Seiji Nakata

Genetic polymorphisms of estrogen receptor alpha, CYP19, catechol-O-methyltransferase are associated with familial prostate carcinoma risk in a Japanese population.

Estrogen is one of the crucial hormones participating in the proliferation and carcinogenesis of the prostate glands. Genetic polymorphisms in the estrogen metabolism pathway might be involved in the risk of prostate carcinoma development. The authors evaluated the association between genetic polymorphisms in estrogen‐related enzymes and receptors and the risk of developing familial prostate carcinoma.

A p53 codon 72 polymorphism associated with prostate cancer development and progression in Japanese

An association between the Pro/Pro genotype of p53 codon 72 and a lower risk of prostate cancer in Caucasians was recently reported. However, the association of this polymorphism with prostate cancer risk in a Japanese population has not been clarified. We performed a case-control study consisting of 114 prostate cancer patients and 105 noncancer controls. Sixty-nine percent (79 of 114) of the patients had a positive family history. The genotypic frequencies in the controls were 39.0% for Arg/Arg, 54.3% for Arg/Pro and 6.7% for Pro/Pro; they were in Hardy-Weinberg equilibrium. When a comparison of the distribution of the p53 codon 72 polymorphism was made between patients with a first-degree family history and all control subjects, the adjusted odds ratios (ORs) for prostate cancer associated with the Arg/Arg, Arg/Pro and Pro/Pro genotypes were 1.00, 0.99 [95% confidence interval (CI) 0.53-1.88] and 2.80 (95% CI 1.04-7.53), respectively. When stratification of cases was performed based on clinical stage (localized or metastatic cancer) and pathological grade (a Gleason score of <7 or > or =7), there tended to be a greater number of patients with localized cancers among those patients with the Arg/Pro genotype than among those with the Arg/Arg genotype (overall cases: age-adjusted OR 0.36, 95% CI 0.13-1.00, p = 0.049; positive family history cases: age-adjusted OR 0.25, 95% CI 0.075-0.84, p = 0.025). In addition, there tended to be a greater number of patients with low-grade cancers among those with the Pro/Pro genotype than among those with other genotypes (overall cases: age-adjusted OR 0.41, 95% CI 0.13-1.30, p = 0.13; positive family history cases: age-adjusted OR 0.20, 95% CI 0.004-0.89, p = 0.035). The present findings suggest that the Pro/Pro genotype of p53 codon 72 played a role in prostate cancer susceptibility in a Japanese population. However, the Pro allele did not appear to worsen such clinical parameters as clinical stage or pathological grade.

Vitamin D receptor gene polymorphism in familial prostate cancer in a Japanese population

Aim: Vitamin D acts as an antiproliferative agent against prostate cells. Epidemiological study has shown that a low level of serum vitamin D concentration is a risk factor for prostate cancer. Vitamin D acts via vitamin D receptor (VDR), and an association of genetic polymorphisms of the VDR gene has been reported. In the current study, we examined the association of VDR gene polymorphisms with familial prostate cancer in a Japanese population.

Association of the genetic polymorphism in cytochrome P450 (CYP) 1A1 with risk of familial prostate cancer in a Japanese population: a case-control study

Association between genetic polymorphisms of CYP1A1 and familial prostate cancer risk was examined by a case-control study of 185 individuals. Although the individual analysis of m1 or m2 genotype of CYP1A1 showed no significant association with prostate cancer risk, the presence of any mutated alleles significantly increased prostate cancer risk in comparison with wild-type genotypes by combination analysis (odds ratio [OR]=2.38; 95% confidence interval [CI]=1.72-3.29; P=0.0069). Furthermore, metastatic cancer had a significant association with mutated alleles of m1 and m2. These finding suggested that CYP1A1 polymorphisms has an association with prostate cancer risk, especially with progression of prostate cancer.

