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ABSTRACT: PURPOSE: Arsenic is a known human carcinogen and has been linked to adverse health outcomes, including cancer. However, the effects of arsenic exposure from food on health are still unknown. We researched to examine the association between arsenic exposure from food and incidence of cancer in a Japanese population. METHODS: We conducted a population-based prospective study in 90,378 Japanese men and women aged 45-74 years. Participants responded to a validated questionnaire that included 138 food items. We estimated dietary arsenic intake from 12 food groups (75 items) based on the questionnaire data. During 11 years of follow-up, 7,002 cancer cases were identified. Hazard ratios (HRs) and 95 % confidence intervals (CIs) for cancer were calculated by Cox proportional hazards modeling. RESULTS: Total arsenic and inorganic arsenic showed no association with the risk of total cancer in both men and women. Total arsenic and inorganic arsenic intake tended to be associated with an increased risk of lung cancer in men. In particular, these positive associations were strengthened in currently smoking men, with HRs (95 % CI) in the highest categories of arsenic and inorganic arsenic intake compared with the lowest of 1.29 (95 % CI = 1.03-1.61) and 1.36 (95 % CI = 1.09-1.70), respectively. We also detected an interaction between arsenic and inorganic arsenic intake and smoking status in men (p interaction < 0.01 and 0.07, respectively). CONCLUSION: A significant dose-response trend was seen in the association of arsenic and inorganic intake with lung cancer risk in currently smoking men.
Cancer Causes and Control 05/2013; · 2.88 Impact Factor
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ABSTRACT: BACKGROUND: Studies conducted in Western countries have found a robust association between higher social support and improved cancer outcomes, particularly for breast cancer incidence and prognosis. However, less is known about the influence of social support on cancer among Asian populations where the measures of social support may differ in social relationships. In this prospective cohort study in Japan, we sought to examine the associations between the incidence and mortality of total and site-specific cancer. METHODS: We examined prospectively the association between social support and risk of cancer incidence and mortality within a cohort of 44,152 Japanese men and women, aged 40-69 years, free of prior diagnosis of cancer and cardiovascular disease. Social support was measured by emotional support defined as receipt of confidant support and esteem support from family members or friends and by social isolation. A total of 3,444 cases of newly diagnosed cancer and 1,561 cancer deaths occurred between the baseline questionnaire (1993-1994) and the end of follow-up in January 2004. RESULTS: The multivariate hazard ratios (HR) and 95 % confidence intervals for colorectal cancer incidence and mortality in the highest social support versus lowest social support group were 1.48 (1.06-2.05) and 3.07 (1.65-5.69) in men, respectively. Social support was not associated with other site-specific cancer incidence or cancer outcomes in women. CONCLUSIONS: Low social support was associated with higher risk of both colorectal cancer incidence and mortality in men. Social support may affect colorectal cancer onset and prognosis via a range of factors, including healthier lifestyles as well as adherence to therapeutic regimens.
Cancer Causes and Control 04/2013; · 2.88 Impact Factor
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Hiroaki Itoh, Motoki Iwasaki,
Norie Sawada,
Ribeka Takachi,
Yoshio Kasuga,
Shiro Yokoyama,
Hiroshi Onuma,
Hideki Nishimura,
Ritsu Kusama,
Kazuhito Yokoyama,
Shoichiro Tsugane
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ABSTRACT: Cadmium, an environmental pollutant, may act like an estrogen and be a potential risk factor for estrogen-dependent diseases such as breast cancer. We examined the hypothesis that higher dietary cadmium intake is associated with risk of overall and hormone receptor-defined breast cancer in Japanese women, a population with a relatively high cadmium intake. The study was conducted under a case-control design in 405 eligible matched pairs from May 2001 to September 2005 at four hospitals in Nagano Prefecture, Japan. Dietary cadmium intake was estimated using a food frequency questionnaire. Multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of breast cancer and its hormone-receptor-defined subtypes were calculated by tertile of dietary cadmium intake. We found no significant association between dietary cadmium and risk of total breast cancer in either crude or multivariable-adjusted analysis. Adjusted ORs for tertiles of cadmium intake were 1.00, 1.19, and 1.23 (95% CI, 0.76-2.00; P for trend=0.39) for whole breast cancer. Further, no significant associations were seen across strata of menopausal status, smoking, and diabetes in multivariable-adjusted models except for adjusted OR for continuous cadmium intake in postmenopausal women. A statistically significant association was found for estrogen receptor-positive (ER+) tumors among postmenopausal women (adjusted OR=1.00, 1.16, and 1.94 [95% CI, 1.04-3.63; P for trend=0.032]). Although the present study found no overall association between dietary cadmium intake and breast cancer risk, higher cadmium intake was associated with increased risk of ER+ breast cancer in postmenopausal women, at least at regular intake levels in Japanese women in the general population. Further studies are needed to confirm this association.
