bluuebunny/crossref_metadata_2025 huggingface dataset:
Safety and Efficacy of Weekly Oral Oltipraz in Chronic Smokers
Authors: Kelley Michael J. , Glaser Elizabeth M. , Herndon James E. , Becker Frank , Bhagat Rajesh , Zhang Yu-Jing , Santella Regina M. , Carmella Steven G. , Hecht Stephen S. , Gallot Lilia , Schilder Lawrence , Crowell James A. , Perloff Marjorie , Folz Rodney J. , Bergan Raymond C.
Published: September 2005

Cigarette smoking is thought to contribute to carcinogenesis by formation of DNA adducts of tobacco smoke constituents leading to genotoxic damage. The dithiolethione, oltipraz, is a putative cancer chemopreventive agent that induces phase II detoxifying enzymes in preclinical models and reduces aflatoxin adducts in humans living in areas with high dietary levels. To determine if oltipraz could reduce adduct levels of tobacco smoke constituents in the lungs and other target organs, chronic smokers were enrolled to one of three arms: 400 or 200 mg/wk oral oltipraz or placebo. Endobronchial tissue and bronchoalveolar lavage were done before and after 12 weeks of drug treatment; peripheral blood, urine, and oral saline rinse were also collected. Toxicity was assessed every 4 weeks. Fifty-nine of the 77 enrolled subjects completed the study. Of those receiving oltipraz, 15% experienced grade 2/3 toxicity, which was predominantly gastrointestinal. All subject withdrawals occurred in the oltipraz groups. There was no significant difference between pre- and post-polycyclic aromatic hydrocarbon-DNA adduct levels in lung epithelial cells measured by immunoperoxidase staining between treatment and placebo groups. Likewise, no significant differences were found in polycyclic aromatic hydrocarbon or benzo(a)pyrene-7,8-diol-9,10-epoxide adducts measured in blood, oral lining cells, or bladder lining cells. There was also no increase in mRNA or enzymatic activity of phase II enzymes and no change in glutathione levels. Thus, despite moderate drug-related toxicity, there was no significant effect on pharmacodynamic or surrogate risk biomarkers. Other agents with lower toxicity and greater activity to induce phase II enzymes are needed to definitively test the detoxification-induction paradigm in smokers.
TheMTHFR 1298A>CPolymorphism and Genomic DNA Methylation in Human Lymphocytes
Authors: Friso Simonetta , Girelli Domenico , Trabetti Elisabetta , Olivieri Oliviero , Guarini Patrizia , Pignatti Pier Franco , Corrocher Roberto , Choi Sang-Woon
Published: September 2005

Methylenetetrahydrofolate reductase (MTHFR) balances the pool of folate coenzymes in one-carbon metabolism for DNA synthesis and methylation, both implicated in carcinogenesis. Epidemiologic studies have shown that two functional polymorphisms in MTHFR gene, 677C>T and 1298A>C, are related to increased cancer risk. We aimed to analyze lymphocyte DNA from 198 subjects to evaluate the MTHFR 1298A>C polymorphism and folate status affecting genomic DNA methylation as a possible mechanism underlying the relationship between MTHFR polymorphisms and cancer susceptibility. Carriers of the 1298AA wild-type genotype showed lower genomic DNA methylation compared with 1298AC or 1298CC genotypes [3.72 versus 8.59 or 6.79 ng 5-methyl-2′-deoxycytidine (5-mCyt)/μg DNA, P < 0.0001 and P = 0.007, respectively]. When DNA methylation was evaluated according to plasma folate status, only 1298AA with low folate levels revealed diminished DNA methylation (P < 0.0001). Moreover, when the two MTHFR polymorphisms were concomitantly evaluated at the low folate status, DNA methylation was reduced only in 1298AA/677TT compared with 1298AA/677CC (3.11 versus 7.29 ng 5-mCyt/μg DNA, P = 0.001) and 1298CC/677CC genotypes (3.11 versus 7.14 ng 5-mCyt/μg DNA, P = 0.004). However, the high prevalence of 677TT mutants within the 1298AA group (79%) and the similar biochemical features of 1298AA/677CC and 1298CC/677CC combined genotypes suggest that the gene-nutrient interaction affecting DNA methylation in 1298AA is mainly due to the coexistence of the 677TT genotype and that the 1298A>C polymorphism may convey its protective effect not through this interaction but through another pathway in one-carbon metabolism. Further mechanistic studies are warranted to investigate how single polymorphisms as well as MTHFR combined genotypes exert their effect on cancer susceptibility.
Maternal Diet and Infant Leukemia: The DNA Topoisomerase II Inhibitor Hypothesis: A Report from the Children's Oncology Group
Authors: Spector Logan G. , Xie Yang , Robison Leslie L. , Heerema Nyla A. , Hilden Joanne M. , Lange Beverly , Felix Carolyn A. , Davies Stella M. , Slavin Joanne , Potter John D. , Blair Cindy K. , Reaman Gregory H. , Ross Julie A.
Published: September 2005

Background: The MLL 11q23 translocation arises in utero and is present in 75% of infant leukemias. That MLL+ acute myeloid leukemia (AML) can arise following chemotherapy with DNA topoisomerase II (DNAt2) inhibitors suggests that these substances, which also occur naturally in foods, may contribute toward infant leukemia. We hypothesized that maternal consumption of dietary DNAt2 inhibitors during pregnancy would increase the risk of infant leukemia, particularly AML(MLL+).

Methods: This Children's Oncology Group case-control study consisted of 240 incident cases of infant acute leukemia [AML and acute lymphoblastic leukemia (ALL)] diagnosed during 1996 to 2002 and 255 random digit dialed controls. Maternal diet during pregnancy was determined through a food frequency questionnaire. An index of specific foods identified a priori to contain DNAt2 inhibitors as well as vegetables and fruits were created and analyzed using unconditional logistic regression.

