Level of education and the risk of lymphoma in the European prospective investigation into cancer and nutrition

INTRODUCTION

Lymphomas belong to the few cancer sites with increasing incidence over past decades, and only a few risk factors have been established. We explored the association between education and the incidence of lymphoma in the prospective EPIC study.

MATERIALS AND METHODS

Within 3,567,410 person-years of follow-up, 1,319 lymphoma cases [1,253 non-Hodgkin lymphomas (NHL) and 66 Hodgkin lymphomas (HL)] were identified. Cox proportional hazard regression was used to examine the association between highest educational level (primary school or less, technical/professional school, secondary school, university) and lymphoma risk.

RESULTS

Overall, no consistent associations between educational level and lymphoma risk were observed; however, associations were found for sub-groups of the cohort. We observed a higher risk of B-NHL (HR = 1.31, 95% CI = 1.02–1.68; n = 583) in women with the highest education level (university) but not in men. Concerning sub-classes of B-NHL, a positive association between education and risk of B cell chronic lymphatic leukaemia (BCLL) was observed only in women. In both genders, the risk of diffuse large B cell lymphoma (DLBCL) was significantly lower for subjects with university degree (HR = 0.46, 95% CI = 0.27–0.79) versus lowest educational level. No association was found for HL.

CONCLUSION

We could not confirm an overall consistent association of education and risk of HL or NHL in this large prospective study; although, education was positively related to the incidence of BCLL and B-NHL (in women) but inversely to incidence of DLBCL. Due to limited number of cases in sub-classes and the large number of comparisons, the possibility of chance findings can not be excluded.

Occupation and risk of lymphoma: a multicentre prospective cohort study (EPIC)

OBJECTIVES

Evidence suggests that certain occupations and related exposures may increase the risk of malignant lymphoma. Farming, printing and paper industry, wood processing, meat handling and processing, welding, shoe and leather manufacturing and teaching profession are among the categories that have been implicated in previous studies. The relationship between occupation and malignant lymphoma has been investigated in a large European prospective study.

METHODS

We investigated occupational risks for lymphomas in the European Prospective Investigation into Cancer and Nutrition (EPIC). The mean follow-up time for 348,555 subjects was 9 years (SD: 2 years). The analysis was based on 866 and 48 newly diagnosed cases of non-Hodgkin's lymphoma (NHL) and Hodgkin's lymphoma (HL). These were identified in the EPIC subcohorts with occupational data. Data on 52 occupations were collected through standardised questionnaires. Cox proportional hazard models were used to explore the association between occupation and risk of malignant lymphoma.

RESULTS

The following occupations were positively associated with malignant NHL after adjustment for study centre, age, sex, socioeconomic status (SES), smoking and alcohol: butchers (HR=1.53, 95% CI 1.05 to 2.48, including multiple myeloma/plasmacytoma; HR=1.30, 95% CI 1.00 to 2.66, excluding multiple myeloma/plasmacytoma) and car repair workers (HR=1.50, 95% CI 1.01 to 2.00, including multiple myeloma/plasmacytoma; HR=1.51, 95% CI 1.01 to 2.31, excluding multiple myeloma/plasmacytoma). HL was associated with gasoline station occupation (HR=4.59, 95% CI 1.08 to 19.6).

CONCLUSION

The findings in this current study of a higher risk of NHL among car repair workers and butchers and a higher risk of HL among gasoline station workers suggest a possible role from occupationally related exposures, such as solvents and zoonotic viruses, as risk factors for malignant lymphoma.

Evaluation of a candidate breast cancer associated SNP in ERCC4 as a risk modifier in BRCA1 and BRCA2 mutation carriers. Results from the Consortium of Investigators of Modifiers of BRCA1/BRCA2 (CIMBA)

Background:

In this study we aimed to evaluate the role of a SNP in intron 1 of the ERCC4 gene (rs744154), previously reported to be associated with a reduced risk of breast cancer in the general population, as a breast cancer risk modifier in BRCA1 and BRCA2 mutation carriers.

Methods:

We have genotyped rs744154 in 9408 BRCA1 and 5632 BRCA2 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and assessed its association with breast cancer risk using a retrospective weighted cohort approach.

Results:

We found no evidence of association with breast cancer risk for BRCA1 (per-allele HR: 0.98, 95% CI: 0.93–1.04, P=0.5) or BRCA2 (per-allele HR: 0.97, 95% CI: 0.89–1.06, P=0.5) mutation carriers.

Conclusion:

This SNP is not a significant modifier of breast cancer risk for mutation carriers, though weak associations cannot be ruled out.

Genetic variants in association studies--review of strengths and weaknesses in study design and current knowledge of impact on cancer risk

Sequencing of the human genome has recently been completed and mapping of the complete genomic variation is ongoing. During the last decade there has been a huge expansion of studies of genetic variants, both with respect to association studies of disease risk and for studies of genetic factors of prognosis and treatments response, i.e., pharmacogenomics. The use of genetics to predict a patient's risk of disease or treatment response is one step toward an improved personalised prevention and screening modality for the prevention of cancer and treatment selection. The technology and statistical methods for completing whole genome tagging of variants and genome wide association studies has developed rapidly over the last decade. After identifying the genetic loci with the strongest, statistical associations with disease risk, future studies will need to further characterise the genotype-phenotype relationship to provide a biological basis for prevention and treatment decisions according to genetic profile. This review discusses some of the general issues and problems of study design; we also discuss challenges in conducting valid association studies in rare cancers such as paediatric brain tumours, where there is support for genetic susceptibility but difficulties in assembling large sample sizes. The clinical interpretation and implementation of genetic association studies with respect to disease risk and treatment is not yet well defined and remains an important area of future research.

MNS16A minisatellite genotypes in relation to risk of glioma and meningioma and to glioblastoma outcome

The human telomerase reverse transcriptase (hTERT) gene is upregulated in a majority of malignant tumours. A variable tandem repeat, MNS16A, has been reported to be of functional significance for hTERT expression. Published data on the clinical relevance of MNS16A variants in brain tumours have been contradictory. The present population-based study in the Nordic countries and the United Kingdom evaluated brain-tumour risk and survival in relation to MNS16A minisatellite variants in 648 glioma cases, 473 meningioma cases and 1,359 age, sex and geographically matched controls. By PCR-based genotyping all study subjects with fragments of 240 or 271 bp were judged as having short (S) alleles and subjects with 299 or 331 bp fragments as having long (L) alleles. Relative risk of glioma or meningioma was estimated with logistic regression adjusting for age, sex and country. Overall survival was analysed using Kaplan-Meier estimates and equality of survival distributions using the log-rank test and Cox proportional hazard ratios. The MNS16A genotype was not associated with risk of occurrence of glioma, glioblastoma (GBM) or meningioma. For GBM there were median survivals of 15.3, 11.0 and 10.7 months for the LL, LS and SS genotypes, respectively; the hazard ratio for having the LS genotype compared with the LL was significantly increased HR 2.44 (1.56-3.82) and having the SS genotype versus the LL was nonsignificantly increased HR 1.46 (0.81-2.61). When comparing the LL versus having one of the potentially functional variants LS and SS, the HR was 2.10 (1.41-3.1). However, functionality was not supported as there was no trend towards increasing HR with number of S alleles. Collected data from our and previous studies regarding both risk and survival for the MNS16A genotypes are contradictory and warrant further investigations.