International journal of hygiene and environmental health 03/2013; · 2.64 Impact Factor
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Wei Zheng,
Ben Zhang,
Qiuyin Cai,
Hyuna Sung,
Kyriaki Michailidou,
Jiajun Shi,
Ji-Yeob Choi,
Jirong Long,
Joe Dennis,
Manjeet K Humphreys, [......],
Aiko Sueta,
Mi Kyung Kim,
Ui Soon Khoo, Motoki Iwasaki,
Paul D P Pharoah,
Wanqing Wen,
Per Hall,
Xiao-Ou Shu,
Douglas F Easton,
Daehee Kang
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ABSTRACT: In a consortium including 23 637 breast cancer patients and 25 579 controls of East Asian ancestry, we investigated 70 single-nucleotide polymorphisms (SNPs) in 67 independent breast cancer susceptibility loci recently identified by genome-wide association studies (GWASs) conducted primarily in European-ancestry populations. SNPs in 31 loci showed an association with breast cancer risk at P < 0.05 in a direction consistent with that reported previously. Twenty-one of them remained statistically significant after adjusting for multiple comparisons with the Bonferroni-corrected significance level of <0.0015. Eight of the 70 SNPs showed a significantly different association with breast cancer risk by estrogen receptor (ER) status at P < 0.05. With the exception of rs2046210 at 6q25.1, the seven other SNPs showed a stronger association with ER-positive than ER-negative cancer. This study replicated all five genetic risk variants initially identified in Asians and provided evidence for associations of breast cancer risk in the East Asian population with nearly half of the genetic risk variants initially reported in GWASs conducted in European descendants. Taken together, these common genetic risk variants explain ∼10% of excess familial risk of breast cancer in Asian populations.
Human Molecular Genetics 03/2013; · 7.64 Impact Factor
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Hiroe Ono, Motoki Iwasaki,
Aya Kuchiba,
Yoshio Kasuga,
Shiro Yokoyama,
Hiroshi Onuma,
Hideki Nishimura,
Ritsu Kusama,
Sumiko Ohnami,
Hiromi Sakamoto,
Teruhiko Yoshida,
Shoichiro Tsugane
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ABSTRACT: Global hypomethylation of leukocyte DNA has been associated with an increased risk of cancer. As dietary and genetic factors related to one-carbon metabolism may influence both the methylation and synthesis of DNA, we investigated associations between these factors and the global methylation level of peripheral blood leukocyte DNA based on a cross-sectional study of 384 Japanese women. Dietary intake of folate and vitamins B2, B6, and B12 was assessed with a validated semiquantitative food frequency questionnaire. Five polymorphisms in methylenetetrahydrofolate reductase (MTHFR) (rs1801133 and rs1801131), methionine synthase (MTR) (rs1805087), and methionine synthase reductase (MTRR) (rs10380 and rs162049) were genotyped. Global DNA methylation of leukocyte DNA was quantified using Luminometric Methylation Assay. A linear trend of association between methylation and dietary and genetic factors was evaluated by regression coefficients in a multivariable linear regression model. Mean global methylation level (standard deviation) was 70.2% (3.4) and range was from 59.0% to 81.2%. Global methylation level significantly decreased by 0.36% (95% confidence interval, 0.03-0.69) per quartile category for folate level. Subgroup analysis suggested that alcohol drinking modified the association between folate intake and global methylation level (P(interaction) = 0.01). However, no statistically significant association was observed for intake of vitamins B2, B6, and B12, alcohol consumption, or five single nucleotide polymorphisms of MTHFR, MTR, and MTRR. We found that higher folate intake was significantly associated with a lower level of global methylation of leukocyte DNA in a group of healthy Japanese females.
