cancer diagnosis (70-79 years). However, the prostate cancer risk for relatives of patients diagnosedor = 80 years was again statistically significantly elevated (SIR 1.8, 95% CI 1.3-2.6), suggesting a contribution of genetic factors to prostate cancer also at a late age of onset. Gastric cancer was the only other cancer type with a significantly elevated risk among the relatives. Increased risk of gastric cancer was seen only in male relatives of prostate cancer patients diagnosed at an early age, with the highest risk detected for the male relatives of prostate cancer patients diagnosed at an age of 55 years or less (SIR 5.0, 95% CI 2.8-8.2).Our population-based study indicates that hereditary factors may play an important role in the development of prostate cancer among the relatives of men diagnosed both at younger and older ages. This finding is relevant in the context of our observations that HPCX (hereditary prostate cancer susceptibility locus on Xq27-28) linkage in Finland is found exclusively among families with late age of onset. The association of gastric cancer with prostate cancer has not been reported previously, and may reflect the effects of a novel predisposition locus, which increases the risk to both of these common tumor types.

In epidemiological studies abundant physical activity has been related to decreased breast cancer risk, though the results have been inconsistent. The purpose of this paper was to study the association of physical activity at leisure and commuting to work and incidence of breast cancer.The study cohort consisted of 30,548 female participants of the Finnish adult health behaviour survey, based on annual random samples of Finns aged 15-64, collected in 1978-1993. By the end of 1995, 332 breast cancer cases had been diagnosed in the cohort. Relative risks of breast cancer were adjusted for age at survey, body mass index (BMI), education, length of follow-up, parity and age at first birth using Poisson regression models.Compared to women exercising less than once a week, the adjusted relative risk of breast cancer for women exercising once a week was 0.80 (95% confidence interval (CI): 0.58-1.10), for women exercising 2-3 times per week 0.92 (95% CI: 0.78-1.22) and for women exercising daily 1.01 (95% CI: 0.72-1.42). Women who reported commuting, walking or bicycling to work 30 min or more daily had slightly lower adjusted risk of breast cancer (RR: 0.87, 95% CI: 0.62-1.24) than women working at home, being unemployed or driving a car to working place.Although a small protective effect of regular physical activity for breast cancer incidence was found in physical activity when commuting to work, the role of the physical activity in breast cancer prevention is still an open question.

OBJECTIVE—To evaluate outcome in a cohort of Finnish patients with primary Sjogren's syndrome (pSS). METHODS—Clinical and laboratory data from the time of diagnosis and follow up were collected from 110 patients with pSS (107 women, three men) diagnosed in 1977-1992 in central Finland. The standardised incidence ratio for cancers was determined as the ratio of the observed number of cases to the expected number based on regional population rates. Eighty one of the 93 patients still alive were interviewed, and clinical and laboratory examinations performed in 1994-1997. RESULTS—The mean (SD) erythrocyte sedimentation rate (33 (22) v 45 (28) mm/1st h), serum IgG (18.8 (7.4) v 22.5 (8.5) g/l), and serum IgM (1.6 (1.1) v 2.0 (1.2) g/l) at the control visit were significantly (p

This study was initiated as a consequence of a clinical observation in one hospital of several endometrial carcinomas among users of a fixed combination of a 3-month cycle oral hormonal replacement therapy (HRT), which has been marketed in Finland since 1990. We studied whether the use of 3-month ("long") cycle HRT is accompanied by a higher risk of endometrial cancer than the use of monthly cycle HRT.A nationwide cohort of 15,956 long cycle and 78,549 monthly cycle HRT users since January 1994 was extracted from the files of the national medical reimbursement register and followed up for cancer incidence through the Finnish Cancer Registry up to the end of 1997.There were 61 cases of endometrial cancer among long cycle HRT users which significantly exceeds the average incidence in the Finnish population (standardized incidence ratio (SIRlong) 2.0, 95% confidence interval (CI) 1.6-2.6). The SIR among users of monthly cycle HRT products (SIRmonthly) was 1.3 (1.1-1.6) and the ratio SIRlong/SIRmonthly thus 1.5 (95% CI 1.1-2.1). Endometrial cancers among long cycle HRT users occur more often in early stages than in the general population and are more often highly differentiated. A survey of a sample of endometrial cancer patients in the long cycle HRT group revealed that all of them also had a history of other HRT. Users of both long and monthly cycle HRT had a similar statistically significant 30% excess of breast cancer in comparison to national incidence rates, while the incidence of colon cancer was decreased in both groups. There was no difference between the HRT groups in overall cancer morbidity.Our results imply that all HRT users have an increased risk of endometrial cancer, and long cycle HRT carries a higher relative risk than monthly cycle HRT. However, in this non-randomized setting it is impossible to judge whether this excess is attributable to the type of HRT or to patient selection. In-depth studies are needed to find out possible dose-response associations and to evaluate the role of potential confounders in detail.

