bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variants of DNA Repair Genes and the Risk of Biliary Tract Cancers and Stones: A Population-Based Study in China
Authors: Zhang Mingdong , Huang Wen-Yi , Andreotti Gabriella , Gao Yu-Tang , Rashid Asif , Chen Jinbo , Sakoda Lori C. , Shen Ming-Chang , Wang Bing-Sheng , Chanock Stephen , Hsing Ann W. 
Published: August 2008

Abstract
Biliary tract cancers, which encompass tumors of the gallbladder, extrahepatic ducts, and ampulla of Vater, are relatively rare tumors with a high fatality rate. Other than a close link with gallstones, the etiology of biliary tract cancers is poorly understood. We conducted a population-based case-control study in Shanghai, China, to examine whether genetic variants in several DNA repair genes are associated with biliary tract cancers or biliary stones. Genomic DNA from 410 patients with biliary tract cancers (236 gallbladder, 127 bile duct, and 47 ampulla of Vater), 891 patients with biliary stones, and 786 healthy subjects randomly selected from the Shanghai population were genotyped for putative functional single nucleotide polymorphisms in four DNA repair genes (MGMT, RAD23B, CCNH, and XRCC3). Of the five single nucleotide polymorphisms examined, only one (MGMT EX5-25C&gt;T, rs12917) was associated with biliary tract cancer. Independent of gallstones, subjects carrying the CT genotype of the MGMT EX5-25C&gt;T marker had a significantly reduced risk of gallbladder cancer [odds ratio (OR), 0.63; 95% confidence interval (95% CI), 0.41-0.97; P = 0.02] and nonsignificant reduced risks of bile duct (OR, 0.61; 95% CI, 0.35-1.06) and ampulla of Vater (OR, 0.85; 95% CI, 0.39-1.87) cancers. However, this marker was not associated with biliary stones, and the other markers examined were not significantly associated with either biliary tract cancers or stones. Findings from this population-based study in Shanghai suggest that MGMT gene variants may alter susceptibility to biliary tract cancer, particularly gallbladder cancer. Confirmation in future studies, however, is required. (Cancer Epidemiol Biomarkers Prev 2008;17(8):2123–7)
Assessment of Serum Proteomics to Detect Large Colon Adenomas
Authors: Ransohoff David F. , Martin Christopher , Wiggins Wesley S. , Hitt Ben A. , Keku Temitope O. , Galanko Joseph A. , Sandler Robert S. 
Published: August 2008

Abstract
A noninvasive blood test that could reliably detect early colorectal cancer or large adenomas would provide an important advance in colon cancer screening. The purpose of this study was to determine whether a serum proteomics assay could discriminate between persons with and without a large (≥1 cm) colon adenoma. To avoid problems of “bias” that have affected many studies about molecular markers for diagnosis, specimens were obtained from a previously conducted study of colorectal cancer etiology in which bloods had been collected before the presence or absence of neoplasm had been determined by colonoscopy, helping to assure that biases related to differences in sample collection and handling would be avoided. Mass spectra of 65 unblinded serum samples were acquired using a nanoelectrospray ionization source on a QSTAR-XL mass spectrometer. Classification patterns were developed using the ProteomeQuest® algorithm, performing measurements twice on each specimen, and then applied to a blinded validation set of 70 specimens. After removing 33 specimens that had discordant results, the “test group” comprised 37 specimens that had never been used in training. Although in the primary analysis, no discrimination was found, a single post hoc analysis, done after hemolyzed specimens had been removed, showed a sensitivity of 78%, a specificity of 53%, and an accuracy of 63% (95% confidence interval, 53-72%). The results of this study, although preliminary, suggest that further study of serum proteomics, in a larger number of appropriate specimens, could be useful. They also highlight the importance of understanding sources of “noise” and “bias” in studies of proteomics assays. (Cancer Epidemiol Biomarkers Prev 2008;17(8):2188–93)
Social-Cognitive and School Factors in Lifetime Smoking among Adolescents
Authors: Bidstrup Pernille Envold , Frederiksen Kirsten , Siersma Volkert , Mortensen Erik Lykke , Ross Lone , Vinther-Larsen Mathilde , Grønbæk Morten , Johansen Christoffer 
Published: August 2008

