Evidence of space-time clustering of childhood acute lymphoblastic leukaemia in Sweden

We have examined 645 recorded cases of childhood acute lymphatic leukaemia (ALL) in Sweden during 1973-89 to identify space-time clustering by using the close-pair method of Knox. The records included date of birth and of diagnosis as well as addresses at birth and at diagnosis. There was a significant excess of case pairs close in date of birth and place of birth in the 5- to 15-year age group.     

Primary brain tumors following traumatic brain injury--a population-based cohort study in Sweden

Objectives: The aim of this study was to explore the association between traumatic brain injury and brain tumor development. Methods: A cohort of patients hospitalized for traumatic brain injury during 1965–1994 was compiled using the Swedish Inpatient Register. Complete follow-up through 1995 was attained through record linkage with the Swedish Cancer Register, the Cause of Death Register, and the Emigration Register. Standardized incidence ratios (SIRs), defined as the ratios of the observed to the expected numbers of brain tumors, were used as the measure of relative risk. The expected number of brain tumors was calculated by multiplying the observed person-time by age-, gender- and calendar year-specific incidence-rates derived from the general Swedish population. Results: The cohort included 311,006 patients contributing 3,225,317 person-years. A total of 281 cases of brain tumors were diagnosed during follow-up. No associations were found between traumatic brain injury and the risk of primary brain tumors, neither overall (SIR: 1.0; 95% confidence interval (CI): 0.9–1.2), nor in analyses broken down by main groups of brain tumors. Stratified analyses according to age at entry into the cohort, year of follow-up, and severity of the brain injury all showed essentially the same null results. Conclusion: No association between traumatic head injury and primary brain tumors has been found.     

Global increases in kidney cancer incidence, 1973-1992.

Reports of increasing rates for kidney cancers in several count prompted this analysis of global incidence trends for total kidney cancers and by subsite. International incidence data for 5-year periods 1973-1977, 1978-1982, 1983-1987 and 1988-1992 were obtained from volumes IV to VII of Cancer Incidence in Five Continents published by the International Agency for Research on Cancer. The USA data for the same 5-year periods were obtained from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute. Percentage changes in incidence rates were computed using the relative difference between the time periods 1973-1977 and 1988-1992, and annual percentage changes in incidence rates were computed using log linear regression. In 1988-1992, kidney cancer incidence rates (age-adjusted to the world-standard population) were highest in France (16.1/100,000 man-years and 7.3/100,000 woman-years) and lowest in India (2.0 and 0.9, respectively). Between 1973-1977 and 1988-1992, incidence rates rose among men and women in all regions and ethnic groups, with a few exceptions, mostly in Scandinavian countries. The largest percentage increase for men was in Japan (171%) and for women in Italy (107%). Rates for renal pelvis cancer were less than 1/100,000 person-years in almost all regions in both sexes, and the temporal trends were inconsistent. Incidence trends for renal parenchyma cancer tracked those for total kidney cancers, and appeared to result from increases in the prevalence of risk factors and in use of diagnostic imaging procedures.     

Reproductive factors and the risk of brain tumors: A population-based study in Sweden

Possible associations between childbearing and the risk of brain cancer were explored in a case-control study “nested” within a large nationwide cohort defined by the Swedish Fertility Registry. Among women born between 1925–1975, 1,088 patients with meningiomas and 1,657 patients with gliomas were identified in the Swedish Cancer Registry. For every woman diagnosed with brain tumor, 5 age-matched controls were selected among those in the Fertility Registry. Relative risks were estimated by odds ratios from conditional logistic regression. Ever-parous women were at a reduced risk of glioma compared to nulliparous women, while parity was unrelated to meningioma risk. Age at first birth was unrelated to both meningioma and glioma risk. The gradient in risk between ever-parous and nulliparous women for gliomas, but not meningiomas, is difficult to explain biologically. A possible explanation is that pregnancy-induced alterations in androgen levels reduce the risk of glioma in parous women. Alternatively, childlessness may represent a marker of an occult glioma, negatively affecting fecundity. Overall, our present results do not support the notion that hormonal changes, or other physiological changes induced by childbearing, play an important role in the development of brain tumors. Int. J. Cancer 72:389–393, 1997. © 1997 Wiley-Liss, Inc.     

Incidence of childhood tumors in Shanghai, 1973-77

Data of the Shangai Tumor Registry were analyzed for incidence of cancer in children under 15 years of age, 1973-77. The incidence of all malignant neoplasms combined was 104.7 per million boys and 89.2 per million girls. Leukemia, brain tumors, and lymphomas comprised 70% of all childhood tumors in Shangai. Compared with U.S. whites, Shangai children had higher rates of myeloid leukemia and liver cancer and lower rates of lymphoid cancers and tumors of the kidney, eye, soft tissue, and testis. Effects of migration on tumor rates among Chinese children are largely unknown and merit additional study.     