Cancer Science 09/2012; · 3.33 Impact Factor
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ABSTRACT: BACKGROUND: Food sources and intakes of zinc and heme iron may differ between Western and Asian populations. However, all of the studies on the association between zinc and heme iron intakes and colorectal cancer have been conducted in Western populations. OBJECTIVE: We investigated the association between zinc and heme iron intakes and colorectal cancer risk in a Japanese general population. DESIGN: We conducted a large, population-based prospective study in 39,721 men and 45,376 women aged 45-74 y. Heme iron and zinc intakes were measured by using a validated food-frequency questionnaire in either 1995 or 1998. RESULTS: During as many as 808,053 person-years of follow-up until the end of 2006, 1284 colorectal cancer cases were identified. In multivariate-adjusted models, zinc and heme iron intakes were not associated with colorectal cancer in either men or women. In comparison with the lowest quartile, the HRs (95% CIs) for developing colorectal cancer in the fourth quartile of zinc and heme iron intakes were 0.77 (0.58, 1.03; P-trend = 0.2) and 1.06 (0.79, 1.42; P-trend = 0.6), respectively, for men and 1.05 (0.77, 1.44; P-trend = 0.4) and 0.88 (0.61, 1.29; P-trend = 0.4), respectively, for women. CONCLUSION: Our results in a Japanese population with lower intakes and different major food sources of zinc and heme iron in comparison with those of Western populations suggest that zinc and heme iron intakes are not associated with colorectal cancer.
American Journal of Clinical Nutrition 09/2012; 96(4):864-873. · 6.67 Impact Factor
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ABSTRACT: The Dietary Record by Cooked Dishes (DRcd) method, which enables simple assessment of food and nutrient intake, is unique because it uses a nutrient database of cooked dishes. Although this method has been validated among the rural Japanese populations for which the database was developed, the applicability of the DRcd for other populations is unclear. In this study, we have examined the applicability of DRcd among an urban population.
Subjects were selected from among patients who underwent cancer screening between 2004 and 2006 at the Research Center for Cancer Prevention and Screening, National Cancer Center, Japan. Subjects aged 40-69 years, who lived in Tokyo and the surrounding suburbs, were stratified into groups by sex and age. A total of 144 men and women agreed to participate in the study after random selection. Subjects were instructed to keep 4-day dietary records (4d-DR) of all consumed foods and beverages, including dish names, and all dishes were then coded using DRcd codes on the basis their names. The intake of 17 food groups and 40 nutrients was estimated using the dish-based nutrient composition table of the DRcd. Simultaneously, 4d-DR were used to calculate dietary intake independently, which served as a reference. We examined the applicability of the DRcd method using percentage difference and Pearson's correlation coefficients for intakes estimated using 4d-DR and the DRcd. Moreover, the results were compared to those of a previous study.
A total of 88% of the recorded dishes matched the dish codes of the DRcd database by name. Pearson's correlation coefficient scores of 0.6 or higher were observed for 12 and 10 food groups, and for 34 and 27 nutrients in men and women, respectively. Notably, the intake of majority of the nutrients tended to be underestimated, a difference that was more pronounced in men. In comparison with a previous study, the percentage differences and Pearson's correlation coefficient scores for intake tended to be lower in our study.
As the correlation coefficients (0.6) were high for a majority of food groups and nutrients estimated by DRcd, the DRcd method may be applicable for urban populations. However, regional intake data may be necessary for the estimation of absolute value for the intake of some nutrients.
[Nippon kōshū eisei zasshi] Japanese journal of public health 09/2012; 59(9):700-11.
