Immunosuppressive therapy in the posttransplant period and skin cancer.

AIMS: To determine the incidence of malignancies in renal transplant recipients (RTRs) and to analyze the association between the risk of skin cancer and immunosuppressive regiments used in the posttransplant period. MATERIALS AND METHODS: A cohort study was performed on 797 RTRs. Standardized morbidity ratio (SMR) was calculated for the most common types of cancer developed in the posttransplant period and different types of immunosuppressive therapy used in the cohort. RESULTS: 192 cases of malignancies were diagnosed in 86 RTRs (10.8%). Nonmelanoma skin cancer (NMSC) was the most frequent type of cancer (SMR = 6.42, p = 0.000), followed by renal cancer (SMR = 5.9, p = 0.000), malignant melanoma (SMR = 2.59, p = 0.080), and prostate cancer (SMR = 1.21, p = 0.593). The risk to develop NMSC was significantly higher in the group where cyclosporine has been used besides tacrolimus, mycophenolatemophetil and steroids as well as in the group treated with the combination without cyclosporine (SMR = 9.62, p = 0.001 and SMR = 5.18, p = 0.000). Furthermore, the risk was significantly higher in RTRs receiving anti-thymocyte globulin within induction therapy (SMR = 4.14, p = 0.000). CONCLUSION: The preliminary results indicate that the risk of NMSC in RTRs is significantly higher than in the general population and thus emphasize the need to improve preventive strategies in the Czech transplant population.

Relative Importance of Traditional Risk Factors for Malignant Melanoma in the Czech Population.

AIM: The Czech Republic is one of the leading European countries in incident cases of malignant melanoma (MM), which is on the rise. The study objective was to assess the strength of associations between MM and the known generally accepted risk factors for MM in the population of the Czech Republic. METHODS: The study was designed as a case-control study where cases were incident cases of MM detected at the Department of Dermatology and Venereology of the Bulovka Hospital. Controls were selected from cancer-free patients admitted to departments other than Dermatology and Venereology. Validated questionnaires were used to collect demographic, epidemiological, and clinical data. RESULTS: The binary logistic model shows the main risk factors for MM: male, female (OR=0.292, 95% CI=0.175-0.486), a changed mole (OR=6.371, 95% CI=3.774-10.756), a history of skin cancer (OR=95.704, 95% CI=37.241-10.756), and sunbeds use (OR=3.594, 95% CI=1.288-10.028). Using sunscreen products was considered as a protective factor against MM (OR=0.253, 95% CI=0.137-0.466). CONCLUSION: The primary and secondary prevention increasingly emerges as a public health priority in the effort to reverse the negative trend in cases of MM and mortality from this disease in the Czech Republic. A prerequisite for an effective secondary prevention through screening is, among others, the identification of the population groups at highest risk for MM.

Gastrointestinal comorbidities in patients with psoriasis in the Czech Republic: The results of 189 patients with psoriasis and 378 controls.

AIMS: The aim of the study was to investigate gastrointestinal comorbidities, identify risk factors and detect the early stages of autoimmune gastrointestinal diseases, such as Crohn's disease, ulcerative colitis and coeliac disease in patients with psoriasis. METHODS: This was a hospital-based case-control study. Patients with chronic plaque psoriasis were included as cases. The control group consisted of patients with other skin diseases and who complied with the same selection criteria as cases. Two controls were selected per one case. We analysed the following antibodies (ASCA, AEP, p-ANCA, AGC, EMA, ARA, tTG, AGA) and non-specific signs of gastrointestinal diseases. RESULTS: There were significant differences between cases and controls in several parameters. Leucocyte count, CRP, total protein, transglutaminase IgA antibodies and p-ANCA were statistically significant between groups (P < 0.05). In the binary logistic model, leucocyte count and p-ANCA (for all parameters included in the logistic model P ≤ 0.001) were associated with psoriasis. CONCLUSION: Patients with psoriasis should be regularly screened for coeliac and inflammatory bowel disease. Early diagnosis of gastrointestinal diseases and risk factors may prevent complications and greatly improve the patient's quality of life.

