Colorectal cancer (CRC) is currently the most common type of cancer in Japan, and its prognosis has improved because of development of diagnosis and advancement in treatments including surgery and ...chemotherapy. However, because of intratumor heterogeneity and clonal evolution, tumors often develop resistance to treatment. Genotyping tumor tissue in search of somatic genetic alterations for actionable information has become routine examination in clinical practice. However, the inherent molecular heterogeneity of metastatic tumors and the ability of cancer genomes to dynamically evolve are not properly captured by tissue specimens only. Circulating tumor DNA (ctDNA) carrying tumor‐specific genetic or epigenetic alterations is released into the circulation from tumor cells undergoing apoptosis or necrosis. Analysis of ctDNA has the potential to change clinical practice by exploiting blood rather than tissue, as a source of information. Here, we provide an overview of the characteristics of ctDNA and focus on detection methods for ctDNA, and the feasibility of use of ctDNA to monitor tumor dynamics for patients with colorectal cancer.
Circulating tumor DNA (ctDNA) carrying tumor‐specific genetic or epigenetic alterations is released into the circulation from tumor cells undergoing apoptosis or necrosis. Analysis of ctDNA has the potential to change clinical practice by exploiting blood rather than tissue, as a source of information. In this article, we provide an overview of the characteristics of ctDNA and focus on detection methods for ctDNA, and the feasibility of the use of ctDNA to monitor tumor dynamics for patients with colorectal cancer.
The BioBank Japan (BBJ) Project was launched in 2003 with the aim of providing evidence for the implementation of personalized medicine by constructing a large, patient-based biobank (BBJ). This ...report describes the study design and profile of BBJ participants who were registered during the first 5-year period of the project.
The BBJ is a registry of patients diagnosed with any of 47 target common diseases. Patients were enrolled at 12 cooperative medical institutes all over Japan from June 2003 to March 2008. Clinical information was collected annually via interviews and medical record reviews until 2013. We collected DNA from all participants at baseline and collected annual serum samples until 2013. In addition, we followed patients who reported a history of 32 of the 47 target diseases to collect survival data, including cause of death.
During the 5-year period, 200,000 participants were registered in the study. The total number of cases was 291,274 at baseline. Baseline data for 199,982 participants (53.1% male) were available for analysis. The average age at entry was 62.7 years for men and 61.5 years for women. Follow-up surveys were performed for participants with any of 32 diseases, and survival time data for 141,612 participants were available for analysis.
The BBJ Project has constructed the infrastructure for genomic research for various common diseases. This clinical information, coupled with genomic data, will provide important clues for the implementation of personalized medicine.
•The BioBank Japan Project (BBJ) enrolled 200,000 patients with 47 target diseases.•The BBJ is one of the largest patient-based biobanks in the world.•The BBJ may allow for personalized medicine in the future.
Tamoxifen has been used not only for the treatment or prevention of recurrence in patients with estrogen receptor positive breast cancers but also for recurrent breast cancer. Because CYP2D6 is known ...to be an important enzyme responsible for the generation of the potent tamoxifen metabolite, 'endoxifen', lots of studies reported that genetic variation which reduced its enzyme activity were associated with poor clinical outcome of breast cancer patients treated with tamoxifen. However, there are some discrepant reports questioning the association between CYP2D6 genotype and clinical outcome after tamoxifen therapy. Dose-adjustment study of tamoxifen based on CYP2D6 genotypes provides the evidence that dose adjustment is useful for the patients carrying reduced or null allele of CYP2D6 to maintain the effective endoxifen level. This review describes critical issues in pharmacogenomic studies as well as summarizes the results of the association of CYP2D6 genotype with tamoxifen efficacy.
Molecular‐targeted drugs specifically interfere with molecules that are frequently overexpressed or mutated in cancer cells. As such, these drugs are generally considered to precisely attack cancer ...cells, thereby inducing fewer adverse drug reactions (ADRs). However, molecular‐targeted drugs can still cause characteristic ADRs that, although rarely severe, can be life‐threatening. Therefore, it is becoming increasingly important to be able to predict which patients are at risk of developing ADRs after treatment with molecular‐targeted therapy. The emerging field of pharmacogenetics aims to better distinguish the genetic variants associated with drug toxicity and efficacy to improve the selection of therapeutic strategies for each genetic profile. Here, we provide an overview of the current reports on the relationship between genetic variants and molecular‐targeted drug‐induced severe ADRs in oncology.
