Biomedical subjects

Nilanjan Chatterjee

Publications and source records attributed to Nilanjan Chatterjee.

At least 37 records · Page 2Linked to original sources

PubMed2005

Decreased levels of CXC-chemokines in serum of benzene-exposed workers identified by array-based proteomics.

Benzene is an important industrial chemical and environmental contaminant that causes leukemia. To obtain mechanistic insight into benzene's mechanism of action, we examined the impact of benzene on the human serum proteome in a study of exposed healthy shoe-factory workers and unexposed controls. Two sequential studies were performed, each using sera from 10 workers exposed to benzene (overall mean benzene air level >30 ppm) and 10 controls. Serum samples were subjected to anion-exchange fractionation and bound to three types of ProteinChip arrays (Ciphergen Biosystems, Fremont, CA) [hydrophobic (H50), metal affinity (IMAC3-Cu), and cation exchange (WCX2)]. Protein-expression patterns were detected by surface-enhanced laser desorption/ionization (SELDI)-TOF MS. Three proteins (4.1, 7.7, and 9.3 kDa) were consistently down-regulated in exposed compared with control subjects in both studies. All proteins were highly inversely correlated with individual estimates of benzene exposure (r > 0.75). The 7.7- and 9.3-kDa proteins were subsequently identified as platelet factor (PF)4 and connective tissue activating peptide (CTAP)-III. Initial proteomic results for PF4 and CTAP-III were subsequently confirmed in a single experiment using a ProteinChip-array-based immunoassay(Ciphergen Biosystems). The altered expression of the platelet-derived CXC-chemokines (40% and 63% for PF4 and CTAP-III, respectively) could not be explained by changes in absolute platelet counts. Thus, SELDI-TOF analysis of a limited number of exposed and unexposed subjects revealed that lowered expression of PF4 and CTAP-III proteins is a potential biomarker of benzene's early biologic effects and may play a role in the immunosuppressive effects of benzene.

Benzene↗

PubMed2005

CYP1A1 Val462 and NQO1 Ser187 polymorphisms, cigarette use, and risk for colorectal adenoma.

Cigarette use is a risk factor for colorectal adenoma, a known precursor of colorectal cancer. Polymorphic variants in NQO1 and CYP1A1 influence the activation of carcinogenic substances in tobacco smoke, possibly impacting on tobacco-associated risks for colorectal tumors. We investigated the association of cigarette smoking with risk for advanced colorectal adenoma in relation to the CYP1A1 Val(462) and NQO1 Ser(187) polymorphic variants. Subjects were 725 non-Hispanic Caucasian cases with advanced colorectal adenoma of the distal colon (descending colon, sigmoid and rectum) and 729 gender- and ethnicity-matched controls, randomly selected from participants in the prostate, lung, colorectal and ovarian cancer screening trial. Subjects carrying either CYP1A1 Val(462) or NQO1 Ser(187) alleles were weakly associated with risk of colorectal adenoma; however, subjects carrying both CYP1A1 Val(462) and NQO1 Ser(187) alleles showed increased risks (OR = 2.2, 95% CI = 1.1-4.5), particularly among recent (including current) (OR = 17.4, 95% CI = 3.8-79.8, P for interaction = 0.02) and heavy cigarette smokers (>20 cigarettes/day) (OR = 21.1, 95% CI = 3.9-114.4, P for interaction = 0.03) compared with non-smokers who did not carry either of these variants. These genotypes were unassociated with risk in non-smokers. In analysis of adenoma subtypes, the combined gene variants were most strongly associated with the presence of multiple adenoma (P = 0.002). In summary, joint carriage of CYP1A1 Val(462) and NQO1 Ser(187) alleles, particularly in smokers, was related to colorectal adenoma risk, with a propensity for formation of multiple lesions.

Adenoma↗

PubMed2005

Exploiting gene-environment independence in family-based case-control studies: increased power for detecting associations, interactions and joint effects.