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ABSTRACT: OBJECTIVE: To assess the validity of a 161-item quantitative FFQ (QFFQ) that was developed to evaluate dietary risk factors for a colorectal adenoma case-control study. DESIGN: A cross-sectional validation study of the QFFQ against 4 d food diary using Pearson correlation coefficients, cross-classification, weighted κ statistics and Bland-Altman plotting. SETTING: Two hospitals in São Paulo, Brazil. SUBJECTS: Ninety-seven healthy Japanese-Brazilian adults (40-75 years) were recruited. One participant was excluded from the analysis due to unusual energy intake report. RESULTS: Mean daily nutrient intakes from the QFFQ were higher than from the food diary. The mean Pearson correlation coefficient for nutrient intakes between the QFFQ and the average of the 4 d food diary was 0·43, and increased to 0·45 after correcting correlations for attenuation due to residual day-to-day variation in the food diary measurements. Adjustment for total energy and further adjustment for age and gender decreased the correlation; however, 77 % of observations remained in the same or adjacent quartiles with a mean weighted κ of 0·22. Bland-Altman plots on loge-transformed data showed no linear trend between the differences and means for energy, fat, protein, total folate and vitamin C. Compared with the food diary, the QFFQ showed consistently reasonable performance for dietary fibre, total folate, retinol, riboflavin and vitamin C. CONCLUSIONS: This investigation supports the relative validity of the QFFQ as a method for assessing long-term dietary intake. The instrument will be a useful tool in the analysis of diet-adenoma associations in the case-control study.
Public Health Nutrition 08/2012; · 2.17 Impact Factor
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ABSTRACT: Immunoglobulin GM allotypes, antigenic determinants of γ chains, are encoded by three very closely linked codominant genes on chromosome 14q32. Particular GM alleles/haplotypes are associated with antibody responses to certain tumor antigens and contribute to the cytotoxicity of breast cancer cells, but their possible role in susceptibility to this malignancy has not been adequately examined. Using a matched case-control design, we genotyped a large (1710 subjects) study population from Japan and Brazil for several GM alleles to determine whether these determinants are associated with susceptibility to breast cancer. After adjusting for the potential confounders, the GM 3 allele of IgG1 was significantly associated with susceptibility to breast cancer in white subjects from Brazil (OR=2.07, CI 1.16-3.71; p=0.0147). These data show that Caucasians with the GM 3 allele are over twice as likely to develop breast cancer as those who lack this allele. Since this allele modulates an immune evasion strategy of cytomegalovirus, the results also shed light on the possible mechanism underlying the reported involvement of this virus in the etiology of breast cancer.
Human immunology 08/2012; 73(11):1155-8. · 2.55 Impact Factor
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ABSTRACT: Object The uncovertebral joints are peculiar but clinically important anatomical structures of the cervical vertebrae. In the aged or degenerative cervical spine, osteophytes arising from an uncovertebral joint can cause cervical radiculopathy, often necessitating decompression surgery. Although these joints are believed to bear some relationship to head rotation, how the uncovertebral joints work during head rotation remains unclear. The purpose of this study is to elucidate 3D motion of the uncovertebral joints during head rotation. Methods Study participants were 10 healthy volunteers who underwent 3D MRI of the cervical spine in 11 positions during head rotation: neutral (0°) and 15° increments to maximal head rotation on each side (left and right). Relative motions of the cervical spine were calculated by automatically superimposing a segmented 3D MR image of the vertebra in the neutral position over images of each position using the volume registration method. The 3D intervertebral motions of all 10 volunteers were standardized, and the 3D motion of uncovertebral joints was visualized on animations using data for the standardized motion. Inferred contact areas of uncovertebral joints were also calculated using a proximity mapping technique. Results The 3D animation of uncovertebral joints during head rotation showed that the joints alternate between contact and separation. Inferred contact areas of uncovertebral joints were situated directly lateral at the middle cervical spine and dorsolateral at the lower cervical spine. With increasing angle of rotation, inferred contact areas increased in the middle cervical spine, whereas areas in the lower cervical spine slightly decreased. Conclusions In this study, the 3D motions of uncovertebral joints during head rotation were depicted precisely for the first time.
