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Disruption of telomere length (TL) homeostasis in peripheral blood lymphocytes has been previously assessed as a potential biomarker of breast cancer (BC) risk. The present study addressed the relationship between lymphocyte TL (LTL), prognosis and clinicopathological features in the BC patients since these associations are insufficiently explored at present. LTL was measured in 611 BC patients and 154 healthy controls using the monochrome multiplex quantitative Polymerase Chain Reaction assay. In addition, we genotyped nine TL-associated single-nucleotide polymorphisms that had been identified through genome-wide association studies. Our results showed that the patients had significantly (P = 0.001, Mann–Whitney U-test) longer LTL [median (interquartile range); 1.48 (1.22–1.78)] than the healthy controls [1.27 (0.97–1.82)]. Patients homozygous (CC) for the common allele of hTERT rs2736108 or the variant allele (CC) of hTERC rs16847897 had longer LTL. The latter association remained statistically significant in the recessive genetic model after the Bonferroni correction (P = 0.004, Wilcoxon two-sample test). We observed no association between LTL and overall survival or relapse-free survival of the patients. LTL did not correlate with cancer staging based on Union for International Cancer Control (UICC), The tumor node metastasis (TNM) staging system classification, tumour grade or molecular BC subtypes. Overall, we observed an association between long LTL and BC disease and an association of the hTERC rs16847897 CC genotype with increased LTL. However, no association between LTL, clinicopathological features and survival of the patients was found.

We review here data on familial risk in colorectal cancer (CRC) generated from the Swedish Family-Cancer Database, the largest resource of its kind in the world. Although the concordant familial risk for CRC (i.e. CRC risk in families of CRC patients) has been reasonably well established, the studies on discordant familial risks (i.e. CRC risk in families with any other cancers) are rare. Because different cancers could be caused by shared genetic susceptibility or shared environment, data of associations of discordant cancers may provide useful information for identifying common risk factors. In analyses between any of 33 discordant cancers relative risks (RRs) for discordant cancers were estimated in families with increasing numbers of probands with CRC; in the reverse analyses, RRs for CRC were estimated in families with increasing numbers of probands with discordant cancers. In separate analyses, hereditary non-polyposis colorectal cancer (HNPCC) families were excluded from the study, based on HNPCC related double primary cancers, to assess the residual familial RRs. We further reviewed familial risks of colon and rectal cancers separately in search for distinct discordant associations. The reviewed data suggested that colon cancer was associated with a higher familial risk for CRC compared to rectal cancer. The previous data had reported associations of CRC with melanoma, thyroid and eye cancers. Nervous system cancer was only associated with colon cancer, and lung cancer only associated with rectal cancer. The reviewed data on discordant association may provide guidance to gene identification and may help genetic counseling.

International audience; The region of North Africa (NA) represents a striking locality regarding migration with several migration patterns, namely emigration in the form of labour export to Europe and North America and, to a lesser extent, to the Arab Gulf area. The latter has increased enormously in the last decade because of the political instability in most of the NA countries. The aim of the present chapter was to explore the patterns of migration stocks and flows in NA countries, based on several websites, systematic review of journals, comparable data available by the United Nations and by the International Organization of Migration. The NA region has become an area of transit migration and labour migration. Emigrant flows from NA countries towards Europe and North America are increasing this decade more than towards the Arab Gulf countries after being replaced by Asian labour. The recent increase in the proportion of women among the migrant population is remarkable. Remittances sent by African migrants have become an important source of external finance for countries of origin. Transient and irregular migration to Egypt originates at the borders with Sudan, Palestine and Libya with destination to the Euro Mediterranean countries. In Tunisia and Morocco, irregular migrants originate from Sub-Saharan Africa to the northern borders. The NA countries serve as departure rather than destination countries, and migration flows to the Euro-Mediterranean countries through legal or illegal routes.

Colorectal cancer (CRC) is one of the most common cancer worldwide. However, a large number of genetic risk factors involved in CRC have not been understood. Copy number variations (CNVs) might partly contribute to the 'missing heritability' of CRC. An increased overall burden of CNV has been identified in several complex diseases, whereas the association between the overall CNV burden and CRC risk is largely unknown. We performed a genome-wide investigation of CNVs on genomic DNA from 384 familial CRC cases and 1285 healthy controls by the Affymetrix 6.0 array. An increase of overall CNV burden was observed in familial CRC patients compared with healthy controls, especially for CNVs larger than 50kb (case/control ratio = 1.66, P = 0.025). In addition, we discovered for the first time a novel structural variation at 12p12.3 and determined the breakpoints by strategic PCR and sequencing. This 12p12.3 structural variation was found in four of 2862 CRC cases but not in 6243 healthy controls (P = 0.0098). RERGL gene (RERG/RAS-like), the only gene influenced by the 12p12.3 structural variation, sharing most of the conserved regions with its close family member RERG tumor suppressor gene (RAS-like, estrogen-regulated, growth inhibitor), might be a novel CRC-related gene. In conclusion, this is the first study to reveal the contribution of the overall burden of CNVs to familial CRC risk and identify a novel rare structural variation at 12p12.3 containing RERGL gene to be associated with CRC.

A functionally normal TP53 is essential to protect organisms from developing cancer. Somatic mutations in the gene represent one of the highest recurring perturbations in human tumours, including colorectal cancer (CRC). However, the variegated phenotype of wide spectrum of somatic mutations in TP53 and the complexity of the disease prevent a straight interpretation of the mutational analysis in tumours. In addition to the presence of somatic mutations, polymorphic features of the gene may also contribute to alteration of the normal TP53 functioning and variants, mainly in the form of single nucleotide polymorphisms, can be expected to impact susceptibility to sporadic CRC. In the present study, we reviewed the potential role of alterations in the TP53 gene, both somatic mutations and inherited sequence variations, in predisposition to CRC and in the prognosis and response to therapy. The available data from association studies have mostly shown contradictory outcomes. The majority of the studies were based on limited sample sizes and focussed on a limited number of polymorphisms, with main being the rs1042522 (Arg72Pro). Thus far, there is no possible generalisation of the role of TP53 as also a predictor of therapeutic response and prognosis. The effects of TP53, and its abnormalities, on the response of tumours to cytotoxic drugs, radiation and chemoradiation are complex. However, from studies it is emerging that the inherited genetics of TP53 pathway components could be utilised to further define patient populations in their abilities to induce p53 activity in response to either DNA damaging or p53-targeted therapies.

Every year, approximately 1 million new colorectal cancer (CRC) cases are diagnosed and about half a million people worldwide die due to this cancer. Known differences in CRC incidence rates are mainly attributed to differences in diet and other environmental factors represented, among others, by nutrition-related complex diseases (e.g. obesity and diabetes mellitus type II). Within the last years, it has become evident that environmental risk factors can be complemented by a genetic component when considering the risk of CRC. For example, a number of polymorphisms are known to be associated with an increased risk of obesity and obesity is a risk factor for CRC. Several studies have shown that the 'ancestral-susceptibility model' can be reasonably applied to nutrition-related complex diseases such as obesity. The work in hand shortly discusses whether the ancestral-susceptibility model can also be applied to CRC as a nutrition-related complex disease.

Basal cell carcinoma (BCC) of the skin is the most common neoplasm among the Caucasian population of the Western world. Inflammation may result in oxidative stress and contribute to promotion and progression of tumors, including BCC. The role of cytokines, which are inflammatory modulators, in the biology of tumors has been extensively studied and it is well known that they are aberrantly produced by cancer cells, macrophages and other phagocytic cells. Genetic polymorphisms are known in several cytokine genes, which result in altered expression. In the present association study, we investigated the association of 14 functional polymorphisms in 11 cytokines genes with BCC risk in 529 BCC cases and 532 healthy controls. We have also tested the possible interactions between the genetic variants and three known risk factors for BCC: skin complexion, sun effect and skin response to sun exposure. We did not observe any statistically significant association between SNPs and BCC risk. However, we found that, in a subgroup of subjects more prone to skin burns, carriers of at least one copy of the G allele of rs1800629 (TNF) had an increased risk of BCC [odds ratio (OR) = 2.40, 95% confidence interval (CI) 1.38-4.16, P = 0.0005]. Moreover, in subjects less prone to sunburns, we observed that carriers of the C allele of rs1143627 (IL1B) showed a decreased risk (OR = 0.53, 95% CI 0.34-0.82, P = 0.0019). In conclusion, we found that two polymorphisms in inflammatory genes interacting with environmental risk factors could modulate BCC risk.