Several predisposition loci for hereditary prostate cancer (HPC) have been suggested, including HPC1 at 1q24-q25 (OMIM #601518) and HPCX at Xq27-q28 (OMIM #300147). Genetically homogeneous populations, such as that of Finland, and distinct subsets of families may help to minimize the genetic heterogeneity that complicates the genetic dissection of complex traits. Here, the role of the HPC1, and HPCX loci in a series of Finnish prostate cancer families was studied, especially in subgroups of families defined by age, number of affected cases, and the mode of disease transmission. DNA samples were collected from 57 Finnish HPC families with at least two living prostate cancer patients. Linkage analysis was carried out with 39 microsatellite markers for the HPC1 region and 22 markers for the HPCX region. The maximum two-point LOD score for the HPCX was 2.05 (marker DXS1205, at theta = 0.14), whereas HPC1 LOD scores were all negative. In HOMOG3R analyses, significant evidence of heterogeneity was observed. Subgroup analyses performed to explore the nature of this heterogeneity indicated that families with no male-to-male (NMM) transmission and a late age of diagnosis (65 years) accounted for most of the HPCX-linked cases. The maximum HPCX LOD score in this subgroup was 3.12 (theta = 0.001). Nonparametric sibling pair analyses gave a peak LOD score of 3.04 (P0.000093) for the NMM transmission subgroup. No subgroup showed any positivity for HPC1. This study suggests that the HPCX-linked prostate cancer families represent a distinct subgroup characterized by NMM transmission of disease and late age of diagnosis.

Human papillomavirus (HPV) infection has been established as a cause of cervical cancer. Epidemiologic studies suggest that Chlamydia trachomatis infection also confers increased risk for cervical squamous cell carcinoma (SCC). Whether this risk is serotype-specific is unknown.To study the association between exposure to different C trachomatis serotypes and subsequent development of cervical SCC.Longitudinal, nested case-control study within a cohort of 530 000 women who provided samples to serum banks in Finland, Norway, and Sweden. The data files were linked to respective national cancer registries.One hundred twenty-eight women who had developed invasive cervical SCC at least 12 months following serum donation. Each case had 3 matched controls.Risk for the development of cervical SCC by IgG antibodies to 10 different C trachomatis serotypes, adjusted for antibodies to HPV types 16, 18, and 33 and for serum cotinine levels.Of specific C trachomatis serotypes, serotype G was most strongly associated with SCC (adjusted odds ratio [OR], 6.6; 95% confidence interval [CI], 1. 6-27.0). Other serotypes associated with SCC were I (OR, 3.8; 95% CI, 1.3-11.0) and D (OR, 2.7; 95% CI, 1.3-5.6). Presence of serum IgG antibodies to more than 1 serotype increased the adjusted ORs for SCC (P.001 for trend).Chlamydia trachomatis serotype G is most strongly associated with subsequent development of cervical SCC. Increasing numbers of exposures to different C trachomatis serotypes also increases risk. Our results strengthen the evidence that there is a link between past C trachomatis infection and cervical SCC.

Identification of predisposition loci to complex diseases, such as prostate cancer, requires high-quality family material, the ascertainment of which is often laborious, time-consuming and inaccurate with conventional methods. Here, we describe a new method for rapid, nationwide cancer family ascertainment using Finnish Cancer Registry data on 35,761 prostate cancer cases over a 40-year period. As members of a prostate cancer family are likely to share the same family name and place of birth, we stratified all prostate cancer cases by these 2 parameters (10,721 different names and 596 municipalities). Data were compared with the distribution of family names and places of birth for all 3.3 million Finnish men to derive standardized prevalence ratios (SPRs). A significantly elevated SPR of prostate cancer was detected for 468 (1.6%) of the 28,459 evaluable combinations of family name and place of birth. Of the 20 highest SPR values, 19 corresponded to true nuclear families, most of these having 3 or more affected cases. Two-thirds of our 50 previously established Finnish prostate cancer families were classified among this 1.6% fraction of the highest SPR values. Finally, many of the highest SPR values originated from municipalities in southern and south-western Finland. To explore whether such clusters could highlight local founder effects, we applied genealogical research to link together several families with elevated SPRs and identified an extended family with 20 prostate cancer cases with common ancestors in the early seventeenth century. In summary, a rapid novel method was developed and validated for identification of prostate cancer families from nationwide cancer registry data and for the identification of putative regional founder effects.