Results: There was little evidence of an association between the specific DNAt2 index and leukemia overall and by subtype. An exception was AML(MLL+); odds ratios (95% confidence intervals) comparing the second to fourth quartiles to the first were 1.9 (0.5-7.0), 2.1 (0.6-7.7), and 3.2 (0.9-11.9), respectively (P for trend = 0.10). For the vegetable and fruit index, there were significant or near-significant inverse linear trends for all leukemias combined, ALL(MLL+), and AML(MLL−).

Conclusion: Overall, maternal consumption of fresh vegetables and fruits during pregnancy was associated with a decreased risk of infant leukemia, particularly MLL+. However, for AML(MLL+) cases, maternal consumption of specific DNAt2 inhibitors seemed to increase risk. Although based on small numbers, these data provide some support for distinct etiologic pathways in infant leukemia.
Urinary Cadmium and Serum Levels of Estrogens and Androgens in Postmenopausal Japanese Women
Authors: Nagata Chisato , Nagao Yasuko , Shibuya Chiken , Kashiki Yoshitomo , Shimizu Hiroyuki
Published: September 2005

Background: Recent laboratory studies have suggested that cadmium is an estrogenic compound and may be a potential risk factor for breast cancer.

Methods: We investigated the relationship between urinary cadmium concentrations and serum concentrations of estrone, testosterone, and dehydroepiandrosterone sulfate in 164 postmenopausal Japanese women.

Results: There was a significant positive association between the urinary cadmium and serum testosterone levels after controlling for age and body mass index. The mean testosterone level was 28% higher in women with high urinary cadmium (≥3.00 μg/g creatinine) than in those with low urinary cadmium (<2.00 μg/g creatinine). Urinary cadmium was not significantly associated with serum estrone and dehydroepiandrosterone sulfate levels. Additional adjustment for smoking, alcohol and reproductive factors including known risk factors for breast cancer did not substantially alter the results.

Conclusion: Data suggested that cadmium exposure is associated with increased testosterone levels. As high testosterone levels have been associated with the risk of breast cancer, the involvement of cadmium exposure in breast cancer risk should be evaluated in future studies.
MT1G Hypermethylation Is Associated with Higher Tumor Stage in Prostate Cancer
Authors: Henrique Rui , Jerónimo Carmen , Hoque Mohammad O. , Nomoto Shuji , Carvalho André L. , Costa Vera L. , Oliveira Jorge , Teixeira Manuel R. , Lopes Carlos , Sidransky David
Published: September 2005

Purpose: Zinc is involved in several physiologic processes, including cell growth and proliferation. Although in normal prostate tissue zinc levels are high, there is a marked decrease in prostate cancer. Metallothioneins control the bioavailability of zinc and one isoform, MT1G, was reported down-regulated in prostate cancer. Here, we investigated whether promoter methylation might cause MT1G silencing in prostate cancer.

Patients and Methods: The MT1G promoter was assessed by quantitative methylation-specific PCR on prospectively collected tissue samples from 121 patients with prostate cancer, 39 paired high-grade prostatic intraepithelial neoplasias (HGPIN), 29 patients with benign prostatic hyperplasia, 13 normal prostate tissue samples from cystoprostatectomy specimens, and prostate cancer cell lines. The methylation levels were calculated and were correlated with clinical and pathologic variables. Reverse transcription-PCR was done in cell lines to assess MT1G mRNA expression before and after demethylating treatment.

Results: MT1G promoter hypermethylation was found in 29 of 121 prostate cancer, 5 of 39 HGPIN, 3 of 29 benign prostatic hyperplasia, and 0 of 13 normal prostate tissue samples. No significant differences in methylation frequencies or levels were found (P = 0.057, for both). Methylation levels were found to correlate with tumor stage but not with Gleason grade. MT1G hypermethylation was more frequent in prostate cancer that spread beyond the prostate capsule. All prostate cancer cell lines tested showed MT1G promoter methylation, but no differences in expression were apparent after demethylation.

Conclusions: Our findings suggest that MT1G promoter methylation is associated with tumor aggressiveness in prostate cancer and it might be a marker of locally advanced disease.
A Prospective Study of C-Peptide, Insulin-like Growth Factor-I, Insulin-like Growth Factor Binding Protein-1, and the Risk of Colorectal Cancer in Women
Authors: Wei Esther K. , Ma Jing , Pollak Michael N. , Rifai Nader , Fuchs Charles S. , Hankinson Susan E. , Giovannucci Edward
Published: September 2005

Hyperinsulinemia, hyperglycemia, and elevated insulin-like growth factor (IGF)-1 levels have been implicated in the etiology of colorectal cancer. However, the joint effects of insulin and IGF-I have not been considered, and whether hyperinsulinemia or hyperglycemia is more etiologically relevant is unclear. IGF binding protein-1 (IGFBP-1) has been hypothesized to mediate the effects of insulin, but epidemiologic data on IGFBP-1 are sparse. We conducted a nested case-control study among the 32,826 women of the Nurses' Health Study who provided a blood sample in 1989 to 1990. After excluding diabetics, we confirmed 182 incident colorectal cancer cases over 10 years of follow-up and 350 controls. Cases were matched to two controls on year of birth, date of blood draw, and fasting status. C-peptide levels were weakly associated with risk of colon cancer [top quartile (Q4) versus bottom quartile (Q1): multivariable relative risk (MVRR), 1.76; 95% confidence interval (95% CI), 0.85-3.63]. Fasting IGFBP-1 was inversely associated with risk of colon cancer (MVRR, 0.28; 95% CI, 0.11-0.75). We observed no clear association between glycosylated hemoglobin and risk for colorectal cancer. The IGF-I to IGFBP-3 molar ratio was associated with colon cancer risk (MVRR, 2.82; 95% CI, 1.35-5.88), and women with low levels of both IGF-I/IGFBP-3 and C-peptide (or high IGFBP-1) were at low risk, and elevation of either was sufficient to increase risk. Although altering IGF-I levels may not be practical, the growing burden of obesity and consequently hyperinsulinemia, which seems increasingly important for colon cancer, may be a target for effective prevention.
Physical Activity and Risk of Endometrial Cancer: A Report from the Shanghai Endometrial Cancer Study
Authors: Matthews Charles E. , Xu Wang Hong , Zheng Wei , Gao Yu Tang , Ruan Zhi Xian , Cheng Jia Rong , Xiang Yong Bing , Shu Xiao Ou
Published: September 2005