Genomewide linkage analysis of familial prostate cancer in the Japanese population

AbstractProstate cancer (PC) is one of the most common causes of cancer mortality in Western countries, and familial aggregation of PC is well known. Multiple PC susceptibility loci have been reported in Western countries, but attempts to confirm the loci in independent data sets have proven to be inconsistent. We performed a genomewide linkage analysis with 53 affected sib pairs to identify genetic loci related to PC in a Japanese population. Two linkage analyses, GENEHUNTER-PLUS and SIBPAL, were applied and detected nominal statistical significance of linkage to PC at chromosome 1p and 8p, which were reported as being loci for PC in Caucasians. The best evidence of linkage was detected near D8S550 on 8p23 (maximum Zlr=2.25, P=0.037), and the second-best evidence of linkage was observed near D1S2667 on 1p36 (maximum Zlr=2.24, P=0.034). This is the first genetic mapping of PC in Japanese, and the results suggest that susceptibilities to PC lie close to D8S550 on 8p23 and D1S2667 on 1p36.

Trends and characteristics in prostate cancer mortality in Japan

Background : In North America, the incidence and mortality of prostate cancer has been declining since the early 1990s. We calculated the age‐adjusted death rates, age‐specific death rates and standardized mortality ratio (SMR) for prostate cancer in Japan and analyzed their features.

Incidence of Urogenital Cancers in Gunma Prefecture, Japan: A 10‐Year Summary

Background: Although the incidence of urogenital cancers in Japan is lower than that of other cancers, it is increasing steadily. Thus, an epidemiologic study was necessary to determine the measures that would decrease the mortality rate associated with these cancers.

Moderate dose diethylstilbestrol diphosphate therapy in hormone refractory prostate cancer.

Objective: To examine the efficacy and toxicity of a moderate dose (250 mg/day) of diethylstilbestrol diphosphate (DES-DP) intravenously administered to patients with hormone refractory prostate cancer (HRPC) as well as the influence of this agent on the endocrine system. Patients and methods: Sixteen patients with HRPC were treated with a daily intravenous injection of 250 mg of DES-DP for 28 days. Eastern Cooperation Oncology Group (ECOG) performance status and pain score were used for subjective evaluation and PSA was used for objective evaluation. Testosterone, free testosterone, dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) were used for hormonal parameters. Results:OBJECTIVE To examine the efficacy and toxicity of a moderate dose (250 mg/day) of diethylstilbestrol diphosphate (DES-DP) intravenously administered to patients with hormone refractory prostate cancer (HRPC) as well as the influence of this agent on the endocrine system. PATIENTS AND METHODS Sixteen patients with HRPC were treated with a daily intravenous injection of 250 mg of DES-DP for 28 days. Eastern Cooperation Oncology Group (ECOG) performance status and pain score were used for subjective evaluation and PSA was used for objective evaluation. Testosterone, free testosterone, dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) were used for hormonal parameters. RESULTS Fourteen patients were eligible. The mean patient age was 75.2 years. With respect to the ECOG pain score, 5 patients scored 1 or higher, in 4 patients, the pain completely disappeared, and in 1 patient, the pain score improved from 4 to 1. The PSA level decreased significantly from 528 +/- 556 ng/ml (mean +/- SD) to 154 +/- 197 ng/ml. The DHEA level was not changed during DES-DP administration. The DHEA-S level decreased significantly from 882 +/- 430 ng/ml to 480 +/- 236 ng/ml. Testosterone and free testosterone were in the castration level before and during the treatment. Toxicity was minimal. None of the patients developed cardiovascular disorder. CONCLUSION A moderate dose (250 mg/day) of DES-DP decreased PSA levels and relieved pain without causing serious toxicity in patients with HRPC. It is suggested that the mechanism of the DES-DP effect on the decrease in PSA and pain relief involves a decrease in DHEA-S.

Familial Prostate Cancer in Japan

Background:

Polymorphisms of DNA repair genes, XRCC1 and XRCC3, and susceptibility to familial prostate cancer in a Japanese population

Aim:  DNA repair systems play an important role in protecting the genome damaged by endogeneous and exogeneous mutagens. Deficiency in these systems has been reported to increase the risk of various types of cancer. We investigated two DNA repair genes, X‐ray repair cross‐complementing group 1 (XRCC1) and X‐ray repair cross‐complementing group 3 (XRCC3), to assess the association between DNA repair genes and familial prostate cancer susceptibility in the Japanese population.