Incidence trends of vestibular schwannomas in Denmark, Finland, Norway and Sweden in 1987-2007.

BACKGROUND: The reported incidence rates of vestibular schwannomas (VS) vary substantially, but it is unclear as to what extent the variation reflects differences in risk or recording practices. Our aim was to describe the incidence rates of VS in Denmark, Finland, Norway and Sweden between 1987 and 2007. METHODS: Comprehensive data were available from all registries only for the period from 1987 to 2007. An analysis of a longer time period (1965-2007) was conducted with the Norwegian and Swedish data. RESULTS: The average age-standardised incidence rates during 1987-2007 varied from 6.1 per 1,000,000 person-years (95% confidence interval (CI), 5.4-6.7) among Finnish men to 11.6 (95% CI, 10.4-12.7) in Danish men, and from 6.4 per 1,000,000 person-years (95% CI, 5.7-7.0) among Swedish women to 11.6 (95% CI, 10.5-12.8) among Danish women. An overall annual increase of 3.0% (95% CI 2.1-3.9) was observed when all countries and both sexes were combined, with considerable differences between countries. However, the practices of both reporting and coding VS cases varied markedly between countries and over time, which poses a challenge for interpretation of the results. CONCLUSION: The overall incidence of VS increased in all the four Nordic countries combined between 1987 and 2007, with marked differences between countries. However, the incidence rates more or less stabilised in the late 1990s, showing relatively constant incidence rates and even some decline after 2000.

Chronic lymphocytic leukaemia patients have a high risk of Merkel-cell polyomavirus DNA-positive Merkel-cell carcinoma.

BACKGROUND: Immunosuppression and Merkel-cell polyomavirus (MCPyV) infection may have a role in the pathogenesis of Merkel-cell carcinoma (MCC), a rare neuroendocrine carcinoma of the skin. METHODS: We studied incidence of chronic lymphocytic leukaemia (CLL) and MCC from the files of the Finnish Cancer Registry and the largest hospital of Finland, Helsinki University Central Hospital, from 1979 to 2006. Presence of MCPyV DNA in MCCs was investigated by quantitative PCR. RESULTS: We identified 4164 patients diagnosed with CLL and 172 diagnosed with MCC. Six patients diagnosed with both diseases were found; CLL was the first diagnosis in four cases and MCC in two. The standardised incidence ratio (SIR) for CLL after the diagnosis of MCC was highly elevated, 17.9 (95% confidence interval (CI), 2.2-64.6; P<0.001), and the SIR for MCC after the diagnosis of CLL was also elevated, 15.7 (3.2-46.0, P<0.01). Merkel-cell polyomavirus DNA was present in all five MCCs with tumour tissue available for analysis. CONCLUSIONS: We conclude that patients diagnosed with CLL have a substantially increased risk for MCC, and vice versa. Merkel-cell polyomavirus DNA is frequently present in MCCs that occur in CLL patients. Immunosuppression related with CLL and viral infection might explain the association between CLL and MCC.

Is the incidence of meningiomas underestimated? A regional survey.

We assessed the undercount of meningiomas in a population-based cancer registry. A comprehensive material was formed by compiling hospital sources with the Finnish Cancer Registry database. The completeness of each source ranged 62-69%. The corrected age-standardised meningioma incidence was 2.9/100,000 for men and 13.0/100,000 for women, a third higher than the cancer registry figures.

Scholastic achievements of children with brain tumors at the end of comprehensive education: a nationwide, register-based study.

BACKGROUND: Cancer treatment may affect school performance. Scholastic achievements after childhood brain tumors have not been previously reported on the level of actual grades. PATIENTS AND METHODS: Patients with brain tumor (n = 300) were identified from the Finnish Cancer Registry. Population controls (n = 1,473) were matched for age, gender, and place of living. Their ninth grade school reports were obtained from Statistics Finland. Age at diagnosis and cranial irradiation (CRT) were considered in analyses, and the level of parental education was taken into model as a covariate. RESULTS: Six percent of patients did not finish their comprehensive school at the usual age. Patients had lower overall averages than their controls (95% CI for the difference -0.30, -0.16). Girls differed from their controls independently of the age at diagnosis or CRT. Boys treated with CRT at school age, but not before school age, had poorer results than their controls (95% CI -0.65, -0.18). The grades of patients were significantly lower in each school subject, and differed most in foreign language. Young girls with CRT had greatest differences from their controls (95% CI -1.73, -0.86) in this subject. In mathematics, patients diagnosed before school age had greatest difference from their controls. In their mother tongue, patients differed less from their controls. CONCLUSIONS: Few patients with brain tumor missed the ninth grade certificate at the age of 16. Grades in foreign language (representing verbal performance) were most affected. However, the patients fared poorer than controls in each subject. The difference was most pronounced among girls. Girls were more sensitive to the adverse effects of irradiation.