Background: A family history of melanoma is associated with an increased risk of melanoma and probably of other, discordant cancers. Limited data are available on familial mortality in melanoma. If fatal forms of melanoma were associated with fatal forms of melanoma or of some other cancers, only studies on familial mortality rather than on familial incidence might be able to detect them. Furthermore, estimates on familial aggregation based on mortality are free from bias of overdiagnosis. Objectives: The aim of this study was the estimation of familial aggregation of concordant melanoma and of melanoma and any other cancers both based on incidence and mortality. Methods: We used the nation-wide Swedish Family-Cancer Database to calculate standardized incidence ratios (SIR) for incident melanoma for relatives of any cancer patients and standardized mortality ratios (SMR) for death in melanoma for relatives of individuals who died from any other cancer. Similar risks were determined for any common cancer when relatives were affected by melanoma. Results: For concordant melanoma, familial incidence equalled familial mortality, SIR=SMR. Familial clustering (SIRs increased) of melanoma and esophageal, colorectal, breast, prostate, kidney, nervous system and connective tissue cancers and myeloma and leukaemia was observed. The SMRs for pancreatic and nervous system cancers were increased in relatives whose parents had died from melanoma. Conclusions: These data should encourage search for fatal subtypes of familial cancer, which may eventually have clinical implications.

Background Increased cancer risk after psoriasis has been observed in previous studies, whereas little is known about the prognosis in cancer patients with previously diagnosed psoriasis. Objectives We aimed at examining the cancer-specific and overall mortality among psoriatic cancer patients compared with the reference population. Methods The population-based Swedish registers were used to identify psoriatic cancer patients and cancer patients without psoriasis. We estimated hazard ratios (HRs) showing the probability of death in the two groups. Results In total, 1746 psoriatic cancer patients and 1 011 757 other cancer patients were identified from 1964 to 2006, showing a significant survival disparity [overall HR 1·27, 95% confidence interval (CI) 1·20-1·35 and cancer-specific HR 1·26, 95% CI 1·18-1·35]. An overall mortality excess after psoriasis was observed for nine cancer sites and a cancer-specific mortality excess for seven cancer sites. Stratified analyses showed that the prognosis was worse for psoriatic cancer patients diagnosed below age 65 years and for those who had been treated for alcohol-related diseases. Those with more than one hospitalization for psoriasis were more likely to be associated with an increased risk of cancer-specific mortality. Conclusions A previous diagnosis of psoriasis worsens the prognosis of many cancers. A worse prognosis was more pronounced in psoriatic cancer patients diagnosed at an earlier age, previously hospitalized for alcohol-related diseases, or with severe symptoms. Our study provides clinicians and patients with information about mortality risk and prognostic factors for psoriatic cancer patients. The mechanisms underlying this disparity warrant further studies. (Less)

Background. A recent rise in the incidence of prostate cancer and a more favorable outcome have increased the proportions of other causes of death in affected men. Extending the survival of prostate cancer patients thus requires knowledge of all causes of death. Methods. Data on the population, cancers, and causes of death were gathered from the nationwide Swedish Family-Cancer Database. A Cox regression model, comparing prostate cancer patients with all other men, was applied. Hazard ratios (HR) were calculated both for the underlying cause and for dying with a specific cause listed among multiple causes of death. Findings. Among 686,500 observed deaths, 62,500 were prostate cancer patients. For underlying causes other than prostate cancer, the highest cause-specific HRs were found for external causes (HR, 1.24; 95% confidence interval [CI], 1.16–1.31), diseases of the pulmonary circulation (HR, 1.22; 95% CI, 1.09–1.37), and heart failure (HR, 1.18; 95% CI, 1.11–1.24). For specific multiple causes, the highest HRs were found for anemia (HR, 2.28; 95% CI, 2.14–2.42), diseases of the pulmonary circulation (HR, 1.61; 95% CI, 1.55–1.68), and urinary system disease (HR, 1.90; 95% CI, 1.84–1.96). Interpretations. Prostate cancer patients have a higher risk for dying from various causes other than prostate cancer, including external causes and heart failure. Mechanisms have been proposed linking these elevated risks to both cancer and treatment. More attention should be paid to comorbidities in men with prostate cancer. The present study fulfills a gap in the knowledge of death causes in prostate cancer patients.

The present study assessed subsequent cancer risks in type 2 diabetes patients first hospitalized for this disease at age >39 years. Twenty-four cancer types showed an elevated risk when follow-up was started after the last hospitalization for type 2 diabetes. No additional risk was found in familial diabetics., Objectives. Cancer and type 2 diabetes (T2D) are two common diseases that may share risk factors. We aimed at determining subsequent cancer risks in patients hospitalized for T2D in Sweden. Methods. T2D patients were obtained from the nationwide Hospital Discharge Register; cancers were recorded from the Swedish Cancer Registry. Standardized incidence ratios (SIRs) were calculated for cancer following last hospitalization for T2D. The comparison group was the general Swedish population. Results. The number of hospitalized T2D patients from 1964 to 2007 was 125,126, of whom 26,641 had an affected family member. Altogether 24 cancers showed an elevated risk when follow-up was started after the last hospitalization. The highest SIRs were for pancreatic (6.08) and liver (4.25) cancers. The incidences of these cancers were even elevated when follow-up was started 5 years after the last hospitalization for T2D, with primary liver cancer showing the highest SIR of 4.66. Also increased were the incidences of upper aerodigestive tract, esophageal, colon, rectal, pancreatic, lung, cervical, endometrial, ovarian, and kidney cancers. Prostate cancer showed a lower risk. Familial T2D patients showed no exceptional elevated cancer risks but their prostate cancer and melanoma risks were lower. Conclusions. This study, covering approximately one half of Swedish T2D patients, showed an elevated risk for several cancers after hospitalization for T2D, probably indicating the profound metabolic disturbances of the underlying disease. The highest risks were found for liver and pancreatic cancers. No excess cancer risks were observed in familial diabetics. The lower risk for prostate cancer remains intriguing.

Objectives. Studies reporting cancer risk after PMR and GCA are few, but it remains an issue of both concern and controversy. We examined the overall and specific cancer risks among Swedish subjects following hospitalization for these diseases. Methods. PMR and GCA patients were identified from the Swedish Hospital Discharge Register and by linking them with the Cancer Registry. Follow-up of patients was carried out from the last hospitalization through year 2006. Standardized incidence ratios (SIRs) were calculated in these patients compared with subjects without the diseases. Results. A total of 35 918 patients were hospitalized for PMR and GCA during the years 1965-2006; the hospitalization rate increased towards late age. A total of 3941 patients developed subsequent cancer, giving an overall SIR of 1.19; and for cancer diagnosed later than 1 year of follow-up, the SIR was 1.06. A significant excess was noted for skin (squamous cell carcinoma and melanoma), stomach, lung, prostate, kidney, nervous system and endocrine gland tumours, and additionally for non-Hodgkin's lymphoma, myeloma and leukaemia. Decreased risk was noted for endometrial cancer. Conclusions. Patients hospitalized for PMR and GCA had a marginally increased risk of cancer, with the highest risk noted for the first year after hospitalization. However, for specific cancers, such as skin cancer and leukaemia, the increases were still significant for patients diagnosed later than 1 year after hospitalization, suggesting that these could be true associations, but the mechanisms remain to be established. (Less)