The aim of this study was to investigate whether patients with basal-cell carcinoma (BCC) of the skin have an increased risk of developing other cancers. A total of 71,924 patients diagnosed with BCC between 1953 and 1995 were identified from the Finnish Cancer Registry. They were followed up for subsequent primary cancers from the date of the first BCC diagnosis to the end of 1995. Standardized incidence ratios (SIR) with 95% confidence intervals (CI) were calculated based on national rates. Altogether 11,042 subsequent primary cancers occurred among the study cohort during 625,000 person-years of follow-up. Risk increases were observed for non-melanoma skin cancer (SIR 3.79, 95% CI 3.59-4.00) and skin melanoma (SIR 2.34, 95% CI 2.08-2.61). The five other primary sites presenting the highest SIRs were salivary glands (SIR 3.30), lip (2. 19), small intestine (1.85), nose (1.73) and pharynx (1.71). Patients who were less than 40 years of age at the time of BCC diagnosis had a significantly higher relative risk for a subsequent new cancer than the older patients (ratio of the SIRs 1.29, 95% CI 1. 10-1.51). Time since BCC diagnosis did not materially influence the overall relative risk of subsequent cancers. Part of the increase in the risk of skin cancer is likely to be due to enhanced diagnostic activity after an initial diagnosis of BCC. However, the increases in the risk of several non-cutaneous cancers suggest a generalized carcinogenic role of some factors in the BCC pathogenic pathways.

We evaluate the validity of the family history of breast cancer reported by the patient and the number of families and individuals at risk and potentially benefiting from surveillance. Family history of cancer was systematically screened in three different series of breast cancer patients. Breast cancer families were defined by the selection criterion of at least three first- or second-degree relatives with breast or ovarian cancer (including the proband) and their genealogy and cancer diagnoses were confirmed. Family history of breast or ovarian cancer was reported by approximately 30% of the patients and 7-9% were classified as breast cancer families. On average, there were 3.1 healthy female (age: 20-70 years) first degree relatives per family potentially at high risk. Index patients reported 87% of all confirmed diagnoses and the primary site was correct in 93-95% of the reported cases. The incompleteness and errors in accuracy should be considered in epidemiological studies and verification of the diagnoses is important when deciding clinical management.

Twin studies integrate genetic and environmental (including physical environment and life-style) information by comparing monozygotic and dizygotic twins for the occurrence of disease. Our objectives were to compare cancer incidence in twins with national rates and to estimate both the probability that co-twins of affected twins may develop cancer and the importance of genetic predisposition and environment in cancer development. The nationwide record linkage of the Finnish Twin Cohort Study, the Finnish Cancer Registry and the Central Population Register allowed the follow-up of 12,941 same-sexed twin pairs for incident primary cancers from 1976 to 1995. Zygosity was determined by use of a validated questionnaire in 1975. Methods included calculation of standardized incidence ratios and concordances and fitting of structural equation models. A total of 1,613 malignant neoplasms occurred in the cohort. The overall cancer incidence among twins resembled that among the general population. Monozygotic co-twins of affected twins were at 50% higher risk than were dizygotic co-twins. Based on genetic modeling, inherited genetic factors accounted for 18% (95% confidence interval 4-32%) of the liability in inter-individual variation in the risk of overall cancer, while non-genetic factors shared by twins accounted for 7% (0-16%) and unique environmental factors for 75% (65-85%). Our results appear to exclude a contribution greater than one-third for genetic predisposition in the development of cancer in the general population, thus pointing to the earlier confirmed substantial role of environment.