Geographical comparison of cancer survival in European children (1988-1997): report from the Automated Childhood Cancer Information System project.

The aim of this study was to assess regional survival differences among childhood cancer patients in Europe. For this exercise, the Automated Childhood Cancer Information System (ACCIS) database was utilised. Survival data from 54 population-based cancer registries on 49,651 childhood cancer patients aged 0-14 years and diagnosed in 1988-1997 were analysed using life-table method. Overall, the 5-year survival was 72% among all patients, varying from 62% to 77% between the five geographical regions. The East region generally had lower survival rates than the rest of Europe. The geographical differences indicate the need for more co-ordination, systematisation and standardisation in diagnosis, referral and the treatment of childhood cancers in Europe. Increase of resources is necessary to improve the lower survival in the East region. Continuing data collection on a European level will facilitate monitoring of population-based survival of childhood cancer patients.

Breast and other cancers in 1445 blood relatives of 75 Nordic patients with ataxia telangiectasia.

Epidemiological studies have consistently shown elevated rates of breast cancer among female blood relatives of patients with ataxia telangiectasia (AT), a rare autosomal recessive disease. A large proportion of the members of AT families are carriers of AT-causing gene mutations in ATM (Ataxia Telangiectasia Mutated), and it has been hypothesised that these otherwise healthy carriers are predisposed to breast cancer. This is an extended and enlarged follow-up study of cancer incidence in blood relatives of 75 patients with verified AT in 66 Nordic families. Blood relatives were identified through population registry linkages, and the occurrence of cancer was determined from cancer registry files in each country and compared with national incidence rates. The ATM mutation carrier probabilities of relatives were assigned from the combined information on location in family, consanguinity, if any, and supplementary carrier screening in some families. Among the 1445 blood relatives of AT patients, 225 cancers were observed, with 170.4 expected, yielding a standardised incidence ratio (SIR) of 1.3 (95% confidence interval (CI), 1.1-1.4). Invasive breast cancer occurred in 34 female relatives (SIR, 1.7; 95% CI, 1.2-2.4) and was diagnosed in 21 women before the age of 55 years (SIR, 2.9; 95% CI, 1.8-4.5), including seven mothers of probands (SIR, 8.1; 95% CI, 3.3-17). When the group of mothers was excluded, no clear relationship was observed between the allocated mutation carrier probability of each family member and the extent of breast cancer risk. We concluded that the increased risk for female breast cancer seen in 66 Nordic AT families appeared to be restricted to women under the age of 55 years and was due mainly to a very high risk in the group of mothers. The findings of breast cancer risk in mothers, but not other likely mutation carriers, in this and other studies raises questions about the hypothesis of a simple causal relationship with ATM heterozygosity.

Does anyone survive pancreatic ductal adenocarcinoma? A nationwide study re-evaluating the data of the Finnish Cancer Registry.

BACKGROUND: Worldwide survival data for ductal adenocarcinoma of the pancreas are the lowest among the 60 most frequent types of organ cancers. Hence published data on long time survivors of this disease are controversial. We performed a nationwide study comprising all Finnish patients diagnosed with pancreatic cancer in the period 1990-1996 who survived for at least five years after diagnosis. METHODS: Data on patients registered as five year survivors of pancreatic cancer were obtained from the Finnish Cancer Registry and Statistics Finland. Slides or paraffin blocks were collected from patients recorded as having histologically proven pancreatic ductal adenocarcinoma (PDAC) and were re-evaluated in a double blind fashion by three pathologists with special expertise in pancreatic pathology. RESULTS: Between 1990 and 1996, the Finnish Cancer Registry recorded 4922 pancreatic cancer patients, 89 of whom survived for at least five years. Reviewing this series of patients revealed 45 (49%) non-PDACs and 18 cases without histological verification. In 26 patients recorded as having histologically proven PDAC, re-evaluation of histological specimens confirmed PDAC in only 10 patients. CONCLUSIONS: This study indicates that (1) the prognosis of PDAC remains poor and (2) careful histopathological review of all patients with pancreatic cancer is mandatory if survival data are to be meaningful.