Pre-emptive treatment with rituximab of molecular relapse after autologous stem cell transplantation in mantle cell lymphoma

PURPOSE

Minimal residual disease (MRD) is predictive of clinical progression in mantle-cell lymphoma (MCL). According to the Nordic MCL-2 protocol we prospectively analyzed the efficacy of pre-emptive treatment using rituximab to MCL patients in molecular relapse after autologous stem cell transplantation (ASCT).

PATIENTS AND MATERIALS

MCL patients enrolled onto the study, who had polymerase chain reaction (PCR) detectable molecular markers and underwent ASCT, were followed with serial PCR assessments of MRD in consecutive bone marrow and peripheral blood samples after ASCT. In case of molecular relapse with increasing MRD levels, patients were offered pre-emptive treatment with rituximab 375 mg/m(2) weekly for 4 weeks.

RESULTS

Of 160 MCL patients enrolled, 145 underwent ASCT, of whom 78 had a molecular marker. Of these, 74 were in complete remission (CR) and four had progressive disease after ASCT. Of the CR patients, 36 underwent a molecular relapse up to 6 years (mean, 18.5 months) after ASCT. Ten patients did not receive pre-emptive treatment mainly due to a simultaneous molecular and clinical relapse, while 26 patients underwent pre-emptive treatment leading to reinduction of molecular remission in 92%. Median molecular and clinical relapse-free survival after pre-emptive treatment were 1.5 and 3.7 years, respectively. Of the 38 patients who remain in molecular remission for now for a median of 3.3 years (range, 0.4 to 6.6 years), 33 are still in clinical CR.

CONCLUSION

Molecular relapse may occur many years after ASCT in MCL, and PCR based pre-emptive treatment using rituximab is feasible, reinduce molecular remission, and may prevent clinical relapse.

A case for the worldwide collection of primary benign brain tumors

BACKGROUND

Incidence data on malignant tumors are reported by the International Agency for Research on Cancer, with 189,485 new malignant brain tumors globally in 2002. However, collection and reporting of benign brain tumors are not universal. The objective here is to encourage the collection of primary benign brain tumors worldwide.

METHODS

Worldwide numbers of primary benign brain tumors were estimated through published articles and cancer registry reports presenting directly or indirectly reported benign incidence rates or frequencies for regions or countries.

RESULTS

An estimated 186,678 benign brain tumors were diagnosed worldwide in 2002. The estimated numbers of benign brain tumors were higher in females than males (105,918 vs. 80,759). Since many countries do not report primary benign brain tumors, the incidence rate estimates vary significantly by region.

CONCLUSIONS

This is the first survey to assess worldwide numbers of benign brain tumors. Under-reporting, non-standardized collection, lack of age-adjustment, and other causes of the varying incidence rates must be considered. However, the estimated number of benign brain tumors approximately equals, and could exceed, the number of malignant brain tumors globally. Registration of primary benign brain histologies in different geographical areas and ethnicities could provide clues to the underlying causes of these tumors.

ErbB 1-4 expression alterations in primary colorectal cancers and their corresponding metastases

BACKGROUND

EGFR (epidermal growth factor receptor) targeted therapies are important new tools in colorectal cancer treatment. EGFR analysis of the primary tumour was previously recommended to identify patients who will benefit from the EGFR targeted therapy. Previous studies have displayed diverging results regarding the expression of EGFR in the primary tumour compared to the metastases. The present study was performed to investigate whether EGFR and ErbB2-4 expression differed between 64 primary tumours and their corresponding metastases.

PATIENTS AND METHODS

EGFR and ErbB2-4 expression were analysed in the primary tumour and in the corresponding metastases using immunohistochemistry (IHC).

RESULTS

In 49/64 samples (76%), the primary tumours were EGFR positive; in 33% (16/49) of EGFR positive samples, the tumours lost the EGFR expression in the metastasis compared to the primary tumour. From the primary tumours, 15/64 (23%) were negative and 5 of these (33%) developed EGFR expression in the metastasis. ErbB2, ErbB3, and ErbB4 expression was evident in 54%, 67%, and 81%, respectively. There was no significant difference between ErbB2, ErbB3, and ErbB4 expression in primary tumours and metastases. The co-expression of the ErbB family members was also analysed, with a significant increase of ErbB3/ErbB4 co-expression in late stage tumours.

CONCLUSION

The EGFR expression was lost in 33% of metastasising primary colorectal cancer tumours, a finding that agrees with at least one previous study. Thus, the present results clearly implicate the need for EGFR analysis of both the primary tumour and metastases to accurately determine EGFR status when considering the use of EGFR targeted therapies.

Tumor-associated epilepsy and glioma: are there common genetic pathways?

BACKGROUND

Patients with glioma exhibit a great variability in clinical symptoms apart from variations in response to therapy and survival. Many patients present with epileptic seizures at disease onset, especially in case of low-grade gliomas, but not all have seizures. A large proportion of patients develop refractory seizures. It is likely that the variability in epileptic symptoms cannot exclusively be explained by tumor-related factors, but rather reflects complex interaction between tumor-related, environmental and hereditary factors.

MATERIAL AND METHODS

No data exist on susceptibility genes associated with epileptic symptoms in patients with glioma. However, an increasing number of candidate genes have been proposed for other focal epilepsies such as temporal lobe epilepsy. Some of the susceptibility candidate genes associated with focal epilepsy may contribute to epileptic symptoms also in patients with glioma.

RESULTS

This review presents an update on studies on genetic polymorphisms and focal epilepsy and brings forward putative candidate genes for tumor-associated epilepsy, based on the assumption that common etiological pathways may exist for glioma development and glioma-associated seizures. Conclusion. Genes involved in the immune response, in synaptic transmission and in cell cycle control are discussed that may play a role in the pathogenesis of tumor growth as well as epileptic symptoms in patients with gliomas.

XRCC1 and XRCC3 variants and risk of glioma and meningioma

Several single nucleotide polymorphisms (SNPs) affecting DNA repair capacity and modifying cancer susceptibility have been described. We evaluated the association of SNPs Arg194Trp, Arg280His, and Arg399Gln in the X-ray cross-complementing group 1 (XRCC1) and Thr241Met in the X-ray cross-complementing group 3 (XRCC3) DNA repair genes with the risk of brain tumors. The Caucasian study population consisted of 701 glioma (including 320 glioblastoma) cases, 524 meningioma cases, and 1,560 controls in a prospective population-based case-control study conducted in Denmark, Finland, Sweden, and the UK. The studied SNPs were not significantly associated with the risk of brain tumors. The highest odds ratios (ORs) for the associations were observed between the homozygous variant genotype XRCC1 Gln399Gln and the risk of glioma (OR = 1.32; 95% confidence interval, CI, 0.97-1.81), glioblastoma (OR = 1.48; 95% CI, 0.98-2.24), and meningioma (OR = 1.34; 95% CI, 0.96-1.86). However, in pair-wise comparisons a few SNP combinations were associated with the risk of brain tumors: Among others, carriers of both homozygous variant genotypes, i.e., XRCC1 Gln399Gln and XRCC3 Met241Met, were associated with a three-fold increased risk of glioma (OR = 3.18; 95% CI, 1.26-8.04) and meningioma (OR = 2.99; 95% CI, 1.16-7.72). In conclusion, no significant association with brain tumors was found for any of the polymorphisms, when examined one by one. Our results indicated possible associations between combinations of XRCC1 and XRCC3 SNPs and the risk of brain tumors.