We evaluated the type and amount of physical activity associated with risk of endometrial cancer. In this population-based case-control study, in-person interviews were completed among 832 incident endometrial cancer cases and 846 age-matched controls. Physical activity from exercise, household activities, and transportation was assessed in adolescence and adulthood, as was lifetime occupational activity. Logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence limits (95% CL). Women reporting exercise participation in both adolescence and adulthood were at nearly a 40% reduced risk (OR, 0.63; 95% CL, 0.42-0.95), compared with women reporting no exercise in either life period. Postmenopausal women who initiated exercise in adulthood were also at reduced risk (OR, 0.76; 95% CL, 0.56-1.02). Reductions in risk were also observed for common lifestyle activities, including household activity (both life periods) and walking for transportation (adulthood). Examination of the independent and combined effect of exercise and lifestyle activities revealed that women with less active lifestyles but who reported exercise were at 35% reduced risk (OR, 0.65; 95% CL, 0.41-1.02), whereas nonexercisers with more active lifestyles were at 40% to 45% reduced risk. These findings suggest that both lifestyle activities of lower intensity (e.g., walking and doing household chores) and intentional exercise can reduce endometrial cancer risk.
Carcinogen Exposure during Short-term Switching from Regular to “Light” Cigarettes
Authors: Benowitz Neal L. , Jacob Peyton , Bernert John T. , Wilson Margaret , Wang Langing , Allen Faith , Dempsey Delia
Published: September 2005

Objectives: “Light” cigarettes are extremely popular and are perceived by many smokers as less hazardous than higher-yield cigarettes. The objectives of this study were (a) to assess a battery of biomarkers of tobacco smoke exposure that includes tobacco smoke carcinogens, (b) to examine the behavioral nature of compensation, and (c) to examine the consistency of an individual's tobacco smoke exposure when smoking the same cigarette at different times.

Methods: The study was a 3-week crossover study in which smokers smoked their usual cigarettes during weeks 1 and 3, and a light cigarette, with a machine-determined nicotine yield of about 50% of the usual cigarette, during week 2. Blood and urine biomarkers of exposure and subjective questionnaires were collected weekly.

Results: Based on cotinine and carboxyhemoglobin levels, compensation averaged 78% and 83%, respectively. Urinary excretion of 4-(methylnitrosamino)-1-(3-pyridyl)-butanol, a metabolite of the tobacco specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-butanone, and a number of polycyclic aromatic hydrocarbon metabolites was similar in all conditions. Compensation was accomplished both by smoking cigarettes more intensively and by smoking more cigarettes per day. Exposures to various tobacco smoke constituents while smoking the usual brand of cigarette in weeks 1 and 3 were highly correlated.

Conclusion: Our findings support the idea that smokers compensate to a high degree when switched from their usual brand to a light cigarette. Short-term switching resulted in no significant reduction in carcinogen exposure. Our assessment, based on measures of biochemical exposures, supports the idea that switching to light cigarettes is unlikely to reduce the health risks of cigarette smoking.
Evaluation of Risk Factors for Nasopharyngeal Carcinoma in High-Risk Nasopharyngeal Carcinoma Families in Taiwan
Authors: Yang Xiaohong (Rose) , Diehl Scott , Pfeiffer Ruth , Chen Chien-Jen , Hsu Wan-Lun , Dosemeci Mustafa , Cheng Yu-Juen , Sun Brenda , Goldstein Alisa M. , Hildesheim Allan ,   The Chinese and American Genetic Epidemiology of NPC Study Team
Published: September 2005

A study of nasopharyngeal carcinoma (NPC) families with two or more affected members was conducted in Taiwan (265 families with 2,444 individuals, 502 affected and 1,942 unaffected) to determine the association between NPC and potential etiologic factors in NPC high-risk families. Similar to results from a previous case-control study in Taiwan, Guangdong salted fish consumption during childhood, exposure to wood, and betel nut consumption were all associated with elevated NPC risk using conditional logistic regression, although these associations were not as strong as in the case-control study possibly due to shared environment among family members. Risk associated with cumulative wood exposure and salted fish consumption before age 10 was stronger in families with early NPC age-onset [odds ratio (ORwood), 5.10; 95% confidence interval (95% CI), 1.50-17.34; ORfish, 3.94; 95% CI, 1.47-10.55] or three or more affected members (ORwood, 4.41; 95% CI, 1.58-12.30; ORfish, 4.27; 95% CI, 1.10-16.47). In contrast, a tendency for elevated risk was noted for betel nut use in late age-onset families (OR, 2.44; 95% CI, 1.16-5.13) and the CYP2E1 c2 allele in families with less than three affected members (OR, 2.06; 95% CI, 1.04-3.35). Risk estimates associated with these exposures were similar when the analyses were restricted to EBV-seropositive subjects. To better adjust for degree of relationship among family members and residual genetic correlations, we also calculated ORs using a variance components model. The results from the two methods were similar indicating that the risk estimates from conditional logistic regression were unbiased.
Interactions of Peroxisome Proliferator–Activated Receptor γ and Diet in Etiology of Colorectal Cancer
Authors: Murtaugh Maureen A. , Ma Khe-ni , Caan Bette J. , Sweeney Carol , Wolff Roger , Samowitz Wade S. , Potter John D. , Slattery Martha L.
Published: September 2005

