Naoto Miyanaga

A case-control study of diet and prostate cancer in Japan: possible protective effect of traditional Japanese diet.

The age‐adjusted incidence of prostate cancer is low in Japan, and it has been suggested that the traditional Japanese diet, which includes many soy products, plays a preventive role against prostate cancer. We performed a case‐control study on dietary factors and prostate cancer in order to assess the hypothesis that the traditional Japanese diet reduces the risk of prostate cancer. Four geographical areas (Ibaraki, Fukuoka, Nara, and Hokkaido) of Japan were selected for the survey. Average daily intake of food from 5 years before the diagnosis was measured by means of a semi‐quantitative food frequency questionnaire. We studied 140 cases and 140 individually age (±5 years)‐matched hospital controls for analysis. Estimates of age‐adjusted odds ratios (ORs) and linear trends were calculated by conditional logistic regression models with adjustment for cigarette smoking and total energy intake as confounding factors. Consumption of fish, all soybean products, tofu (bean curds), and natto (fermented soybeans) was associated with decreased risk. ORs of the fourth vs. first quartile and 95% confidence intervals (95%CIs) were 0.45 (0.20–1.02) for fish, 0.53 (0.24–1.14) for all soybean products, 0.47 (0.20–1.08) for tofu, and 0.25 (0.05–1.24) for natto. Consumption of fish and natto showed significantly decreasing linear trends for risk (P<0.05). Consumption of meat was significantly associated with increased risk (the OR of the second vs. first quartile was 2.19, 95%CI 1.00–4.81). Consumption of milk, fruits, all vegetables, green‐yellow vegetables, and tomatoes showed no association. Our results provide support to the hypothesis that the traditional Japanese diet, which is rich in soybean products and fish, might be protective against prostate cancer.

Habitual Intake of Lactic Acid Bacteria and Risk Reduction of Bladder Cancer

Introduction: A kind of lactic acid bacteria, Lactobacillus casei strain Shirota, shows antitumor activity in experimental animals. One clinical trial using L. casei showed a significant decrease in the recurrence of superficial bladder cancer. So, to assess the preventive effect of the intake of L. casei, widely taken as fermented milk products in Japan, against bladder cancer, we conducted a case-control study. Methods: A total of 180 cases (mean age: 67 years, SD 10) were selected from 7 hospitals, and 445 population-based controls matched by gender and age were also selected. Interviewers asked them 81 items. The conditional logistic regression was used to estimate adjusted odds ratios (OR). Results: The OR of smoking was 1.61 (95% confidence interval: 1.10–2.36). Those of previous (10–15 years ago) intake of fermented milk products were 0.46 (0.27–0.79) for 1–2 times/week and 0.61 (0.38–0.99) for 3–4 or more times/week, respectively. Conclusion: It was strongly suggested that the habitual intake of lactic acid bacteria reduces the risk of bladder cancer.

Antineoplastic activity of honey in an experimental bladder cancer implantation model: In vivo and in vitro studies

Objectives: The antitumor effect of bee honey against bladder cancer was examined in vitro and in vivo. Methods: Three human bladder cancer cell lines (T24, 253J and RT4) and one murine bladder cancer cell line (MBT‐2) were used in these experiments. In an in vitro study, the antitumor activity was assessed by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assay, TdT‐mediated dUTP‐biotin nick end labeling (TUNEL) assay, 5‐Bromodeoxyuridine (BrdU) labeling index and flowcytometry (FCM). In the in vivo study, cancer cells were implanted subcutaneously in the abdomens of mice, and the effects were assessed by the tumor growth.

The impact of real-time tissue elasticity imaging (elastography) on the detection of prostate cancer: clinicopathological analysis

BackgroundWe evaluated the accuracy and feasibility of real-time elastography for detecting prostate cancer, using prostatectomy specimens.MethodsThis study was based on clinicopathological findings in 51 patients with prostate cancer who were referred for elastography at the time of prostate biopsy. We compared transverse pathology sections with elastographic moving images (EMIs) to determine the detection rate of cancer, the relationship between tumor location and the elastographic findings, and the relationship between the Gleason score and the elastographic findings.ResultsIn 15 patients (29%), all EMIs were in complete agreement with tumor location (category I), in 28 patients (55%), the EMIs agreed with tumor location, but showed some disagreement (category II), and in 8 patients (16%) there was disagreement of the elastographic findings with tumor location or the tumors were undetectable by elastography (category III). However, in category III, all tumors were detected as low-echoic by B-mode ultrasonography. We divided the prostate into three different regions (anterior, middle, and posterior), and found that 30/32 (94%) anterior tumors, 13/17 (76%) middle tumors, and 16/28 (57%) posterior tumors were detected by elastography. The proportions of cancers detected by elastography (categories I+II/total) was 100% in the patients with a Gleason score of 6, 85% in those with a score of 7 or 8, and 63% in those with a score of 9 or 10.ConclusionReal-time elastography in conjunction with B-mode ultrasonography significantly improves the detection of prostate cancer. One of the characteristic findings of elastography is its excellent detection of anterior tumors. The low detection rate of high-grade tumors in this analysis was likely due to the predominance of high-grade tumors in a peripheral location compared to the anterior location of the low-grade tumors.