SLEEP DISORDERED BREATHING (SDB) IS A CONDITION CHARACTERIZED BY INTERMITTENT PARTIAL OR COMPLETE UPPER AIRWAY OBSTRUCTION THAT disrupts normal ventilation during sleep and normal sleep patterns.1 There is no consensus on the definition of pediatric SDB, but clinically there is a spectrum of symptoms, in which the milder forms only have primary snoring and mouth-breathing, while the more severe forms have symptoms similar to the more defined entity obstructive sleep apnea syndrome (OSAS), i.e., intermittent breathing pauses (apneas), habitual snoring, snorts or gasps, disturbed sleep,1 and daytime neurobehavioral problems with impaired school performance.2 Complications of OSAS include failure to thrive and, in severe cases, cor pulmonale and even death.1 To diagnose OSAS, sleep studies are required; the gold standard is full-night polysomnography (PSG) with electroencephalography (EEG).1 However, PSG is expensive, time-consuming, and not widely available; thus the term SDB is most often clinically used. The correlation between clinical history of snoring and apnea and the polysomnographic findings have been investigated. One study showed that apneic episodes every night detected by parents were the most important single risk factor for OSAS.3 Further, previous adenoidectomy was a risk factor, suggesting that the epipharyngeal space does not play a central role in pediatric OSAS.3 Another study showed that tonsillar hypertrophy was correlated to more severe apnea among pre-school-age children, but not among school-age children.4 The most important risk factor to SDB and OSAS is adenotonsillar hypertrophy.5 There are diverging results concerning if the severity of OSAS is proportional to the size of the tonsils and adenoids,6 or not.7 Other risk factors are obesity, craniofacial anomalies, and/or neuromuscular disorders etc.8,9 Surgical removal of adenotonsillar hypertrophy is the first treatment option in children.8,10–12 Removal of adenoids from the nasopharynx alone may not be sufficient to treat OSAS and is mostly performed to treat primary snoring and mouth breathing.3 A recent epidemiologic review suggests that the prevalence of parent-reported symptoms of SDB on questionnaire is 4% to 11%; OSA diagnosed by varying criteria on diagnostic studies, 1% to 4%.13 The prevalence of SDB is higher among boys than girls, and among African Americans compared to other races.13 In addition, obesity and overweight showed to have different importance among older versus younger children, in whom enlarged tonsils are believed to play a major role in SDB risk.13 The prevalence of adenotonsillar hypertrophy in children is unknown. Genetic studies of adults and children indicate that also heredity can be an important risk factor for OSA or SDB.14–18 Genome scan of white adults in USA has been performed.14 Evidence for linkage to the apnea-hypopnea index (severity of OSA) was found in 2 chromosome regions. The Cleveland Family Study in the United States suggested that the angiotensin-converting enzyme (ACE) deletion allele may protect against hypertension in the setting of obstructive sleep apnea.15 Further shown in OSA children is that RNA derived from peripheral leukocytes confirms the presence of involved genes related to the inflammatory response.16 Apolipoprotein E (ApoE) epsilon4 allele was associated with not only increased odds of having SDB, but also with an increased risk for neurocognitive dysfunction,17 and polymorphisms involving more than one locus in the ApoE gene and its regulatory region were associated with OSA in Caucasian children.18 In Sweden, there is a special hospital diagnostic code for OSAS. However, it is seldom used for children as they only occasionally undergo sleep studies, i.e., polysomnography at hospitals, with measurements of breathing, pulse oximetry, and/or transcutaneous carbon dioxide, can be performed. SDB has no special diagnostic code and therefore, children with such symptoms and suspected OSAS get the code adenotonsillar hypertrophy instead. If a child previously has undergone adenoidectomy but still has symptoms, the code of hypertrophy of tonsils is used. The construction of a large population-based patient register has led to the rapid development of genetic-epidemiological studies in Sweden.19,20 In addition, a recently published large-scale population-based study from our group has found that, after accounting for socioeconomic status, age, geographic region, and period of diagnosis, adults with at least one sibling who had a hospital diagnostic code of OSAS had a 3-fold increased risk of getting diagnosed with the same code during 8 years.21 In the present study we included hospital data on all children in Sweden during the study period between 1997 and 2004, i.e., a total of 2.7 million individuals. The individual study population was siblings born in 1978 and onward. The use of hospital register data eliminated recall bias. Recall bias is a potential problem when conducting case-control studies of familial risk because patients in the case group are prone to report a positive family history of the disease or other health problem being studied. The main aim of this study was to define the familial risk of hospitalization for primary diagnostic codes of (1) OSAS and/or (2) suspected OSAS, with clinical signs of SDB and adenotonsillar hypertrophy, in Swedish children less than 19 years of age. A further aim was to determine whether there were any differences by age and gender.

MicroRNAs (miRNAs) negatively regulate expression of target transcripts by hybridization to complementary sites of their messenger RNA targets. Chen et al. have described several putative functional single nucleotide polymorphisms (SNPs) in miRNA target sites. Here, we selected 11 miRNA target site SNPs located in 3' untranslated regions of genes involved in cancer and breast cancer to analyze their impact on breast cancer risk using a large familial study population. Whereas no association was observed for 10 SNPs, a significant association was revealed for the variant affecting a miRNA target site in the estrogen receptor (ESR) 1. Age stratification showed that the association was stronger in premenopausal women [C versus T: odds ratio (OR) = 0.60, confidence interval (CI) = 0.41-0.89, P = 0.010]. Furthermore, the effect was stronger in high-risk familial cases (C versus T: OR = 0.42, CI = 0.25-0.71, P = 0.0009). Clinical studies have shown that elimination of ESR1 significantly reduces breast cancer risk. Thus, therapies that inhibit ESR1 are used for breast cancer treatment. According to in silico analysis, ESR1_rs2747648 affects the binding capacity of miR-453, which is stronger when the C allele is present. In contrast, the T allele attenuates the binding of miR-453, which might lead to a reduced miRNA-mediated ESR1 repression, in consequence higher ESR1 protein levels and an increased breast cancer risk. Thus, the breast cancer protective effect observed for the C allele in premenopausal women is biologically reasonable. The analysis of large study populations in multicentre collaboration will be needed to verify the association and answer questions regarding the possible impact of this variant on therapeutic and clinical outcome.

The common single-nucleotide polymorphism (SNP) rs3802842 at 11q23.1 has recently been reported to be associated with risk of colorectal cancer (CRC). To examine this association in detail we genotyped rs3802842 in eight independent case-control series comprising a total of 10 638 cases and 10 457 healthy individuals. A significant association between the C allele of rs3802842 and CRC risk was found (per allele OR = 1.17; 95% confidence interval [CI]: 1.12-1.22; P = 1.08 x 10(-12)) with the risk allele more frequent in rectal than colonic disease (P = 0.02). In combination with 8q21, 8q24, 10p14, 11q, 15q13.3 and 18q21 variants, the risk of CRC increases with an increasing numbers of variant alleles for the six loci (OR(per allele) = 1.19; 95% CI: 1.15-1.23; P(trend) = 7.4 x 10(-24)). Using the data from our genome-wide association study of CRC, LD mapping and imputation, we were able to refine the location of the causal locus to a 60 kb region and screened for coding changes. The absence of exonic mutations in any of the transcripts (FLJ45803, LOC120376, C11orf53 and POU2AF1) mapping to this region makes the association likely to be a consequence of non-coding effects on gene expression.

Objectives. To quantify the sibling risk of RA, SLE and AS. To analyse the concordant and discordant associations between RA, SLE and AS. Methods. Follow-up study of all individuals and their siblings born in or after 1932 and hospitalized for RA, SLE or AS between 1973 and 2004 (32 yrs). Data were retrieved from a comprehensive dataconstructed by using several national Swedish data registers, including the Total Population Register, the Swedish Hospital Discharge Register and the Multigeneration Register. Standardized incidence ratios (SIRs) were used to estimate sibling risks. Results. For males, the overall significant SIRs were 4.72, 4.35 and 4.14 for RA, SLE and AS, respectively, if a sibling was affected by any inflammatory disease. The corresponding significant SIRs for females were 4.12, 3.73 and 4.73. The concordant significant SIRs in siblings were 5.12, 17.02 and 17.14 for RA, SLE and AS, respectively. There were also discordant associations between RA and SLE, whereas AS was only associated with AS. Conclusions. This study was able objectively to quantify the sibling risk of RA, SLE and AS, which represents useful knowledge for clinicians and geneticists. The analysis of concordant and discordant associations may be useful in future studies aimed at finding specific genes associated with these diseases.