Journal of neurosurgery. Spine 08/2012; 17(4):327-33. · 1.61 Impact Factor
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ABSTRACT: BACKGROUND: Although global hypomethylation of leukocyte DNA has been associated with an increased risk of several sites of cancer, including breast cancer, determinants of global methylation level among healthy individuals remain largely unexplored. Here, we examined whether postmenopausal endogenous sex hormones were associated with the global methylation level of leukocyte DNA. METHODS: A cross-sectional study was conducted using the control group of a breast cancer case-control study in Nagano, Japan. Subjects were postmenopausal women aged 55 years or over who provided blood samples. We measured global methylation level of peripheral blood leukocyte DNA by luminometric methylation assay; estradiol, estrone, androstenedione, dehydroepiandrosterone sulfate, testosterone and free testosterone by radioimmunoassay; bioavailable estradiol by the ammonium sulfate precipitation method; and sex-hormone binding globulin by immunoradiometric assay. A linear trend of association between methylation and hormone levels was evaluated by regression coefficients in a multivariable liner regression model. A total of 185 women were included in the analyses. RESULTS: Mean global methylation level (standard deviation) was 70.3% (3.1) and range was from 60.3% to 79.2%. Global methylation level decreased 0.27% per quartile category for estradiol and 0.39% per quartile category for estron while it increased 0.41% per quartile category for bioavailable estradiol. However, we found no statistically significant association of any sex hormone level measured in the present study with global methylation level of leukocyte DNA. CONCLUSIONS: Our findings suggest that endogenous sex hormones are not major determinantsof the global methylation level of leukocyte DNA.
BMC Cancer 07/2012; 12(1):323. · 3.01 Impact Factor
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ABSTRACT: Aim: To examine the impact of C-reactive protein on the risks of stroke and its subtypes, particularly among Asian populations in which median C-reactive protein levels are typically lower than in Western populations.Methods: A prospective, nested case-control study was conducted to examine the associations between high sensitivity-CRP (hs-CRP) and risks of cardiovascular disease within a cohort of 29,876 men and women aged 40-69 years, with no history of stroke, ischemic heart disease or cancer, who submitted blood samples between 1990 and 1993. Systematic cardiovascular surveillance was performed throughout 2007. One control for each stroke and two controls for each ischemic heart disease were matched for sex, age, date of blood drawing, time since last meal and study location.Results: We documented 1,132 incident strokes (638 ischemic and 494 hemorrhagic strokes) and 209 ischemic heart diseases (168 myocardial infarctions and 41 sudden cardiac deaths), and observed a linear association between hs-CRP levels and risks of ischemic stroke and ischemic heart disease, more specifically myocardial infarction. The multivariable odds ratios associated with 1-SD increment of logarithmically transformed hs-CRP were 1.13 (0.99-1.29),p= 0.07 for ischemic stroke, 1.16 (0.96-1.41),p= 0.13 for lacunar infarction, 1.41 (0.98-2.01),p= 0.06 for embolic infarction, and 1.28 (1.03-1.59),p= 0.03 for myocardial infarction. The predictive value of hs-CRP for ischemic stroke was reduced primarily after adjustment for hypertensive status and body mass index. No association was found between hs-CRP levels and the risk of hemorrhagic or total stroke.Conclusions: High serum hs-CRP levels were associated with the risk of myocardial infarction and more weakly with the risk of ischemic stroke among middle-aged Japanese men and women.
Journal of atherosclerosis and thrombosis 07/2012; 19(8):756-66. · 2.69 Impact Factor
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ABSTRACT: The purpose of the present study was to develop a risk estimation model for the 10-year risk of hepatocellular carcinoma (HCC) that could be easily used in a general population to aid in the prevention of HCC.
Our prediction model was derived from data obtained on 17,654 Japanese aged 40 to 69 years who participated in health checkups (follow-up: 1993-2006). Cox proportional hazards regression was applied to obtain coefficients for each predictor.