Increasing incidence of non-Hodgkin's lymphomas in Sweden 1958-1992

In recent years, there have been many reports from Europe and North-America describing non-Hodgkin's-lymphoma (NHL) as one of the most rapidly increasing malignancies. The reasons for this are poorly understood. This study describes the incidence pattern of NHL in Sweden during 1958-1992. A total of 26,925 cases (14,854 males and 12 071 females aged 15 years or older reported to the Swedish Cancer Registry between 1958 and 1992 were analysed. The increase in the age-adjusted incidence during this period was 433% among men and 386% among women, a mean yearly increase of 3.6% in men and 2.9% in women. The highest rates were seen during the most recent years and in the oldest age group, although there was a clear trend with increased age-adjusted incidence over time in both the male and the female groups in ages over 35. The incidence was low in the ages below 35 years. Known etiologic factors including viruses, environmental exposures and immunosuppression of different types are discussed. It is concluded that there has been a true increase in the age-adjusted incidence of non-Hodgkin's lymphomas in Sweden during the years 1958-1992.     

Increasing incidence rates of childhood malignant diseases in Sweden during the period 1960-1998

We analysed the trends in incidence rates of childhood cancer in Sweden. All cases of malignant diseases and benign brain tumours in children, 0-14 years old, reported to the Swedish Cancer Registry 1960 to 1998 were included, n=9298. Cases were classified according to the International Classification of Childhood Cancer. Average annual change in incidence rate was calculated to +1.01%, (95% confidence interval CI=0.80, 1.22). An increase in incidence rate per year was found for leukaemia, +0.85% (95% CI=0.42, 1.28), lymphomas +1.87% (95% CI=1.17, 2.58), CNS (central nervous system) tumours +1.45% (95% CI=1.02, 1.88), sympathetic nervous system tumours +1.61% (95% CI=0.79, 2.44), hepatic tumours +2.62% (95% CI=2.02, 3.21), and germ cell and gonadal tumours +1.21% (95% CI=0.23, 2.19). Of the CNS tumours, significant changes were seen for low-grade glioma/astrocytoma +2.10% (95% CI=1.41, 2.80), benign brain tumours +3.77% (95% CI=2.47, 5.10), and PNET/medulloblastoma +1.96% (95% CI=0.48, 3.46). Changes in diagnostic criteria and better diagnostic tools may have contributed to these results.     

Development in incidence of breast cancer in non-screened Danish women, 1973-2002--a population-based study

The authors report on the incidence rates of breast cancer overall and by histology in a population of unscreened women constituting approximately 80% of the total population of women in Denmark from 1973-2002, utilizing the files of the nationwide Danish Cancer Registry. The age-specific incidence rates of breast cancer increased throughout the period, and further, marked changes in the age-specific incidence pattern were observed, where the plateau and change of slope around the age of 46-48 in 1973-1981 shifted to around age 64-66 years in 1994-2002. Age-period-cohort modeling indicated that these changes were not attributable to a birth cohort effect. Although lobular breast cancer incidence increased more than ductal breast cancer incidence, this was only observed in the first decade after the introduction of the ICD-O system in Denmark and probably is attributable to this, whereas we observed no disproportionate changes by histology in any age group from 1988-2002. Thus, previous reports of a disproportionate increase in lobular breast cancer could not be confirmed in a non-screened population, whereas important changes over the past decade in the age-specific incidence pattern of breast cancer particular around the time of menopause were indicated.     

Incidence and survival of brain tumors: a population-based study

Since 1976 the Lombardy Cancer Registry (RTL) has recorded all malignant tumors and the benign tumors of the nervous system, bladder and liver occurring in the Varese province. The aims of this report are: to describe age-specific incidence rates of the different oncotypes of primary nervous system tumors (PNSTs) and to analyze the duration of survival of the patients according to the histotype of the neoplasm. From 1976 to 1981, the RTL recorded 498 PNST: 213 tumors of glial origin, 132 tumors of mesodermal tissues, 15 tumors of multipotential cell origin, 37 tumors of nerve roots, 8 of vascular origin, and 54 PNST in which the histotype was not specified. For tumors of glial origin, the 60-69 year age class showed the highest incidence rate: 16 per 100,000/year. The incidence rate of tumors of mesodermal tissues reached the maximum value of 7.9 per 100,000/year in the age group of 75 years and over. Tumors of multipotential cell origin had a maximum incidence of 2.2 in the 60-69 year age class. The probability of survival at 5 years after diagnosis was computed by the method of Kaplan and Meier, and the log rank procedure was used to test statistical differences among survivors. Tumors of glial origin, excluding ependymomas and papillomas of choroid plexus, had a 5-year survival probability of 14%. Age (categorized in less than or equal to 50 and greater than 50 years) and histologic grade (grades I + II and grades III + IV) were analyzed as prognostic factors for tumors of glial origin: a younger age was the most predictive prognostic factor in grade I + II tumors (probability of survival = 53% in the group less than or equal to 50 years vs 0 in the group greater than 50 years; p less than 0.005). In the less differentiated tumors there were no differences between the two age groups. Patients with tumors of mesodermal tissues had a 5-year probability of survival of 83%. Subjects younger than 50 years had a probability of survival of 95%, whereas older patients had a probability of 79%. For the other oncotypes, the 5-year survival probability was: 50% for tumors of multipotential cell origin, 63% for ependymomas and papillomas of the choroid plexus, 64% for tumors of vascular derivation, and 21% for PNST with not specified histotype.     