Brain tumor epidemiology: consensus from the Brain Tumor Epidemiology Consortium

Epidemiologists in the Brain Tumor Epidemiology Consortium (BTEC) have prioritized areas for further research. Although many risk factors have been examined over the past several decades, there are few consistent findings, possibly because of small sample sizes in individual studies and differences between studies in patients, tumor types, and methods of classification. Individual studies generally have lacked samples of sufficient size to examine interactions. A major priority based on available evidence and technologies includes expanding research in genetics and molecular epidemiology of brain tumors. BTEC has taken an active role in promoting understudied groups, such as pediatric brain tumors; the etiology of rare glioma subtypes, such as oligodendroglioma; and meningioma, which, although it is not uncommon, has only recently been registered systematically in the United States. There also is a pressing need for more researchers, especially junior investigators, to study brain tumor epidemiology. However, relatively poor funding for brain tumor research has made it difficult to encourage careers in this area. In this report, BTEC epidemiologists reviewed the group's consensus on the current state of scientific findings, and they present a consensus on research priorities to identify which important areas the science should move to address.

Functional polymorphisms in folate metabolism genes influence the risk of meningioma and glioma

Folate metabolism plays an important role in carcinogenesis. To test the hypothesis that polymorphic variation in the folate metabolism genes 5,10-methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTRR), and methionine synthase reductase (MTR) influences the risk of primary brain tumors, we genotyped 1,005 glioma cases, 631 meningioma cases, and 1,101 controls for the MTHFR C677A and A1298C, MTRR A66G, and MTR A2756G variants. MTHFR C677T-A1298C diplotypes were associated with risk of meningioma (P = 0.002) and glioma (P = 0.02); risks were increased with genotypes associated with reduced MTHFR activity. The highest risk of meningioma was associated with heterozygosity for both MTHFR variants [odds ratio (OR), 2.11; 95% confidence interval (95% CI), 1.42-3.12]. The corresponding OR for glioma was 1.23 (95% CI, 0.91-1.66). A significant association between risk of meningioma and homozygosity for MTRR 66G was also observed (OR, 1.41; 95% CI, 1.02-1.94). Our findings provide support for the role of folate metabolism in the development of primary brain tumors. In particular, genotypes associated with increased 5,10-methylenetetrahydrofolate levels are associated with elevated risk.

The common D302H variant of CASP8 is associated with risk of glioma

Caspase 8 (CASP8) is a key regulator of apoptosis or programmed cell death, and, hence, a defense against cancer. We tested the hypothesis that the CASP8 polymorphism D302H influences risk of glioma through analysis of five series of glioma case patients and controls (n = 1,005 and 1,011, respectively). Carrier status for the rare allele of D302H was associated with a 1.37-fold increased risk (95% confidence interval, 1.10-1.70; P = 0.004). The association of CASP8 D302H with glioma risk indicates the importance of inherited variation in the apoptosis pathway in susceptibility to this form of primary brain tumor.

Aggregation of cancer in first-degree relatives of patients with glioma

BACKGROUND

Previous studies have been inconclusive in estimating the risk of different cancer sites among close relatives of glioma patients; however, malignant melanoma has consistently been described.

METHODS

We obtained family history information from 1,476 glioma patients under age 75 years who registered at M. D. Anderson Cancer Center between June 1992 and June 2006. The number of observed cancers (N=1,001) among 8,746 first-degree relatives (FDR) was compared with the number expected from age-, sex-, and calendar year-specific rates from the Surveillance, Epidemiology, and End Results Program using standardized incidence ratios (SIR).

RESULTS

The overall SIR for any cancer was 1.21 (95% confidence interval, 1.14-1.29). Among FDRs under 45 years the overall SIR was 5.08, and for relatives >45 years the overall SIR was 0.95. The SIRs were significantly elevated for brain tumors (2.14), melanoma (2.02), and sarcoma (3.83). We observed an excess of pancreatic cancer, which was significantly higher only among mothers.

CONCLUSION

We observed an overall 21% increase in cancer among the FDRs of glioma patients including excess cases of brain tumors and melanoma, which could point to similar genetic contributions to these two malignancies. A large international linkage study is under way to examine potential genomic regions important for familial glioma.

An international case-control study of interleukin-4Ralpha, interleukin-13, and cyclooxygenase-2 polymorphisms and glioblastoma risk

Previous studies found that allergies are inversely related to risk of glioma. In an earlier publication, using data from a Swedish case-control study, Schwartzbaum et al. report an inverse relation between risk of glioblastoma and four single nucleotide polymorphisms (SNP) on two genes [interleukin (IL)-4Ralpha, IL-13] that are associated with allergies. In addition, recent studies suggest that IL-4 and IL-13 induce cyclooxygenase-2 (COX-2) to resolve brain inflammation. To see whether previous Swedish results (110 cases, 430 controls) would be replicated, we estimated the association between glioblastoma and two IL-4Ralpha (rs1805015, rs1801275) and two IL-13 (rs20541, rs1800925) SNPs and their haplotypes and one COX-2 SNP (-765GC) using additional English, Danish, and Finnish data (217 cases, 1,171 controls). Among general population controls, we evaluated associations between these haplotypes, the COX-2 SNP, and self-reported allergies. Our data did not support our original observations relating individual IL-4Ralpha, IL-13, or COX-2 SNPs to glioblastoma risk. However, the T-G IL-4Ralpha haplotype was associated with glioblastoma risk (odds ratio, 2.26; 95% confidence interval, 1.13-4.52) and there was a suggestion of an inverse relation between this haplotype and hayfever prevalence among controls (odds ratio, 0.38; 95% confidence interval, 0.14-1.03). The lack of support for a link between four IL-4Ralpha and IL-13 SNPs and glioblastoma may reflect the absence of associations or may result from uncontrolled confounding by haplotypes related both to those that we examined and glioblastoma. Nonetheless, the association between the T-G IL-4Ralpha haplotype and glioblastoma risk may indicate a role of immune factors in glioblastoma development.