During follow-up, a total of 104 cases of HCC were newly diagnosed. After checking the model fit, we incorporated age, sex, alcohol consumption, body mass index, diabetes, coffee consumption, and hepatitis B and C virus infection into the prediction model. The model showed satisfactory discrimination (Harrell's c-index=0.94) and was well calibrated (the overall observed/expected ratio=1.03, 95% confidence interval=0.83-1.29). We also developed a simple risk scoring system. Those subjects with total scores of 17 or more under this system (score range: -1 to 19) had an estimated 10-year HCC risk of over 90%; those with 4 points or less had an estimated risk of less than 0.1%.
We developed a simple 10-year risk prediction model for HCC in the Japanese general population as a public education tool.
Preventive Medicine 06/2012; 55(2):137-43. · 3.22 Impact Factor
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Xiangyu Ma,
Alicia Beeghly-Fadiel,
Wei Lu,
Jiajun Shi,
Yong-Bing Xiang,
Qiuyin Cai,
Hongbing Shen,
Chen-Yang Shen,
Zefang Ren,
Keitaro Matsuo, [......],
Xiaoming Xie,
Hidemi Ito,
Yoshio Kasuga,
Kelvin Y K Chan,
Hiroji Iwata,
Shoichiro Tsugane,
Yu-Tang Gao,
Xiao Ou Shu,
Harold L Moses,
Wei Zheng
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ABSTRACT: The TGF-β signaling pathway plays a significant role in the carcinogenic process of breast cancer.
We systematically evaluated associations of common variants in TGF-β signaling pathway genes with breast cancer risk using a multistage, case-control study among Asian women.
In the first stage, 341 single-nucleotide polymorphisms with minor allele frequencies ≥ 0.05 across 11 genes were evaluated among 2,926 cases and 2,380 controls recruited as a part of the Shanghai Breast Cancer Genetics Study (SBCGS). In the second stage, 20 SNPs with promising associations were evaluated among an additional 1,890 cases and 2,000 controls from the SBCGS. One variant, TGFBR2 rs1078985, had highly consistent and significant associations with breast cancer risk among participants in both study stages, as well as promising results from in silico analysis. Additional genotyping was carried out among 2,475 cases and 2,343 controls from the SBCGS, as well as among 5,077 cases and 5,384 controls from six studies in the Asian Breast Cancer Consortium (stage III). Pooled analysis of all data indicated that minor allele homozygotes (GG) of TGFBR2 rs1078985 had a 24% reduced risk of breast cancer compared with major allele carriers (AG or AA; OR, 0.76; 95% CI, 0.65-0.89; P = 8.42 × 10(-4)).
These findings support a role for common genetic variation in TGF-β signaling pathway genes, specifically in TGFBR2, in breast cancer susceptibility.
These findings may provide new insights into the etiology of breast cancer as well as future potential therapeutic targets.
Cancer Epidemiology Biomarkers & Prevention 04/2012; 21(7):1176-84. · 4.12 Impact Factor
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Motoki Iwasaki,
Gerson Shigeaki Hamada,
Ines Nobuko Nishimoto,
Mario Mourão Netto,
Juvenal Motola,
Fábio Martins Laginha,
Yoshio Kasuga,
Shiro Yokoyama,
Hiroshi Onuma,
Hideki Nishimura,
Ritsu Kusama,
Minatsu Kobayashi,
Junko Ishihara,
Seiichiro Yamamoto,
Tomoyuki Hanaoka,
Shoichiro Tsugane
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ABSTRACT: Although epidemiologic studies have shown an inverse association between isoflavones and breast cancer risk, little evidence
for a dose–response relation is available. We conducted hospital-based case–control studies of patients aged 20–74years with
primary, incident, histologically confirmed invasive breast cancer, and matched controls from medical checkup examinees in
Nagano, Japan and from cancer-free patients in São Paulo, Brazil. A total of 850 pairs (390 Japanese, 81 Japanese Brazilians
and 379 non-Japanese Brazilians) completed validated food frequency questionnaires. The odds ratio of breast cancer according
to isoflavone intake was estimated using a conditional logistic regression model. We found a statistically significant inverse
association between isoflavone intake and the risk of breast cancer for Japanese Brazilians and non-Japanese Brazilians. For
Japanese, a non-significant inverse association was limited to postmenopausal women. In the three populations combined, breast
cancer risk linearly decreased from ‘no’ to ‘moderate’ isoflavone intake and thereafter leveled off. Compared to non-consumers,
adjusted odds ratios (95% confidence interval) for consumers in increasing quintile intake categories (median intake in each
category: 8.7, 23.1, 33.8, 45.7, and 71.3mg/day) were 0.69 (0.44–1.09), 0.54 (0.31–0.94), 0.45 (0.26–0.77), 0.34 (0.19–0.62),
and 0.43 (0.24–0.76), respectively. Overall, we found an inverse association between dietary isoflavone intake and risk of
breast cancer. Our finding suggests a risk-reducing rather than risk-enhancing effect of isoflavones on breast cancer within
the range achievable from dietary intake alone. In addition, women may benefit from risk reduction if they consume at least
moderate amounts of isoflavones.