Significantly higher incidence of skin cancer than other malignancies in patients after heart transplantation. A retrospective cohort study in the Czech Republic.

AIMS: To perform the first study in Czech Republic on heart transplant recipients (HTRs), compare the risks for different types of cancer and provide comprehensive analysis of skin cancer and other types of cancer morbidity from which we would be able to derive an evidence-based skin cancer surveillance program. MATERIALS AND METHODS: A retrospective cohort study was performed to determine and compare standardized morbidity ratio (SMR) of different types of cancer developed after heart transplantation. We analysed data obtained from medical documentation of 603 HTRs transplanted between 1993 and 2010. RESULTS: 191 incident cases of malignancy occurred in123 HTRs (20.4%). According to expectations, nonmelanoma skin cancer was the most frequent type of malignancy (119 cases) with SMR 7.6 (P < 0.001), followed by lung cancer with SMR 2.7 (P < 0.001). SMR for melanoma was 2.5, P = 0.129. Other types of cancer in HTRs (prostate and kidney cancer) were less frequent (SMR 2.06, P = 0.038 and SMR 2.03, P = 0.122). CONCLUSION: The risk of malignancy development is significantly higher for HTRs compared to the general population. Squamous cell carcinoma of the skin is the most frequent type of cancer followed by basal cell carcinoma. These findings emphasise the importance of regular skin cancer screening in HTRs.

Structural chromosomal aberrations as potential risk markers in incident cancer patients.

Epidemiological prospective studies have shown that increased chromosomal aberrations (CAs) in peripheral blood lymphocytes may predict cancer risk. Here, we report CAs in newly diagnosed 101 colorectal, 87 lung and 158 breast cancer patients and corresponding healthy controls. Strong differences in distributions of aberrant cells (ACs), CAs, chromatid-type aberrations (CTAs) and chromosome-type aberrations (CSAs) were observed in lung and breast cancer patients as compared to healthy controls. In colorectal cancer (CRC) patients, only CTAs were significantly elevated. Binary logistic regression, adjusted for main confounders, indicates that all the analysed cytogenetic parameters along with smoking were significantly associated with breast and lung cancer risks. Significant differences in terminal deletions between breast cancer patients and corresponding female controls were recorded (0.39 vs. 0.18; P ≤ 0.05). We did not find any association of CAs with TNM (tumor nodus metastasis) stages or histopathological grade in either cancer type. CAs were neither associated with additional tumor characteristics-invasivity, ductal and lobular character, estrogene/progesterone receptors in breast tumors nor with non-small/small cell and bronchogenic/pulmonary types of lung tumors. Our study demonstrates that CAs serve as a predictive marker for breast and lung cancer, whereas only CTAs were elevated in incident CRC patients.

Metabolic gene variants associated with chromosomal aberrations in healthy humans.

Nonspecific chromosomal aberrations (CAs) are found in about 1% of lymphocytes drawn from healthy individuals. They include chromosome-type aberrations (CSAs), which are increased in exposure to ionizing radiation, and chromatid-type aberrations (CTAs) which in experimental systems are formed by DNA binding carcinogens and mutagens. The frequency of CAs is associated with the risk of cancer, but the causes of CAs in general population are unknown. Here, we want to test whether variants in metabolic genes associate with CAs in healthy volunteers. Cases were considered those whose total CA (CAtot) frequency was >2% and for CSA and CTA the limit was >1%. Controls had lower frequencies of CAs. Functional polymorphisms in seven genes were selected for analysis: cytochrome P450 1B1 (CYP1B1), epoxide hydrolase 1 (EPHX1), NAD(P)H:quinone oxidoreductase 1 (NQO1), each coding for phase 1 enzymes, and glutathione S-transferase P1 (GSTP1), glutathione S-transferases M1 (GSTM1) and T1 (GSTT1), coding for enzymes which conjugate reactive metabolites, that is, phase 2 enzymes. The number of volunteers genotyped for each gene varied from 550 to 1,500. Only EPHX1 was individually associated with CAtot; high activity genotypes decreased CAtot. A total of six significant (P < 0.01) pair-wise interactions were observed, most including a GST variant as one of the pair. In all genotype combinations with significant odds ratios for CAs a GST variant was involved. The present data provide evidence that variants in genes coding for metabolic enzymes, which individually have small effects, interact and are associated with CA frequencies in peripheral lymphocytes of healthy volunteers.