Family-based case-control studies are popularly used to study the effect of genes and gene-environment interactions in the etiology of rare complex diseases. We consider methods for the analysis of such studies under the assumption that genetic susceptibility (G) and environmental exposures (E) are independently distributed of each other within families in the source population. Conditional logistic regression, the traditional method of analysis of the data, fails to exploit the independence assumption and hence can be inefficient. Alternatively, one can estimate the multiplicative interaction between G and E more efficiently using cases only, but the required population-based G-E independence assumption is very stringent. In this article, we propose a novel conditional likelihood framework for exploiting the within-family G-E independence assumption. This approach leads to a simple and yet highly efficient method of estimating interaction and various other risk parameters of scientific interest. Moreover, we show that the same paradigm also leads to a number of alternative and even more efficient methods for analysis of family-based case-control studies when parental genotype information is available on the case-control study participants. Based on these methods, we evaluate different family-based study designs by examining their relative efficiencies to each other and their efficiencies compared to a population-based case-control design of unrelated subjects. These comparisons reveal important design implications. Extensions of the methodologies for dealing with complex family studies are also discussed.

Alleles↗

PubMed2005

Analysis of case-control studies of genetic and environmental factors with missing genetic information and haplotype-phase ambiguity.

Case-control studies of unrelated subjects are now widely used to study the role of genetic susceptibility and gene-environment interactions in the etiology of complex diseases. Exploiting an assumption of gene-environment independence, and treating the distribution of environmental exposures as completely nonparametric, Chatterjee and Carroll recently developed an efficient retrospective maximum-likelihood method for analysis of case-control studies. In this article, we develop an extension of the retrospective maximum-likelihood approach to studies where genetic information may be missing on some study subjects. In particular, special emphasis is given to haplotype-based studies where missing data arise due to linkage-phase ambiguity of genotype data. We use a profile likelihood technique and an appropriate expectation-maximization (EM) algorithm to derive a relatively simple procedure for parameter estimation, with or without a rare disease assumption, and possibly incorporating information on the marginal probability of the disease for the underlying population. We also describe two alternative robust approaches that are less sensitive to the underlying gene-environment independence and Hardy-Weinberg-equilibrium assumptions. The performance of the proposed methods is studied using simulation studies in the context of haplotype-based studies of gene-environment interactions. An application of the proposed method is illustrated using a case-control study of ovarian cancer designed to investigate the interaction between BRCA1/2 mutations and reproductive risk factors in the etiology of ovarian cancer.

Algorithms↗

PubMed2005

Hepatitis C virus load and survival among injection drug users in the United States.

Persons chronically infected with hepatitis C virus (HCV), some of whom may be coinfected with HIV and human T-lymphotropic virus type II (HTLV-II), are at high risk for end-stage liver disease (ESLD). We evaluated whether ESLD death was associated with premorbid HCV RNA level or specific HCV protein antibodies among persons with or without HIV/HTLV-II coinfection in a cohort of 6,570 injection drug users who enrolled in 9 US cities between 1987 and 1991. We compared 84 ESLD descendents and 305 randomly selected cohort participants with detectable HCV RNA, stratified by sex, race, HIV, and HTLV-II strata. Relative hazard (RH) of ESLD death was derived from the proportional hazard model. Risk of ESLD death was unrelated to the intensity of antibodies against the HCV c-22(p), c-33(p), c-100(p), and NS5 proteins, individually or combined, but it increased with HCV RNA level (RH(adj) = 2.26 per log(10) IU/mL, 95% CI: 1.45-5.92). The association between HCV RNA level and ESLD death remained significant after adjustment for alcohol consumption (RH(adj) = 2.57 per log(10) IU/mL, 95% CI: 1.50-8.10). Deaths from AIDS (n = 45) and other causes (n = 43) were unrelated to HCV RNA (RH(adj)= 1.14 and 1.29 per log(10) IU/mL, respectively). HIV infection was not associated with ESLD risk in multivariate analyses adjusted for HCV RNA. Men had an increased risk of ESLD death in unadjusted analyses (RH = 1.92, 95% CI: 1.15-3.56) but not in multivariate analysis (RH(adj) = 0.98, 95% CI: 0.48-2.88). Non-black patients were at increased risk for ESLD death (RH(adj)= 2.76, 95% CI: 1.49-10.09). In conclusion, HCV RNA level is a predictor of ESLD death among persons with chronic HCV infection.

Adult↗

PubMed2005

On a supplemented case-control design.