It has been suggested that trioxsalen bath and ultraviolet (UV) A (PUVA) is associated with a very low or no risk of non-melanoma skin cancer, but the numbers of patients in individual studies have been limited. In order to attain statistically relevant information about the cancer risk associated with trioxsalen bath PUVA, two follow-up studies were combined and the joined cancer incidence was analysed among 944 Swedish and Finnish patients with psoriasis. The mean follow-up time for skin cancer was 14.7 years. Standardized incidence ratios (SIR) were calculated as a ratio of observed and expected numbers of cases. The expected numbers of cases were based on the national cancer incidence rates in the respective countries. There was no excess of squamous cell skin carcinoma [SIR 1.1, 95% confidence interval (CI) 0.2-3.2] or malignant melanoma (SIR 0.9, 95% CI 0.1-3.2) in the combined cohort. Basal cell skin carcinoma was not studied. The incidence of all non-cutaneous cancers was not increased (SIR 1.1, 95% CI 0.8-1.4). A threefold excess risk of squamous cell skin carcinoma after trioxsalen bath PUVA could therefore be excluded, which is a markedly lower risk than that associated with oral 8-methoxypsoralen PUVA. The result needs to be confirmed in a future follow-up, however, as the number of patients with high PUVA exposures was low.

Six statistics are compared in a simulation study for their ability to identify geographical areas with a known excess incidence of a rare disease. The statistics are the standardized incidence ratio, the empirical Bayes method of Clayton and Kaldor, Poisson probability, a statistic based on the 'Breslow T' test (BT) and two statistics based on the 'Potthoff-Whittinghill' test (PW) for extra-Poisson variance. Two alternative processes of clustering are simulated in which high-risk locations could be caused by environmental sources or could be sites of microepidemics of an infectious agent contributing to a rare disease such as childhood leukaemia. The simulation processes use two parameters (proportion of cases found in clusters and mean cluster size) which are varied to embrace a variety of situations. Real and artificial data sets of small area populations are considered. The most extreme of the artificial sets has all areas of equal population size. The other data sets use the small census areas (municipalities) in Finland since these have extremely heterogeneous population size distribution. Subset selection allows examination of this variability. Receiver operator curve methodology is used to compare the efficacy of the statistics in identifying the cluster areas; statistics are compared for the proportion of true high-risk areas identified in the top 1 per cent and 10 per cent of ranked areas. One of the PW statistics performed consistently well under all circumstances, although the results for the BT statistic were marginally better when only the top 1 per cent of ranked areas was considered. The standardized incidence ratio performed consistently worst.

To describe the cancer risk pattern of Finnish persons with visual impairment.A cohort of 17,557 persons identified from the Finnish Register of Visual Impairment was followed-up for cancer through the Finnish Cancer Registry from 1983-95. The degree of visual impairment ranged from moderate low vision with visual acuity less than 0.3, to total blindness with no perception of light. The standardized incidence ratios (SIR) and 95% confidence intervals (CI) were calculated by primary site; the expected rates were based on national cancer incidence rates.The SIR for overall cancer among totally blind men was 2.2 (CI = 1.3-3.5) while in the entire cohort the incidence was increased by only 15% (1,255 cancers observed cf 1,093 expected). Excesses were observed in both genders in cancers of the liver (SIR = 1.8, CI = 1.2-2.5) and lung (SIR = 1.5, CI = 1.3-1.7); in females in cancers of the stomach (SIR = 1.5, CI = 1.2-1.9) and the colorectum (SIR = 1.3, CI = 1.1-1.6); and in males in cancers of the kidney (SIR = 1.8, CI = 1.1-2.6) and the eye (5.8, CI = 1.9-13). The excess in lung cancer was entirely attributable to age-related macular degeneration (which is most common among smokers).Cancer incidence among the visually impaired tended to be increased for most cancer types. Attention should be paid to lifestyle factors underlying the observed risk increases, such as unbalanced diet.