Risk factors for comorbidities in Czech psoriatic patients: results of a hospital-based case-control study.

BACKGROUND: Psoriasis is now known to be associated with multiple other diseases/comorbidities - including the metabolic syndrome, atherosclerosis and gastrointestinal diseases which are all significantly higher in psoriasis patients. Research results however are highly variable and the conclusions are ambiguous. As no similar study has been performed to date in Czech psoriatic patients, this study aimed at identifying risk factors and early stages of selected diseases/comorbidities in the patients. METHODS AND RESULTS: The study was designed as a hospital-based case-control study. 131 patients with chronic plaque psoriasis formed the cases and 267 patients with other skin disorders formed the controls. A comparison was made of basic demographic and anthropometric indicators, metabolic parameters, the presence of specific antibodies (ASCA, AEP, p-ANCA, AGC, EMA, ARA, t-TG, AGA) and non-specific signs of gastrointestinal diseases. The chi squared, MWU tests and binary logistical model were used to evaluate the data. The results showed significant differences (P<0.05) for the following parameters: blood pressure, waist circumference, weight, BMI values, leucocytes values, HDL cholesterol level, glycemia and gliadine antibody IgA level. All differences were to the detriment of psoriasis patients. In the binary logistical model the following parameters were associated with psoriasis: diastolic blood pressure, leucocyte value and glycemia. For all variables included in the logistical model P≤0.001. CONCLUSIONS: The results were coherent and consistent with existing data. They indicate that psoriasis is interconnected with hypertension, higher BMI and a decreased level of HDL cholesterol. These parameters have been clearly demonstrated as risk factors for the development of cardiovascular diseases. Higher levels of gliadine IgA antibodies are one of the diagnostic markers of celiac disease. Higher values of leukocytes may be interpreted as a nonspecific indicator of gastrointestinal inflammatory diseases. The associations between psoriasis and diastolic blood pressure, BMI value and glycemia are statistically significant in the binary logistic regression model. Care for psoriatic patients should focus especially on secondary prevention of predisposing diseases.

Chromosomal damage among medical staff occupationally exposed to volatile anesthetics, antineoplastic drugs, and formaldehyde.

OBJECTIVES: Structural chromosomal aberrations in blood lymphocytes represent a biomarker for cellular damage caused by genotoxic carcinogens and are an indicator of increased cancer risk. We evaluated the association between frequencies of total chromosomal aberrations, chromatid- and chromosome-type aberrations, and occupational exposures to volatile anesthetics, antineoplastic agents, and formaldehyde among 601 medical professionals. METHODS: Chromosomal damage among exposed individuals and unexposed controls was determined by conventional cytogenetic analysis. We used binary logistic regression to evaluate the effects of workplace exposures and major confounders on chromosomal damage. RESULTS: Significantly higher frequencies of total chromosomal, chromatid-type and chromosome-type aberrations were observed among subjects occupationally exposed to volatile anesthetics, antineoplastic agents, and formaldehyde compared to age- and sex-matched controls (P<0.0001). The risk of an increased frequency of chromosomal aberrations was associated with exposure to anesthetics [odds ratio (OR) 3.9, 95% confidence interval (95% CI) 2.7-5.8], cytostatics (OR 2.7, 95% CI 1.9-3.9), and formaldehyde (OR 1.7, 95% CI 1.1-2.7). No other covariate contributed significantly to the model. Chromatid- and chromosome-type aberrations were associated with exposure to anesthetics and cytostatics without any contribution of other variables. Stratified data analysis showed the risk of increased chromosomal aberrations among non-smoking female nurses and physicians exposed to anesthetics, cytostatics and, partially, formaldehyde. Chromatid and chromosome exchanges were significantly higher in the exposed groups than among controls. CONCLUSION: Our findings indicate that the presence of genotoxic compounds in operating rooms, oncological units, and pathological departments results in a significant increase of chromosomal damage (impair of chromosomal integrity) among medical workers employed in these facilities.