The supplemented case-control design consists of a case-control sample and of an additional sample of disease-free subjects who arise from a given stratum of one of the measured exposures in the case-control study. The supplemental data might, for example, arise from a population survey conducted independently of the case-control study. This design improves precision of estimates of main effects and especially of joint exposures, particularly when joint exposures are uncommon and the prevalence of one of the exposures is low. We first present a pseudo-likelihood estimator (PLE) that is easy to compute. We further adapt two-phase design methods to find maximum likelihood estimates (MLEs) for the log odds ratios for this design and derive asymptotic variance estimators that appropriately account for the differences in sampling schemes of this design from that of the traditional two-phase design. As an illustration of our design we present a study that was conducted to assess the influence to joint exposure of hepatitis-B virus (HBV) and hepatitis-C virus (HCV) infection on the risk of hepatocellular carcinoma in data from Qidong County, Jiangsu Province, China.

Biometry↗

PubMed2005

GSTM1, GSTT1, and GSTP1 polymorphisms and risk of advanced colorectal adenoma.

Cigarette smoking is a risk factor for colon adenoma. The glutathione S-transferase enzymes are involved in the detoxification of carcinogenic compounds including those found in tobacco smoke, and thus, may be important modifiers of individual risk of developing this disease. We examined the prevalence of GSTM1 and GSTT1 gene deletions, and two GSTP1 polymorphisms in 772 cases with advanced colorectal adenomas (>1 cm, villous elements or high-grade dysplasia) of the distal colon (descending or sigmoid colon or rectum) and 777 sigmoidoscopy negative controls enrolled in the screening arm of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Epidemiologic data on smoking was collected by self-administered questionnaire and DNA was extracted from whole blood or buffy coat. For GSTM1 and GSTT1, we used a newly developed TaqMan-based assay capable of discriminating heterozygous (+/-) individuals from those with two active alleles (+/+) and homozygous deletions (-/-). For GSTP1, the I105V and the A114V substitutions were identified using end point 5' nuclease assays (TaqMan). Adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were determined using unconditional logistic regression, controlling for age, race, and gender. Advanced adenoma risk was increased in current/former smokers (OR, 1.4; 95% CI, 1.2-1.8). Risks were decreased in subjects with > or =1 inactive GSTM1 alleles (OR, 0.6; 95% CI, 0.4-0.9); and the association was independent of smoking status (P interaction = 0.59). Having > or =1 inactive GSTT1 allele was associated with increased risk among smokers (OR, 1.4; 95% CI, 1.1-1.9; P trend = 0.02) but not among never smokers (OR, 0.9; 95% CI, 0.6-1.3) and a significant interaction between smoking and genotype was observed (P interaction = 0.05). In summary, this is the first study to report associations between colorectal adenomas and GSTM1 wild-type and GSTT1 null allele among smokers. These findings only became apparent using a newly developed assay able to distinguish heterozygous from wild-type individuals. Our data provide evidence that phenotypic differences between these two groups exist.

Adenoma↗

PubMed2005

Calcium from diet and supplements is associated with reduced risk of colorectal cancer in a prospective cohort of women.

We investigated the association between calcium intake and colorectal cancer in a prospective cohort of 45,354 women without a history of colorectal cancer who successfully completed a 62-item National Cancer Institute/Block food-frequency questionnaire. Women were followed for an average of 8.5 years, during which time 482 subjects developed colorectal cancer. We used Cox proportional hazards models, with age as the underlying time metric, to estimate risk of colorectal cancer. Cut points between quintiles of energy-adjusted dietary calcium were 412, 529, 656, and 831 mg/day. We created categories for calcium from supplements as follows: 0 mg/day (n = 25,441), 0 to 400 mg/day (n = 9,452), 401 to 800 mg/day (n = 4,176), and >800 mg/day (n =6,285). Risk ratios and confidence intervals (95% CI) for increasing quintiles of dietary calcium relative to the lowest quintile were 0.79 (0.60-1.04), 0.77 (0.59-1.02), 0.78 (0.60-1.03), and 0.74 (0.56-0.98), P(trend) = 0.05. For increasing categories of calcium from supplements, the risk ratios (and 95% CI) relative to no supplement use were 1.08 (0.87-1.34), 0.96 (0.70-1.32), and 0.76 (0.56-1.02), P(trend) = 0.09. Simultaneously high consumption of calcium from diet and calcium from supplements resulted in even further risk reduction, RR = 0.54 (95% CI, 0.37-0.79) compared with low consumption of both sources of calcium. These data indicate that a difference of < 400 to > 800 mg of calcium per day was associated with an approximately 25% reduction in risk of colorectal cancer, and this reduction in risk occurred regardless of the source of the calcium (i.e., diet or supplements).