The peroxisome proliferator–activated receptor γ (PPARγ) is one of a group of ligand-activated nuclear receptors responsible for regulation of glucose, lipid homeostasis, cell differentiation, and apoptosis. The 12 proline-to-alanine (Pro12Ala) substitution polymorphism in PPARγ produces proteins with lower activity. Variation in PPARγ expression in the bowel and the role of dietary fatty acids as ligands for PPARγ led investigation of whether the associations of diet with colon and rectal cancer risk were modified by PPARγ genotype. Data (diet, lifestyle, and DNA) came from case-control studies of colon (1,577 cases and 1,971 controls) and rectal cancer (794 cases and 1,001 controls) conducted in Northern California, Utah, and the Twin City, Minnesota Metropolitan area (colon cancer study only). Unconditional logistic regression models were adjusted for age at selection, body mass index, physical activity, energy intake, dietary fiber, and calcium. We found no significant interactions between macronutrient (fat, protein, and carbohydrate) and colorectal cancer. High lutein intake [odds ratio (OR), 0.63; 95% confidence interval (95% CI), 0.44-0.89], low refined grain intake (OR, 0.70; 95% CI, 0.53-0.94), or a high prudent diet score (OR, 0.66; 95% CI, 0.49-0.89) and PA/AA PPARγ genotype were associated with reduced colon cancer risk. Risk of rectal cancer was increased among those with the PA/AA PPARγ genotype and a high mutagen index (OR, 1.63; 95% CI, 1.12, 2.36). Its unclear whether the alterations in risk in those with the less active phenotype for PPARγ is related to activation of PPARγ by nutrients or dietary patterns acting as ligands or direct influences of these nutrients on colon and rectal cancer processes that are important with lower PPARγ activity.
APC Asp1822Val and Gly2502Ser Polymorphisms and Risk of Colorectal Cancer and Adenoma
Authors: Tranah Gregory J. , Giovannucci Edward , Ma Jing , Fuchs Charles , Hunter David J.
Published: September 2005

Mutation of the adenomatous polyposis coli (APC) tumor suppressor gene is an important initiating factor in the early stages of the adenoma-carcinoma sequence. The aim of this study was to investigate the two most common APC variants (Asp1822Val and Gly2502Ser) and their association with colorectal cancer and adenoma and whether these relationships are influenced by dietary and lifestyle factors. We analyzed 556 adenoma cases and 557 matched controls and 197 cancer cases and 490 matched controls nested within the Nurses' Health Study cohort, 274 cancer cases and 456 matched controls nested within the Physicians' Health Study cohort, and 375 adenoma cases and 724 matched controls nested within the Health Professionals Follow-up Study cohort. APC Asp1822Val and Gly2502Ser polymorphisms were not associated with risk of colorectal cancer or adenoma. For colorectal cancer, a significant interaction was found between Asp1822Val genotype and postmenopausal hormone (PMH) use among postmenopausal women (Pinteraction = 0.03). Current PMH use was associated with reduced risk overall and a statistically significant lower risk of colorectal cancer among carriers of one or two copies of the APC 1822Val allele (relative risk, 0.46; 95% confidence interval, 0.24-0.88) relative to wild-type never or past PMH users. Our results suggest that cigarette smoking, alcohol intake, and family history of colorectal cancer were positively associated and regular aspirin intake was inversely associated with colorectal adenoma in men and women. No gene-environment interactions were observed with these risk factors or with other dietary risk factors previously hypothesized to interact with the APC Asp1822Val polymorphism.
The Association of XRCC1 Haplotypes and Chromosomal Damage Levels in Peripheral Blood Lymphocyte among Coke-Oven Workers
Authors: Leng Shuguang , Cheng Juan , Zhang Linyuan , Niu Yong , Dai Yufei , Pan Zufei , Li Bin , He Fengsheng , Zheng Yuxin
Published: September 2005

Theoretically, a haplotype has a higher level of heterozygosity than individual single nucleotide polymorphism (SNP) and the association study based on the haplotype may have an increased power for detecting disease associations compared with SNP-based analysis. In this study, we investigated the effects of four haplotype-tagging SNPs (htSNP) and the inferred haplotype pairs of the X-ray cross-complementing group 1 (XRCC1) gene on chromosome damage detected by the cytokinesis-block micronucleus assay. The study included 141 coke-oven workers with exposure to a high level of polycyclic aromatic hydrocarbons and 66 nonexposed controls. The frequencies of total MN and MNed cells were borderline associated with the Arg194Trp polymorphism (P = 0.053 and P = 0.050, respectively) but not associated with the Arg280His, Arg399Gln and Gln632Gln polymorphisms among coke-oven workers. Five haplotypes, including CGGG, TGGG, CAGG, CGAG, and CGGA, were inferred based on the four htSNPs of XRCC1 gene. The haplotype CGGG was associated with the decreased frequencies of total MN and MNed cells, and the haplotypes TGGG and CGAG were associated with the increased frequencies of total MN and MNed cells with adjustment for covariates among coke-oven workers. This study showed that the haplotypes derived from htSNPs in the XRCC1 gene were more likely than single SNPs to correlate with the polycyclic aromatic hydrocarbon–induced chromosome damage among coke-oven workers.
Cigarette Smoking and Risk of Non-Hodgkin Lymphoma: A Pooled Analysis from the International Lymphoma Epidemiology Consortium (InterLymph)
Authors: Morton Lindsay M. , Hartge Patricia , Holford Theodore R. , Holly Elizabeth A. , Chiu Brian C.H. , Vineis Paolo , Stagnaro Emanuele , Willett Eleanor V. , Franceschi Silvia , La Vecchia Carlo , Hughes Ann Maree , Cozen Wendy , Davis Scott , Severson Richard K. , Bernstein Leslie , Mayne Susan T. , Dee Fred R. , Cerhan James R. , Zheng Tongzhang
Published: September 2005