LRIG1 expression in colorectal cancer

In the present study the expression of LRIG1 (leucine rich repeats and immunoglobin-like domains 1) and its relation to EGFR (epidermal growth factor receptor) was examined in tumour samples and adjacent non-neoplastic tissues from 30 patients with colorectal cancer. The LRIG1 gene, at chromosome 3p14, encodes an intergral membrane protein, which counteracts signalling by receptor tyrosine kinases belonging to the ERBB (epidermal growth factor receptor) family. LRIG1 is expressed in all tissues and organs analysed to date, including breast, brain, skin, kidney, spleen and colon. Overexpression of EGFR is seen in 70 - 90% of colorectal cancers, and is associated with a poor survival. Western blot analysis showed LRIG1 upregulation in 43% and downregulation in 43% of the colorectal cancers compared to adjacent non-neoplastic tissue. No correlation was evident between LRIG1, analysed by Western Blot and the expression of EGFR analysed by immunohistochemistry. FISH (fluoroscence in situ hybridisAtion) analysis showed increased LRIG1 copy number in one of nine tumours. Four colorectal cancer cell lines demonstrated two LRIG1 gene copies. In conclusion, there was a great heterogeneity in the expression of the LRIG1 protein in colorectal cancer, which was not related to gene dosage of the LRIG1 gene. Further studies can be of interest to evaluate whether alteration in LRIG1 expression in colorectal cancer is of biological or clinical significance.

Treatment schedule is of importance when gefitinib is combined with irradiation of glioma and endothelial cells in vitro

Amplified epidermal growth factor receptor (EGFR) signaling is supposed to contribute to clinical radiation resistance of glioblastoma multiforme (GBM). Therefore, inhibition of EGFR signaling pathways by the selective EGFR tyrosine kinase inhibitor, gefitinib (ZD1839, Iressa), may increase the therapeutic effects of radiotherapy. The effects of different schedules for administration of gefitinib on sensitivity to irradiation of the human glioma cell lines (251MG and SF-767), a rat glioma cell line (BT4C), and an immortalized rat brain endothelial cell line (RBE4) is reported. Differences in effects of the combined treatment on cell toxicity were determined by a fluorometric cytotoxicity assay, and nuclear DNA fragmentation was used for quantification of apoptosis. Pre-administration with gefitinib for 30 min prior to irradiation followed by continuous incubation with gefitinib significantly increased the cytotoxicity of SF-767, BT4C, and RBE4 cells. However, the human glioma cell line 251MG was protected against radiation-induced damage by this treatment schedule, at lower concentrations of gefitinib. Pre-administration with gefitinib for 24 h prior to irradiation without following incubation with gefitinib increased the cytotoxicity of SF-767 and BT4C cells. Post-irradiation treatment with gefitinib significantly increased the cytotoxicity in all cell lines except for 251MG. We demonstrated heterogeneity in the cytotoxic effects of gefitinib between cell lines. Response to gefitinib might be due to other mechanisms than through the EGF receptor as some of the cell lines showed sensitivity to gefitinib despite no or low expression of EGFR. This study also demonstrates the importance of timing of gefitinib administration when this agent is combined with irradiation.

Family history of cancer as a risk factor for second malignancies after Hodgkin's lymphoma

This study estimated the risk of second primary malignancies after Hodgkin's lymphoma (HL) in relation to family history of cancer, age at diagnosis and latency, among 6946 patients treated for HL in Sweden in 1965-1995 identified through the Swedish Cancer Register (SCR). First-degree relatives (FDRs) to the HL patients and their malignancies were then ascertained together with their malignancies through the Multi-Generation Registry and SCR. The HL patient cohort was stratified on the number of FDRs with cancer, and standardised incidence ratios (SIRs) of developing SM were analysed. In the HL cohort, 781 SM were observed 1 year or longer after HL diagnosis. The risk for developing SM increased with the number of FDRs with cancer, SIRs being 2.26, 3.01, and 3.45 with 0, 1, or >or=2 FDRs with cancer, respectively. Hodgkin's lymphoma long-term survivors treated at a young age with a family history of cancer carry an increased risk for developing SM and may represent a subgroup where standardised screening for the most common cancer sites could be offered in a stringent surveillance programme.

Comprehensive analysis of DNA repair gene variants and risk of meningioma

BACKGROUND

Meningiomas account for up to 37% of all primary brain tumors. Genetic susceptibility to meningioma is well established, with the risk among relatives of meningioma patients being approximately threefold higher than that in the general population. A relationship between risk of meningioma and exposure to ionizing radiation is also well known and led us to examine whether variants in DNA repair genes contribute to disease susceptibility.

METHODS

We analyzed 1127 tagging single-nucleotide polymorphisms (SNPs) that were selected to capture most of the common variation in 136 DNA repair genes in five case-control series (631 case patients and 637 control subjects) from four countries in Europe. We also analyzed 388 putative functional SNPs in these genes for their association with meningioma. All statistical tests were two-sided.

RESULTS

The SNP rs4968451, which maps to intron 4 of the gene that encodes breast cancer susceptibility gene 1-interacting protein 1, was consistently associated with an increased risk of developing meningioma. Across the five studies, the association was highly statistically significant (trend odds ratio = 1.57, 95% confidence interval = 1.28 to 1.93; P(trend) = 8.95 x 10(-6); P = .009 after adjusting for multiple testing).

CONCLUSIONS

We have identified a novel association between rs4968451 and meningioma risk. Because approximately 28% of the European population are carriers of at-risk genotypes for rs4968451, the variant is likely to make a substantial contribution to the development of meningioma.

GLIOGENE an International Consortium to Understand Familial Glioma

Evidence for familial aggregation of glioma has been documented in both case-control and cohort studies and occurs apart from the well-described rare inherited genetic syndromes involving glioma: neurofibromatosis type 1 and 2, tuberous sclerosis, Turcot's syndrome, and Li-Fraumeni syndrome. Nonsyndromic glioma families have been studied but no genes have been identified in the two published linkage studies of familial glioma probably due to the small number of families. Because glioma is a rare but devastating cancer, and a family history of glioma has been observed in approximately 5% of the cases, we initiated an international consortium to identify glioma families not affected by syndromes to better understand the inherited factors related to this disease. The international consortium GLIOGENE is an acronym for "glioma gene" and includes 15 research groups in North America, Europe, and Israel to study familial glioma. The overarching goal is to characterize genes in glioma families using a genome-wide single-nucleotide polymorphism approach and conducting linkage analysis to identify new genomic regions or loci that could harbor genes important for gliomagenesis. Here, we review the rationale for studying familial glioma and our proposed strategy for the GLIOGENE study.

Comprehensive analysis of the role of DNA repair gene polymorphisms on risk of glioma

Much of the variation in inherited risk of glioma is likely to be explained by combinations of common low risk variants. The established relationship between glioma risk and exposure to ionizing radiation led us to examine whether variants in the DNA repair genes contribute to disease susceptibility. We evaluated 1127 haplotype-tagging single-nucleotide polymorphisms (SNPs) supplemented with 388 putative functional SNPs to capture most of the common variation in 136 DNA repair genes, in five unique case-control series from four different countries (1013 cases, 1016 controls). We identified 16 SNPs associated with glioma risk at the 1% significance level. The highest association observed across the five independent case-control datasets involved rs243356, which maps to intron 3 of CHAF1A (trend odds ratio, 1.32; 95% confidence interval 1.14-1.54; P = 0.0002; false-positive report probability = 0.055, based on a prior probability of 0.01). Our results provide additional support for the hypothesis that low penetrance variants contribute to the risk of developing glioma and suggest that a genetic variant located in or around the CHAF1A gene contributes to disease risk.