Adult↗

PubMed2005

Microsomal epoxide hydrolase polymorphisms and risk for advanced colorectal adenoma.

Cigarette smoking is a risk factor for colorectal adenoma, a precursor of colorectal cancer. Microsomal epoxide hydrolase (EPHX1) metabolizes polycyclic aromatic hydrocarbons, carcinogens found in cigarette smoke. Nonsynonymous variants of EPHX1 at Tyr(113)His (exon 3) and His(139)Arg (exon 4) are associated, respectively, with low ((113)His) and high ((139)Arg) predicted activity. Among participants randomized to the screening arm of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, we evaluated risks for advanced adenoma in relation to cigarette use and these two EPHX1 variants. We compared 772 cases with advanced adenoma (adenoma >/=1 cm or containing high-grade dysplasia or villous, including tubulovillous, elements) of the distal colon (left-sided, descending colon and sigmoid or rectum) to 777 gender- and age-matched controls who were screen-negative for left-sided adenoma. Compared to those with homozygous genotypes predicting low EPHX1 activity, advanced adenoma risks tended to be elevated for carriers of (113)TyrTyr [odds ratios (OR), 1.5; 95% confidence intervals (CI), 1.0-2.2] and (139)ArgArg (OR, 1.4; 95% CI, 0.8-2.5) and for subjects who carried a greater number of the alleles ((113)Tyr or (139)Arg) associated with high predicted enzymatic activity (P(trend) = 0.03). The increased risk associated with the increasing number of putative high-activity alleles was most apparent among current and recent (quit <10 years) cigarette smokers (P(trend) = 0.02). In conclusion, EPHX1 variants at codon 113 and 139 associated with high predicted enzymatic activity appear to increase risk for colorectal adenoma, particularly among recent and current smokers.

Adenoma↗

PubMed2004

Hepatitis C virus infection and non-Hodgkin lymphoma: results of the NCI-SEER multi-center case-control study.

Several studies have noted elevated hepatitis C virus (HCV) prevalence among patients with non-Hodgkin lymphoma (NHL), suggesting that HCV infection increases NHL risk through chronic immune stimulation. Population-based data from the U.S. are lacking. In a population-based case-control study of NHL in the United States, we identified HCV infection using an enzyme immunoassay, confirmed by recombinant immunoblot assay or HCV RNA detection. The association between HCV and NHL was assessed using logistic regression, adjusting for demographic factors, illicit drug use or medical history. Thirty-two of 813 (3.9%) NHL cases and 14 of 684 (2.1%) controls were HCV-infected [odds ratio (OR) 1.96, 95%CI 1.07-4.03]. For separate NHL subtypes, numbers were limited. Nonetheless, positive associations were noted for follicular (OR 2.46, 95%CI 1.01-5.81), marginal zone (3.99, 0-13.6) and mucosa-associated lymphoid tissue (2.04, 0-7.20) NHLs. For all NHLs combined, the HCV-NHL association changed little after adjustment for sex, age, race and study center (OR 1.89, 95%CI 1.00-4.00). HCV was common in controls who had injected drugs (40%) or used other illicit drugs (6.5%), but adjustment for drug use did not affect the HCV-NHL association (OR 1.87, 95%CI 0.95-4.10). Transfusion history was unrelated to HCV status, and adjustment for this exposure did not attenuate the HCV-NHL association (OR 2.15, 95%CI 1.12-4.76). Excluding 4 subjects with a history of hemodialysis or 3 subjects with organ transplants also did not affect the results. Our study demonstrates an association between HCV infection and NHL in the United States. HCV infection may be a cause of NHL.

Adult↗

PubMed2004

Kin-cohort estimates for familial breast cancer risk in relation to variants in DNA base excision repair, BRCA1 interacting and growth factor genes.