Background: The International Lymphoma Epidemiology Consortium (InterLymph) provides an opportunity to analyze the relationship between cigarette smoking and non-Hodgkin lymphoma with sufficient statistical power to consider non-Hodgkin lymphoma subtype. The results from previous studies of this relationship have been inconsistent, likely due to the small sample sizes that arose from stratification by disease subtype. To clarify the role of cigarette smoking in the etiology of non-Hodgkin lymphoma, we conducted a pooled analysis of original patient data from nine case-control studies of non-Hodgkin lymphoma conducted in the United States, Europe, and Australia.

Methods: Original data were obtained from each study and uniformly coded. Risk estimates from fixed-effects and two-stage random-effects models were compared to determine the impact of interstudy heterogeneity. Odds ratios (OR) and 95% confidence intervals (95% CI) were derived from unconditional logistic regression models, controlling for study center, age, sex, and race.

Results: In our pooled study population of 6,594 cases and 8,892 controls, smoking was associated with slightly increased risk estimates (OR, 1.07; 95% CI, 1.00-1.15). Stratification by non-Hodgkin lymphoma subtype revealed that the most consistent association between cigarette smoking and non-Hodgkin lymphoma was observed among follicular lymphomas (n = 1452). Compared with nonsmokers, current smokers had a higher OR for follicular lymphoma (1.31; 95% CI, 1.12-1.52) than former smokers (1.06; 95% CI, 0.93-1.22). Current heavy smoking (≥36 pack-years) was associated with a 45% increased OR for follicular lymphoma (1.45; 95% CI, 1.15-1.82) compared with nonsmokers.

Conclusions: Cigarette smoking may increase the risk of developing follicular lymphoma but does not seem to affect risk of the other non-Hodgkin lymphoma subtypes we examined. Future research is needed to determine the biological mechanism responsible for our subtype-specific results.
Variation in Plasma Insulin-Like Growth Factor-1 and Insulin-Like Growth Factor Binding Protein-3: Genetic Factors
Authors: Morimoto Libby M. , Newcomb Polly A. , White Emily , Bigler Jeannette , Potter John D.
Published: September 2005

Insulin-like growth factors (IGFs) play key roles in cell proliferation and apoptosis. Whereas relatively stable within individuals, IGFs vary substantially between individuals, and a large component of this variation may be determined by genetic factors. Several polymorphisms in IGF genes have been identified, although their functional significance is not clear. We evaluated the association of polymorphisms in IGF-1 and IGFBP-3 and circulating levels of IGF-1 and IGFBP-3 in 323 population-based control subjects enrolled in a case-control study of colorectal cancer from September 1999 through February 2002. Total IGF-1 and IGFBP-3 levels were measured using ELISA assays, and all subjects were genotyped for a microsatellite polymorphism in IGF-1 and a single nucleotide polymorphism in IGFBP-3. Multiple linear regression was used to assess the association of genotype with circulating IGFs. IGF-1 levels were unrelated to either polymorphism. IGFBP-3 was significantly associated with IGFBP-3 genotype, with IGFBP-3 levels increasing from CC (1,895 ng/mL) → GC (2,029 ng/mL) → GG (2,182 ng/mL), (p-trend < 0.001). Having an IGF-1 genotype other than homozygous for the 19-repeat allele was associated with higher IGFBP-3 levels (1,945 versus 2,052 ng/mL). Furthermore, both IGF-1 and IGFBP-3 genotypes modified the relationship between postmenopausal hormone use and IGFs. This analysis provides evidence that common variation in IGF genes may contribute to the variation in circulating levels observed between individuals.
Mortality From Lung Cancer and Tobacco Smoking in Ohio (U.S.): Will Increasing Smoking Prevalence Reverse Current Decreases in Mortality?
Authors: Tyczynski Jerzy E. , Berkel Hans J.
Published: September 2005

Background: Despite significant changes in smoking patterns within the past few decades, lung cancer remains a major cause of cancer deaths in many developed countries in people of each sex, and one of the most important public health issues. The study aims to analyze the possible impact of changes in tobacco smoking practices in the state of Ohio (U.S.) on current and future trends and patterns of lung cancer mortality.

Materials and Methods: Mortality rates from lung cancer were calculated for the period 1970 to 2001 on the basis of data from the National Center for Health Statistics. The Joinpoint regression approach was used to evaluate changes in time trends by sex, age, and race. Data on smoking prevalence in Ohio were retrieved from the Centers for Disease Control and Prevention website.

Results: Lung cancer mortality rates in Ohio have declined among men of all ages as well as in specific age groups in the 1990s, and the rate of increase among middle-aged and elderly women has dropped over time. The mortality rate among young women (ages 20-44) began to increase during the early 1990s. The prevalence of smoking in Ohio has increased since the early 1990s, especially among young persons.