Breast Cancer Research and Treatment 04/2012; 116(2):401-411. · 4.43 Impact Factor
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ABSTRACT: ObjectiveThe association between metabolic factors and hepatocellular carcinoma (HCC) has not been well clarified. We prospectively
examined whether metabolic factors predicts the subsequent risk of HCC in the Japan Public Health Center-based Prospective
Study Cohort II, in consideration of hepatitis virus infection status.
MethodsA total of 17,590 subjects aged 40–69 participating in a questionnaire and health checkup survey during 1993–1994 were followed
for incidence of HCC through 2006. A total of 102 cases of HCC were newly documented. Hazard ratios (HRs) and 95% confidence
intervals (CIs) were calculated for metabolic factors controlling for potential confounding factors.
ResultsThe presence of metabolic factors in the aggregate was associated with a significantly increased risk of HCC, especially with
hepatitis virus infection. HCC was positively associated particularly with high glucose (HR=1.75, CI=1.11–2.74) and overweight
(HR=2.22, CI=1.42–3.48). Results were similar when analyses were limited to subjects with HCV infection.
ConclusionsAlthough metabolic factors in the aggregate may be associated with an increased risk of HCC, the main contributors to this
association under HCV infection appear to be overweight and high glucose. Improvement of these factors may be a crucial target
in preventing progression to HCC in those with HCV infection.
Cancer Causes and Control 04/2012; 20(5):741-750. · 2.88 Impact Factor
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ABSTRACT: ObjectiveThere is some evidence that folate may prevent colorectal cancer by stabilizing DNA sufficiently and methylating DNA appropriately.
Plasma folate is a good marker to assess folate status in the body, but it has not been adequately examined in prospective
epidemiologic studies. We investigated the association between plasma folate and the risk of colorectal cancer in a nested
case-control study.
MethodsDuring a 11.5-year follow-up, 375 newly diagnosed colorectal cancers were identified in a cohort of 38,373 adults who had
returned their baseline questionnaires and provided blood samples. Two controls for each case were selected from the cohort.
The odds ratios (OR) and 95% confidence intervals (CI) of colorectal cancer for plasma folate was estimated using the conditional
logistic regression model adjusted for potential confounding factors.
ResultsPlasma folate was not associated with the risk of colorectal cancer in either men or women, although a small reduction of
OR in men was observed in the second (OR, 0.70; 95% CI, 0.37–1.3), the third (OR, 0.72; 95% CI, 0.38–1.3), and the highest
quartiles (OR, 0.86; 95% CI, 0.45–1.6) without a dose–response relationship (P for trend 0.88). A similar association was observed in the risk of colon or rectal cancer. No statistical interaction with
the risk of colorectal cancer was observed between plasma folate and alcohol consumption.
ConclusionOur results did not support the hypothesis that a folate-rich status may prevent colorectal cancer, though that finding may
be due to an insufficient number of folate-deficient subjects in our study population.
Cancer Causes and Control 04/2012; 19(1):67-74. · 2.88 Impact Factor
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ABSTRACT: IntroductionAlthough many in vitro and animal studies have demonstrated a protective effect of green tea against breast cancer, findings from epidemiological
studies have been inconsistent, and whether high green tea intake reduces the risk of breast cancer remains unclear.