To study the asbestos-associated risk of lung cancer according to the histological type of cancer, the time of and time since diagnosis of asbestosis, the asbestos-associated risk for cancers other than lung cancer or mesothelioma, and the predictive value of asbestos-related pleural abnormalities as regards the risk of cancer.Finnish patients with asbestosis (n = 1,376) or asbestos-related benign pleural disease (n = 4,887) notified as an occupational disease since 1964 were followed-up through the Finnish Cancer Registry for cancer in 1967-95.Compared with the total cancer incidence in Finland, men with asbestosis had a raised risk of lung cancer (standardized incidence ratio [SIR] = 6.7; 95% confidence interval [CI] = 5.6-7.9), mesothelioma (SIR = 32, CI = 14-60) and cancer of the larynx (SIR = 4.2, CI = 1.4-9.8). The risk of lung cancer was similarly raised for all histological types of lung cancer (the highest in insulators) and did not change markedly over time of notification or duration of follow-up. Men with benign pleural disease had a raised risk of mesothelioma (SIR = 5.5, CI = 1.5-14) and a slightly elevated risk of lung cancer (SIR = 1.3, CI = 1.0-1.8). Among women with asbestosis, significant excess was found for lung cancer and mesothelioma.Asbestosis and asbestos-related benign pleural disease seem to possess different predictive values as regards the risk of lung cancer.

Nationwide, computer-based reporting of all arthroplasties performed in Finland was started in January 1980. Using data from these records, a cohort of 31,651 polyethylene-on-metal total hip arthroplasty (THA) patients was followed up for cancer, using Finnish Cancer Registry data, from 1980 to 1995. During follow-up, 2,367 cancers were observed. There were statistically significantly fewer cancers among the THA patients (standardized incidence ratio [SIR], 0.90; 95% confidence interval [CI], 0.87-0.93). SIRs for cancers of the lung (0.69) and stomach (0.77) were significantly below unity. There was no significantly increased risk at any site. The SIR for cancer overall in male THA patients was below unity during the first 3 years after THA but returned to unity thereafter. The low SIR among men during the first 3 years was largely because the lung cancer SIR was 0.47 (95% CI, 0.35-0.62). In women, the SIR remained around 0.93 throughout follow-up. The SIR for stomach cancer was below unity only in women (SIR, 0.67; 95% CI, 0.51-0.86). For cancer of the urinary bladder, the SIR during the first 3 years after THA was below unity but later slightly above it (SIR, 1.24 in relation toor =3 years of follow-up; 95% CI, 0.99-1.52). For myeloma and leukemia, SIRs were greater than unity only for THA patients followed up for 3 to 9 years. The study findings, in contrast to previously reported findings, do not indicate that there is any increased risk of hematopoietic cancers after THA using polyethylene-on-metal prostheses. SIRs relating to soft tissue cancers and bone sarcomas did not differ significantly from unity. No sarcoma was observed at the site of a prosthesis. THA seems to play no major role in cancer causation.

Excessive incidence of various cancers is a challenging feature of the hereditary-non-polyposis-colorectal-cancer (HNPCC) syndrome. This study estimated the cancer incidences in HNPCC compared with the general population. Individuals in a cohort of 1763 members of 50 genetically diagnosed families were categorized according to their genetic status as mutation carriers, non-carriers, or individuals at 50 or 25% risk of being a carrier. Incidences of cancers in these groups were compared with those in the Finnish population overall. In 360 mutation carriers, standardized incidence ratios (SIR) were significantly increased for colorectal [68; 95% confidence intervals (CI), 56 to 81], endometrial (62; 95% CI, 44 to 86), ovarian (13; 95% CI, 5.3 to 25), gastric (6.9; 95% CI, 3.6 to 12), biliary tract (9.1; 95% CI, 1.1 to 33), uro-epithelial (7.6; 95% CI, 2.5 to 18) and kidney (4.7; 95% CI, 1 to 14) cancers and for central-nervous-system tumours (4.5; 95% CI, 1.2 to 12). The SIR increased with increasing likelihood of being a mutation carrier. The cumulative cancer incidences were 82, 60, 13 and 12% for colorectal, endometrial, gastric and ovarian cancers respectively. For other tumours associated with increased risk, corresponding incidences were below 4%. Interestingly, the incidence of endometrial cancer (60%) exceeded that for colorectal cancer in women (54%). The tumour spectrum associated with germline mutations of DNA-mismatch-repair genes involves 8 or more organ sites, suggesting a need to develop methods to screen for extra-colonic cancer also.