Conclusions: Recent trends in tobacco smoking in Ohio indicate that the declining trends in lung cancer mortality might be reversed in the future. An early indicator of possible change is the recent increase in mortality among young women. Implementation of the Ohio Comprehensive Tobacco Use Prevention Strategic Plan might help to disseminate proven prevention strategies among the inhabitants of Ohio and might thus prevent future increases in lung cancer mortality rates in the state.
Insulin-Like Growth Factor-I, IGF-Binding Protein-3, and Mammographic Breast Density
Authors: Diorio Caroline , Pollak Michael , Byrne Celia , Mâsse Benoît , Hébert-Croteau Nicole , Yaffe Martin , Coté Gary , Bérubé Sylvie , Morin Carol , Brisson Jacques
Published: September 2005

Some studies have suggested that insulin-like growth factor (IGF) pathway is related to premenopausal breast density, one of the strongest known breast cancer risk factors. This study was designed specifically to test the hypothesis that higher levels of IGF-I and lower levels of IGF-binding protein (IGFBP)-3 are associated with high mammographic breast density among premenopausal but not among postmenopausal women. A total of 783 premenopausal and 791 postmenopausal healthy women were recruited during screening mammography examinations. Blood samples were collected at the time of mammography, and plasma IGF-I and IGFBP-3 levels were measured by ELISA. Mammographic breast density was estimated using a computer-assisted method. Spearman's partial correlation coefficients (rs) were used to evaluate the associations. Adjusted mean breast density was assessed by joint levels of IGF-I and IGFBP-3 using generalized linear models. Among premenopausal women, high levels of IGF-I and low levels of IGFBP-3 were independently correlated with high breast density (rs = 0.083; P = 0.021 and rs = −0.124; P = 0.0005, respectively). Correlation of IGF-I with breast density was stronger among women in the lowest tertile of IGFBP-3 than among those in the highest tertile of IGFBP-3 (rs = 0.138; P = 0.027 and rs = −0.039; P = 0.530, respectively). In contrast, the correlation of IGFBP-3 with breast density was stronger among women in the highest tertile of IGF-I than among those in the lowest tertile of IGF-I (rs = −0.150; P = 0.016 and rs = −0.008; P = 0.904, respectively). Women in the combined top tertile of IGF-I and bottom tertile of IGFBP-3 had higher mean breast density than those in the combined bottom tertile of IGF-I and top tertile of IGFBP-3 (53.8% versus 40.9%; P = 0.014). No significant association was observed among postmenopausal women. Our findings confirm that IGF-I and IGFBP-3 are associated with breast density among premenopausal women. They provide additional support for the idea that, among premenopausal women, these growth factors may affect breast cancer risk, at least in part, through their influence on breast tissue morphology as reflected on mammogram.
Response Rates to a Mailed Survey Targeting Childhood Cancer Survivors: A Comparison of Conditional versus Unconditional Incentives
Authors: Rosoff Philip M. , Werner Cary , Clipp Elizabeth C. , Guill Ann Bebe , Bonner Melanie , Demark-Wahnefried Wendy
Published: September 2005

Objective: Mailed surveys are widely used to collect epidemiologic and health service data. Given that nonresponse can threaten the validity of surveys, modest incentives are often used to increase response rates. A study was undertaken among childhood cancer survivors and their parents to determine if response rate to a mailed survey differed with provision of immediate versus delayed incentives.

Design: A self-administered survey designed to ascertain health behaviors was mailed to 397 childhood cancer survivors (and their parents if the survivor was <18 years of age). Subjects were randomized into two groups based on gender, age, race, and cancer type. One group received a $10 incentive with their blank survey (unconditional incentive), whereas the other group received the incentive upon receipt of their completed survey (conditional incentive). If children were minors, both the parent and the child received incentives.

Results: No significant differences in response rates were observed with respect to gender, age, race, or cancer type. However, significant differences in response rates were observed between incentive groups, with unconditional incentives yielding significantly higher response rates than conditional incentives for child survivors who were ≥18 years (64.4% versus 49.0%), as well as younger child survivors (62.5% versus 43.6%) and their parents (64.8% versus 41.5%; all P < 0.05).

Conclusions: The provision of an immediate incentive generated significantly higher response rates to this mailed health survey among childhood cancer survivors and their parents. Given that survey studies are commonly conducted across various pediatric populations, these findings may help inform the design of future pediatric survey research.
Mammographic Features and Subsequent Risk of Breast Cancer: A Comparison of Qualitative and Quantitative Evaluations in the Guernsey Prospective Studies
Authors: Torres-Mejía Gabriela , De Stavola Bianca , Allen Diane S. , Pérez-Gavilán Juan J. , Ferreira Jorge M. , Fentiman Ian S. , dos Santos Silva Isabel
Published: September 2005

Mammographic features are known to be associated with breast cancer but the magnitude of the effect differs markedly from study to study. Methods to assess mammographic features range from subjective qualitative classifications to computer-automated quantitative measures. We used data from the UK Guernsey prospective studies to examine the relative value of these methods in predicting breast cancer risk. In all, 3,211 women ages ≥35 years who had a mammogram taken in 1986 to 1989 were followed-up to the end of October 2003, with 111 developing breast cancer during this period. Mammograms were classified using the subjective qualitative Wolfe classification and several quantitative mammographic features measured using computer-based techniques. Breast cancer risk was positively associated with high-grade Wolfe classification, percent breast density and area of dense tissue, and negatively associated with area of lucent tissue, fractal dimension, and lacunarity. Inclusion of the quantitative measures in the same model identified area of dense tissue and lacunarity as the best predictors of breast cancer, with risk increasing by 59% [95% confidence interval (95% CI), 29-94%] per SD increase in total area of dense tissue but declining by 39% (95% CI, 53-22%) per SD increase in lacunarity, after adjusting for each other and for other confounders. Comparison of models that included both the qualitative Wolfe classification and these two quantitative measures to models that included either the qualitative or the two quantitative variables showed that they all made significant contributions to prediction of breast cancer risk. These findings indicate that breast cancer risk is affected not only by the amount of mammographic density but also by the degree of heterogeneity of the parenchymal pattern and, presumably, by other features captured by the Wolfe classification.
Association of Breast Cancer Risk with a Common Functional Polymorphism (Asp327Asn) in the Sex Hormone–Binding Globulin Gene
Authors: Cui Yong , Shu Xiao-Ou , Cai Qiuyin , Jin Fan , Cheng Jia-Rong , Cai Hui , Gao Yu-Tang , Zheng Wei
Published: September 2005