AbstractBackground: Smoking is a serious health threat and identifying risk factors for smoking is thus of great importance. The aim of the study was to examine the effects of social-cognitive factors and school factors on lifetime smoking status among adolescents.Methods: The study was based on cross-sectional data on 2,913 Danish adolescents in grade 7 attending 118 randomly selected public schools. Social-cognitive factors were examined with five measures: self-efficacy to resist pressure to smoke, social influence (norms), social influence (behavior), social influence (pressure), and attitude. We used multilevel analyses to estimate the associations between social-cognitive factors and lifetime smoking status as well as the group-level effects of school, school class, and gender group in the school class.Results: Each social-cognitive factor was significantly associated with lifetime smoking status, even when several potential confounders and the effects of school, school class, and gender group were taken into account. Of the three group-level school factors, gender group in the school class had the strongest effect on smoking status.Conclusion: We conclude that self-efficacy to resist pressure to smoke, attitude, and the three types of social influence are significantly associated with lifetime smoking status, even when the effects of group-level school factors are taken into account. The strong effect of gender group in school class on lifetime smoking status indicates that prevention actions should address the social context of adolescents. (Cancer Epidemiol Biomarkers Prev 2008;17(8):1862–71)
Association of Mitochondrial DNA Displacement Loop (CA)n Dinucleotide Repeat Polymorphism with Breast Cancer Risk and Survival among Chinese Women
Authors: Ye Chuanzhong , Gao Yu-Tang , Wen Wanqing , Breyer Joan P. , Shu Xiao Ou , Smith Jeffrey R. , Zheng Wei , Cai Qiuyin 
Published: August 2008

Abstract
Mitochondrial genome alternations may be involved in carcinogenesis. The noncoding region of the mitochondrial DNA (mtDNA) displacement loop (D-loop) has emerged as a mutational hotspot. Using data from a population-based case-control study conducted among Chinese women in Shanghai, we evaluated associations of breast cancer risk and survival with the mtDNA D-loop (CA)n dinucleotide repeat polymorphism. Included in the study were 1,058 cases and 1,129 age frequency–matched community controls that participated in the Shanghai Breast Cancer Study between 1996 and 1998. Breast cancer patients were followed to determine intervals of overall survival and disease-free survival. Overall, there was no association between the mtDNA D-loop (CA)n repeat polymorphism and breast cancer risk. Patients with multiple alleles of the mtDNA D-loop (CA)n polymorphism (heteroplasmy) had significantly poorer disease-free survival than those with one allele of the mtDNA D-loop (CA)n polymorphism (hazard ratio 1.62; 95% confidence interval, 1.16-2.26). These results suggest that the mtDNA D-loop (CA)n repeat polymorphism may be associated with breast cancer survival. Additional studies with a larger sample size are warranted. (Cancer Epidemiol Biomarkers Prev 2008;17(8):2117–22)
Vitamins B2, B6, and B12 and Risk of New Colorectal Adenomas in a Randomized Trial of Aspirin Use and Folic Acid Supplementation
Authors: Figueiredo Jane C. , Levine A. Joan , Grau Maria V. , Midttun Øivind , Ueland Per M. , Ahnen Dennis J. , Barry Elizabeth L. , Tsang Shirley , Munroe David , Ali Iqbal , Haile Robert W. , Sandler Robert S. , Baron John A. 
Published: August 2008

AbstractBackground: Folate, other vitamin B cofactors, and genes involved in folate-mediated one-carbon metabolism all may play important roles in colorectal neoplasia. In this study, we examined the associations between dietary and circulating plasma levels of vitamins B2, B6, and B12 and risk colorectal adenomas.Methods: The Aspirin/Folate Polyp Prevention Study is a randomized clinical trial of folic acid supplementation and incidence of new colorectal adenomas in individuals with a history of adenomas (n = 1,084). Diet and supplement use were ascertained through a food frequency questionnaire administered at baseline. Blood collected at baseline was used to determine plasma B-vitamin levels. We used generalized linear regression to estimate risk ratios (RR) and 95% confidence intervals (95% CI) as measures of association.Results: We found a borderline significant inverse association with plasma B6 [pyridoxal 5′-phosphate (PLP)] and adenoma risk (adjusted RR Q4 versus Q1, 0.78; 95% CI, 0.61-1.00; Ptrend = 0.08). This association was not modified by folic acid supplementation or plasma folate. However, the protective association of PLP with adenoma risk was observed only among subjects who did not drink alcohol (Pinteraction = 0.03). Plasma B2 (riboflavin) was inversely associated with risk of advanced lesions (adjusted RR Q4 versus Q1, 0.51; 95% CI, 0.26-0.99; Ptrend = 0.12). No significant associations were observed between adenoma risk and plasma vitamin B12 or dietary intake of vitamin B2 and B6. When we examined specific gene-B-vitamin interactions, we observed a possible interaction between methylenetetrahydrofolate reductase -C677T and plasma B2 on risk of all adenomas.Conclusion: Our results suggest that high levels of PLP and B2 may protect against colorectal adenomas. (Cancer Epidemiol Biomarkers Prev 2008;17(8):2136–45)
Effect of Prediagnostic Alcohol Consumption on Survival after Breast Cancer in Young Women
Authors: Reding Kerryn W. , Daling Janet R. , Doody David R. , O'Brien Cecilia A. , Porter Peggy L. , Malone Kathleen E. 
Published: August 2008