European health systems and cancer care.

INTRODUCTION: Data on the survival of all incident cases collected by population-based cancer registries make it possible to evaluate the overall performance of diagnostic and therapeutic actions on cancer in those populations. EUROCARE-3 is the third round of the EUROCARE project, the largest cancer registry population based collaborative study on survival in European cancer patients. The EUROCARE-3 study analysed the survival of cancer patients diagnosed from 1990 to 1994 and followed-up to 1999. Sixty-seven cancer registries of 22 European countries characterised by differing health systems participated in the study. This paper includes essays providing brief overviews of the state and evolution of the health systems of the considered countries and comments on the relation between cancer survival in Europe and some European macro-economic and health system indicators, in the 1990s. OVERVIEW OF THE EUROPEAN HEALTH SYSTEMS: The European health systems underwent a great deal of reorganisation in the last decade; a general tendency being to facilitate expanding involvement of the private sector in health care, a process which occurred mainly in the eastern countries (i.e. the Czech Republic, Estonia, Poland, Slovakia and Slovenia). In contrast, organisational changes in the northern European countries (i.e. Denmark, Iceland, Finland and Sweden) tended to confirm the established public sector systems. Other countries, including the UK and some southern European countries (i.e. England, Scotland, Wales, Malta and Italy) have reduced the public role while the systems remain basically public, at least at present. Our findings clearly suggest that cancer survival (all cancer combined) is related to macro-economic variables such as the gross domestic product (GDP), the total national (public and private) expenditure on health (TNEH) and the total public expenditure on health (TPEH). We found, however, that survival is related to wealth (GDP), but only up to a certain level, after which survival continues to be related to the level of health investment (both TNEH and TPEH). According to the Organisation for Economic Co-operation and Development (OECD), the TNEH increased during the 1990s in all EUROCARE-3 countries, while the ratio of TPEH to TNEH reduced in all countries except Portugal. CONCLUSIONS: Cancer survival depends on the widespread application of effective diagnosis and treatment modalities, but our enquiry suggests that the availability of these depends on macro-economic determinants, including health and public health investment. Analysis of the relationship between health system organisation and cancer outcome is complicated and requires more information than is at present available. To describe cancer and cancer management in Europe, the European Cancer Health Indicator Project (EUROCHIP) has proposed a list of indicators that have to be adopted to evaluate the effects on outcome of proposed health system modifications.

Breast cancer incidence and mortality trends in 16 European countries.

Trends in the incidence of and mortality from breast cancer result from a variety of influences including screening programmes, such as those introduced in several European countries in the late 1980s. Incidence and mortality rates for 16 European countries are analysed. Incidence increased in all countries. The estimated annual percent change (EAPC) varied from 0.8 to 2.8% in prescreening years in 6 'screened' countries and from 1.2 to 3.0% in 10 'non-screened' countries. Screening related temporary increases were visible. Earlier mortality trends were maintained in the most recent decade in Estonia (EAPC +1.8%) and Sweden (-1.2%). In other countries, previously increasing trends changed. Trends flattened in Finland, Denmark, France, Italy and Norway (EAPC 0.0 to -0.3%), while they declined in England and Wales (-3.1%), Scotland (-2.0%), and The Netherlands (-1.0%), all of which have national screening programmes, and in Slovakia (-1.1%), Spain (-0.7%), and Switzerland (-1.1%). In some countries with screening programmes, declines in mortality started before screening was introduced, and declines also occurred in non-screened age groups and in some countries without national screening programmes. This suggests that the major determinants of the observed trends vary among the countries and may include earlier detection through screening in countries where this has been introduced, but also improvements in therapy, in countries with or without screening.

Estimates of cancer incidence and mortality in Europe in 1995.