Second primary tumors following a diagnosis of meningioma in Sweden, 1958-1997

This study quantifies the risk of second primary tumors following a diagnosis of meningioma. 12,012 meningiomas and 926 second primary cancers were identified (ICD7, path code 461) between 1958 and 1997 using Swedish Cancer Registry data. Standardized incidence ratios (SIRs) and exact 95% confidence intervals (CIs) were calculated. An elevated risk of any second primary cancer diagnosis (SIR = 1.2, 95% CI = 1.1-1.3) was observed. Elevated and statistically significant SIRs were observed for renal cancer (SIR = 1.6), melanoma (SIR = 1.7), thyroid cancer (SIR = 2.6) and brain tumors (SIR = 2.6). A consistent pattern of risk over time supports the evaluation of common risk factor profiles for renal, melanoma and thyroid cancers. Radiation exposures increase the risk of these rare tumors, so quantifying the cumulative and shared effects of environmental and treatment exposures is of further interest.

An international case-control study of glutathione transferase and functionally related polymorphisms and risk of primary adult brain tumors

BACKGROUND

Glutathione transferases (GST) detoxify environmental and endogenous compounds and levels of two polymorphic GST proteins, GSTM3 and GSTP1, are high in the brain. Previous studies of GSTM3 and GSTP1 polymorphisms and adult brain tumor risk have produced inconsistent results, whereas the GSTM3 -63 variant is newly identified and, therefore, has not yet been studied in this context. We therefore examined associations between GSTM3 -63, GSTM3 *A/*B, GSTP1 105, and GSTP1 114 variants and adult brain tumor risk and the interaction of the effects of these same polymorphisms with cigarette smoking. In addition, the enzymes NQO1 and CYP1A1 alter susceptibility to oxidative brain damage. Because there is less previous evidence for a role of NQO1, CYP1A1, GSTM1, and GSTT1 variants, we restricted analysis of these variants to a small preliminary study.

METHODS

We genotyped DNA collected for an international population-based case-control study of 725 glioma cases, 329 of which were glioblastoma cases, 546 meningioma cases and 1,612 controls. Study participants were residents of Sweden, southeast England, Denmark, and Finland.

RESULTS

We found no associations between the GSTM3, GSTP1, NQO1, CYP1A1, GSTM1, or GSTT1 polymorphisms and adult brain tumor risk with the possible exception of a weak association between the G-C (Val-Ala) GSTP1 105/114 haplotype and glioma [odds ratio (OR), 0.73; 95% confidence interval (95% CI), 0.54, 0.99], nor was there an interaction between the effects of the GSTM3 or GSTP1 polymorphisms and cigarette smoking.

CONCLUSIONS

Overall, we observed no strong evidence for an association between GST or related enzyme polymorphisms and adult brain tumor risk.

Estrogen receptor beta polymorphism is associated with prostate cancer risk

PURPOSE

After cloning of the second estrogen receptor, estrogen receptor beta (ERbeta) in 1996, increasing evidence of its importance in prostate cancer development has been obtained. ERbeta is thought to exert an antiproliferative and proapoptotic effect. We examined whether sequence variants in the ERbeta gene are associated with prostate cancer risk.

EXPERIMENTAL DESIGN

We conducted a large population-based case-control study (CAncer Prostate in Sweden, CAPS) consisting of 1,415 incident cases of prostate cancer and 801 controls. We evaluated 28 single nucleotide polymorphisms (SNP) spanning the entire ERbeta gene from the promoter to the 3'-untranslated region in 94 subjects of the control group. From this, we constructed gene-specific haplotypes and selected four haplotype-tagging SNPs (htSNP: rs2987983, rs1887994, rs1256040, and rs1256062). These four htSNPs were then genotyped in the total study population of 2,216 subjects.

RESULTS

There was a statistically significant difference in allele frequency between cases and controls for one of the typed htSNPs (rs2987983), 27% in cases and 24% in controls (P = 0.03). Unconditional logistics regression showed an odds ratio of 1.22 (95% confidence interval, 1.02-1.46) for men carrying the variant allele TC or CC versus the wild-type TT, and an odds ratio of 1.33 (95% confidence interval, 1.08-1.64) for localized cancer. No association of prostate cancer risk with any of the other SNPs or with any haplotypes were seen.

CONCLUSION

We found an association with a SNP located in the promoter region of the ERbeta gene and risk of developing prostate cancer. The biological significance of this finding is unclear, but it supports the hypothesis that sequence variation in the promoter region of ERbeta is of importance for risk of prostate cancer.

Breast Cancer as a Second Primary in Patients With Prostate Cancer—Estrogen Treatment or Association With Family History of Cancer?

PURPOSE

In a large population based study we reported an increased risk of male breast cancer after prostate cancer. In the current study we performed a comprehensive investigation of whether treatment for prostate cancer and/or family history is responsible for the excess risk.

MATERIALS AND METHODS

This study had 2 parts. 1) We performed a nested case-control study in 41 men who had previously been identified with first prostate cancer, followed by male breast cancer and in 81 matched controls with prostate cancer only. The medical records of these men were retrieved and clinical data such as stage, grade and treatment were extracted. 2) We also performed a family study including relatives of men with a diagnosis of prostate as well as breast cancer, irrespective of which was first. The 878 relatives were identified through parish offices and linked to the Swedish Cancer Registry to evaluate the occurrence of breast, prostate and other cancers and calculate if there were any excess risks for different cancers.

RESULTS

Cases with prostate plus breast cancer received estrogen treatment more often than controls with prostate cancer only (p = 0.03). The period of estrogen treatment was longer in the cases, although it was not statistically significant. Mean time from prostate cancer diagnosis to breast cancer diagnosis was 47.6 months. Cases and controls did not differ in grade or stage. In the family study an increased risk of prostate cancer was found in relatives (SIR 2.14, 95% CI 1.09 to 3.18). For other cancers no significantly increased risks were found. In 2 families pedigree analysis using the BRCAPRO program (http://www3.utsouthwestern.edu/cancergene/) revealed an estimated 100% and 49% probability in families 1 and 2, respectively, that the proband was a BRCA2 carrier.

CONCLUSIONS

Our data suggest that most of the increased risk of breast cancer following prostate cancer can be explained by estrogen treatment. However, in a small number of men with prostate as well as breast cancer pedigree analysis suggests that BRCA2 mutation might be the underlying cause.

A road map for efficient and reliable human genome epidemiology

Networks of investigators have begun sharing best practices, tools and methods for analysis of associations between genetic variation and common diseases. A Network of Investigator Networks has been set up to drive the process, sponsored by the Human Genome Epidemiology Network. A workshop is planned to develop consensus guidelines for reporting results of genetic association studies. Published literature databases will be integrated, and unpublished data, including 'negative' studies, will be captured by online journals and through investigator networks. Systematic reviews will be expanded to include more meta-analyses of individual-level data and prospective meta-analyses. Field synopses will offer regularly updated overviews.