AbstractBackground: Alcohol consumption has been comprehensively investigated as an etiologic risk factor for breast cancer but has received little attention in terms of its effect on prognosis after breast cancer, particularly for young women.Methods: 1,286 women diagnosed with invasive breast cancer at age ≤45 years from two population-based case-control studies in the Seattle-Puget Sound region were followed from their diagnosis of breast cancer (between January 1983 and December 1992) for survival through June 2002, during which time 364 women had died. Cox proportional hazards modeling was used to assess the effect of prediagnostic alcohol consumption on the risk of dying.Results: After adjusting for age and diagnosis year, compared with nondrinkers, women who consumed alcohol in the 5 years before diagnosis had a decreased risk of death [&gt;0 to &lt;3 drinks per week: hazard ratio, 0.7; 95% confidence interval (95% CI), 0.6-0.95; 3 to &lt;7 drinks per week: risk ratio, 0.6; 95% CI, 0.4-0.8;7 drinks per week: risk ratio, 0.7; 95% CI, 0.5-0.9]. This association was unchanged on additional adjustment for potential confounders including most notably treatment, stage at diagnosis, and mammogram history.Conclusion: These results suggest that women who consume alcohol before a diagnosis of breast cancer have improved survival, which does not appear to be attributable to differences in stage, screening, or treatment. (Cancer Epidemiol Biomarkers Prev 2008;17(8):1988–96)
B-Vitamin Intake, One-Carbon Metabolism, and Survival in a Population-Based Study of Women with Breast Cancer
Authors: Xu Xinran , Gammon Marilie D. , Wetmur James G. , Bradshaw Patrick T. , Teitelbaum Susan L. , Neugut Alfred I. , Santella Regina M. , Chen Jia 
Published: August 2008

AbstractBreast cancer is the second leading cause of cancer mortality among women. Given its important role in DNA methylation and synthesis, one-carbon metabolism may affect breast cancer mortality. We used a population-based cohort of 1,508 women with breast cancer to investigate possible associations of dietary intake of B vitamins before diagnosis as well as nine polymorphisms of one-carbon metabolizing genes and subsequent survival. Women newly diagnosed with a first primary breast cancer in 1996 to 1997 were followed for vital status for an average of 5.6 years. Kaplan-Meier survival and Cox proportional hazard regression analyses were used to evaluate the association between dietary intakes of B vitamins (1,479 cases), genotypes (∼1,065 cases), and all-cause as well as breast cancer–specific mortality. We found that higher dietary intake of vitamin B1 and B3 was associated with improved survival during the follow-up period (Ptrend = 0.01 and 0.04, respectively). Compared with the major genotype, the MTHFR 677 T allele carriers have reduced all-cause mortality and breast cancer–specific mortality in a dominant model [hazard ratio (95% confidence interval): 0.69 (0.49-0.98) and 0.58 (0.38-0.89), respectively]. The BHMT 742 A allele was also associated with reduced all-cause mortality [hazard ratio, 0.70 (0.50-1.00)]. Estrogen receptor/progesterone receptor status modified the association between the MTHFR C677T polymorphism and survival (P = 0.05). The survival associations with one-carbon polymorphisms did not differ with the use of chemotherapy, although study power was limited for examining such effect modification. Our results indicate that one-carbon metabolism may be an important pathway that could be targeted to improve breast cancer survival. (Cancer Epidemiol Biomarkers Prev 2008;17(8):2109–16)
Mechanisms and Consequences of Chromosomal Translocation
Authors: Rabkin Charles S. , Janz Siegfried 
Published: August 2008