Differences in nucleotide excision repair capacity between newly diagnosed colorectal cancer patients and healthy controls.

Alteration of DNA integrity is a potential cause of cancer and it is assumed that reduced DNA repair capacity and accumulation of DNA damage may represent intermediate markers in carcinogenesis. In this case-control study, DNA damage and nucleotide excision repair capacity (NER-DRC) were assessed in association with sporadic colorectal cancer (CRC). Both parameters were quantified by comet assay in blood cells of 70 untreated incident patients and 70 age-matched healthy controls. mRNA expression and polymorphisms in relevant NER genes were concurrently analyzed. The aim of this study was to characterize incident CRC patients for NER-DRC and to clarify possible relations between investigated variables. Comet assay and mRNA expression analysis showed that CRC patients differ in repair capacity as compared to controls. Patients had a lower NER-DRC and simultaneously they exhibited higher endogenous DNA damage (for both P < 0.001). Accumulation of DNA damage and decreasing NER-DRC behaved as independent modulating parameters strongly associated with CRC. Expression levels of 6 out of 9 studied genes differed between groups (P ≤ 0.001), but none of them was related to DRC or to any of the studied NER polymorphisms. However, in patients only, XPC Ala499Val modulated expression levels of XPC, XPB and XPD gene, whereas XPC Lys939Gln was associated with XPA expression level in controls (for all P < 0.05). This study provides evidence on altered DRC and DNA damage levels in sporadic CRC and proposes the relevance of the NER pathway in this malignancy. Further, alterations in a complex multigene process like DNA repair may be better characterized by functional quantification of repair capacity than by quantification of individual genes transcripts or gene variants alone.

Association of serum bilirubin and promoter variations in HMOX1 and UGT1A1 genes with sporadic colorectal cancer.

Heme oxygenase-1 (HMOX1) and bilirubin UDP-glucuronosyltransferase (UGT1A1) enzymes, both involved in bilirubin homeostasis, play an important role in the oxidative stress defense. The objective of our study was to assess the effect of promoter variations of HMOX1 and UGT1A1 genes and of serum bilirubin on the risk of sporadic colorectal cancer (CRC). This exploratory case-control study was based on 777 CRC patients and 986 controls from the Czech Republic. The (GT)(n) and (TA)(n) dinucleotide variations in HMOX1 and UGT1A1 gene promoters, respectively, were determined by fragment analysis. In addition, the A(-413)T variant in HMOX1 promoter was also analyzed using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Serum bilirubin levels were compared in a subset of 174 cases and 247 controls, for whom biochemical data were available. After adjustment for age, a significant association between CRC risk and UGT1A1*28 allele carrier status was detected [odds ratio (95% confidence intervals) = 0.80 (0.60-0.97), p = 0.022]. No association between CRC risk and individual HMOX1 gene variants was observed, although a diplotype analysis revealed an increased risk for a specific HMOX1 genotype combination. These effects were more pronounced in males. Substantially lower serum bilirubin levels were detected in CRC patients compared to the controls (p < 0.001); each 1 µmol/L decrease in serum bilirubin was associated with a 7% increase of CRC risk (p < 0.001). In conclusion, UGT1A1*28 allele carrier status might be a protective factor against the development of CRC in the male population, whereas low serum bilirubin levels are associated with an increased risk of CRC in both genders.

DNA damage and nucleotide excision repair capacity in healthy individuals.