Tissue elasticity imaging for diagnosis of prostate cancer: A preliminary report

Background: Elastography is a diagnostic imaging technique that evaluates the hardness of a lesion. It is expected to become a new diagnostic modality for prostate cancer. The aim of this study was to examine the usefulness of elastography in the diagnosis of prostate cancer.

Institutional variability in the accuracy of urinary cytology for predicting recurrence of transitional cell carcinoma of the bladder

To assess the contemporary inter‐institutional accuracy of urinary cytology in predicting the recurrence of transitional cell carcinoma (TCC) of the bladder, in a large multi‐institutional cohort from four continents, as cystoscopy and urinary cytology represent the ‘gold standards’ for surveillance of TCC recurrences, but the ability of cytology to predict recurrence varies.

Real-time Elastography for the Diagnosis of Prostate Cancer: Evaluation of Elastographic Moving Images

OBJECTIVE Elastography is a technique for detecting the stiffness of tissues. We applied elastography for the diagnosis of prostate cancer and evaluated the usefulness of elastography for prostate biopsy. METHODS The subjects of this study were 311 patients who underwent elastography during prostate needle biopsy at Hitachi General Hospital. Strain images obtained during compression of the prostate tissue were displayed on a monitor and recorded on the computer. The elastographic moving images (EMI) were evaluated retrospectively. The evaluable images and biopsy results were compared in terms of the feasibility and accuracy. RESULTS The median patient age was 67 years (range 50-85 years), the median serum level of prostate-specific antigen was 8.4 ng/ml (range 0.3-82.5 ng/ml) and the median prostate volume was 42.6 ml (range 12-150 ml). Among the 311 patients, prostate cancer was detected in 95 patients (30%) by biopsy. The diagnostic sensitivity was 37.9% for digital rectal examination (DRE) and 59.0% for transrectal ultrasonography (TRUS), whereas it was 72.6% for elastography and 89.5% for the combination of TRUS and elastography. Elastography-positive EMIs with negative biopsies were eventually determined to be due to benign prostatic hyperplasia. CONCLUSION Elastography has a significantly higher sensitivity for the detection of prostate cancer than the conventionally used examinations including DRE and TRUS. It is a useful real-time diagnostic method because it is not invasive, and simultaneous evaluation is possible while performing TRUS.

Urinary nuclear matrix protein 22 as a new marker for the screening of urothelial cancer in patients with microscopic hematuria.

Purpose: The aim of the present study was to determine the clinical usefulness of nuclear matrix protein 22 (NMP22) as a new urinary marker for the screening of urothelial cancer in patients with microscopic hematuria, especially in comparison with that of voided urine cytology.

Isolation and characterization of the equol-producing bacterium Slackia sp. strain NATTS

AbstractsSeveral kinds of carbohydrates such as sorbose, adonitol, and melezitose were found to enhance equol production from daidzein in an in vitro human fecal culture. Sorbose, one of the most effective carbohydrates, was used as a carbohydrate source for isolating the NATTS strain, which was a Gram-positive, non-spore-forming rod bacterium with high ability to convert daidzein to equol isolated from the 7th maintenance culture. The strain was found to belong to the genus Slackia family Coriobacteriaceae by 16S rRNA sequence-based analysis, and the prevalence of the Slackia sp. in Japanese adults was examined by reverse transcription-quantitative PCR (RT-qPCR), which was found to be 40% at a mean population level of 106 cells per gram of feces.

Isoflavone supplements stimulated the production of serum equol and decreased the serum dihydrotestosterone levels in healthy male volunteers

The aim of this study was to evaluate the effect of supplementing healthy men with soy isoflavones on the serum levels of sex hormones implicated in prostate cancer development. A total of 28 Japanese healthy volunteers (18 equol producers and 10 equol non-producers) between 30 and 59 years of age were given soy isoflavones (60 mg daily) supplements for 3 months, and the changes in their sex hormone levels were investigated at the baseline and after administration. The serum and urine concentrations of daidzein, genistein, and the levels of equol in the fasting blood samples and 24-h stored urine samples were also measured. All 28 volunteers completed the 3-month supplementation with isoflavone. No changes in the serum levels of estradiol and total testosterone were detected after 3-month supplementation. The serum levels of sex hormone-binding globulin significantly increased, and the serum levels of free testosterone and dihydrotestosterone (DHT) decreased significantly after 3-month supplementation. Among the 10 equol non-producers, equol became detectable in the serum of two healthy volunteers after 3-month supplementation. This study revealed that short-term administration of soy isoflavones stimulated the production of serum equol and decreased the serum DHT level in Japanese healthy volunteers. These results suggest the possibility of converting equol non-producers to producers by prolonged and consistent soy isoflavones consumption.