Sex hormones play a central role in the development of breast cancer. Sex hormone–binding globulin (SHBG) modulates the bioavailability of circulating sex hormones and regulates their signaling system in the breast tissue. We evaluated the association of a common functional polymorphism (Asp327Asn) in the SHBG gene with breast cancer risk in a population-based case-control study (1,106 cases and 1,180 controls) conducted in Shanghai, China. The variant Asn allele was associated with a reduced breast cancer risk in postmenopausal women [odds ratio (OR), 0.73; 95% confidence interval (95% CI), 0.53-0.99], but not in premenopausal women (OR, 1.03; 95% CI, 0.82-1.27). The protective association was much stronger in postmenopausal women with a low body mass index (BMI; OR, 0.46; 95% CI, 0.29-0.75) or waist-to-hip ratio (OR, 0.51; 95% CI, 0.32-0.83) than those with a high BMI or waist-to-hip ratio (P for interaction < 0.05). Furthermore, the association was stronger for estrogen receptor–positive (OR, 0.64; 95% CI, 0.42-0.98) than for estrogen receptor–negative breast cancer (OR, 0.85; 95% CI, 0.50-1.45). Among postmenopausal controls, blood SHBG levels were 10% higher in carriers of the variant Asn allele than noncarriers (P = 0.06). Postmenopausal control women with the Asn allele and low BMI or waist-to-hip ratio had 20% higher SHBG levels (P < 0.05). This study suggests that the Asn allele in the SHBG gene may be related to a reduced risk of breast cancer among postmenopausal women by increasing their blood SHBG levels.
Childhood and Adult Cancer in Twins: Evidence from the Utah Genealogy
Authors: Neale Rachel E. , Mineau Geraldine , Whiteman David C. , Brownbill Pat A. , Murphy Michael F.G.
Published: September 2005

Objective: Evidence suggests that the in utero environment may contribute to subsequent development of cancers in childhood and adulthood. Raised levels of estrogen during pregnancy may be the primary in utero etiologic factor. Mothers of twins have higher estrogen levels during pregnancy than mothers of singletons, therefore, assessment of cancer risk in twins may be informative.

Method: We conducted a retrospective cohort study of cancer among twin and singleton newborns selected from the Utah Population Database, matched on birth year and sex. Cancer diagnoses were determined by linkage with the Utah state cancer register. Relative rates of all cancers in childhood and in adulthood in twins compared with singletons, and for specific cancers including testicular, breast and melanoma, were calculated using Poisson regression.

Results: Twin (35,271) and singleton (74,199) births were identified, among whom there were 336 and 691 cancer diagnoses, respectively. The relative risk (RR) of childhood cancer in twins compared with singletons was 0.82 [95% confidence interval (CI) 0.55-1.24] and of adult cancer was 1.06 (0.92-1.22). We found nonsignificant increases in risk among adult twins for cancers of the breast, prostate, testis, lymphatic system, thyroid, and large bowel. The largest departures from unity were for testicular cancer (RR 1.47; 95% CI, 0.73-2.95) and melanoma (RR 0.67; 95% CI, 0.42-1.06).

Conclusions: These results are consistent with the body of evidence suggesting that twins have a reduced risk of cancer in childhood. Although there is no overall differential in adult cancer risk, these data support the hypothesis that the in utero environment may play an important role in specific cancers.
Association of Genetic Polymorphisms with Serum Estrogens Measured Multiple Times During a 2-Year Period in Premenopausal Women
Authors: Lurie Galina , Maskarinec Gertraud , Kaaks Rudolf , Stanczyk Frank Z. , Le Marchand Loïc
Published: September 2005

There is evidence that circulating estrogens are associated with breast cancer risk. In this study of premenopausal women, we explored the association of polymorphisms in genes in the estrogen synthesis and metabolism pathways with serum and urinary levels of estrone (E1) and estradiol (E2) and with the urinary ratio of 2-hydroxyestrone (2-OHE1)/16α-hydroxyestrone (16α-OHE1). This analysis included 220 women, who were participants in a 2-year randomized soy intervention. Blood specimens were collected in the luteal phase of the menstrual cycle an average of 4.4 times over 2 years. Overnight urinary specimens were collected on the same cycle day, only at baseline. Levels of E1, E2, 2-OHE1, and 16α-OHE1 were measured by enzyme immunoassays. The DNA samples were analyzed by PCR/RFLP for the COMT Val158Met, CYP1A1*2A, CYP1A1*2B, CYP1A2*1F, CYP1B1 Val432Leu, and CYP17 T27C polymorphisms. We applied mixed models to investigate the relations between genotypes and repeated serum hormone measurements and generalized linear models to assess associations between genotypes and urinary estrogen metabolites. The CYP1A2 C allele was significantly associated with lower serum E2 levels; in CC genotype carriers, serum E2 levels were 26.3% lower than in homo- and heterozygous common allele carriers combined (P = 0.01). CYP1A2*1F also affected the urinary 2-OHE1/16α-OHE1 ratio; carriers of the variant C allele had a markedly lower ratio than individuals with the AA genotype (1.37 versus 1.76; P = 0.002). These data suggest that CYP1A2*1F is associated with lower circulating levels of E2, and that it may be a susceptibility locus for breast cancer.
Tobacco-Specific Nitrosamines and Their Pyridine-N-glucuronides in the Urine of Smokers and Smokeless Tobacco Users
Authors: Stepanov Irina , Hecht Stephen S.
Published: September 2005