This population-based study investigated the occurrence of breast cancer over a 20-year period in a cohort of monozygotic (MZ) and dizygotic (DZ) twins in Finland. Altogether, 13,176 female twins of known zygosity who were living in Finland at the end of 1975 were identified from the Finnish Twin Cohort Study and followed-up for cancer through the Finnish Cancer Registry for the years 1976-1995. Standardized incidence ratios (SIRs) were calculated, based on national cancer incidence rates. The relative risk of breast cancer for MZ twins compared to DZ twins was decreased [SIR(MZ)/SIR(DZ) ratio = 0.78; 95% confidence interval (CI), 0.58-1.0]; the decreased risk for MZ twins (SIR = 0.76; 95% CI, 0.58-1.0) accounted for this result, whereas the risk for DZ twins did not differ from the general population risk (SIR = 0.98; 95% CI, 0.84-1.1). There was no risk decrease among MZ twins in other cancers related to reproductive behavior; i.e., number of children and age at first birth seem not to explain the decreased risk of breast cancer. Our results, which are in line with earlier studies on the same topic, suggest that prenatal influences or postnatal behavioral factors may protect MZ female twins from breast cancer.

Human papillomavirus (HPV) types 16 and 18 are the major risk factors for cervical carcinoma, whereas HPV types 6 and 11 cause benign genital lesions. We wanted to study the joint effect of simultaneous infections with the oncogenic and non-oncogenic HPV types on risk of subsequent development of cervical carcinoma. A cohort of 530,000 women who had donated blood samples to Nordic serum banks between 1973 and 1994 was followed up by linkage to national cancer registries. We identified 182 prospective cases with invasive cervical carcinoma and selected 538 matched controls at random. HPV 6, 11, 16, 18 and 33 seropositivity was used as a marker for the different HPV infections, and seropositivity for Chlamydia trachomatis and cotinine were used as markers for risk-taking sexual behavior and smoking respectively. The adjusted odds ratio (OR) of cervical squamous-cell carcinoma (SCC) was 2.2 for HPV6/11 among HPV16 seronegatives and 5.5 for HPV16 among HPV6/11 seronegatives. Assuming multiplicative joint effect, the expected OR for seropositivity to both HPV6/11 and HPV16 would have been 12, but the observed OR was 1.0. The antagonistic interaction was statistically significant (p = 0.001) and present also under deterministic considerations of possible misclassification bias. Antagonistic interactions were also detected for combinations of HPV16 and HPV18 and of HPV16 and HPV33. The results are in line with the concept that HPV-specific immunity protects against SCC and support primary prevention of SCC by vaccination against the HPVs.

Previous job-exposure matrices (JEM) have usually cross-tabulated classified exposure information by chemical agent and occupational class. A new Finnish job-exposure matrix (FINJEM) was constructed for exposure assessment in large register-based studies. Unlike most other JEMs, FINJEM was designed to contain definitions, inferences, exposure data, and references. This documentation enables FINJEM to be applied also as a general exposure information system for hazard control, risk quantification and hazard surveillance. The system includes, e.g., workforce data, and it provides information on the numbers of exposed workers in Finland by agent, occupation, and level of exposure. The exposures of FINJEM cover major physical, chemical, microbiological, ergonomic, and psychosocial factors. The assessment period is 1945-1997, divided into several subperiods. Exposure is described by the prevalence of exposure and the level of exposure among the exposed, both estimated mainly on continuous scales. The user may also define the final criteria of exposure, and thereby influence the magnitude of misclassification.

A cohort of 4,742 men from Estonia who had participated in the cleanup activities in the Chernobyl area sometime between 1986 and 1991 and were followed through 1993 was analyzed with respect to the incidence of cancer and mortality. Incidence and mortality in the cleanup workers were assessed relative to national rates. No increases were found in all cancers (25 incident cases compared to 26.5 expected) or in leukemia (no cases observed, 1.0 expected). Incidence did not differ statistically significantly from expectation for any individual cancer site or type, though lung cancer and non-Hodgkin's lymphoma both occurred slightly more often than expected. A total of 144 deaths were observed [standardized mortality ratio (SMR) = 0.98; 95% confidence interval (CI) = 0.82-1.14] during an average of 6.5 years of follow-up. Twenty-eight deaths (19.4%) were suicides (SMR = 1.52; 95% CI = 1.01-2.19). Exposure to ionizing radiation while at Chernobyl has not caused a detectable increase in the incidence of cancer among cleanup workers from Estonia. At least for the short follow-up period, diseases directly attributable to radiation appear to be of relatively minor importance when compared with the substantial excess of deaths due to suicide.