Molecular‐targeted drugs can still cause characteristic adverse drug reactions (ADRs) that, although rarely severe, can be life‐threatening. Therefore, it is becoming increasingly important to identify variants associated with drug response and toxicity for the plethora of clinically available drugs to improve treatment safety and to help physicians select the best treatment strategy in medical decision making. This review summarizes the current reports on the relationship between genetic variants and molecular‐targeted drug‐induced severe ADRs in oncology.
The "watch-and-wait" approach is a common treatment option amongst patients with locally advanced rectal cancer (LARC). However, the diagnostic sensitivity of clinical modalities, such as colonoscopy ...and magnetic resonance imaging to determine pathological response, is not high. We analysed the clinical utility of circulating tumour DNA (ctDNA) of patients with LARC to predict response to preoperative therapy and postoperative recurrence.
A serial ctDNA analysis of 222 plasma samples from 85 patients with LARC was performed using amplicon-based deep sequencing on a cell-free DNA panel covering 14 genes with over 240 hotspots.
ctDNA was detected in 57.6% and 22.3% of samples at baseline and after preoperative treatment, respectively, which was significantly different (P = 0.0003). Change in ctDNA was an independent predictor of complete response to preoperative therapy (P = 0.0276). In addition, postoperative ctDNA and carcinoembryonic antigen (CEA) were independent prognostic markers for risk of recurrence after surgery (ctDNA, P = 0.0127 and CEA, P = 0.0105), with a combined analysis having cumulative effects on recurrence-free survival (P = 1.0 × 10
).
Serial ctDNA analysis may offer clinically useful predictive and prognostic markers for response to preoperative therapy and postoperative recurrence in patients with LARC.
Cancer is a complex genetic disease that develops from the accumulation of genomic alterations in which germline variations predispose individuals to cancer and somatic alterations initiate and ...trigger the progression of cancer. For the past 2 decades, genomic research has advanced remarkably, evolving from single‐gene to whole‐genome screening by using genome‐wide association study and next‐generation sequencing that contributes to big genomic data. International collaborative efforts have contributed to curating these data to identify clinically significant alterations that could be used in clinical settings. Focusing on breast cancer, the present review summarizes the identification of genomic alterations with high‐throughput screening as well as the use of genomic information in clinical trials that match cancer patients to therapies, which further leads to cancer precision medicine. Furthermore, cancer screening and monitoring were enhanced greatly by the use of liquid biopsies. With the growing data complexity and size, there is much anticipation in exploiting deep machine learning and artificial intelligence to curate integrative “−omics” data to refine the current medical practice to be applied in the near future.
Focusing on breast cancer, this review summarizes the discovery of germline variations and somatic alterations with genome‐wide association studies and next‐generation sequencing that contributes to big genomic data. These genetic biomarkers could be integrated in clinical settings to identify individuals who are at risk for cancer, drug‐induced toxicity, as well as match cancer patients to therapies, which further leads to cancer precision medicine. This review will also discuss the potential use of liquid biopsies in cancer screening and monitoring.
Next-generation sequencing (NGS) has identified variations in cytochrome P450 (CYP) 2D6 associated with drug responses. However, determination of novel haplotypes is difficult because of the short ...reads generated by NGS. We aimed to identify novel CYP2D6 variants in the Japanese population and predict the CYP2D6 phenotype based on in vitro metabolic studies. Using a targeted NGS panel (PKSeq), 990 Japanese genomes were sequenced, and then novel CYP2D6 haplotypes were determined. K
, V
, and intrinsic clearance (V
/K
) of N-desmethyl-tamoxifen 4-hydroxylation were calculated by in vitro metabolic studies using cDNA-expressed CYP2D6 proteins. After determination of the CYP2D6 diplotypes, phenotypes of the individuals were predicted based on the in vitro metabolic activities. Targeted NGS identified 14 CYP2D6 variants not registered in the Pharmacogene Variation Consortium (PharmVar) database. Ten novel haplotypes were registered as CYP2D6*128 to *137 alleles in the PharmVar database. Based on the V
/K
value of each allele, *128, *129, *130, *131, *132, and *133 were predicted to be nonfunctional alleles. According to the results of the present study, six normal metabolizers (NM) and one intermediate (IM) metabolizers were designated as IM and poor metabolizers (PM), respectively. Our findings provide important insights into novel haplotypes and haplotypes of CYP2D6 and the effects on in vitro metabolic activities.