BACKGROUND: Subtle functional deficiencies in highly conserved DNA repair or growth regulatory processes resulting from polymorphic variation may increase genetic susceptibility to breast cancer. Polymorphisms in DNA repair genes can impact protein function leading to genomic instability facilitated by growth stimulation and increased cancer risk. Thus, 19 single nucleotide polymorphisms (SNPs) in eight genes involved in base excision repair (XRCC1, APEX, POLD1), BRCA1 protein interaction (BRIP1, ZNF350, BRCA2), and growth regulation (TGFss1, IGFBP3) were evaluated. METHODS: Genomic DNA samples were used in Taqman 5'-nuclease assays for most SNPs. Breast cancer risk to ages 50 and 70 were estimated using the kin-cohort method in which genotypes of relatives are inferred based on the known genotype of the index subject and Mendelian inheritance patterns. Family cancer history data was collected from a series of genotyped breast cancer cases (N = 748) identified within a cohort of female US radiologic technologists. Among 2,430 female first-degree relatives of cases, 190 breast cancers were reported. RESULTS: Genotypes associated with increased risk were: XRCC1 R194W (WW and RW vs. RR, cumulative risk up to age 70, risk ratio (RR) = 2.3; 95% CI 1.3-3.8); XRCC1 R399Q (QQ vs. RR, cumulative risk up to age 70, RR = 1.9; 1.1-3.9); and BRIP1 (or BACH1) P919S (SS vs. PP, cumulative risk up to age 50, RR = 6.9; 1.6-29.3). The risk for those heterozygous for BRCA2 N372H and APEX D148E were significantly lower than risks for homozygotes of either allele, and these were the only two results that remained significant after adjusting for multiple comparisons. No associations with breast cancer were observed for: APEX Q51H; XRCC1 R280H; IGFPB3 -202A>C; TGFss1 L10P, P25R, and T263I; BRCA2 N289H and T1915M; BRIP1 -64A>C; and ZNF350 (or ZBRK1) 1845C>T, L66P, R501S, and S472P. CONCLUSION: Some variants in genes within the base-excision repair pathway (XRCC1) and BRCA1 interacting proteins (BRIP1) may play a role as low penetrance breast cancer risk alleles. Previous association studies of breast cancer and BRCA2 N372H and functional observations for APEX D148E ran counter to our findings of decreased risks. Due to the many comparisons, cautious interpretation and replication of these relationships are warranted.

Aged↗

PubMed2004

Fat, fiber, fruits, vegetables, and risk of colorectal adenomas.

A case-control study was conducted at the National Naval Medical Center (Maryland, USA) from 1994 to 1996 to investigate the possible association between dietary factors and colorectal adenomas. Cases (n = 239) were subjects diagnosed with adenomas (146 new and 93 recurrent) by sigmoidoscopy or colonoscopy. Those with no evidence of adenomas found by sigmoidoscopy were recruited as controls (n = 228). Dietary variables, assessed by a 100-item food frequency questionnaire, were analyzed by the logistic regression model, which was adjusted for age, gender and total energy intake. Variables of fat intake were further adjusted for red meat intake. An increased risk of 7% [odds ratio (OR): 1.07; 95% confidence interval (95% CI): 0.94-1.22] per 5% energy/day from total fat was observed. Every additional 5% unit of oleic acid intake/day significantly increased the adenoma risk by 115% (OR: 2.15; 95% CI: 1.05-4.39). Red meat fat increased the risk by 20% (OR: 1.20; 95% CI: 0.71-2.04), and white meat fat decreased the risk by 67% (OR: 0.33; 95% CI: 0.19-0.95) for every additional 5% unit of respective intake/day. Risk decreased by 41% (OR: 0.59; 95% CI: 0.41-0.86) for every additional 5% unit of fiber intake/day. Vegetable [OR per 100 g of vegetable intake/day: 0.83, 95% CI: 0.67-1.04] and fruit (OR per 100 g of fruit intake/day: 0.92, 95% CI: 0.82-1.03) intake showed an inverse association, and the results are suggestive of an association with the risk for adenomas. In conclusion, a strong positive association between oleic acid intake and colorectal adenoma risk was observed. This is likely to be an indicator of "unhealthy" food (meat, dairy, margarine, mayonnaise, sweet baked food) consumption in this population. Increased intake of dietary fiber was associated with a moderately decreased risk of adenomas.

Adenoma↗

PubMed2004

Calcium intake and colorectal adenoma in a US colorectal cancer early detection program.