Interindividual differences in DNA repair capacity (DRC) represent an important source of variability in genome integrity and thus influence health risk. In the last decade, DRC measurement has attracted attention as a potential biomarker in cancer prediction. Aim of the present exploratory study was to characterize the variability in DNA damage and DRC on 100 healthy individuals and to identify biological, lifestyle, or genetic factors modulating these parameters. The ultimate goal was to obtain reference data from cancer-free population, which may constitute background for further investigations on cancer patients. The endogenous DNA damage was measured as a level of DNA single-strand breaks and DRC, specific for nucleotide excision repair (NER), was evaluated using modified comet assay, following the challenge of peripheral blood mononuclear cells with benzo[a]pyrene diolepoxide. Additionally, genetic polymorphisms in NER genes (XPA, XPC, XPD, and XPG) were assessed. We have observed a substantial interindividual variability for both examined parameters. DNA damage was significantly affected by gender and alcohol consumption (P = 0.003 and P = 0.012, respectively), whereas DRC was associated with family history of cancer (P = 0.012). The stratification according to common variants in NER genes showed that DNA damage was significantly modulated by the presence of the variant T allele of XPC Ala499Val polymorphism (P = 0.01), while DRC was modulated by the presence of the A allele of XPA G23A polymorphism (P = 0.048). Our results indicate the range of endogenous DNA single-strand breaks and capacity of NER in healthy volunteers as well as the role of potentially relevant confounders. Environ. Mol. Mutagen. 2011. © 2011 Wiley-Liss, Inc.

DNA damage, DNA repair rates and mRNA expression levels of cell cycle genes (TP53, p21(CDKN1A), BCL2 and BAX) with respect to occupational exposure to styrene.

We studied the relationship between DNA damage, DNA repair rates and messenger RNA (mRNA) expression levels of cell cycle genes TP53, p21(CDKN1A), BCL2 and BAX in a group of 71 styrene-exposed workers and 51 control individuals. The exposure was assessed by measuring the concentration of styrene at workplace and in blood. Parameters of DNA damage [measured as single-strand breaks (SSBs) and endonuclease III-sensitive sites], γ-irradiation-specific DNA repair rates and mRNA levels of studied genes were analyzed in peripheral blood lymphocytes. The workers were divided into low (<50 mg/m³) and high (>50 mg/m³) styrene exposure groups. We found negative correlations between mRNA expression of TP53, BCL2, BAX and styrene exposure (P < 0.001 for all parameters). In contrast, p21(CDKN1A) mRNA expression significantly increased with increasing styrene exposure (P = 0.001). SSBs and endonuclease III-sensitive sites increased with increasing mRNA levels of TP53 (P < 0.001 for both) and BCL2 (P = 0.038, P = 0.002, respectively), whereas the same parameters decreased with increasing mRNA levels of p21(CDKN1A) (P < 0.001, P = 0.007, respectively). γ-Irradiation-specific DNA repair rates increased with p21(CDKN1A) mRNA levels up to the low exposure level (P = 0.044). Our study suggests a possible relationship between styrene exposure, DNA damage and transcript levels of key cell cycle genes.

Superoxide dismutase and nicotinamide adenine dinucleotide phosphate: quinone oxidoreductase polymorphisms and pancreatic cancer risk.

OBJECTIVES: Pancreatic carcinoma etiology and molecular pathogenesis is weakly understood. According to the assumption that genetic variation in carcinogen metabolism further modifies the risk of exposure-related cancers, an association of functional polymorphisms in oxidative stress-modifying genes superoxide dismutase 2 (SOD2 [Ala16Val, rs4880]), SOD3 (Arg231Gly, rs1799895), nicotinamide adenine dinucleotide phosphate:quinone oxidoreductase (NQO1 [Pro187Ser, rs1800566], and NQO2 (Phe47Leu, rs1143684) with pancreatic cancer risk was studied. METHODS: Polymorphisms were studied by allelic discrimination. RESULTS: In a hospital-based case-control study on 500 individuals (235 cases and 265 controls) of Czech white origin, SOD2, SOD3, NQO1, and NQO2 polymorphisms showed no significant association with pancreatic cancer risk. Major lifestyle factors such as smoking and alcohol, coffee, or tea consumption did not modify the effect of the studied polymorphisms. CONCLUSIONS: The first European study of the SOD2, SOD3, NQO1, and NQO2 roles in pancreatic cancer etiology did not find significant associations. Despite this observation, other populations with different lifestyle(s) may be at risk and should be further studied.

Bile acid malabsorption in inflammatory bowel disease: assessment by serum markers.

