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Although many in vitro and animal studies have suggested a protective effect of green tea against breast cancer, only a few epidemiological studies have examined this association, and findings have been inconsistent. We examined the association between green tea consumption and breast cancer risk in consideration of the hormone receptor status of tumors and investigated whether the association was modified by dietary and genetic factors based on a hospital-based case-control study in Nagano, Japan. A total of 369 pairs completed a validated food frequency questionnaire and provided blood samples. Four single nucleotide polymorphisms (SNPs) were genotyped:CYP19A1(rs10046),COMT(rs4680),MTHFRC677T (rs1801133), andMTHFRA1298C (rs1801131). We found no inverse association between green tea consumption and breast cancer risk. Compared with women who drank less than 120 ml of green tea per day, the adjusted odds ratio for women who drank more than 600 ml was 1.27 (95% confidence interval = 0.75–2.14;Pfor trend = 0.20). We also found no inverse association for either tumor subtype. No substantial effect modification was observed for menopausal status, 4 SNPs, or dietary intake of folate or isoflavone. This study provides additional evidence that green tea consumption is not associated with a decreased risk. [ABSTRACT FROM AUTHOR]

We tested the hypothesis that polymorphisms in cytochrome P450c17α (CYP17), aromatase (CYP19), 17β-hydroxysteroid dehydrogenase type I (17β-HSD1) and sex hormone-binding globulin (SHBG) genes may modify the association between isoflavone intake and breast cancer risk. We conducted hospital-based, case-control studies in Nagano, Japan and Sao Paulo, Brazil. A total of 846 pairs (388 Japanese, 79 Japanese Brazilians, and 379 non-Japanese Brazilians) completed validated food frequency questionnaires. Four single nucleotide polymorphisms (SNPs) in CYP17 (rs743572), CYP19 (rs10046), 17β-HSD1 (rs605059), and SHBG (rs6259) genes were genotyped. We found no association between the 4 SNPs and breast cancer risk. In combination analyses of isoflavone intake and SNPs, an inverse association between intake and risk was limited to women with at least one A allele of the rs605059 polymorphism for all 3 populations, albeit without statistical significance. For the rs6259 polymorphism, the inverse association was limited to postmenopausal Japanese with the GG genotype (odds ratio [OR] for highest vs. lowest tertile = 0.50, 95% confidence interval [CI] = 0.29-0.87; P for trend < 0.01), and to non-Japanese Brazilians with at least one A allele (OR for consumers vs. nonconsumer = 0.21, 95% CI = 0.06-0.77). We found no remarkable difference for the rs743572 and rs10046 polymorphisms. Our findings suggest that polymorphisms in the 17β-HSD1 and SHBG genes may modify the association between isoflavone intake and breast cancer risk. [ABSTRACT FROM AUTHOR]

Objective. Although associations between dietary HCA intake and colorectal cancer risk have been investigated, results have been suggestive but inconsistent. The aim of this hospital-based case-control study was to examine the impact of heterocyclic amine (HCA) intake on colorectal cancer risk. A further objective was to investigate the possible effect of genetic polymorphisms of NAT2, CYP1A1, and CYP1A2 on colorectal cancer. Material and methods. HCA exposure data were assessed using a self-administered food frequency questionnaire, and estimated HCA intake was verified by measuring the PhIP value in human hair. A total of 117 cases and 238 controls were included in these analyses. Odds ratios (ORs) were calculated using conditional logistic regression analysis to compare intake levels between the first and third tertiles. Results. No statistically significant increase in the risk of colorectal cancer with respect to total HCA intake was shown by analysis (OR = 0.99, 95% CI = 0.21-4.81). Furthermore, no association with risk was seen for individual HCAs, including PhIP, MeIQ, and MeIQx. Although variant alleles of CYP1A2 were associated with colorectal cancer (OR = 0.27; 95% CI = 0.07-0.99), genetic polymorphisms of NAT2, CYP1A1, and CYP1A2 did not influence the association of HCA intake with colorectal cancer. Conclusions. In the present study in subjects with low HCA exposure and with a limited sample size, no association was found between HCA intake and colorectal cancer, or any evidence of influence by genetic polymorphisms of NAT2, CYP1A1, and CYP1A2. [ABSTRACT FROM AUTHOR]

We investigated associations among intake of folate, vitamin B2, vitamin B6, vitamin B12, and polymorphisms of 5,10-methylenetetrahydrofolate reductase (MTHFR) and methionine synthase (MTR) genes and breast cancer risk in a Japanese population. A hospital based, case-control study was conducted in Nagano Prefecture, Japan, in 388 pairs of patients with histologically confirmed invasive breast cancer and age- and area-matched controls selected from medical checkup examinees. Energy-adjusted intakes of folate and other B vitamins were derived from a validated food frequency questionnaire. Genotyping was completed for MTHFR (C677T and A1298T) and MTR (A2756G). Odds ratios and 95% confidence intervals were calculated by the conditional logistical regression model. Median dietary folate intake (μg/day) in the control group was 438.2 (interquartile range: 354.9-542.9). Neither dietary intake of folate, vitamin B2, vitamin B6, or vitamin B12 nor polymorphisms of MTHFR or MTR genes were significantly associated with breast cancer risk. Further, no significant interaction was found among nutrients, polymorphisms, and breast cancer risk. Associations of nutrients with breast cancer risk did not differ by hormone receptors status. We conclude that dietary intake of folate and related B vitamins and genotypes of MTHFR or MTR have no overall association with breast cancer risk in Japanese women. [ABSTRACT FROM AUTHOR]