Abstract
A 2006 National Cancer Institute workshop on chromosomal translocations brought together laboratory, clinical, and population scientists to cross-fertilize and catalyze research on this important disease process. The deliberations revealed significant contrasts between two types of translocations that result in either deregulated expression of oncogenes or formation of novel fusion genes. The classic oncogene-activating translocation, MYC-IGH, has been elucidated in terms of molecular structure and functional consequences yet has little epidemiologic characterization. In comparison, the archetypal fusion-gene translocation, BCR-ABL, has well-described clinical manifestations but is less defined with regard to mechanism of generation. Interdisciplinary collaboration on chromosomal translocations should yield additional insights regarding their biological significance and potential as targets for intervention. (Cancer Epidemiol Biomarkers Prev 2008;17(8):1849–51)
Self-Sampling for Human Papillomavirus in a Community Setting: Feasibility in Hispanic Women
Authors: De Alba Israel , Anton-Culver Hoda , Hubbell F. Allan , Ziogas Argyrios , Hess James R. , Bracho America , Arias Caleb , Manetta Alberto 
Published: August 2008

Abstract
Background: The aim of the study was (a) to assess sensitivity and specificity of self-sampling in a community setting for identifying high-risk human papillomavirus (HPV) infection and abnormal Papanicolaou (Pap) smears and (b) to assess satisfaction with this collection method among Hispanic women.
Methods: Lay health workers distributed self-collection kits to Hispanic women in the community. Participants collected an unsupervised vaginal sample at home or in the place and time of their preference.
Results: A total of 1,213 Hispanics were included and provided a self-sample for HPV testing and were invited for a Pap smear; 662 (55%) of them had a Pap smear and the first 386 of these also had a physician-collected sample for HPV retesting. Using physician collection as the gold standard, unsupervised self-collection had a sensitivity of 90% and specificity of 88% for identifying high-risk HPV. Compared with physician sampling, self-sampling in a community setting had comparable sensitivity for identifying a low-grade lesions or greater in the Pap smear (50% versus 55%; P = 0.45) but lower specificity (94% versus 79%). Overall experience with self-sampling was reported as excellent or very good by 64% and only 2.6% reported a poor or fair experience.
Conclusions: Unsupervised self-collection of vaginal samples for HPV testing in a community setting has a high sensitivity for identifying high-risk HPV and a high satisfaction among Hispanics. This approach may benefit populations with limited access to health care or with cultural barriers to cervical cancer screening. (Cancer Epidemiol Biomarkers Prev 2008;17(8):2163–8)
Involuntary Smoking and Head and Neck Cancer Risk: Pooled Analysis in the International Head and Neck Cancer Epidemiology Consortium
Authors: Lee Yuan-Chin Amy , Boffetta Paolo , Sturgis Erich M. , Wei Qingyi , Zhang Zuo-Feng , Muscat Joshua , Lazarus Philip , Matos Elena , Hayes Richard B. , Winn Deborah M. , Zaridze David , Wünsch-Filho Victor , Eluf-Neto Jose , Koifman Sergio , Mates Dana , Curado Maria Paula , Menezes Ana , Fernandez Leticia , Daudt Alexander W. , Szeszenia-Dabrowska Neonila , Fabianova Eleonora , Rudnai Peter , Ferro Gilles , Berthiller Julien , Brennan Paul , Hashibe Mia 
Published: August 2008

Abstract
Although active tobacco smoking has been identified as a major risk factor for head and neck cancer, involuntary smoking has not been adequately evaluated because of the relatively low statistical power in previous studies. We took advantage of data pooled in the International Head and Neck Cancer Epidemiology Consortium to evaluate the role of involuntary smoking in head and neck carcinogenesis. Involuntary smoking exposure data were pooled across six case-control studies in Central Europe, Latin America, and the United States. Adjusted odds ratios (OR) and 95% confidence interval (95% CI) were estimated for 542 cases and 2,197 controls who reported never using tobacco, and the heterogeneity among the study-specific ORs was assessed. In addition, stratified analyses were done by subsite. No effect of ever involuntary smoking exposure either at home or at work was observed for head and neck cancer overall. However, long duration of involuntary smoking exposure at home and at work was associated with an increased risk (OR for &gt;15 years at home, 1.60; 95% CI, 1.12-2.28; Ptrend &lt; 0.01; OR for &gt;15 years at work, 1.55; 95% CI, 1.04-2.30; Ptrend = 0.13). The effect of duration of involuntary smoking exposure at home was stronger for pharyngeal and laryngeal cancers than for other subsites. An association between involuntary smoking exposure and the risk of head and neck cancer, particularly pharyngeal and laryngeal cancers, was observed for long duration of exposure. These results are consistent with those for active smoking and suggest that elimination of involuntary smoking exposure might reduce head and neck cancer risk among never smokers. (Cancer Epidemiol Biomarkers Prev 2008;17(8):1974–81)
Does Pretreatment Seropositivity to Human Papillomavirus Have Prognostic Significance for Head and Neck Cancers?
Authors: Smith Elaine M. , Rubenstein Linda M. , Ritchie Justine M. , Lee John H. , Haugen Thomas H. , Hamsikova Eva , Turek Lubomir P. 
Published: August 2008