Cancer incidence and mortality estimates for 1995 are presented for the 38 countries in the four United Nations-defined areas of Europe, using World Health Organization mortality data and published estimates of incidence from national cancer registries. Additional estimation was required where national incidence data was not available, and the method involved incorporating the high quality incidence and mortality data available from the expanding number of population-based cancer registries in Europe. There were an estimated 2.6 million new cases of cancer in Europe in 1995, representing over one-quarter of the world burden of cancer. The corresponding number of deaths from cancer was approximately 1.6 million. After adjusting for differing population age structures, overall incidence rates in men were highest in the Western European countries (420.9 per 100,000), with only Austria having a rate under 400. Eastern European men had the second highest rates of cancer (414.2), with extremely high rates being observed in Hungary (566.6) and in the Czech Republic (480.5). The lowest male all-cancer rate by area was observed in the Northern European countries, with fairly low rates seen in Sweden (356.6) and the UK (377.8). In contrast to men, the highest rates in women were observed in Northern Europe (315.9) and were particularly high in Denmark (396.2) and the other Nordic countries excepting Finland. The rates of cancer in Eastern European women were lower than in the other three areas, although as with men, female rates were very high in Hungary (357.2) and in the Czech Republic (333.6). There was greater disparity in the mortality rates within Europe--generally, rates were highest in Eastern European countries, notably in Hungary, reflecting a combination of poorer cancer survival rates and a higher incidence of the more lethal neoplasms, notably cancer of the lung. Lung cancer, with an estimated 377,000 cases, was the most common cancer in Europe in 1995. Rates were particularly high in much of Eastern Europe reflecting current and past tobacco smoking habits of many of its inhabitants. Together with cancers of colon and rectum (334,000), and female breast (321,000), the three cancers represented approximately 40% of new cases in Europe. In men, the most common primary sites were lung (22% of all cancer cases), colon and rectum (12%) and prostate (11%), and in females, breast (26%), colon and rectum (14%) and stomach (7%). The number of deaths is determined by survival, as well as incidence; by far the most common cause of death was lung cancer (330,000)--about one-fifth of the total number of cancer deaths in Europe in 1995. Deaths from cancers of the colon and rectum (189,000) ranked second, followed by deaths from stomach cancer (152,000), which due to poorer survival ranked higher than breast cancer (124,000). Lung cancer was the most common cause of death from cancer in men (29%). Breast cancer was the leading cause of death in females (17%). Cancer registries are a unique source of information on cancer incidence and survival, and are used here with national mortality to demonstrate the very substantial burden of cancer in Europe, and the scope for prevention. Despite some provisos about data quality, the general patterns which emerge in Europe verify the role of past exposures and interventions, and more importantly, firmly establish the need for cancer control measures which target specific populations. In particular, there is a clear urgency to combat the ongoing tobacco epidemic, now prevalent in much of Europe, particularly in the Eastern countries.

Cancer in siblings of children with cancer in the Nordic countries: a population-based cohort study.

BACKGROUND: In some rare inherited disorders such as Li-Fraumeni syndrome, relatives of children with cancer are at increased risk of cancer. We aimed to assess relations between childhood cancer and sibling risk, and evaluate the influence of recessive conditions in cancer causation. METHODS: We did a population-based cohort study in the Nordic countries of 42277 siblings of 25605 children with cancer. Children with cancer were identified from records in the five Nordic cancer registries, and their siblings from nationwide population registries. Cancers in siblings were documented through record linkage with cancer registries and compared with national incidence rates. We also assessed cancer incidence in parents to identify familial cancer syndromes. FINDINGS: 284.2 cancers were expected in siblings, whereas 353 were diagnosed (standardised incidence ratio 1.24 95% CI 1.12-1.38). Risk ratios for siblings were highest in the first decade of life (2.59, 1.89-3.46). We excluded 56 families with genetic syndromes linked to cancer, which reduced this ratio from 1.7 to 1.0 (0.7-1.3) for siblings younger than 20 years, and from 1.3 to 1.0 (0.8-1.3) for those aged 20-29 years. We found no new patterns of familial cancer that indicated inherited susceptibility, or evidence that recessive conditions might contribute to cancers not explained by syndromes. 40% of cancers in siblings that occurred before age 20 years could be attributed to known genetic factors, whereas 60% remained unexplained. INTERPRETATION: Apart from rare cancer syndromes, paediatric cancer is not an indicator of increased cancer risk in siblings.