Data from several studies have suggested that polymorphisms in A-kinase anchoring proteins (AKAPs), which are key components of signal transduction, contribute to carcinogenesis. To evaluate the impact of AKAP variants on breast cancer risk, we genotyped six nonsynonymous single-nucleotide polymorphisms that were predicted to be deleterious and found two (M463I, 1389G>T and N2792S, 8375A>G) to be associated with an allele dose-dependent increase in risk of familial breast cancer in a German population. We extended the analysis of AKAP9 M463I, which is in strong linkage disequilibrium with AKAP9 N2792S, to 9523 breast cancer patients and 13770 healthy control subjects from seven independent European and Australian breast cancer studies. All statistical tests were two-sided. The collaborative analysis confirmed the association of M463I with increased breast cancer risk. Among all breast cancer patients, the combined adjusted odds ratio (OR) of breast cancer for individuals homozygous for the rare allele TT (frequency = 0.19) compared with GG homozygotes was 1.17 (95% confidence interval [CI] = 1.08 to 1.27, P = .0003), and the OR for TT homozygotes plus GT heterozygotes compared with GG homozygotes was 1.10 (95% CI = 1.04 to 1.17, P = .001). Among the combined subset of 2795 familial breast cancer patients, the respective ORs were 1.27 (95% CI = 1.12 to 1.45, P = .0003) and 1.16 (95% CI = 1.06 to 1.27, P = .001).

OBJECTIVES: Patients diagnosed with RA have been at an increased risk of many cancers and at a decreased risk of some cancers. We planned to revisit the theme by using a nation-wide population of RA patients.METHODS: An RA research database was constructed by identifying hospitalized RA patients from the Hospital Discharge Register and cancer patients from the Cancer Registry. Earlier studies from Sweden have shown that some 75% of RA patients have been hospitalized at some time point. Follow-up of 42,262 RA patients was carried out from year 1980 to 2004 including separate follow-ups for shorter intervals. Standardized incidence ratios (SIRs) were calculated for cancer in RA patients by comparing with subjects without RA.RESULTS: Many cancers were in excess in RA patients, especially Hodgkin disease, non-Hodgkin lymphoma and squamous cell skin cancer; a novel association was found for non-thyroid endocrine tumours. Colon, rectal and endometrial cancers were decreased in RA patients. When RA patients were first hospitalized after 1999, the SIRs for melanoma, squamous cell skin and upper aerodigestive tract cancers and for leukaemia were increased compared with previous periods.CONCLUSIONS: This study, the largest so far published, quantified the increased and decreased site-specific risks of cancer in RA patients. The recent increases in the risks of squamous cell skin and upper aerodigestive tract cancers, melanoma and leukaemia call for continuous vigilance and recording of changes in treatment. (Less)

A paper by Bond et al. reported that a single-nucleotide polymorphism (SNP) in the intronic promoter region of the mouse double minute 2 (MDM2) gene (called SNP309) can significantly change the expression of MDM2 and thereby suppress the p53 pathway. Furthermore, it was shown that SNP309 accelerates tumor formation in Li-Fraumeni patients. This initial report aroused the attention of many researchers, which investigated the role of SNP309 for the risk and the onset of cancer in different tissues. To provide a more robust estimate of the effect of this polymorphism on cancer risk, we combined the available genotype data for breast, colorectal and lung cancers. For breast cancer, we combined the data from 11 studies including 5737 cases and 6703 controls. For colorectal cancer, we combined the data from five studies with 1620 cases and 886 controls. For lung cancer, we performed a fixed-effect meta-analysis from seven studies including 4276 cases and 5318 controls. Our results suggest that the SNP309 variant does not have an impact on the risk of breast [odds ratio (OR) = 0.97, 95% confidence interval (CI) = 0.87-1.08] or colorectal cancers (OR = 0.97, 95% CI = 0.76-1.25). However, the combined estimate of the ORs for lung cancer revealed an increased risk for GG versus TT (OR = 1.27, 95% CI = 1.12-1.44). The data show that SNP309 alone has little or no effect on the risk of common cancers, but it might modify the time of tumor onset and prognosis.

Background: Survivors of childhood leukemia and lymphoma experience high risks of second malignant neoplasms. We quantified such risk using a large dataset from 13 population-based cancer registries. Methods: The registries provided individual data on cases of leukemia, Hodgkin lymphoma, and non-Hodgkin lymphoma occurring in children aged 0-14 years and on subsequent second malignant neoplasms for different time periods from 1943 to 2000. Risks of second malignant neoplasms were assessed through standardized incidence ratios (SIRs) and corresponding 95% confidence intervals (CIs), using the incidence rates in the general populations covered by the registries as a reference. Cumulative absolute risks were also calculated. Results: A total of 133 second malignant neoplasms were observed in 16 540 patients (12 731 leukemias, 1246 Hodgkin lymphomas, and 2563 non-Hodgkin lymphomas) after an average follow-up of 6.5 years. The most frequent second malignancies after leukemia were brain cancer (19 cases, SIR = 8.52, 95% CI = 5.13 to 13.3), non-Hodgkin lymphoma (nine cases, SIR = 9.41, 95% CI = 4.30 to 17.9), and thyroid cancer (nine cases, SIR = 18.8, 95% CI = 8.60 to 35.7); the most frequent after Hodgkin lymphoma were thyroid cancer (nine cases, SIR = 52.5, 95% CI = 24.0 to 99.6), breast cancer (six cases, SIR = 20.9, 95% CI = 7.66 to 45.4), and neoplasms of skin (non-melanoma) (six cases, SIR = 34.0, 95% CI = 12.5 to 74.0); and the most frequent after non-Hodgkin lymphoma were thyroid cancer (six cases, SIR = 40.4, 95% CI = 14.8 to 88.0) and brain cancer (four cases, SIR = 6.97, 95% CI = 1.90 to 17.9). Cumulative incidence of any second malignant neoplasm was 2.43% (95% CI = 1.09 to 3.78), 12.7% (95% CI = 8.29 to 17.2), and 2.50% (95% CI = 1.04 to 3.96) within 30 years from diagnosis of leukemia, Hodgkin lymphoma, and non-Hodgkin lymphoma, respectively. Conclusions: This population-based study provides, to our knowledge, the most precise and up-to-date estimates for relative and absolute risks of second malignant neoplasms after childhood leukemia and lymphoma. © The Author 2007. Published by Oxford University Press. All rights reserved.

Copy number variants (CNVs), insertions, deletions and duplications, contribute considerably to human genetic variation and disease development. A recent study has characterized 100 CNVs including a deletion in the mitochondrial tumor suppressor gene 1 (MTUS1) lacking the coding exon 4. MTUS1 maps to chromosome 8p, a region frequently deleted and associated with disease progression in human cancers, including breast cancer (BC). To investigate the effect of the MTUS1 CNV on familial BC risk, we analyzed 593 BC patients and 732 control individuals using a case-control study design. We found a significant association of the deletion variant with a decreased risk for both familial and high-risk familial BC (odds ratio (OR) = 0.58, 95% confidence interval (CI) = 0.37-0.90, P = 0.01 and OR = 0.41, 95% CI = 0.23-0.74, P = 0.003), supporting its role in human cancer. To our knowledge, the present study is the first to determine the impact of a CNV in a tumor suppressor gene on cancer risk.