BACKGROUND: Calcium can reduce the risk of colorectal tumors by binding secondary bile and fatty acids, which leads to antiproliferative effects in the bowel, or by acting directly on the colonic epithelium, which affects differentiation and apoptosis. OBJECTIVE: We investigated calcium intake and risk of colon adenoma to evaluate the association of calcium intake with early stages of colorectal tumor development. DESIGN: We compared the supplemental and dietary calcium intakes of 3696 participants with histologically verified adenoma of the distal colon (ie, descending colon, sigmoid colon, or rectum) with the calcium intakes of 34 817 sigmoidoscopy-negative control participants in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Calcium intake was assessed at study entry with a 137-item food-frequency questionnaire and additional questions on the amount and duration of calcium supplement use. RESULTS: After adjustment for known risk factors, adenoma risk was lower by 12% for participants in the highest quintile of total calcium intake (>1767 mg/d) than for participants in the lowest quintile (<731 mg/d) (odds ratio: 0.88; 95% CI: 0.76, 1.02; P for trend = 0.04). The protective association between total calcium and colorectal adenoma was largely due to calcium supplement use, with a 27% decrease in adenoma risk for participants taking >1200 mg/d than for nonusers of supplements (odds ratio: 0.73; 95% CI: 0.56, 0.91; P for trend = 0.005). The protective associations of total and supplemental calcium were strongest for colon adenoma (descending and sigmoid colon). CONCLUSION: High calcium intake, particularly from supplements, is associated with a reduced risk of distal colorectal adenoma.

Adenoma↗

PubMed2004

A haplotype-based test of association using data from cohort and nested case-control epidemiologic studies.

Haplotype-based risk models can lead to powerful methods for detecting the association of a disease with a genomic region of interest. In population-based studies of unrelated individuals, however, the haplotype status of some subjects may not be discernible without ambiguity from available locus-specific genotype data. A score test for detecting haplotype-based association using genotype data has been developed in the context of generalized linear models for analysis of data from cross-sectional and retrospective studies. In this article, we develop a test for association using genotype data from cohort and nested case-control studies where subjects are prospectively followed until disease incidence or censoring (end of follow-up) occurs. Assuming a proportional hazard model for the haplotype effects, we derive an induced hazard function of the disease given the genotype data, and hence propose a test statistic based on the associated partial likelihood. The proposed test procedure can account for differential follow-up of subjects, can adjust for possibly time-dependent environmental co-factors and can make efficient use of valuable age-at-onset information that is available on cases. We provide an algorithm for computing the test statistic using readily available statistical software. Utilizing simulated data in the context of two genomic regions GPX1 and GPX3, we evaluate the validity of the proposed test for small sample sizes and study its power in the presence and absence of missing genotype data.

Algorithms↗

PubMed2004

Circulating vitamin D metabolites, polymorphism in vitamin D receptor, and colorectal adenoma risk.

OBJECTIVE: Vitamin D is a potential agent for the prevention of colorectal cancer possibly through mechanisms mediated by the vitamin D receptor (VDR). We investigated the association of circulating vitamin D metabolites and a genetic variant of the VDR gene with advanced colorectal adenoma, a precursor lesion of colorectal cancer. METHODS: Cases with advanced adenoma of the distal large bowel and gender- and ethnicity-matched controls with a negative sigmoidoscopy were randomly selected from participants in the Prostate, Lung, Colorectal and Ovarian Cancer Screening trial. Genotype analysis of the VDR TaqI polymorphism was completed on 763 cases and 774 controls. Serum levels of 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)(2)D] were measured in a subset of 394 cases and 397 controls. RESULTS: Serum levels of 25(OH)D were inversely associated with advanced adenoma risk in women but not in men. Comparing those in the highest quintile with those in the lowest quintile, the risk for advanced adenoma decreased by 73% in women [odds ratio (OR) = 0.27, 95% confidence interval (95% CI) = 0.11-0.69; P for trend = 0.0002], while the risk did not decrease in men (OR = 1.10, 95% CI = 0.60-2.05; P for trend = 0.85). In women, 25(OH)D levels were significantly higher in current users of hormone replacement therapy (HRT) than in former or never HRT users. Neither serum 1,25(OH)(2)D nor VDR TaqI genotype was associated with advanced adenoma risk. CONCLUSION: Higher serum 25(OH)D levels were associated with decreased adenoma risk. Serum 1,25(OH)(2)D and VDR TaqI genotype were not associated with adenoma risk.

Adenoma↗

PubMed2004

Risk of non-Hodgkin's lymphoma and family history of lymphatic, hematologic, and other cancers.