Risk of cancer in BRCA1 and BRCA2 mutation-positive and -negative breast cancer families (Finland).

OBJECTIVES: To compare the risk of cancer between BRCA1 or BRCA2 mutation-positive and -negative families. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Survival of breast cancer patients in BRCA1, BRCA2, and non-BRCA1/2 breast cancer families: a relative survival analysis from Finland.

Reports on the prognosis of familial breast cancer patients have been contradictory. True differences in survival, if they exist, would have important implications for genetic counselling and in treatment of hereditary breast cancer. We assessed the survival rates of 359 familial breast cancer patients (32 patients from BRCA1-positive families, 43 patients from BRCA2-positive families and 284 patients from BRCA1/2-negative breast cancer families) and compared them with those of all other breast cancer patients diagnosed in Finland from 1953 to 1995 (n = 59,517). Cumulative relative survival rates (RSR) were calculated by dividing the observed survival rates by the expected ones. The expected survival rates were derived from the sex, age and calendar year specific life-tables of the general population in Finland. Regression model was used to calculate relative excess risk of death (RR) and to adjust for confounding factors. The overall 5-year RSR of the patients in the BRCA1 families, BRCA2 families, non-BRCA1/2 families and among sporadic cases was 67%, 77%, 86% and 78%, respectively. However, we found no significant differences in the RR adjusted for age, stage and year of diagnosis between the different familial patient groups or the general breast cancer population. In the BRCA1 families the RR tended to be higher [RR 1.30, 95% confidence interval (CI) 0.63--2.70] and in the BRCA2 families lower (RR 0.78, 95% CI 0.39--1.57) than among the general breast cancer patient population. The RR among patients in the non-BRCA1/2 families did not differ from that of the general patient population.

Decreasing late mortality among five-year survivors of cancer in childhood and adolescence: a population-based study in the Nordic countries.

PURPOSE: To assess the risk of death in patients who survive more than 5 years after diagnosis of childhood cancer and to evaluate causes of death in fatal cases. PATIENTS AND METHODS: This was a population-based study in the five Nordic countries (Denmark, Finland, Iceland, Norway, and Sweden) using data of the nationwide cancer registries and the cause-of-death registries. The study cohort included 13,711 patients who were diagnosed with cancer before the age of 20 years between 1960 and 1989 and who survived at least 5 years from diagnosis. By December 31, 1995, 1,422 patients had died, and death certificates were assessed in 1,402. Standardized mortality ratios (SMRs) for validated causes of death were calculated based on 156,046 patient-years at risk. RESULTS: The overall SMR was 10.8 (95% confidence interval [CI], 10.3 to 11.5), mainly due to high excess mortality from the primary cancer. SMR for second cancer was 4.9 (95% CI, 3.9 to 5.9) and was 3.1 (95% CI, 2.8 to 3.5) for noncancer death. The pattern of causes of death varied markedly between different groups of primary cancer diagnoses and was highly dependent on time passed since diagnosis. Overall late mortality was significantly lower in patients treated during the most recent period of time, 1980 to 1989, compared with those treated from 1960 to 1979 (hazard ratio, 0.61; 95% CI, 0.54 to 0.70), and there was no increase in rates of death due to cancer treatment. CONCLUSION: Long-term survivors of childhood cancer had an increased mortality rate, mainly dying from primary cancers. However, modern treatments have reduced late cancer mortality without increasing the rate of therapy-related deaths.

Population-based cancer survival in Singapore, 1968 to 1992: an overview.