Little or no space-time clustering found amongst cases of childhood lymphoma in North West England

We have examined space-time clustering amongst cases of lymphoma in children, aged 0-14 years, using population-based data from the North West of England for the period 1954-2001. There was little or no evidence for space-time clustering amongst all the lymphomas or amongst those sub-groups identified in advance.     

Gastrointestinal stromal tumors in Iceland, 1990-2003: the icelandic GIST study, a population-based incidence and pathologic risk stratification study

Gastrointestinal stromal tumor (GIST) is a newly defined clinical and pathologic entity. This study examines the whole population-based incidence of GIST as well as pathologic risk stratification schemes. All patients diagnosed in Iceland with a gastrointestinal mesenchymal tumor over the years 1990-2003 were evaluated with an immunohistochemical panel including staining for c-kit. The age-adjusted incidence of GIST was calculated. Size, mitotic rate per 50 HPF and various other pathologic parameters were evaluated. Each tumor was categorized into 1 of 4 recently defined NIH risk stratification categories. Fifty-seven of the mesenchymal gastrointestinal tumors were positive for c-kit and therefore categorized as GIST. The annual incidence for the study period is 1.1 per 100,000. The median age of patients was 65.8 years and median tumor size was 4.6 cm. Only 2 of 35 gastric tumors fall into the NIH high-risk category while half of the nongastric tumors (11 of 22) fall into this high-risk category. Eight of the 57 tumors (14%) metastasized, 7 of which were nongastric. The positive predictive value for malignant behavior of the high-risk category is 46%. The negative predictive value of low- and very-low-risk NIH category is 100%. Pathologic predictors of malignant behavior are tumor size, mitotic rate, mucosal disruption, necrosis and high cellularity. Nongastric GISTs are clearly at much higher risk of a malignant behavior than gastric GISTs. This population-based GIST study estimates the incidence of GISTs at 1.1 per 100,000 and furthermore supports the NIH consensus categories for the prediction of malignant behavior of GISTs.     

Gastrointestinal stromal tumors: the incidence, prevalence, clinical course, and prognostication in the preimatinib mesylate era--a population-based study in western Sweden

BACKGROUND: Recent breakthroughs regarding gastrointestinal stromal tumors (GIST) and their pathogenesis have redefined diagnostic criteria and have led to the development of molecularly targeted drug therapy. New treatment options mandate more accurate information regarding the incidence, prevalence, clinical behavior, and prognostic factors of GIST. METHODS: All patients (n=1460) who potentially had GIST diagnosed from 1983 to 2000 in western Sweden (population, 1.3-1.6 million) were reviewed, and 288 patients with primary GIST were identified. The incidence and prevalence of GIST were determined, and predictive prognostic factors, including current risk-group stratifications, were analyzed statistically. RESULTS: Ninety percent of GISTs were detected clinically due to symptoms (69%) or were incidental findings at surgery (21%); the remaining 10% of GISTs were found at autopsy. Forty-four percent of symptomatic, clinically detected GISTs were categorized as high risk (29%) or overtly malignant (15%), with tumor-related deaths occurring in 63% of patients and 83% of patients, respectively (estimated median survival, of 40 months and 16 months, respectively). Tumor-related deaths occurred in only 2 of 170 of patients (1.2%) with very-low-risk, low-risk, or intermediate-risk tumors. The annual incidence of GIST was 14.5 per million. The prevalence of all GIST risk groups was 129 per million (31 per million for the high-risk group and the overtly malignant group). CONCLUSIONS: GIST has been under recognized: Its incidence, prevalence, and clinical aggressiveness also have been underestimated. Currently existing risk-group stratification systems based on tumor size and mitotic rate delineate GIST patients who have a poor prognosis. Prognostication in patients with GIST can be refined using a proposed risk score based solely on tumor size and proliferative index.     