Background: Personal history of autoimmune diseases is consistently associated with increased risk of non-Hodgkin lymphoma. In contrast, there are limited data on risk of Hodgkin lymphoma following autoimmune diseases and al most no data addressing whether there is a familial association between the conditions. Methods: Using population-based linked registry data from Sweden and Denmark, 32 separate autoimmune and related conditions were identifi ed from hospital diagnoses in 7476 case subjects with Hodgkin lymphoma, 18 573 matched control subjects, and more than 86 000 fi rstdegree relatives of case and control subjects. We calculated odds ratios (ORs) and 95% confi dence intervals (CIs) as measures of relative risks for each condition using logistic regression and also applied multivariable hierarchical regression models. All P values are two-sided. Results: We found statistically signifi cantly increased risks of Hodgkin lymphoma associated with personal histories of several autoimmune conditions, including rheumatoid arthritis (OR = 2.7, 95% CI = 1.9 to 4.0), systemic lupus erythematosus (OR = 5.8, 95% CI = 2.2 to 15.1), sarcoidosis (OR = 14.1, 95% CI = 5.4 to 36.8), and immune thrombocytopenic purpura (OR = ∞ , P = .002). A statistically signifi cant increase in risk of Hodgkin lymphoma was associated with family histories of sarcoidosis (OR = 1.8, 95% CI = 1.01 to 3.1) and ulcerative colitis (OR = 1.6, 95% CI = 1.02 to 2.6). Conclusions: Personal or family history of certain autoimmune conditions was strongly associated with increased risk of Hodgkin lymphoma. The association between both personal and family histories of sarcoidosis and a statistically signifi cantly increased risk of Hodgkin lymphoma suggests shared susceptibility for these conditions. [J Natl Cancer Inst 2006;98: 1321 – 30 ]

Candidate gene studies have become very popular but some of their implicit constraints, such as the familial risk and the population attributable fraction (PAF) conferred by the gene under study, are poorly understood. We model here these parameters for susceptibility genes in terms of genotype relative risk (GRR), allele frequency and statistical power in simulated genetic association studies, assuming 500 or 2000 case-control pairs and different modes of inheritance. The results show that the common association studies on genes with minor allele frequency >10% have sufficient power to detect disease-causing variants conferring PAFs >10%, which can be compared to known genes, such as BRCA1 with a PAF of 1.8%. Yet, common low-risk variants confer low familial relative risks (FRRs), typically

Summary Background Basal cell carcinoma (BCC) is one of the most common neoplasms in the world. Development of BCC is associated with environmental factors (especially sun exposure) as well as heritable factors. Objectives To analyse three single nucleotide polymorphisms (SNPs) in the promoter regions of interleukin (IL) genes in genomic DNA from 527 cases of BCC and 530 matched controls and to examine if DNA pooling is a useful method on which to base decisions regarding further SNP analysis. Methods The SNPs analysed were IL6–597, IL10–1082 and IL1B–511. The SNPs were first analysed from pooled DNA and afterwards from individual samples. The DNA pools resulted from a division of the samples into cases and controls, female and male, and three age groups. In these pools the allele frequencies were estimated by two methods, real-time polymerase chain reaction with allele-specific primers, and quantitative sequencing. Results No significant association was found when the allele frequencies in cases and controls were compared. However, by analysis of the individual genotypes we found SNP IL6–597 G/A to be significantly associated with BCC risk (P =0·007). Hereby the heterozygous genotype ‘GA’ had a protective effect (odds ratio 0·64, 95% confidence interval 0·49–0·84). No significant association was found for IL10–1082 and IL1B–511. Conclusions The association of SNP IL6–597 with BCC could be found only by individual genotyping, but would have been missed if only data from the pooling analysis had been known.

The mitogen effect of the ovarian steroid estrogen is a strong risk factor for breast cancer development. This effect is mainly mediated by the estrogen receptor alpha, a hormone inducible transcription factor, which activates gene expression through recruiting multiple coactivators, such as PPARGC1A, PPARGC1B and EP300. We tested the hypothesis that non-conservative, putative functional amino acid exchanges in PPARGC1A, PPARGC1B and EP300 act as low-penetrance familial breast cancer risk factors. The analysis of 816 BRCA1/2 mutation-negative familial breast cancer patients and 1012 controls revealed an association of the PPARGC1A Thr612Met polymorphism with familial breast cancer (OR = 1.35, 95% CI 1.00-1.81, P = 0.049), high-risk familial breast cancer (OR = 1.51, 95% CI 1.08-2.12, P = 0.017) and bilateral familial breast cancer (OR = 2.30, 95% CI 1.24-4.28, P = 0.009). Logistic regression analyses of the PPARGC1B Ala203Pro variant showed an increased familial breast cancer risk of heterozygous and homozygous variant allele carriers (OR = 1.48, 95% CI 1.15-1.91, P = 0.002). The genotype-combination analysis of the associated PPARGC1A Thr612Met variant and the associated PPARGC1B Ala203Pro variant suggests an allele dose-dependent breast cancer risk (P(trend) = 0.0004). Our results indicate for the first time the importance of inherited variants in the estrogen receptor coactivator genes PPARGC1A and PPARGC1B for familial breast cancer susceptibility. Owing to their impact on estrogen signaling, these polymorphisms might also influence adjuvant anti-estrogen therapy, using agents such as tamoxifen and raloxifen, and outcome of breast cancer patients.

Studies of pancreatic cancer in the setting of second primary malignant neoplasms can provide etiologic clues. An international multicenter study was carried out using data from 13 cancer registries with a registration period up to year 2000. Cancer patients were followed up from the initial cancer diagnosis, and the occurrence of second primary malignant neoplasms was compared with expected values derived from local rates, adjusting for age, sex, and period of diagnosis. Results from individual registries were pooled by use of a fixed-effects model. People were at higher risk of developing pancreatic cancer within 10 years of a diagnosis of cancers of the pharynx, stomach, gallbladder, larynx, lung, cervix, corpus uteri, bladder, and eye and 10 years or later following a diagnosis of cancers of the stomach, colon, gallbladder, breast, cervix, placenta, corpus uteri, ovary, testis, bladder, kidney, and eye, as well as Hodgkin's and non-Hodgkin's lymphomas. Pancreatic cancer was connected with smoking-related cancers, confirming the etiologic role of tobacco. The associations with uterine and ovarian cancers suggest that reproductive factors might be implicated in pancreatic carcinogenesis. The elevated pancreatic cancer risk in young patients observed among several types of cancer implies a role of genetic factors. Radiotherapy is also suggested as a risk factor. Copyright © 2006 by the Johns Hopkins Bloomberg School of Public Health All rights reserved.

Biomarkers of individual susceptibility: field studiesBiomarker (including alleles if genetic): XPC(A>C;K939Q), XPD(A>C;K715Q), XPG(G>C;D1104H), APEX1(T>G;D148E), XRCC1(G>A;R399Q), XRCC3(C>T;T241M), NBS1(G>C;E185Q)Effect studied (phenotype/pathology):modulation of BCC riskTissue/biological material/sample size: BLOODMethod of analysis: PCRStudy design: case-controlStudy size: 529 subjects with BCC, 533 controlsImpact on outcome (including dose-response): XRCC3(C>T;T241M) decreased risk for BCC, PR 0.66, CI95%, 0.51-0.86, P=0.002NBS1(G>C;E185Q) increased risk for BCC in men OR1.44, CI95%, 1.1-1.88, P=0.008, not in women OR0.96, CI95%, 0.74-1024, P=0.76All other polymorphisms no correlation found with risk. KEYWORDS CLASSIFICATION: adverse effects;Adolescent;Adult;Aged;Aged,80 and over;biomarkers of individual susceptibility: field studies;cancer epidemiology;Carcinoma,Basal Cell;Case-Control Studies;Cell Cycle;Cell Cycle Proteins;Child;Child,Preschool;DNA Repair;epidemiology;Female;genetics;Genetic Predisposition to Disease;Genotype;Germany;Humans;Hungary;Male;Middle Aged;Neoplasm Proteins;Nuclear Proteins;Odds Ratio;Polymorphism,Single Nucleotide;Proteins;Research;Risk Factors;Romania;Skin Neoplasms;Slovakia;Ultraviolet Rays. In addition to environmental exposures like UV radiation and, in some cases, arsenic contamination of drinking water, genetic factors may also influence the individual susceptibility to basal cell carcinoma of skin (BCC). In the present study, 529 cases diagnosed with BCC and 533 controls from Hungary, Romania and Slovakia were genotyped for one polymorphism in each of seven DNA repair genes. The variant allele for T241M (C>T) polymorphism in the XRCC3 gene was associated with a decreased cancer risk [odds ratio (OR), 0.73; 95% confidence interval (CI), 0.61-0.88; P = 0.0007, multiple testing corrected P = 0.004]. The risk of multiple BCC was significantly lower among variant allele carriers than in non-carriers (P = 0.04). Men homozygous for the C-allele for E185Q (G>C) polymorphism in the NBS1 gene showed an increased BCC risk (OR, 2.19; 95% CI, 1.23-3.91), but not women (OR, 0.84; 95% CI, 0.49-1.47). In men, the age and nationality adjusted OR for the genotype CC (XRCC3)/CC (NBS1) was 8.79 (95% CI, 2.10-36.8), compared with the genotype TT (XRCC3)/GG (NBS1). The data from this study show overall risk modulation of BCC by variant allele for T241M polymorphism in XRCC3 and gender-specific effect by E185Q polymorphism in NBS1.