BACKGROUND: Bile acid malabsorption (BAM) is a common feature of Crohn's disease (CD). We aimed to determine whether BAM develops only in patients with a resected distal ileum or if it also occurs in patients who have not undergone surgery for CD. METHODS: The study included 347 patients with CD or ulcerative colitis (UC) and 119 healthy subjects (controls). BAM was assessed by measurement of serum levels of 7α-hydroxycholest-4-en-3-one (C4) and fibroblast growth factor 19 (FGF19). We surveyed members of the European Crohn's and Colitis Organization and International Organization for the Study of Inflammatory Bowel Disease to collect current information about BAM diagnosis. RESULTS: The severity of BAM was associated with resection of the distal ileum. Compared with controls, patients who received moderate or extensive ileal resection had significantly increased levels of serum C4 (12 versus 62 versus 243 µg/L, respectively; P < 0.001). However, BAM was also present in a substantial number of the patients with CD who were not treated by surgery who had ileitis or colitis (14% and 11%, respectively). There was an indirect, proportional relationship between levels of C4 and FGF19 (P < 0.001). CONCLUSIONS: The most severe BAM occurs in CD patients after resection of the distal ileum, but BAM can occur in surgically untreated CD patients, regardless of disease localization. Laboratory tests for BAM should become a part of the algorithm for diagnosis of CD to identify patients who might respond to therapies such as bile acid sequestrants. FGF19 appears to be a reliable marker of BAM.

Association between exposure-relevant polymorphisms in CYP1B1, EPHX1, NQO1, GSTM1, GSTP1 and GSTT1 and risk of colorectal cancer in a Czech population.

Associations of functional single nucleotide polymorphisms in cytochrome P450 1B1, epoxide hydrolase 1, NAD(P)H:quinone oxidoreductase 1, glutathione S-transferase Pi-1 and deletions of glutathione S-transferases Mu-1 and θ-1 with colorectal cancer risk were investigated in a hospital-based case-control study on 495 matched pairs of Czech Caucasians. Polymorphisms were assessed by polymerase chain reaction restriction fragment length polymorphism-based methods, allele-specific multiplex and allelic discrimination by real-time polymerase chain reaction. Carriers of variant Ser allele in codon 453 of cytochrome P450 1B1 (rs1800440) were at a significantly lower risk of colorectal cancer compared to carriers of the wild-type allele (adjusted odds ratio, aOR=0.68, CI=0.51-0.89, p=0.006). The combination of polymorphisms in codons 453 and 432 (rs1056836) of cytochrome P450 1B1 further increased the protective effect (aOR=0.53, CI=0.34-0.83, p=0.005). The glutathione S-transferase Mu-1 deletion was associated with a moderately elevated colorectal cancer risk (aOR=1.30, CI=1.01-1.68, p=0.044). Combination of glutathione S-transferase Mu-1 and θ-1 deletion was associated with a significantly higher colorectal cancer risk compared to the presence of both full-length genes (aOR=1.58, CI=1.01-2.47, p=0.044). Genetic polymorphisms in glutathione S-transferase Pi-1, NAD(P)H:quinone oxidoreductase 1, epoxide hydrolase 1 and deduced epoxid hydrolase 1 activity did not modify the risk of colorectal cancer. These results provide further evidence that interaction between metabolic gene variants contributes to colorectal carcinogenesis.

Modulation of DNA repair capacity and mRNA expression levels of XRCC1, hOGG1 and XPC genes in styrene-exposed workers.