Abstract
Background: Human papillomavirus (HPV) is a risk factor for head and neck cancers (HNC), yet HPV-associated tumors have better prognosis than HPV-negative tumors.
Methods: We evaluated whether pretreatment presence of antibodies to HPV capsids [virus-like particles (VLP)] or to HPV-16 oncoproteins E6 and E7 was a predictor of HPV-positive HNC and clinical outcomes. Sera from 156 HNC patients were tested for antibodies to HPV-16–derived antigens using ELISA. HPV-16 in tumors was evaluated by PCR and DNA sequencing.
Results: HPV-16 antibodies were found in 33% with HPV-16 VLP, 21% with HPV-16 E6, and 21% with E7. HPV-16 was detected in 26% of tumors. There was a strong correlation between detection of HPV-16 tumor DNA and antibodies to HPV-16 E6 or E7 (κ = 0.7) but not to HPV-16 VLP (κ = 0.4). Multivariate analyses showed significantly better disease-specific survival in seropositive HPV-16 VLP [hazard ratio (HR), 0.4; 95% confidence interval (95% CI), 0.1-0.9], HPV-16 E6 (HR, 0.1; 95% CI, 0.02-0.5), and HPV-16 E7 (HR, 0.3; 95% CI, 0.1-0.9) cases. Less disease recurrence occurred among those with antibodies to both E6 and E7 compared with those negative to both (P = 0.003). There was better disease-specific survival in patients who were E6 positive at baseline and remained positive at follow-up compared with individuals who were E6 negative at both time points (P = 0.03; κ = 0.9).
Conclusions: The presence of antibodies to HPV-16 E6 and E7 is associated with HPV in tumor cells and with better clinical outcomes. These findings suggest that the presence of E6/E7 antibodies before treatment is predictive of better clinical outcomes and that they may serve as biomarkers for selecting targeted therapeutic modalities developed for HPV-associated tumors. (Cancer Epidemiol Biomarkers Prev 2008;17(8):2087–96)
Measurement of Sex Steroid Hormones in Breast Adipocytes: Methods and Implications
Authors: Falk Roni T. , Gentzschein Elisabet , Stanczyk Frank Z. , Brinton Louise A. , Garcia-Closas Montserrat , Ioffe Olga B. , Sherman Mark E. 
Published: August 2008

Abstract
Background: The lack of validated methods for measuring sex steroid hormones in breast tissue has limited our knowledge of their role in the development of breast cancer. We explored the feasibility of measuring hormones in breast adipocytes for epidemiologic and clinical studies by refining an existing assay procedure and assessing the reliability of hormone measurements using the modified assay. This report presents the reproducibility of measurements of androstenedione (A), testosterone (T), estrone (E1), and estradiol (E2), using breast adipose tissue samples obtained from women undergoing surgical resection for a variety of pathologic conditions.
Methods: Breast adipose tissues were obtained from 20 women. Measurements of the steroid hormones were carried out by harvesting oil from adipocytes following enzymatic digestion of the adipose tissue, extracting and chromatographing the steroids, and quantifying them by RIA. The study was conducted in three phases: first, samples from five women were used to assess the assay procedure; following this, tissues from an additional five women were assayed repeatedly to determine reproducibility of the hormone measurements. Finally, using samples from 10 women undergoing surgical resection of a breast tumor, we evaluated hormone concentrations in samples distal and proximal to the tumor. The assay coefficient of variation and intraclass correlation coefficient were used to assess hormone reproducibility.
Results: The within-batch coefficients of variation ranged from 5% to 17%, and between-batch estimates were between 2% and 10%, suggesting that E1, E2, A, and T can be reliably measured in breast adipocytes. Among samples obtained from women undergoing surgical resection of a breast tumor, hormone levels did not differ between adipose tissue fragments that were distal or proximal to the tumor, with the possible exception of E1 in which levels were 10% higher in distal fragments.
Conclusion: These data support the feasibility of measuring steroid hormone concentrations in breast adipocytes in epidemiologic studies. Future investigations that include the measurement of hormones in the breast microenvironment may have value in understanding breast carcinogenesis, developing prevention strategies, and assessing hormonal treatments. (Cancer Epidemiol Biomarkers Prev 2008;17(8):1891–5)