The A-kinase anchor protein 13 (AKAP13, alias BRX and lbc) tethers cAMP-dependent protein kinase to its subcellular environment and catalyses Rho GTPases activity as a guanine nucleotide exchange factor. The crucial role of members of the Rho family of GTPases in carcinogenesis is well established and targeting Rho proteins with antineoplastic compounds has become a major effort in the fight against cancer. Thus, genetic alterations within the candidate cancer susceptibility gene AKAP13 would be expected to provoke a constitutive Rho signalling, thereby facilitating the development of cancer. Here, we analysed the potential impact of four polymorphic non-conservative amino acid exchanges (Arg494Trp, Lys526Gln, Asn1086Asp and Gly2461Ser) in AKAP13 on familial breast cancer. We performed a case-control study using genomic DNA of BRCA1/2 mutation-negative German female index patients from 601 unrelated families, among a subset of 356 high-risk families, and 1053 German female unrelated controls. The newfound Lys526Gln polymorphism revealed a significant association with familial breast cancer (OR = 1.58, 95% CI = 1.07-2.35) and an even stronger association with high-risk familial breast cancer (OR = 1.85, 95% CI = 1.19-2.88). Haplotype analyses were in line with genotype results displaying a similar significance as analyses of individual polymorphisms. Due to the pivotal role of AKAP13 in the Rho GTPases signalling network, this variant might affect the susceptibility to other cancers as well.

Carcinogenic chemicals act through DNA damage and mitogenic effects. No established mechanism explains the cancer preventive effects, if any, of food items, such as vegetables and fruit. If such data were available, preferably on tumor-initiating genes, the evidence for the protective effects would become stronger. The von Hipple-Lindau (VHL) gene is the tumor suppressor gene predisposing to both sporadic renal cell carcinoma (RCC) and von Hippel-Lindau disease. We have earlier analyzed VHL mutations in RCCs from 102 Swedish patients identified in a case-control study and here examine associations between patient characteristics, including dietary habits and mutations, considering the type of mutation. The results are given as odds ratios (OR), separately for smokers and all patients. In univariate analysis, consumption of vegetables and citrus fruit decreased the frequency of VHL mutations among smokers and citrus fruit among all patients. In multivariate analysis of smokers' characteristics, welding fumes showed a risk of 5.63 for multiple VHL mutations. In smokers, citrus fruit decreased the OR of GC to AT mutations to 0.13 and that of multiple mutations to 0.17; vegetables decreased the OR for single mutations to 0.22. Among all subjects, welding fumes were a risk factor and citrus fruit a protective factor. Additionally, an intake of selenium protected against multiple mutations. The present results provide evidence that the intake of vegetables, selenium and particularly of citrus fruit protects the renal VHL gene from mutational insults that may be endogenous or common in a population. Even though most of the associations are biologically plausible, and vegetables and fruit were an a priori hypothesis, fortuitous results cannot be ruled out in this relatively small study.

Endogenous DNA damage is assumed to be a major contributor to aging and cancer. This study compares the steady-state levels of 7-methyl- and 7-(2-hydroxyethyl)-guanine DNA adducts in lymphocytes isolated from the younger (mean age 39.8 years) and the older (mean age 82.8 years) healthy subjects. Using a 32P-post-labelling method, these adducts were measured in lymphocyte DNA from a total of 34 subjects. The results show that the amount of both 7-methyl- and 7-(2-hydroxyethyl)-guanine adducts in the younger age group was similar to that in the older age group. Our findings show that at steady-state the levels of DNA alkylation products are independent of age, suggesting that endogenous DNA damage, through methylation or lipid peroxidation, and the repair of such damage may not be deficient in lymphocytes of older individuals.

p53R2 is a recently cloned gene that functions in p53-induced DNA repair. In the 5'-untranslated region of the p53R2 gene two direct tandem 8 bp repeats are located. Within the region of these 8 bp direct repeats we have detected the insertion of an additional repeat. In order to determine a possible association of this novel polymorphism with any cancer or population, we carried out genotyping of 843 European and Asian controls and patients with various cancer types. In addition, 26 cancer cell lines were included in the study. No significant difference in polymorphic frequency could be demonstrated for any of the cancer types, although the allelic frequency in melanoma patients was lower than in controls (chi(2) = 3.28; P = 0.07; OR = 0.32; 95% CI 0.07-1.26). A significantly higher frequency of the polymorphism was detected in the compiled Caucasian individuals compared with Asians (chi(2) = 9.19; P = 0.002; OR = 3.13; 95% CI 1.39-7.43). In one tumour cell line we observed two extra inserted copies of the 8 bp repeat. The functional effect of the insertion polymorphism on the p53R2 gene transcription remains to be determined.

Forty-four Finnish volunteers who were previously studied with regard to the repair rate of UV-specific cyclobutane pyrimidine dimers in the skin were genotyped for XPD polymorphisms at codons 312 (exon 10 G-->A, Asp-->Asn) and 751 (exon 23 A-->C, Lys-->Gln). The repair rate was measured at 24 h for two different cyclobutane dimers. The data did not show consistent XPD genotype-specific differences in DNA repair rates among all subjects. The combined exon 10 AA and exon 23 CC genotype was associated with an approximately 50% depression of repair rate but this was of borderline statistical significance. However, the exon 23 C allele was associated with depressed repair among subjects aged 50 years or older and the result was consistent with both dimers.

To study genetic changes associated with the development of breast cancer and the extent of its hereditary predisposition, paraffin-embedded tissue samples were obtained from monozygotic twin pairs concordant for breast cancer through the linked Swedish Twin and Cancer Registries. DNA samples extracted from the matched tumour and normal tissues of nine twin pairs were analysed for allelic imbalance using a series of microsatellite markers on chromosomes 13 and 17, containing loci with known tumour suppressor genes. Multiple losses of constitutional heterozygosity (LOH), consistent with a loss of large genomic region, the whole chromosome or chromosome arm, was found in at least three pairs of twins. One double mitotic crossover was identified in one tumour sample in a pair concordant for LOH at multiple loci on both chromosomes. Recombination breakpoints were mapped to regions delineated by D13S218 and D13S263, and D13S155 and D13S279, respectively. In general, no genetic effect of losing the same allele within a twin pair was found. However, for one marker at chromosome 13 (D13S328, between the BRCA2 and the RB-1 loci) and two markers on chromosome 17 (D17S786, distal to the p53 locus, and D17S855, an intragenic BRCA1 marker) the proportion of twin pairs with the same LOH was significantly higher than expected. These regions may reflect hereditary genomic changes in our sample set. In addition, tumour DNA samples from a subset of 12 twin pairs were analysed for BRCA1 and BRCA2 mutations using exon-by-exon single-strand conformation polymorphism analysis. Two unclassified BRCA2 variants, with a putative pathogenic effect, were identified, but no pathogenic alterations were found in the BRCA1 gene.