BACKGROUND: An elevated risk of developing non-Hodgkin's lymphoma (NHL) has been associated with a family history of NHL and several other malignancies, but the magnitude of risks and mechanisms are uncertain. METHODS: We used self-reported family history data from a recent multicenter U.S.-based case-control studies of NHL to evaluate familial aggregation of NHL with various hematolymphoproliferative and other cancers. Estimates of familial aggregation were obtained as hazard ratios (HR) that compare incidence of different cancers in first-degree relatives of NHL cases with that in the first-degree relatives of NHL controls. Limitations of the study included low participation rates (76% for cases and 52% for controls) and potential differential accuracy of recall. RESULTS: Risk of NHL was elevated in relatives of NHL cases [HR, 2.9; 95% confidence interval (95% CI), 0.95-8.53]; the aggregation seems to be stronger for siblings (HR, 7.6; 95% CI, 0.98-58.8) and for male relatives (HR, 6.2; 95% CI, 0.77-50.0). Risk of Hodgkin's lymphoma seems to be also elevated among relatives of early-onset (<50 years) NHL cases (HR, 3.2; 95% CI, 0.88-11.6). Evaluation of family history of other cancers provided modest evidence for an increased risk of melanoma of the skin (HR, 2.9; 95% CI, 1.08-7.75), pancreatic cancer (HR, 2.1; 95% CI, 0.96-4.43), stomach cancer (HR, 1.8; 95% CI, 0.91-3.63), and prostate cancer (HR, 1.3; 95% CI, 0.87-1.99). CONCLUSIONS: These results are consistent with previous findings of familial aggregation of NHL, Hodgkin's lymphoma, and a few other cancers. The pattern of male-specific and sibling-specific familial aggregation of NHL we observed, if confirmed, may shed new light on the possible mechanisms that underlie familial aggregation of the disease.

Adult↗

PubMed2004

Association of genetic variants in the calcium-sensing receptor with risk of colorectal adenoma.

OBJECTIVE: Evidence suggests that calcium prevents colorectal cancer, possibly mediated through the calcium-sensing receptor (CASR). We assessed the associations between CASR gene variants and risk for colorectal adenoma, a cancer precursor. We further investigated gene-diet interactions between the CASR variants and calcium intake on adenoma risk. METHODS: Individuals with advanced distal adenomas (n = 716) and controls with a negative sigmoidoscopy exam (n = 729) were randomly selected from participants in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Three nonsynonymous variants in the intracellular signaling region of CASR (A986S, R990G, Q1011E) were analyzed by Taqman. RESULTS: Compared with the most common diplotype (haplotype pair), the odds ratios for advanced adenoma were 0.80 [95% confidence interval (CI), 0.60-1.06], 0.79 (95% CI, 0.55-1.13), and 0.56 (95% CI, 0.36-0.88) for the other three common diplotypes (>5% frequency). Although calcium intake was inversely associated with adenoma risk, CASR diplotypes did not modify this association. However, the power to investigate interactions was limited. CONCLUSION: Variants in the CASR intracellular signaling region were significantly associated with the risk of advanced adenoma.

Adenoma↗

PubMed2003

Increased hepatitis C virus load among injection drug users infected with human immunodeficiency virus and human T lymphotropic virus type II.

Coinfection of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) and/or human T-lymphotropic virus type II (HTLV-II) is common among drug users. We compared HCV RNA detection and load in a cohort of 6570 injection drug users from 9 US cities during 1987-1991. Of 385 subjects selected from 16 strata by sex, race (black or nonblack), and HIV/HTLV-II group (HIV positive [HIV(+)]/HTLV-II(+), HIV(+)/HTLV-II negative [HTLV-II(-)], HIV(-)/HTLV-II(+), and HIV(-)/HTLV-II(-)), 376 had HCV antibodies, of whom 305 had detectable HCV load. HCV RNA detection was unrelated to sex, race, and virus groups, but differed by study site. The mean HCV load was 5.4 log(10) IU/mL and was 0.24 log(10) higher in men than in women. Virus load increment with HIV or HTLV-II infection was higher among white subjects than among other subjects. Compared with HIV(-)/HTLV-II(-) subjects, virus load was 0.50, 0.22, and 0.56 log(10) higher in HIV(+)/HTLV-II(-), HIV(-)/HTLV-II(+), and HIV(+)/HTLV-II(+) subjects, respectively. HTLV-II infection significantly increased HCV load in white subjects but not in other racial groups.

Adult↗