Decreased levels of single-strand breaks in DNA (SSBs), reflecting DNA damage, have previously been observed with increased styrene exposure in contrast to a dose-dependent increase in the base-excision repair capacity. To clarify further the above aspects, we have investigated the associations between SSBs, micronuclei, DNA repair capacity and mRNA expression in XRCC1, hOGG1 and XPC genes on 71 styrene-exposed and 51 control individuals. Styrene concentrations at workplace and in blood characterized occupational exposure. The workers were divided into low (below 50 mg/m³) and high (above 50 mg/m³)) styrene exposure groups. DNA damage and DNA repair capacity were analyzed in peripheral blood lymphocytes by Comet assay. The mRNA expression levels were determined by qPCR. A significant negative correlation was observed between SSBs and styrene concentration at workplace (R=-0.38, p=0.001); SSBs were also significantly higher in men (p=0.001). The capacity to repair irradiation-induced DNA damage was the highest in the low exposure group (1.34±1.00 SSB/109 Da), followed by high exposure group (0.72±0.81 SSB/109 Da) and controls (0.65±0.82 SSB/109 Da). The mRNA expression levels of XRCC1, hOGG1 and XPC negatively correlated with styrene concentrations in blood and at workplace (p<0.001) and positively with SSBs (p<0.001). Micronuclei were not affected by styrene exposure, but were higher in older persons and in women (p<0.001). In this study, we did not confirm previous findings on an increased DNA repair response to styrene-induced genotoxicity. However, negative correlations of SSBs and mRNA expression levels of XRCC1, hOGG1 and XPC with styrene exposure warrant further highly-targeted study.

Chromosomal damage in peripheral blood lymphocytes of newly diagnosed cancer patients and healthy controls.

BACKGROUND: The majority of human cancers arise from cells unable to maintain genomic stability. Recent prospective studies indicated that enhanced chromosomal aberrations (CAs) frequencies are predictive of gastrointestinal and lung cancers. However, studies on incident cancer patients are lacking; thus, we investigated chromosomal damage in newly diagnosed cancer patients and healthy individuals. METHODS: We analyzed chromosomal damage in peripheral blood lymphocytes in a group of 300 incident cancer patients (with different malignancies) in comparison with 300 healthy controls. RESULTS AND CONCLUSIONS: The frequencies of aberrant cells (ACs) and CAs were significantly higher in patients (2.38 +/- 1.56 and 2.53 +/- 1.69, respectively) as compared with controls (1.81 +/- 1.31 and 1.94 +/- 1.47, respectively, P < 0.01). The percentual difference in chromatid-type aberrations (CTAs) between patients and controls was moderately significant (1.37 +/- 1.20 and 1.11 +/- 0.99, respectively, P

CYP2A13, ADH1B, and ADH1C gene polymorphisms and pancreatic cancer risk.

OBJECTIVES: Pancreatic carcinoma etiology and molecular pathogenesis are weakly understood. Based on the assumption that genetic variation in carcinogen metabolism further modifies the risk of exposure-related cancers, we studied the association of polymorphisms in the tobacco carcinogen-metabolizing gene CYP2A13 (Arg101Stop) and the alcohol-metabolizing genes ADH1B (Arg48His) and ADH1C (Ile350Val) with pancreatic cancer risk. METHODS: Polymorphisms were studied by allelic discrimination. RESULTS: In a hospital-based case-control study, CYP2A13 variant alleles coding an inactive enzyme were found in 7 of 265 cancer-free controls and in none of 235 pancreatic carcinoma patients. Neither ADH1B or ADH1C polymorphisms alone nor their combinations showed a significant effect on pancreatic cancer risk. CONCLUSIONS: The first study of the roles of CYP2A13, ADH1B, and ADH1C in pancreatic cancer etiology suggested that the controls may have a lower ability to bioactivate tobacco-derived procarcinogens than the cases.

NBN 657del5 heterozygous mutations and colorectal cancer risk in the Czech Republic.

The most frequent Nijmegen breakage syndrome (NBS)-causing mutation is a 5-base pair deletion in gene coding for nibrin (NBN 657del5), which results in a non-fully functional protein product and is particularly frequent in Central and Eastern Europe. Recent studies have investigated whether NBN 657del5 carriage may predispose to an increased risk of different types of cancer. The Czech Republic has one of the highest incidences of colorectal cancer in the world as well as high incidence of NBS. To assess whether NBN 657del5 associates with an increased risk of sporadic colorectal cancer, we have screened 771 colorectal cancer patients, 614 controls with negative colonoscopy and 818 healthy blood donors from the Czech Republic. There were no significant differences between the frequencies of heterozygous carriers among the three groups. The present results do not provide any evidence that the exceeding risk of CRC in this population is attributable to the high frequency of heterozygous carriage of the NBN 657del5.