Tobacco-specific nitrosamines are believed to play a significant role as causes of cancer in people who use tobacco products. Whereas the uptake of one tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, has been shown by analysis of its metabolites in urine, there are no published studies on urinary levels of N′-nitrosonornicotine (NNN), N′-nitrosoanatabine (NAT), and N′-nitrosoanabasine (NAB) or their metabolites in human urine. We developed a method for quantitation of NNN, NAT, NAB, and their pyridine-N-glucuronides NNN-N-Gluc, NAT-N-Gluc, and NAB-N-Gluc in human urine. Total NNN (NNN plus NNN-N-Gluc) was assayed using 5-methyl-N′-nitrosonornicotine as internal standard. Urine was treated with β-glucuronidase. Following solvent partitioning and solid-phase extraction, total NNN was determined using gas chromatography with nitrosamine-selective detection. Total NAT and total NAB were quantified in the same samples. Separate quantitation of NNN and NNN-N-Gluc was accomplished by extraction of the urine with ethyl acetate before β-glucuronidase hydrolysis; NNN was analyzed in the ethyl acetate extract, and after enzyme treatment, NNN released from NNN-N-Gluc was quantified in the extracted urine. Separate analyses of NAT, NAT-N-Gluc, NAB, and NAB-N-Gluc proceeded similarly. Analyte identities were confirmed by gas chromatography-tandem mass spectrometry. Mean levels of total NNN, NAT, and NAB in the urine of 14 smokers were (pmol/mg creatinine) 0.18 ± 0.22, 0.19 ± 0.20, and 0.040 ± 0.039, respectively, whereas the corresponding amounts in the urine of 11 smokeless tobacco users were 0.64 ± 0.44, 1.43 ± 1.10, and 0.23 ± 0.19, respectively. Pyridine-N-glucuronides accounted for 59% to 90% of total NNN, NAT, and NAB. The results of this study show the presence of NNN, NAT, NAB, and their pyridine-N-glucuronides in human urine and provide a quantitative method for application in mechanistic and epidemiologic studies of the role of tobacco-specific nitrosamines in human cancer.
Multistage Carcinogenesis and Lung Cancer Mortality in Three Cohorts
Authors: Hazelton William D. , Clements Mark S. , Moolgavkar Suresh H.
Published: September 2005

Experimental evidence indicates that tobacco smoke acts both as an initiator and a promoter in lung carcinogenesis. We used the two-stage clonal expansion model incorporating the ideas of initiation, promotion, and malignant conversion to analyze lung cancer mortality in three large cohorts, the British Doctors' cohort and the two American Cancer Society cohorts, to determine how smoking habits influence age-specific lung cancer rates via these mechanisms. Likelihood ratio tests indicate that smoking-related promotion is the dominant model mechanism associated with lung cancer mortality in all cohorts. Smoking-related initiation is less important than promotion but interacts synergistically with it. Although no information on ex-smokers is available in these data, the model with estimated variables can be used to project risks among ex-smokers. These projected risks are in good agreement with the risk among ex-smokers derived from other studies. We present 10-year projected risks for current and former smokers adjusted for competing causes of mortality. The importance of smoking duration on lung cancer risk in these cohorts is a direct consequence of promotion. Intervention and treatment strategies should focus on promotion as the primary etiologic mechanism in lung carcinogenesis.
The Association of Physical Activity and Body Mass Index with the Risk of Large Bowel Polyps
Authors: Wallace Kristin , Baron John A. , Karagas Margaret R. , Cole Bernard F. , Byers Tim , Beach Michael A. , Pearson Loretta H. , Burke Carol A. , Silverman William B. , Sandler Robert S.
Published: September 2005

Purpose and Method: Several studies have suggested that physical inactivity and obesity increase the risk for colorectal neoplasia. In this study, we investigated the association of physical activity and body mass index (BMI) with the risk of different types of large bowel polyps. We did an observational analysis nested within a randomized double-blind placebo-controlled chemoprevention trial among patients with one or more recently resected histologically confirmed colorectal adenoma. Nine hundred thirty patients were randomized to calcium (1,200 mg/d, as carbonate) or placebo. Follow-up colonoscopies were conducted approximately 1 and 4 years after the qualifying examination. At study entry, we obtained each subject's current body weight and height, which we used to calculate BMI. After the second study colonoscopy, we asked subjects questions about their leisure time physical activity. Seven hundred eighty-seven subjects completed at least part of the physical activity questionnaire.

Results: We found no association between measures of physical activity or BMI and tubular adenomas or hyperplastic polyps. However, among men, there were strong inverse associations observed between physical activity and advanced neoplastic polyps. Compared with men whose total daily energy expenditure was in the lowest tertile, those in the highest tertile had a risk ratio of 0.35 (95% confidence interval, 17-0.72); there was no similar reduction observed among women (risk ratio, 1.21; 95% confidence interval, 0.36-4.03; P for interaction = 0.04).

Data Interpretations: We found a significant inverse relationship between several measures of physical activity and risk of advanced colorectal neoplasms, particularly among men. No associations were found between BMI and hyperplastic polyps, tubular adenomas, or advanced neoplastic polyps.
The Development of Therapeutic and Preventive Vaccines for Gastric Cancer andHelicobacter pylori
Authors: Chui Stephen Y. , Clay Timothy M. , Lyerly H. Kim , Morse Michael A.
Published: September 2005

Gastric cancer is one of the most important worldwide public health problems. Convincing epidemiologic and etiologic associations have been made between the development of gastric cancer and infection with Helicobacter pylori. H. pylori not only has adapted to survive within the harsh environment of the stomach but also is able to modulate and avoid endogenous immune responses. The design and creation of efficacious vaccine strategies against H. pylori requires an understanding of the complex interactions that make up mucosal immunity. An effective vaccine strategy against H. pylori has the potential to affect significantly on population health worldwide.