Homozygosity mapping of familial glioma in Northern Sweden

About 5% of glioma cases are familial. Most glioma families are not ascribed to the well-known glioma predisposing syndromes. One segregation analysis has supported an autosomal recessive gene in glioma families, which could be studied by homozygosity mapping. The ancestors of seven glioma families from the northern region of Sweden were traced through genealogical databases. A common ancestor and inbreeding were traced to give support to an autosomal recessive gene. Homozygosity mapping was performed with a genome-wide scan of 811 markers with linkage calculations. The families were geographically mapped to see if familial glioma was more common in northern compared with southern Sweden. Three of the seven families were remotely related. Homozygosity mapping did not reveal any allele homozygous for all three families. However, there was a geographical clustering of glioma families in the northern region of Sweden. A non-parametric analysis showed an allele-sharing LOD score of 1.05 for marker D1S196 on chromosome 1q23. Genealogical studies linking glioma families might be a tool for linkage in a small set of families. This study did not support an autosomal recessive gene, implicating a low penetrant dominant gene as a possible explanation to the glioma family clustering.

Polymorphisms associated with asthma are inversely related to glioblastoma multiforme

A reduced risk of primary malignant adult brain tumors is observed among people reporting asthma, hay fever, and other allergic conditions; however, findings may be attributed to prediagnostic effects of tumors or recall bias. To determine whether asthma and allergic condition polymorphisms are inversely related to glioblastoma multiforme (GBM) risk, we conducted a population-based case-control study of 111 GBM patients and 422 controls. We identified five single nucleotide polymorphisms on three genes previously associated with asthma [interleukin (IL)-4RA, IL-13, ADAM33] and one gene associated with inflammation (cyclooxygenase-2). Confirming previous literature, we found that self-reported asthma, eczema, and fever are inversely related to GBM [e.g., asthma odds ratio (OR), 0.64; 95% confidence interval (CI), 0.33-1.25]. In addition, IL-4RA Ser478Pro TC, CC, and IL-4RA Gln551Arg AG, AA are positively associated with GBM (OR, 1.64; 95% CI, 1.05-2.55; 1.61; 95% CI, 1.05-2.47), whereas IL-13 -1,112 CT, TT is negatively associated with GBM (0.56; 95% CI, 0.33-0.96). Each of these polymorphism-GBM associations is in the opposite direction of a corresponding polymorphism-asthma association, consistent with previous findings that self-reported asthmatics and people with allergic conditions are less likely to have GBM than are people who do not report these conditions. Because we used germ line polymorphisms as biomarkers of susceptibility to asthma and allergic conditions, our results cannot be attributed to recall bias or effects of GBM on the immune system. However, our findings are also consistent with associations between IL-4RA, IL-13, and GBM that are independent of their role in allergic conditions.

p53 Genotypes and Risk of Glioma and Meningioma

Brain tumors have previously been associated with the Li-Fraumeni syndrome that often is caused by p53 germ line mutations. Therefore, we investigated if polymorphisms of p53 were associated with an increased risk of meningioma and glioma and integrated the polymorphism analyses with detailed information on family history of cancer. In a population-based case-control study, DNA was extracted from 205 glioma and 164 meningioma cases identified during 2000 to 2002 in Sweden and from 374 controls selected randomly from the general population, stratified on age, sex, and geographic region. The Swedish Cancer Registry confirmed a cancer in family members in 86% of cases and controls that reported a family history of cancer. p53 single nucleotide polymorphism (SNP) analyses were done on three SNPs from the promoter region, codon 72 in exon 4, and intron 6. Overall, no associations were found for any of the SNPs. Analyses of the combinations of the three SNPs were also done. The CC-CG-CC-specific polymorphism combination was associated with an odds ratio (OR) of 1.36 [95% confidence interval (95% CI), 0.68-2.72] for glioma and 1.36 (0.64-2.88) for meningioma. When restricting the analyses to cases and controls with a positive family history of cancer, the corresponding results were OR of 3.62 (95% CI, 1.05-12.48) for glioma and 5.69 (1.81-17.96) for meningioma. This study is novel in suggesting an increased risk of brain tumors when the analysis is restricted to those with a history of cancer in the family. However, we cannot rule out the possibility that these results are due to chance.

Prior hospitalization for epilepsy, diabetes, and stroke and subsequent glioma and meningioma risk

We conducted a case-control study to evaluate the preclinical association between epilepsy, diabetes, and stroke and primary adult brain tumors. We first identified all 1,501 low-grade glioma, 4,587 high-grade glioma (HGG), and 4,193 meningioma cases reported to the Swedish Cancer Registry from 1987 to 1999. Next, controls (137,485) were randomly selected from the continuously updated Swedish Population Registry and matched to cases diagnosed that year on age and sex. Finally, cases and controls were linked to the Swedish Hospital Discharge Registry (1969-1999). We found that > or =8 years before HGG diagnosis (or control reference year) there was an elevated risk of HGG among people discharged with epilepsy [odds ratio (OR), 3.01; 95% confidence interval (95% CI), 1.73-5.22]. Two to 3 years before HGG diagnosis, this risk increased (OR, 5.33; 95% CI, 3.58-7.93) and was especially strong among people ages <55 years (OR, 13.49; 95% CI, 6.99-25.94). During this 2- to 3-year prediagnostic period, we also found an increased risk of HGG among people discharged with meningitis (OR, 3.02; 95% CI, 1.06-8.59) or viral encephalitis (OR, 12.64; 95% CI, 2.24-71.24). Results are similar for glioblastoma multiforme, low-grade glioma, and meningioma. In contrast, risk of HGG among people discharged with diabetes or stroke does not increase until year of brain tumor diagnosis. The occurrence of excess epilepsy > or =8 years before HGG diagnosis suggests a relatively long preclinical phase, but excess diabetes or stroke appear late in HGG development.

Increased copy number at 3p14 in breast cancer

INTRODUCTION

The present study was conducted to investigate if chromosome band 3p14 is of any pathogenic significance in the malignant process of breast cancer. Genetic studies have implicated a tumour suppressor gene on chromosome arm 3p and we have proposed LRIG1 at 3p14 as a candidate tumour suppressor. The LRIG1 gene encodes an integral membrane protein that counteracts signalling by receptor tyrosine kinases belonging to the ERBB family. LRIG1 mRNA and protein are expressed in many tissues, including breast tissue.

METHODS

In the present report we analysed the LRIG1 gene by fluorescence in situ hybridisation (FISH), LRIG1 mRNA by quantitative RT-PCR, and LRIG1 protein by western blot analysis. Two tumour series were analysed; one series consisted of 19 tumour samples collected between 1987 and 1995 and the other series consisted of 9 tumour samples with corresponding non-neoplastic breast tissues collected consecutively.

RESULTS

The LRIG1 gene showed increased copy number in 11 out of 28 tumours (39%) and only one tumour showed a deletion at this locus. Increased LRIG1 copy number was associated with increased levels of LRIG1 mRNA (two of three tumours) and protein (four of four tumours) in the tumours compared to matched non-neoplastic breast tissue, as assessed by RT-PCR and western blot analysis.