Pancreatic cancer is an aggressive, solid tumor, with a grave prognosis. Despite surgical treatment in patients with pancreatic cancer, the rate of recurrence is high. In addition, although tumor ...biomarkers are frequently used to confirm advanced pancreatic cancer, this is not accurate and the biomarkers currently used cannot indicate prognosis. This study sought to evaluate circulating tumor DNA as a tumor biomarker to prognosticate pancreatic cancer. Patients with advanced pancreatic cancer and liver metastasis (N = 104) were included, and blood samples were collected from all patients. The mutant allele frequency was measured using amplicon-based deep sequencing on a cell-free DNA panel covering 14 genes with > 240 hot spots. In patients with advanced pancreatic cancer, 50% (N = 52) had detectable ctDNA levels, with TP53 (45%, N = 47) and KRAS (42.3%, N = 44) mutations the most common. Patients with detectable circulating tumor DNA levels also had significantly worse overall survival and progression free survival than ctDNA negative patients (8.4 vs 16 months, P0.0001 for overall survival; 3.2 vs 7.9 months, P0.0001 for progression-free survival). In a multivariate analysis, ctDNA status was independently associated with overall survival and progression-free survival (HR = 3.1, 95%CI = 1.9-5.0, P0.0001; HR 2.6, 95%CI = 1.7-4.0, P0.0001, respectively). Moreover, circulating tumor DNA significantly correlated with a higher number of liver metastases, the presence of lung and/or peritoneal metastases, tumor burden, and higher carbohydrate antigen 19-9 levels. This study supports the use of circulating tumor DNA as an independent prognostic marker for advanced pancreatic cancer.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To implement personalized medicine, we established a large-scale patient cohort, BioBank Japan, in 2003. BioBank Japan contains DNA, serum, and clinical information derived from approximately 200,000 ...patients with 47 diseases. Serum and clinical information were collected annually until 2012.
We analyzed clinical information of participants at enrollment, including age, sex, body mass index, hypertension, and smoking and drinking status, across 47 diseases, and compared the results with the Japanese database on Patient Survey and National Health and Nutrition Survey. We conducted multivariate logistic regression analysis, adjusting for sex and age, to assess the association between family history and disease development.
Distribution of age at enrollment reflected the typical age of disease onset. Analysis of the clinical information revealed strong associations between smoking and chronic obstructive pulmonary disease, drinking and esophageal cancer, high body mass index and metabolic disease, and hypertension and cardiovascular disease. Logistic regression analysis showed that individuals with a family history of keloid exhibited a higher odds ratio than those without a family history, highlighting the strong impact of host genetic factor(s) on disease onset.
Cross-sectional analysis of the clinical information of participants at enrollment revealed characteristics of the present cohort. Analysis of family history revealed the impact of host genetic factors on each disease. BioBank Japan, by publicly distributing DNA, serum, and clinical information, could be a fundamental infrastructure for the implementation of personalized medicine.
•The BioBank Japan Project (BBJ) annually collected clinical information.•Analysis of the clinical information at enrollment characterized the BBJ cohort.•Analysis of family history revealed impacts of host genetic factors on the diseases.
Tamoxifen has been widely used for the prevention of recurrence in patients with hormone receptor-positive breast cancer. Tamoxifen requires metabolic activation by cytochrome P450 (CYP) enzymes for ...formation of active metabolites, 4-hydroxytamoxifen and endoxifen, which have 30- to 100fold greater affinity to the estrogen receptor and the potency to suppress estrogen-dependent breast cancer cell proliferation. CYP2D6 is a key enzyme in this metabolic activation and it has been suggested that the genetic polymorphisms of CYP2D6 influence the plasma concentrations of active tamoxifen metabolites and clinical outcomes for breast cancer patients treated with tamoxifen. The genetic polymorphisms in the other drug-metabolizing enzymes, including other CYP isoforms, sulfotransferases and UDP-glucuronosyl-transferases might contribute to individual differences in the tamoxifen metabolism and clinical outcome of tamoxifen therapy although their contributions would be small. Recently, involvement of a drug transporter in the disposition of active tamoxifen metabolites was identified. The genetic polymorphisms of transporter genes have the potential to improve the prediction of clinical outcome for the treatment of hormone receptor-positive breast cancer. This review summarizes current knowledge on the roles of polymorphisms in the drug-metabolizing enzymes and transporters in tamoxifen pharmacogenomics.
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