Summary Background Ultraviolet (UV) radiation is mutagenic and induces specific DNA lesions in human skin that are often found at dipyrimidine sites. These photoproducts are likely to be biologically relevant regarding skin carcinogenesis, as p53 mutations in skin tumours are most often found at these UV radiation-specific sites within DNA. Psoriasis patients receiving long-term phototherapy are at an increased risk of non-melanoma skin cancers. Objectives The aim of this study was to quantify DNA photoproducts in human epidermis in vivo following consecutive doses of UVB and to investigate variations in DNA damage according to skin type, UVB dose and age. Methods Eleven psoriasis patients receiving UVB phototherapy three times a week were recruited and underwent skin biopsies on a non-sun-exposed site before starting phototherapy and after three, nine and 18 UVB exposures. A biopsy was also taken at least 4 weeks after stopping phototherapy. DNA was extracted from separated epidermis and three types of photoproducts were quantified using a novel 32 P high-performance liquid chromatographic technique. Results The mean level of cyclobutane dipyrimidine dimers (CPDs) after three doses of UVB (dose range 0·03‐0·15 J cm 22 ) was 3·2 (range 0·8‐8·9) photoproducts per 10 6 normal nucleotides for TTaT dimers and 4·5 (range 0‐14) per 10 6 normal nucleotides for TTaC dimers. The mean levels of TT‐C 6‐4 photoproducts after three doses of UVB were very low (0·2, range 0‐1·8). Overall, the levels of TTaT and TTaC reached a plateau at three exposures and were found to decrease for subsequent exposures despite increasing UVB doses. Skin type was negatively associated with mean levels of CPDs. However, significant differences in levels of photoproducts were seen between individuals, even after adjusting for skin type. No association was found between challenge dose of UVB and photoproduct yield in this study. Conclusions This study showed a great individual variation in the accumulation of DNA photoproducts following exposure to repetitive doses of UVB. Photoadaptive responses of human skin involving DNA repair, tanning and epidermal thickening are likely to explain the overall lack of increase in DNA lesions throughout phototherapy. This in vivo study confirms that psoriasis patients produce a significant amount of DNA photolesions at suberythemal doses of UVB. Further work is needed to investigate which host factors are most likely to predict susceptibility to UV radiationinduced DNA damage.

A C-->T polymorphism in intron 7 of the human tumour suppressor gene p53 was studied in 159 urinary bladder cancer patients and 171 non-cancer controls. The polymorphism was found in 15% of both patients and controls, suggesting that it has no relevance in urinary bladder cancer pathogenesis or aetiology. A second polymorphism, a T-->G change located 20 bp downstream of the C-->T change, was found in all samples with the C-->T change. Our findings indicate that the C-->T and the T-->G changes occur simultaneously and belong to the same allelotype.

We present here the first mass spectroscopic (MS) identification of the main tamoxifen-induced DNA adducts in rat liver. The two main adducts were isolated by high-performance liquid chromatography (HPLC) and identified by MS, MS-MS and ultraviolet spectroscopy. Adduct 1 was the N-desmethyltamoxifen-deoxyguanosine adduct in which the alpha-position of the metabolite N-desmethyltamoxifen is linked covalently to the amino group of deoxyguanosine. Adduct 2 was confirmed to be the trans isomer of alpha-(N2-deoxyguanosinyl)tamoxifen, as previously suggested by co-chromatography.

Summary Background The MDM2 oncoprotein promotes cell survival and cell cycle progression by inhibiting the p53 tumour suppressor protein. Further, overexpression of the MDM2 gene can inhibit DNA double-strand break repair in a p53-independent manner. Recent studies have shown that a single nucleotide polymorphism (SNP) in the intronic promoter region of MDM2 (called SNP309) can significantly change the expression of MDM2 and thereby suppress the p53 pathway. This SNP was also found to be associated with the onset and risk of different cancer types. Basal cell carcinoma of the skin (BCC) is one of the most common neoplasms in the world. BCC development is associated with environmental factors (especially sun exposure) as well as heritable factors. Objectives The present case–control study investigated the association of the MDM2 SNP309 with the risk and the age at onset of BCC. Methods Data from 509 individuals affected by BCC and 513 healthy controls were genotyped with TaqMan polymerase chain reaction. Results Cases and controls showed a similar genotype distribution and the SNP did not modify the age at onset of BCC. Conclusions These results suggest that the MDM2 SNP309 alone affects neither the risk nor the age at onset of BCC.

The goal of the present study was to measure the levels of DNA adducts in human nasal mucosa cells and in total white blood cells in relation to smoking. DNA was isolated from samples of 20 healthy volunteers (six smokers and 14 non-smokers). The levels of DNA adducts were measured by 32P-postlabelling assay. In smokers the mean DNA adduct levels were 3.3 and 17.0 adducts/10(8) nucleotides in total white blood cells and nasal mucosa cells respectively. The corresponding values in non-smokers were 2.0 and 6.8 adducts/10(8) nucleotides. The mean adduct level was significantly higher in nasal mucosa cells than in total white blood cells both in smokers and non-smokers. The mean adduct levels in smokers' nasal mucosa cells were significantly higher than those in non-smokers. Thus the nasal mucosa cells constituted a sensitive tissue for the determination of cigarette smoking induced DNA adducts. Combining the sensitivity of the 32P-postlabelling assay with the specificity of the nasal mucosa to the airborne chemical exposures, the DNA adduct analysis from human nasal mucosa cells represents a method of choice in the assessment of exposure to airborne carcinogens.

P-postlabelling or immunoassay,this time exposure to polycyclic aromatic hydrocarbons have detected job-related increases in the levels of aromatic(PAH) decreased and the level of DNA adducts decreased and PAH types of DNA adducts, correlating to the level ofaccordingly. In the total group exposure was related to the exposure to PAH. The present study in this foundry haslevel of adducts. Adduct levels correlated with urinary 1- involved an annual sampling of workers and controls inhydroxypyrene (LOGU1OH), air benzo[a]pyrene, weekly November/December in four consecutive years, 1990–1993.working hours and daily cigarette consumption. In a Exposure and some 15 different end-points are being assessed.multivariatemodel1-hydroxypyrenehadaconsistenteffect. Several papers on DNA adducts and somatic cell mutations inNeither glutathione transferase M1 (GSTM1) nor the first year of the study have already been published (10–12).cytochrome P450 1A1 (CYP1A1) genotypes had clear The original objective of the study was to follow a homo-effects. Yet the individuals lacking GSTM1 had a stronger genous population, consisting of people exposed to variouseffect of LOGU1OH and some effect by other sources of levels of PAHs, over four years in order to analyse the levelsPAH, such as charcoal broiled food, although all these of the end-points, including DNA adducts. However, economicvariables were not significant in the multivariate model. slump in Finland with layoffs, shortened working hours andThe rare individuals with a CYP1A1 polymorphism MspI changed exposure partially defeated this original purpose.containing an amino acid change at isoleucine had an Instead, the changes in exposure provided a possibility to testincreased level of adducts. The results showed that the the detection levels of the biomarker assays used. To enablepostlabelling method used was able to detect an increase such an analysis, data on the possible confounding factorsin aromatic DNA adducts in leukocytes when exposure to were needed. Fortunately, at the time of blood sampling abenzo[a]pyrene in air was ~5 ng/m

Styrene 7,8-oxide, which reacts preferentially at the N-7 position of guanine, yielded two pairs of diastereomers 7-(1'-hydroxy-2'-phenylethyl)-dGMP (the alpha-isomer) and 7-(2-hydroxy-2-phenylethyl)-dGMP (the beta-isomer) on reaction with deoxyguanosine-3'-monophosphate (3'-dGMP). The alpha- and beta-isomers were formed in the ratio 32:68. T4 polynucleotide kinase preferentially mediated labelling of diastereomers corresponding to the beta-isomer. The beta-diastereomers showed a labelling efficiency of 52%, whereas the alpha-isomers showed a labelling efficiency of 4%. Molecular modelling experiments showed intrinsic differences between the two isomers. The torsion angles of C8-N7-2'-Ar and C8-N7-2'-1' for the alpha-isomers were 149.9 degrees and -26.4 degrees, whereas the torsion angles of C-8-N7-1'-2' and N7-1'-2'-Ar for the beta-isomers were 105.3 degrees and 179.4 degrees. The consequent interatomic distance between one of the hydrogens on the alpha-carbon and the 3'-phosphate group on the sugar residue was 5.3 A in the alpha-isomer whereas the closest distance between the hydrogens attached to the alpha-carbon and 3'-phosphate group in the beta-isomer was 6.2 A. This arrangement probably leads to steric overcrowding at the 3'-phosphate group in alpha-isomers and these are less efficiently phosphorylated than beta-isomers. In in vitro styrene oxide-modified salmon testis DNA alpha- and beta-isomers of 7-alkylguanines were formed in the ratio 37:63. The recovery of two diastereomeric beta-isomers in a 32P-postlabelling assay was 14%, but one of the diastereomers was obtained in 3-fold greater yield than the second isomer.