The Singapore Cancer Registry has provided comprehensive population-based incidence data since 1968. This paper describes the population-based survival analysis of the registry data. All invasive primary cancers diagnosed from January 1, 1968 to December 31, 1992 were passively followed up until December 31, 1997. Only 5.8% were lost to follow-up. Cumulative and observed survival rates were calculated using Hakulinen's method. Overall 5-year relative survival rates have increased dramatically over the 25-year period in both genders. Significant increases are seen with nasopharynx, stomach and colo-rectum cancers, non-Hodgkin's lymphoma, leukemias and cancers of the testis, cervix, ovaries and breast. When compared with the Surveillance, Epidemiology and End Results (SEER) rates in the United States, the 5-year relative survival rates in Singapore are generally lower. However, the rate of change between the two countries is fairly similar. On the average, the rates are 10 to 15 years behind the SEER rates and 5 to 10 years behind Finland, Switzerland and Japan, but they are close to the UK rates. The age-standardized 5-year survival rate for Singapore is higher for most sites compared with other developing countries like Qidong (China), Madras (India), Bombay (India) and Chiang Mai (Thailand). The 25-year trend in cancer survival in Singapore showed two extreme groups: those showing no change and those showing significant improvements. Reducing the incidence of cancers belonging to the first group remains the only viable mode of cancer control. For cancers in the second group, improvement in survival is due to a combination of successful early detection measures and effective treatment services in Singapore.

Relatives of prostate cancer patients have an increased risk of prostate and stomach cancers: a population-based, cancer registry study in Finland.

OBJECTIVE: 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. METHODS: 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 of > 60 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. RESULTS: 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 diagnosed > or = 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). CONCLUSIONS: 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.

Cancer in patients with ataxia-telangiectasia and in their relatives in the nordic countries.

BACKGROUND: Epidemiologic studies of the families of patients with ataxia-telangiectasia (A-T), a recessive genetic neurologic disorder caused by mutation of the ATM gene, suggest that heterozygous carriers of an ATM mutation are at increased risk of cancer. A population-based study of cancer incidence in A-T families with unbiased selection and tracing of relatives would confirm this hypothesis. METHODS: We conducted a study in the Nordic countries of 1218 blood relatives of 56 A-T patients from 50 families. The relatives were identified from population registries, and the occurrence of cancer was determined from cancer registry files in each country and compared with national incidence rates. All statistical tests were two-sided. RESULTS: Among the 56 patients with A-T, we observed six cases of cancer (four leukemias and two non-Hodgkin's lymphomas) compared with 0.16 expected, yielding a standardized incidence ratio (SIR) of 37 (95% confidence interval [CI] = 13 to 80). Among the 1218 relatives, 150 cancers were recorded, with 126 expected (SIR = 1.19; 95% CI = 1.01 to 1.40). Invasive breast cancer occurred in 21 female relatives of A-T patients (SIR = 1.54; 95% CI = 0.95 to 2.36), including five of the 50 mothers (all of whom are obligate ATM mutation carriers) (SIR = 7.1; 95% CI = 2.3 to 17). Relatives who were less likely to be carriers of a mutant ATM allele had no increase or only a modest, statistically nonsignificant increase in the risk of breast cancer. There was no evidence of increased risk for cancer at any other site. CONCLUSIONS: We confirmed the previously recognized high risk of lymphoma and leukemia in A-T patients. Our data are also consistent with an increased risk of breast cancer among blood relatives of A-T patients. The epidemiologic findings suggest, however, that, even if ATM mutations are responsible for some breast cancer cases, ATM is a relatively weak genetic risk factor for the disease.

Analysis of p53 tumor suppressor gene in families with multiple glioma patients.

The high incidence of gliomas in Li-Fraumeni families and the high frequency of somatic p53 mutations in sporadic glial tumors have raised the possibility that germline p53 mutations could play an important role in familial aggregation of gliomas. In the present study, 18 families with two or more gliomas were screened for germline p53 mutation. The families were identified through questionnaires sent to 369 consecutive glioma patients operated at Tampere University Hospital during 1983-1994. In these families, a family history of cancer was verified through the Finnish Cancer Registry. Interestingly, the questionnaires reveled only 15 of 57 cancers (index gliomas excluded) retrieved through the Cancer Registry. None of the 18 families fufilled the criteria for classic Li-Fraumeni syndrome. Immunostaining analysis of p53 protein accumulation suggested that alterations of the p53 gene are as common in familial as in sporadic gliomas. Sequencing analysis of exons 4-10 of the p53 gene revealed no germline mutations in any of the 18 families. Thus, although occasional glioma families carrying germline p53 mutations have been identified in earlier studies, systematic evaluation of familial glioma patients suggests that the p53 gene is not a common susceptibility gene in case of familial gliomas. The p53 tumor suppressor gene seems to have a similar role in the tumorigenesis of most familial and sporadic gliomas.