Technical Evaluation: Identification of Pathogenic Mutations in PKD1 and PKD2 in Patients with Autosomal Dominant Polycystic Kidney Disease by Next-Generation Sequencing and Use of a Comprehensive New Classification System.

Genetic testing of PKD1 and PKD2 is expected to play an increasingly important role in determining allelic influences in autosomal dominant polycystic kidney disease (ADPKD) in the near future. However, to date, genetic testing is not commonly employed because it is expensive, complicated because of genetic heterogeneity, and does not easily identify pathogenic variants. In this study, we developed a genetic testing system based on next-generation sequencing (NGS), long-range polymerase chain reaction, and a new software package. The new software package integrated seven databases and provided access to five cloud-based computing systems. The database integrated 241 polymorphic nonpathogenic variants detected in 140 healthy Japanese volunteers aged >35 years, who were confirmed by ultrasonography as having no cysts in either kidney. Using this system, we identified 60 novel and 30 known pathogenic mutations in 101 Japanese patients with ADPKD, with an overall detection rate of 89.1% (90/101) [95% confidence interval (CI), 83.0%-95.2%]. The sensitivity of the system increased to 93.1% (94/101) (95% CI, 88.1%-98.0%) when combined with multiplex ligation-dependent probe amplification analysis, making it sufficient for use in a clinical setting. In 82 (87.2%) of the patients, pathogenic mutations were detected in PKD1 (95% CI, 79.0%-92.5%), whereas in 12 (12.8%) patients pathogenic mutations were detected in PKD2 (95% CI, 7.5%-21.0%); this is consistent with previously reported findings. In addition, we were able to reconfirm our pathogenic mutation identification results using Sanger sequencing. In conclusion, we developed a high-sensitivity NGS-based system and successfully employed it to identify pathogenic mutations in PKD1 and PKD2 in Japanese patients with ADPKD.

The preventive effects of low-dose enteric-coated aspirin tablets on the development of colorectal tumours in Asian patients: a randomised trial.

OBJECTIVE: To evaluate the influence of low-dose, enteric-coated aspirin tablets (100 mg/day for 2 years) on colorectal tumour recurrence in Asian patients with single/multiple colorectal tumours excised by endoscopy. DESIGN: A double-blinded, randomised, placebo-controlled multicentre clinical trial was conducted. PARTICIPANTS: 311 subjects with single/multiple colorectal adenomas and adenocarcinomas excised by endoscopy were enrolled in the study (152 patients in the aspirin group and 159 patients in the placebo group). Enrolment began at the hospitals (n=19) in 2007 and was completed in 2009. RESULTS: The subjects treated with aspirin displayed reduced colorectal tumourigenesis and primary endpoints with an adjusted OR of 0.60 (95% CI 0.36 to 0.98) compared with the subjects in the placebo group. Subgroup analysis revealed that subjects who were non-smokers, defined as those who had smoked in the past or who had never smoked, had a marked reduction in the number of recurrent tumours in the aspirin-treated group. The adjusted OR for aspirin treatment in non-smokers was 0.37 (CI 0.21 to 0.68, p<0.05). Interestingly, the use of aspirin in smokers resulted in an increased risk, with an OR of 3.44. In addition, no severe adverse effects were observed in either group. CONCLUSIONS: Low-dose, enteric-coated aspirin tablets reduced colorectal tumour recurrence in an Asian population. The results are consistent with those obtained from other randomised controlled trials in Western countries. THE CLINICAL TRIAL REGISTRY WEBSITE AND THE CLINICAL TRIAL NUMBER: http://www.umin.ac.jp (number UMIN000000697).

Preventive effects of low-dose aspirin on colorectal adenoma growth in patients with familial adenomatous polyposis: double-blind, randomized clinical trial.

There are several reports of clinical trials of aspirin in sporadic colon cancer. However, only one double-blind trial of aspirin in patients with familial adenomatous polyposis (FAP) has been reported to date. This double-blind, randomized, placebo-controlled clinical trial was therefore performed to evaluate the influence of low-dose aspirin enteric-coated tablets (100 mg/day for 6-10 months) in 34 subjects with FAP (17 each in the aspirin and placebo groups). The increase in mean diameter of colorectal polyps tended to be greater in the placebo group compared with the aspirin group, which showed a response ratio, that is, aspirin response rate (number of subjects with reduced polyps/total)/placebo response rate (number of subjects with reduced polyps/total), of 2.33 (95% confidence interval: 0.72-7.55). Subgroup analysis revealed that the number of subjects with a mean baseline polyp diameter of ≤2 mm, and the diameter and number of polyps after intervention showed a significant reduction in the aspirin group. Adverse effects of aspirin, such as anastomotic ulcer, aphtha in the large intestine, and progression of anemia, occurred in three subjects. Moreover, none of the subjects developed colorectal cancer. The results thus indicated a potential for aspirin to reduce colorectal adenoma development in patients with FAP, but careful follow-up is needed to avoid or rapidly counter severe adverse effects.

Chemoprevention of colorectal cancer in Japan: a brief introduction to current clinical trials.

The rapidly increasing incidence of colorectal cancer in Japan poses a great challenge to researchers to develop preventive strategies against this disease. Thus far, several clinical trials for this purpose have been planned in Japanese subjects; some have been completed and documented while others are still ongoing. Also, the Ministry of Health, Labour and Welfare of Japan recognizes the significance of cancer prevention studies, especially against colorectal cancer, including it as one of the pillars in the "Third Research Project on General Strategies against Cancer" and funding several large-scale projects. Among them are two chemoprevention studies currently being performed: in patients with previous sporadic colorectal tumors (J-CAPP study) and in patients with familial adenomatous polyposis (J-FAPP study II). Both are double-blind randomized controlled trials with low-dose aspirin (100 mg/day), which is generally considered to be safe for long-term use. This article outlines relevant past clinical data and gives a brief introduction to these two studies.