A 32 P-HPLC method was applied to study the induction of UVB- and UVC-induced DNA lesions (cyclobutane dimers, 6-4 photoproducts and Dewar isomers) in human skin explants. The employed technique was sensitive enough to detect the lesions at a dose of 10 J/m 2 UVB. Comparison of photoadduct formation under UVC and UVB indicated the importance of photosensitization pathways in DNA damage. Dewar isomers were detected only at a high dose of UVB. The compounds were identified by their photochemical reactivity and by spiking with prepared standards. Treatment with nuclease P1 was used to identify the 5'-terminal nucleotide. UVA caused no detectable adducts.

The presence of N7-alkylguanine adducts in DNA was analysed in a group of 46 patients with larynx tumours. All patients were subjected to laryngectomy and the tissues accessible for analysis by (32)P-post-labelling assay were larynx tumour, larynx non-tumour and peripheral blood leucocytes. N7-Alkylguanine adducts were detected in all the studied DNA samples. The average level of N7-alkylguanines was 26.2/10(7) nucleotides in tumour cells, 22.7/10(7) in non-tumour cells and 13.1/10(7) in blood leucocytes. There was significantly higher level of N7-alkylguanines in the larynx tissues in males than in females. The effect of tobacco smoking on DNA adduct levels was shown by an increase in the average levels of N7-alkylguanines in the subject groups classified according to their smoking habits. A moderate age-related increase in levels of N7-alkylguanine was demonstrated in larynx tumour tissue. The levels of N7-alkylguanine adducts in larynx cells were compared with that of aromatic DNA adducts. Pearson correlation coefficients (0.28 for tumour tissue and 0.30 for non-tumour tissue) indicate independent formation and removal of N7-alkylguanine and aromatic DNA adducts resulting from tobacco smoke exposure.

Styrene-specific N-7- and O6-guanine DNA adducts and N-terminal valine adducts were determined in mice tissues after the intraperitoneal administration of styrene. Blood, liver, lungs and spleen were collected 3 h after administration of various doses (from 0 to 4.35 mmol/kg b.w.) of styrene. DNA adducts were analysed by the modified 32P-postlabelling assay and N-terminal valine adducts were detected by GC-MS according to the modified Edman degradation technique. In the dose-range studied, for all adducts a clear dose-response relationship was observed. 7-Alkylguanines and O6-styrene guanine adducts were most abundant in lungs, approximately 30% more than in liver and spleen. In all analysed tissues 7-alkylguanines were more abundant than O6-styrene guanine adducts. We found a considerably lower rate of N-terminal valine adduct formation as compared with both DNA adducts. The ratio between 7-alkylguanines and O6-guanine adducts was 1.9, 1.6 and 7.8 in liver, lung and spleen, respectively. In vitro determination of both DNA adducts by 32P-postlabelling resulted also in a lower ratio than that reported earlier using an HPLC analysis. All correlation's between dose, haemoglobin and DNA adducts were very high and significant. However, at the highest injected doses the adduct formation showed a levelling off. To explain this phenomenon a model simulation was performed revealing that 3 h after the injection of the higher doses styrene was not completely converted into styrene-7,8-oxide.

Using ELISAs, we determined the concentrations of transforming growth factor alpha (TGF-alpha), the extracellular domain of the erbB-2 receptor (erbB-2 ECD), and mutant p53 protein in stored serum samples of asbestosis patients with and without cancer and control subjects (without asbestosis or cancer). The percentage of individuals in these three groups with increased serum concentrations of TGF-alpha, erbB-2 ECD, and mutant p53, respectively, were: asbestosis patients with cancer, 36%, 16%, 19%; asbestosis patients without cancer, 38%, 19%, 6%; control subjects, 0%, 5%, 10%. Although differences in serum positivity for these oncoproteins were apparent among these groups, the differences did not achieve statistical significance (P > 0.05). In several of the cancer cases, increased concentrations of TGF-alpha, erbB-2 ECD, and mutant p53 were also detected in the stored serum samples collected years before the clinical diagnosis of disease.

The objective of this study was to apply the 32 P-postlabelling method for the detection of UV-induced dipyrimidine photoadducts in human skin explants. [ 32 P]TLC and [ 32 P]HPLC analysis were used. These techniques allow detection of different combinations of cyclobutane dimers and 6-4 photoproducts in human skin at low doses of irradiation. Detection limit of the present method for some dinucleotide adducts is

Occupational exposure to styrene was studied in nine workers of a hand lamination plant in Bohemia. Personal dosimeters were used to monitor the styrene workplace exposure, and the levels of styrene in blood and mandelic acid in urine were measured. Blood samples were taken at four occasions during a 7 month period to determine styrene-specific O6-guanine DNA adducts in lymphocytes and granulocytes, DNA strand breaks and hypoxanthine guanine phosphoribosyltransferase (HPRT) mutant frequency in T-lymphocytes. Seven administrative employees in the same factory (factory controls) and eight persons in a research laboratory (laboratory controls) were used as referents. DNA adduct levels determined by the 32P-postlabelling method in lymphocytes of laminators were remarkably constant and significantly higher (P < 0.0001) than in factory controls at all four sampling times. HPRT mutant frequencies (MF) measured by the T-cell cloning assay were higher in the laminators (17.5 x 10(-6), group mean) than in the factory controls (15.7 x 10(-6), group mean) at three of the four sampling times, but the differences were not statistically significant. However, a statistically significant (P = 0.021) difference between MF in the laminators (18.0 x 10(-6), group mean) and laboratory controls (11.8 x 10(-6), group mean) was observed at sampling time 4 (the only sampling time when this latter group was studied). This result indicates that styrene exposure may induce gene mutation in T-cells in vivo. DNA strand breaks were studied by the 'Comet assay' at the fourth sampling time. The laminators were found to have significantly higher levels of DNA strand breaks than the factory controls (P = 0.032 for tail length, TL; P = 0.007 for percentage of DNA in tail, T%; and P = 0.020 for tail moment, TM). A statistically significant correlation was also found between the levels of lymphocyte DNA adducts and all three DNA strand break parameters (TL P = 0.046; T% P = 0.026 and TM P = 0.034). On the contrary, no significant correlations were found between DNA adduct levels and the HPRT mutant frequencies or between the mutant frequencies and DNA strand breaks. Taken together, these results add further support to the genotoxic and possibly mutagenic effects of styrene exposure in vivo. However, no simple quantitative relationship seems to exist between the levels of styrene-induced DNA damage and frequency of HPRT mutation in T-lymphocytes.

UV-induced cyclobutane dimers and 6-4 photoproducts, containing an unmodified nucleotide at the 5'-position were released from DNA by means of digestion with DNase I, snake venom phosphodiesterase and prostatic acid phosphatase. The enzymes were deactivated by proteinase K followed by ethanol precipitation. The products were phosphorylated by polynucleotide kinase and [gamma-32P]ATP. The TLC system used for the analysis enables separation of the different photoproducts and detection at a fmol level. T4 endonuclease treatment was applied to confirm the positions of cyclobutane dimers.