Cutaneous lymphoma in Israel, 1985-1993: a population-based incidence study.

The incidence rate of cutaneous lymphomas (CL) [including mycosis fungoides (MF) and non-mycosis fungoides (non-MF)] for the period 1985-93 in Israel was determined using data from the population-based Cancer Registry supplemented by a field survey that covered approximately 80% of lymphoma cases. After the field survey, corrected rates were 49% and 24% higher for MF and non-MF respectively (37% for CL overall). The age-adjusted incidence rates per 100,000 were 1.18 and 0.63 for Jewish men and women respectively. MF rates (0.77 in men and 0.35 in women) were higher than non-MF (0.41 and 0.28 respectively). Rates of CL were significantly lower in non-Jews. There were no significant differences in incidence among Jewish ethnic subgroups. However, the lack of variability in the incidence of these neoplasms among subpopulations is in contrast with findings for cutaneous malignant melanoma; the observed high rates of CL could, nonetheless, be consistent with the sunlight exposure hypothesis, operating perhaps through a different mechanism.     

Lower incidence rates but thicker melanomas in Eastern Europe before 1992: a comparison with Western Europe

The objective of this study was to investigate the epidemiology of melanoma across Europe with regard to Breslow thickness and body-site distribution. Incidence data from Cancer Incidence in 5 Continents and the EUROCARE-melanoma database were used: 28?117 melanoma cases from 20 cancer registries in 12 European countries, diagnosed between 1978 and 1992. Regression analysis and general linear modelling were used to analyse the data. Melanomas in Eastern Europe were on average 1.4 mm thicker (P<0.05) than in Western Europe and appeared more often on the trunk. From 1978 to 1992, their Breslow thickness had decreased in Western but not Eastern Europe. There was a latitude gradient in incidence, with highest rates in southern regions in Eastern Europe and an inverse gradient in Western Europe, with highest rates in the North. Mortality:incidence ratios were less favourable in southern parts across Europe, especially in Eastern Europe. If Eastern European populations copy the sunbathing behaviour of the West it is likely that in the near future a higher melanoma incidence can be expected there.     

Cancer incidence in patients with type 1 diabetes mellitus: a population-based cohort study in Sweden

Although patients with type 2 diabetes have elevated risks of liver, pancreatic, kidney, and endometrial cancer, little is known about the risk of cancer for patients with type 1 diabetes. We conducted a cohort study to examine cancer incidence among 29 187 patients in Sweden who were hospitalized for type 1 diabetes from 1965 through 1999. Relative risks of cancer were estimated by age-, sex- and calendar year of follow-up--adjusted standardized incidence ratios (SIRs), using data for the entire Swedish population as a reference. After excluding cancers diagnosed during the first year after hospital discharge, we observed 355 incident cases of cancer, which corresponded to a 20% increase in overall cancer incidence among type 1 diabetes patients (SIR = 1.2, 95% confidence interval [CI] = 1.0 to 1.3). Patients with type 1 diabetes had elevated risks of cancers of the stomach (SIR = 2.3, 95% CI = 1.1 to 4.1), cervix (SIR = 1.6, 95% CI = 1.1 to 2.2), and endometrium (SIR = 2.7, 95% CI = 1.4 to 4.7). Type 1 diabetes is associated with a modest excess cancer risk overall and risks of specific cancers that differ from those associated with type 2 diabetes.     

A comparative population-based study of prostate cancer incidence and mortality rates in Singapore, Sweden and Geneva, Switzerland from 1968 to 2006

ABSTRACT: BACKGROUND: Prostate cancer is the most commonly diagnosed malignancy in men in Sweden and Geneva, and the third most common in men in Singapore. This population-based study describes trends in the incidence and mortality rates of prostate cancer in Singapore, Sweden and Geneva (Switzerland) from 1973 to 2006 and explores possible explanations for these different trends. METHODS: Data from patients diagnosed with prostate cancer were extracted from national cancer registries in Singapore (n?=?5,172), Sweden (n?=?188,783) and Geneva (n?=?5,755) from 1973 to 2006. Trends of incidence and mortality were reported using the Poisson and negative binomial regression models. The age, period and birth-cohort were tested as predictors of incidence and mortality rates of prostate cancer. RESULTS: Incidence rates of prostate cancer increased over all time periods for all three populations. Based on the age-period-cohort analysis, older age and later period of diagnosis were associated with a higher incidence of prostate cancer, whereas older age and earlier period were associated with higher mortality rates for prostate cancer in all three countries. CONCLUSIONS: This study demonstrated an overall increase in incidence rates and decrease in mortality rates in Singapore, Sweden and Geneva. Both incidence and mortality rates were much lower in Singapore. The period effect is a stronger predictor of incidence and mortality of prostate cancer than the birth-cohort effect.