Cross-sectional analysis of germline BRCA1 and BRCA2 mutations in Japanese patients suspected to have hereditary breast/ovarian cancer.

The prevalence of BRCA1/2 germline mutations in Japanese patients suspected to have hereditary breast/ovarian cancer was examined by a multi-institutional study, aiming at the clinical application of total sequencing analysis and validation of assay sensitivity in Japanese people using a cross-sectional approach based on genetic factors estimated from personal and family histories. One hundred and thirty-five subjects were referred to the genetic counseling clinics and enrolled in the study. Full sequencing analysis of the BRCA1/2 gene showed 28 types of deleterious mutations in 36 subjects (26.7%), including 13 types of BRCA1 mutations in 17 subjects (12.6%) and 15 types of BRCA2 mutations in 19 subjects (14.1%). Subjects were classified into five groups and 22 subgroups according to their personal and family history of breast and/or ovarian cancer, and the prevalence of deleterious mutations was compared with previously reported data in non-Ashkenazi individuals. Statistical analysis using the Mantel-Haenszel test for groups I through IV revealed that the prevalence of Japanese subjects was significantly higher than that of non-Ashkenazi individuals (P = 0.005, odds ratio 1.87, 95% confidence interval 1.22-2.88). Family history of the probands suffering from breast cancer indicated risk factors for the presence of deleterious mutations of BRCA1/2 as follows: (1) families with breast cancer before age 40 within second degree relatives (P = 0.0265, odds ratio 2.833, 95% confidence interval 1.165-7.136) and (2) families with bilateral breast cancer and/or ovarian cancer within second degree relatives (P = 0.0151, odds ratio 2.88, 95% confidence interval 1.25-6.64).

Successful chemotherapeutic modality of doxorubicin plus dacarbazine for the treatment of desmoid tumors in association with familial adenomatous polyposis.

PURPOSE: Desmoid tumors are locally aggressive and can be fatal in familial adenomatous polyposis (FAP) patients if they are not suitable for surgery or radiation therapy. Here, we prospectively investigated the efficacy of a chemotherapeutic regimen involving doxorubicin (DOX) and dacarbazine (DTIC) for inoperable FAP-associated desmoid tumors. PATIENTS AND METHODS: From an initial group of 120 FAP patients, seven of the 11 individuals with symptomatic unresectable desmoid tumors that were unresponsive to conventional hormone therapy were enrolled onto this study. The general chemotherapy regimen comprised four or five cycles of DOX (20 mg/m2 daily) plus DTIC (150 mg/m2 daily) throughout 4 days of drip intravenous infusion (day 1 through 4) every 28 days, followed by the cyclooxygenase-2 inhibitor meloxicam (10 mg/m2). The primary end point was relapse-free survival. The secondary end points included toxicity, clinical improvement, and tumor regression according to computed tomography. RESULTS: Significant tumor regression was observed clinically and radiologically in all seven patients. Three patients showed a complete response. The average progression-free survival period was 74.0 months (range, 32.5 to 107.5 months). Three patients showed grade 3 adverse events with no treatment-related mortality. All seven patients survived and remained without tumor progression. An adenomatous polyposis coli germline-mutation analysis revealed no mutations in the specified regions. CONCLUSION: A chemotherapeutic regimen of DOX plus DTIC followed by meloxicam is an effective and safe treatment for FAP-associated desmoid tumors. This modality should be considered for use as first-line chemotherapy in symptomatic desmoid tumors that are unresponsive to conventional medical therapy, due to the absence of useful presymptomatic markers.

[Genetic susceptibility testing for hereditary breast and ovarian cancer--approach from a commercial clinical laboratory].

Genetic testing for hereditary cancers and other common diseases are still considered as the research testing, not for the clinical testing in Japan. One of the major reason of this situation is related to the guidelines regarding the human genetic testing issued successively in the spring of 2001, one by joint work of the eight learned societies and the other by the Japan clinical laboratories association. Both of these guidelines warn the condition of the clinical application of genetic testing after research stage must have the evidence data for clinical utility. We describe the situation of the genetic testing in the U.S. focusing the social background of increasing breast cancer cases and the contribution of Myriad Genetic Laboratories, Inc. for the genetic testing industry. We also describe the Japanese situation of the genetic testing and problems to be solved before spreading widely.

[Familial adenomatous polyposis (FAP)--diagnosis and management].

Familial adenomatous polyposis (FAP) is characterized by more than hundreds of colorectal adenomas, colorectal cancer in early adult life, extracolonic features and genetic inheritance. Not only surgical management of FAP (IAA, IACA and IRA) but also methodology of APC gene test is almost established. Surveillance program and management of extracolonic manifestation is going to contribute to patient's prognosis. And now in Japan, two clinical intervention and chemoprevention trial studies of FAP are going on. As these reasons, FAP is most comprehensive model for understanding status quo and future problem of familial cancer syndromes. However, there are many counseling issues of FAP family members, choice of opportunity and method for diagnosis, surveillance, chemoprevention, surgery and to inform family member about hereditary risk. So, Cancer Genetic Counseling for FAP family members must be provided for their lifetime long.