Abstract: We conducted a case-control study to investigate the association of nutrient intake involved in the one-carbon pathway of folate for DNA methylation and DNA synthesis and the related enzyme genetic polymorphisms with colorectal cancer. Cases were 107 patients newly diagnosed with colorectal cancer. Controls were 224 subjects matched with cases by sex, age, and residential area. Nutrient intake was assessed by a self-administered, semiquantitative food-frequency questionnaire. Four genetic polymorphisms—MTHFR C677T and A1298C, MTRR A66G, and ALDH2 Glu487Lys—were determined using blood samples. Odds ratios were calculated using conditional logistic regression analysis adjusted for smoking, alcohol consumption, body mass index, and dietary fiber intake. Although folate intake was inversely associated with colorectal cancer, this association was attenuated after further controlling for dietary fiber intake. Neither vitamin B6, vitamin B12, nor vitamin B2, nor any genetic polymorphism was significantly associated with colorectal cancer. MTRR polymorphism interacted with the association of folate (P for interaction = 0.04) or vitamin (P for interaction = 0.02) with colorectal cancer, although the other polymorphisms did not interact with any nutrient intake. In conclusion, the study did not support the existing hypothesis of gene-nutrient interaction in colorectal carcinogenesis. [ABSTRACT FROM AUTHOR]

We assessed the possible association of gastrointestinal cancers with cruciferous vegetables and mushrooms in a multicenter, hospital-based case-control study in an agricultural area of Japan. One hundred forty-nine cases and 287 controls for stomach cancer and 115 cases and 230 controls for colorectal cancer were matched by age, sex, and residential area. In stomach cancer, the protective effect of vegetables (consumption of total vegetable) was obscure, but it became clearer when we examined specific kinds of vegetables. Marginal associations were observed in the group of the highest consumption of Chinese cabbage (odds ratio [OR] = 0.61; 95% confidence interval [CI] = 0.35-1.07), broccoli (OR = 0.60; 95% CI = 0.34-1.08), Hypsizigus marmoreus (Bunashimeji) (OR = 0.57; 95% CI = 0.31-1.04) and Pholita nameko (Nameko) (OR = 0.56; 95% CI = 0.30-1.06). In colorectal cancer, we observed decreased risks from the highest tertile of total vegetables (OR = 0.22; 95% CI = 0.08-0.66) and low-carotene- containing vegetables (OR = 0.28; 95% CI = 0.08-0.77), and inverse associations were observed in the group of the highest consumption of broccoli (OR = 0.18; 95% CI = 0.06-0.58). Although the sample size was limited, subgroup analyses showed that the associations differed with the histopathological subtype. These findings suggest that cruciferous vegetables decrease the risk of both stomach and colorectal cancer, and that mushrooms are associated with a decreased risk of stomach cancer. [ABSTRACT FROM AUTHOR]

Objective: To find out which factors predict recurrence of cancer in the remnant after unilateral thyroid lobectomy for patients with papillary cancer. Design: Retrospective study. Setting: Teaching hospital, Japan. Subjects: One hundred thirty-three patients with a clinically solitary papillary thyroid cancer who had unilateral lobectomy for the primary disease between 1966 and 1990 and were followed up for more than 60 months. Twelve patients had developed recurrences in the remnant gland by the time of the second operation and 121 patients had not as judged by a second operation, an ultrasound examination, or by palpation. Result: The primary tumour size in those who developed recurrences was significantly larger than in those who did not (p < 0.0001), and clinical signs of regional lymph node involvement or distant metastases were also significantly more common (p = 0.006). No patient died of their cancer. Conclusion: Size of the primary tumour is an important prognostic factor for recurrence of solitary papillary thyroid cancer in the remnant after unilateral lobectomy. Such recurrences are unlikely to be lethal. [ABSTRACT FROM AUTHOR]

Objective: To find out whether subtotal thyroidectomy results in long term stable functional and immunological remission in patients with Graves' disease. Design: Retrospective study. Setting: Teaching hospital, Japan Subjects: 176 patients who underwent subtotal thyroidectomy for Graves' disease, 1970-79. Intervention: Follow up surveys in 1984 and 1992. Main outcome measures: - Changes in thyroid function, antibody titres, and lymphocyte subsets. Results: 29/79 patients (39%) who were euthyroid in 1984 had evidence of thyroid dysfunction in 1992. Of the 8 patients with latent hypothyroidism in 1984, 3 (38%) had become euthyroid by 1992, and none required treatment. Of the 29 patients who were hypothyroid in 1984, 5 had latent hypothyroidism and 1 was euthyroid in 1992, and of the 18 patients with recurrent hyperthyroidism in 1984, 1 had become euthyroid by 1992. The number of positive titres to TSH-binding inhibitory immunoglobulin was significantly higher in the recurrence group (31/36, 86%) compared with the hypothyroid (7/26, 27%), latent hypothyroidism (8/37, 22%), and euthyroid (22/77, 29%) groups ( p < 0.01). There were also significant differences in the mean (SD) number of Leu HLA DR subsets between the control (17 (3), n = 18) and recurrence (21 (6), n = 38), hypothyroid (22 (6), n = 35), latent hypothyroidism (22 (6), n = 22), and euthyroid (22 (9), n = 64) groups (p < 0.002). There were no differences in the number of T cell subsets among the groups. Conclusion: Treatment of Graves' disease by subtotal thyroidectomy does not necessarily result in stable late functional or immunological remission. Long term follow up of such patients may be necessary. [ABSTRACT FROM AUTHOR]