MethodsIn this Japan Public Health Center-based Prospective Study, 581 cases of breast cancer were newly diagnosed in 53,793 women
during 13.6 years' follow-up from the baseline survey in 1990 to 1994. After the five-year follow-up survey in 1995 to 1998,
350 cases were newly diagnosed in 43,639 women during 9.5 years' follow-up. The baseline questionnaire assessed the frequency
of total green tea drinking while the five-year follow-up questionnaire assessed that of two types of green tea, Sencha and Bancha/Genmaicha, separately.
ResultsCompared with women who drank less than one cup of green tea per week, the adjusted hazard ratio (HR) for women who drank
five or more cups per day was 1.12 (95% confidence interval (CI) 0.81 to 1.56; P for trend = 0.60) in the baseline data. Similarly, compared with women who drank less than one cup of Sencha or Bancha/Genmaicha per week, adjusted HRs for women who drank 10 or more cups per day were 1.02 (95% CI 0.55 to 1.89; P for trend = 0.48) for Sencha and 0.86 (0.34 to 2.17; P for trend = 0.66) for Bancha/Genmaicha. No inverse association was found regardless of hormone receptor-defined subtype or menopausal status.
ConclusionsIn this population-based prospective cohort study in Japan we found no association between green tea drinking and risk of
breast cancer.
Breast Cancer Research 04/2012; 12(5):1-10. · 5.33 Impact Factor
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ABSTRACT: Iodine is a suspected risk factor for thyroid cancer. Seaweed accounts for about 80% of Japanese people's iodine intake. We examined the association between seaweed consumption and the risk of thyroid cancer in Japanese women. Women participating in the Japan Public Health Center-based Prospective Study (n=52 679; age: 40-69 years) were followed up for a mean of 14.5 years; 134 new thyroid cancer cases, including 113 papillary carcinoma cases, were identified. Seaweed consumption was assessed using a food-frequency questionnaire and divided into three categories: 2 days/week or less (reference); 3-4 days/week; and almost daily. The Cox proportional hazards model was applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Seaweed consumption was clearly associated with an increased risk of papillary carcinoma (HR for almost daily consumption compared with 2 days/week or less=1.71; 95% CI: 1.01-2.90; trend P=0.04). After stratification for menopausal status, an increased risk was observed in postmenopausal women (papillary carcinoma HR for almost daily consumption compared with 2 days/week or less=3.81, 95% CI: 1.67-8.68; trend P<0.01), but not in premenopausal women (HR=0.91, 95% CI: 0.44-1.91; trend P=0.76). This study identified a positive association between seaweed consumption and the risk of thyroid cancer (especially for papillary carcinoma) in postmenopausal women.
European journal of cancer prevention: the official journal of the European Cancer Prevention Organisation (ECP) 03/2012; 21(3):254-60. · 2.21 Impact Factor
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ABSTRACT: Cadmium, a ubiquitous environmental pollutant, is classified as a carcinogenic substance. Several laboratory and epidemiologic studies of workers and subjects in polluted areas have suggested a positive association between cadmium exposure and risk of several cancers. However, data from general populations are sparse. We prospectively examined the association between cadmium exposure and incidence of cancer in a Japanese population with a relatively high dietary intake of cadmium.
We conducted a population-based prospective study in 90,383 Japanese men and women 45-74 years of age. Participants responded to a validated questionnaire that included 138 food items. We estimated dietary cadmium intake from 6 food groups, based on the questionnaire data. During 9 years of follow-up, 5849 cancer cases were identified. Hazard ratios (HRs) and 95% confidence intervals (CIs) for cancer were calculated by Cox proportional hazards modeling.
There was no evidence of an association of cadmium consumption and total cancer, with HRs in the highest versus lowest cadmium intake group of 0.94 (95% CI = 0.82 to 1.08; test for trend, P = 0.46) for men and 0.96 (0.81 to 1.15; 0.60) for women. No site-specific cancers were associated with cadmium intake in men or women.
We found no associations of cancer with cadmium, at least at the exposure levels observed in a general population in Japan.
Epidemiology (Cambridge, Mass.) 03/2012; 23(3):368-76. · 5.51 Impact Factor