CONCLUSION

The molecular function of LRIG1 as a negative regulator of ERBB receptors questions the biological significance of increased LRIG1 copy number in breast cancer. We propose that a common, but hitherto unrecognised, breast cancer linked gene is located within an amplicon containing the LRIG1 locus at 3p14.3.

Epidermal growth factor receptor family (EGFR, ErbB2-4) in gliomas and meningiomas

Overexpression of epidermal growth factor receptor (EGFR, ErbB1) correlates with enhanced malignant potential of many human tumor types including glioblastoma multiforme. The significance of EGFR expression in meningiomas is, however, unclear. Reports regarding the other EGFR family members, ErbB2-4, in brain tumors are sparse. In this study, the expression of the EGFR family members was analyzed in relation to various parameters for the clinical importance of these receptors in 44 gliomas and 26 meningiomas. In gliomas, quantitative real-time reverse transcription (RT)-PCR revealed the highest EGFR mRNA expression in high-grade gliomas, while ErbB2 and ErbB3 mRNA were detected only in a few high-grade gliomas. In contrast, ErbB4 expression was most pronounced in low-grade gliomas. Immunohistochemistry showed significantly higher EGFR protein expression in high-grade gliomas compared to low-grade gliomas (P= 0.004). ErbB2 protein expression was mainly seen in high-grade gliomas. ErbB3 protein expression was low in all gliomas analyzed. ErbB4 protein expression was significantly higher in low-grade gliomas than in high-grade gliomas (P= 0.007). In meningiomas, quantitative real-time RT-PCR revealed expression of EGFR, ErbB2, and ErbB4 mRNA in the majority of the tumors. ErbB3 was detected in only one of the meningiomas analyzed. Immunohistochemistry demonstrated high ErbB2 protein expression in meningiomas. An intriguing observation in astrocytomas and oligodendrogliomas grade II, was a significantly decreased overall survival for patients with high EGFR protein expression (P= 0.04). The high ErbB4 expression in low-grade compared to high-grade gliomas might suggest that ErbB4 acts as a suppressor of malignant transformation in brain tumors, which is in line with previous studies in other tumor types.

Heterogeneity in the expression of markers for drug resistance in brain tumors

Brain tumors, in general, display a multidrug-resistant phenotype. This study evaluated the immunohistochemical expression and distribution of P-glycoprotein (Pgp), multidrug resistance protein (MRP1), lung resistance protein (LRP) and O6 methylguanine-DNA methyltransferase (MGMT) in low- and high-grade astrocytoma, oligodendroglioma and in different subgroups of meningioma. The results revealed a marked heterogeneity in the expression and distribution among the analyzed tumors. In astrocytoma and oligodendroglioma, Pgp and MRP1 were observed in the capillary endothelium and in scattered tumor cells, whereas LRP occurred only in tumor cells. A pronounced expression of MGMT was found independent of the histopathological grade. An enhanced expression of MRP1 and LRP in astrocytoma and oligodendroglioma were more often evident in older patients (> 50 years). Survival analysis suggested a markedly decreased overall survival for patients suffering from low-grade glioma overexpressing Pgp. In meningioma, a heterogeneous expression of Pgp, MRP1, LRP and MGMT was seen with the most prominent staining localized to the capillary endothelium. Pgp was significantly more often overexpressed (p < 0.05) in transitional compared to meningothelial meningioma. The marked heterogeneity in the expression suggests that analysis of these factors can be of importance in the selection of individualized chemotherapy, regardless of tumor type.

Familial brain tumours-genetics or environment? A nationwide cohort study of cancer risk in spouses and first-degree relatives of brain tumour patients

Our study investigated whether the familial aggregation of glioma is due to environmental or genetic effects and it investigated and compared the risk to spouses and first-degree relatives (FDR) of patients with primary brain tumours (PBT) for developing both PBT and the risk for other types of cancer. All PBT patients identified in Sweden from 1958-97 in The Swedish Cancer Registry (SCR) were linked to the nationwide Swedish Family Database, including persons in Sweden born from 1932-97. The cohorts of spouses and FDR were linked to the SCR to identify observed cases of PBT and other cancer. Standardised incidence ratios (SIR) were calculated using the incidence rates from SCR as the reference. We found that there were no increased risks for any specific type of PBT in the cohort of spouses. In the FDR cohort, generally the risk for a PBT was significantly increased by 2 to 3 times for the same histopathology as the probands. Spouses of PBT patients had an increased risk of skin cancer. We conclude that FDR, not spouses, have a significantly increased risk, which indicates a genetic origin of the familial aggregation of brain tumours.

Reproductive factors have low impact on the risk of different primary brain tumours in offspring

OBJECTIVES

The aim of our study was to investigate whether reproductive factors influence the risk of primary brain tumours (PBT) in offspring.

METHODS

Data on all deliveries in two Swedish counties from 1955 to 1990 were extracted from two birth registries. The follow-up period closed at the end of 1994, with subjects followed up to early middle age. Incidence rates of malignancy for 1958-1994 were obtained from the Swedish Cancer Registry. Standardised incidence ratios (SIR) and relative risks were calculated for astrocytomas, primitive neuroectodermal tumour, ependymoma and meningiomas in offspring.

RESULTS

Few associations were detected. High birth weight indicated an increased risk for astrocytomas grade I and II for all primary brain tumours, and the risk was close to significance for astrocytomas grade I-II (SIR = 3.64; CI = 0.98-9.31). For children under 15 years of age the risk for astrocytomas grade I and II was further increased (SIR = 4.44; CI = 1.19-11.38).

CONCLUSIONS

A consistent pattern of non-association indicated a low impact of intrauterine environment on the future development of primary brain tumours in offspring up to early middle age.

Second primary cancers in men with prostate cancer: an increased risk of male breast cancer

PURPOSE

Evaluation of second primary cancers provides valuable insight about etiology and shared risk factors. Studies of second primary cancers following prostate cancer conclude that overall risk of second primary cancers decreases. However, risk of bladder cancer and kidney cancer increases. We examine the risk of common and rare second primary cancers following prostate cancer in a large population based cohort to identify possible common etiological factors.

MATERIALS AND METHODS

All prostate cancer cases in the Swedish Cancer Registry (135, 713) from 1958 to the end of 1996 constituted the study base. Risk (standardized incidence ratio) of second primary cancers was calculated as the ratio between observed and expected number of cancers. We used 2-tailed 95% confidence intervals (CI) to test significance.

RESULTS

An overall increased risk (standardized incidence ratio 1.17, 95% CI 1.15-1.19) of second primary cancers was found but was only seen in the first 6 months of followup (ratio 3.45, 3.32-3.57). The most interesting finding was an increased risk (ratio 2.01, 95% CI 1.44-2.74) of male breast cancer. Other tumor sites with increased risk were the small intestine (standardized incidence ratio 1.39, 95% CI 1.09-1.51), skin melanoma (ratio 1.33, 95% CI 1.16-1.51) and endocrine tumors (ratio 1.41, 95% CI 1.13-1.74).

CONCLUSIONS

A small but increased risk of second primary cancers following prostate cancer was found, most likely due to increased surveillance during the first 6 months after diagnosis. However, following prostate cancer there is an increased risk of endocrine related second primary cancers such as male breast cancer and carcinoids in the small intestine. To our knowledge these associations have not been reported previously, and they warrant more study.

Does a low frequency of P53 and Pgp expression in familial glioma compared to sporadic controls indicate biological differences?

BACKGROUND

A three-fold increased risk for glioma among first degree relatives (FDR) to glioma patients has previously been shown. This study compared familial cases with sporadic controls of glioma to see if phenotypic differences could be detected. Different pathways to tumour growth and progression were investigated including cell cycle regulating genes (p53) and growth factors (epidermal growth factor receptor, EGFR), angiogenesis (vascular endothelial growth factor, VEGF and microvessel density, MVD), pathways of detoxification (glutathione-S-transferase, GST pi) and multidrug resistance (P-glycoprotein, Pgp).

MATERIALS AND METHODS

Thirty-seven cases of familial gliomas, identified in a population-based study, were compared to 58 sporadic glioma controls chosen with a negative family history of glioma. The immunohistochemistry was performed with standard procedures using the LABSA kit (Zymed lab).

RESULTS

Familial cases had significantly more frequent p53- and Pgp-negative tumours, also when correcting for age, sex and histopathology. However, Pgp was no longer significant after correcting for p53 status indicating a correlation between Pgp and p53. A significant difference between VEGF-negative to VEGF-positive tumours (low- or high-grade) was shown, but it was no longer significant when correcting for p53 status.

CONCLUSION

Our study investigated phenotypic differences of familial glioma compared to sporadic control. Our finding of a distinct pattern of increased p53- and Pgp-negativity among cases warrants further investigation.

Different aetiology of familial low-grade and high-grade glioma? A nationwide cohort study of familial glioma

An increased risk for first-degree relatives (FDR) of glioma patients has previously been observed. The novel objective of this study was to investigate differences in familial risk among FDR of low-grade glioma (LGG) and high-grade glioma (HGG) cases, respectively. Two cohorts were constructed, one from 15,321 FDR of LGG cases and the other from 26,635 FDR of HGG cases calculating standardised incidence ratios (SIR). The risk for LGG among FDR of LGG cases was significantly increased, SIR 3.65 (95% CI 2.31-5.47). The risk was even higher in the cohort of siblings, SIR 7.00 (95% CI 3.35-12.87), and especially in the younger siblings (<40 years), SIR 9.01 (95% CI 4.31-16.57). When calculating the risk for HGG in the LGG cohort and the risk for HGG in the HGG cohort, there was a generally twofold increased risk, but no trends of increased risk in relatives of younger probands. Two different methods calculating familial risk displayed similar results. LGG families apparently have features manifesting a distinct pedigree pattern with sibpairs affected at a young age. These families could provide new insights into the aetiology of glioma.

Microsatellite instability, PTEN and p53 germline mutations in glioma families

Rare inherited syndromes that to some extent explain familial glioma include Turcot's syndrome, Li-Fraumeni syndrome and neurofibromatosis types I and II. The majority of families with glioma do not meet the clinical criteria for any of these syndromes. In order to study the genetic origin of familial glioma, tumour DNA (n = 35) or blood samples (n = 8) were collected from 25 families. The glioma tumours were tested for microsatellite instability (MSI) with two markers, BAT25 and BAT26, since glioma is associated with hereditary non-polyposis colon cancer (HNPCC) in Turcot's syndrome. Furthermore, p53 was screened from blood DNA (exons 2-11) with temporal temperature gradient electrophoresis (TTGE) since germline mutations in p53 are seen in Li-Fraumeni syndrome. In gliomas, there is a wide variety of somatic mutations, such as, for instance, in p53, the epidermal growth factor receptor (EGFR) and p16. The tumour suppressor gene PTEN is also often somatically mutated in glioma, therefore it is attractive as a candidate gene for germline mutations in familial glioma. Blood DNA was directly sequenced for mutations in PTEN exons 1-9. The analysis showed that no mutations were found in either of the studied tumour suppressor genes, and no MSI-positive tumours were found. A common polymorphism in p53 at codon 72 (arginine/proline) was found in 6/8 of the patients. Apparently, mutation in the tested tumour suppressor genes or DNA mismatch repair genes does not explain the familial glioma observed in these families.

Genetic epidemiology of glioma

The present study performed a segregation analysis of a cohort of first-degree relatives (FDR) of glioma patients. The families with two or more gliomas were also expanded to determine if any more gliomas could be detected, and if any other types of cancers were associated. These glioma-prone families (n = 24/432) were extended to include first-, second- and third-degree relatives (n = 807) and a cohort was assembled, the standardized incidence risk for other types of cancer calculated and the pedigrees investigated for a possible mode of inheritance. A segregation analysis of the 2141 FDR in 297 families, performed using the Pointer software, did not clearly reject a multifactorial model chi(2)(3) = 6.13, P< 0.2. However, when letting all parameters be free, the recessive model provided the best fit. In the extended families, no increased risk of other types of cancer was found. This population-based study proposes that familial glioma occurs in about 5% of all glioma cases and that 1% have a possible autosomal dominant inheritance. This first segregation analysis performed in familial glioma must be cautiously interpreted, but an autosomal recessive gene provided the best fit, which could possibly explain 2% of all glioma cases.

Wegener granulomatosis in children and young adults. A case study of ten patients

This retrospective study reports seven children and three young adults (aged 11-30 years) who suffered from Wegener granulomatosis. Nine represent consecutive patients admitted to the Division of Nephrology over a period of 23 years. All patients had respiratory tract symptoms and renal involvement on admission. In several patients infiltrates on chest X-ray developed within 2 weeks of onset of symptoms. All patients survived. The median observation period was 9 years (range 13 months to 23 years). One patient progressed to end-stage renal disease. Nine patients initially received cyclophosphamide and steroids. After a median period of 9 months (range 6-31 months) the cyclophosphamide was replaced by azathioprine. Relapses occurred after a median of 28 months (range 4-120 months) in 80% of patients, in six of the eight patients causing a definite decrease in kidney function. We believe that early diagnosis and initiation of therapy reduce the extent of organ damage. Since relapses are frequent, these patients should be evaluated frequently.

Primary brain tumours as second primary: a novel association between meningioma and colorectal cancer

In a previous study, a decreased risk for first degree relatives of patients with astrocytoma has been observed for breast and colorectal cancer. The aim of this study was to examine the associations between breast and colorectal cancer as first primary cancer and the risk of developing astrocytoma and meningioma as a second primary cancer. Two cohorts were constructed, one from all cases with breast cancer (1,036,466 person-years) and one from all cases of colorectal cancer (572,422 person-years) in Sweden during the period 1958-1994. The risk of developing astrocytoma and meningioma after breast or colorectal cancer was calculated. A significant increased risk for developing meningioma was seen after colorectal cancer, standardized incidence ratio (SIR) 1.60 confidence interval (CI; 1.32-1.94) and after breast cancer, SIR 1. 57 CI (1.36-1.81). The previously observed decreased risk for astrocytoma could not be verified in this study. A novel association between meningioma and colorectal cancer, particularly in females, was observed, which justifies further studies to evaluate common aetiological factors.