1
|
Jia X, Zhang T, Sun J, Lin H, Bai T, Qiao Y, Li Y, Li G, Li G, Peng X, Zhang A. Rs11479 in Thymidine Phosphorylase Associated with Prognosis of Patients with Colorectal Cancer Who Received Capecitabine-Based Adjuvant Chemotherapy. Pharmgenomics Pers Med 2023; 16:277-289. [PMID: 37025557 PMCID: PMC10072144 DOI: 10.2147/pgpm.s397382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 02/17/2023] [Indexed: 04/03/2023] Open
Abstract
Objective Thymidine Phosphorylase (TYMP) gene was of potential significance in the process of colorectal cancer (CRC) development and played an important role in capecitabine metabolism. This study was to identify the association between TYMP polymorphism and prognosis of postoperative patients with CRC who received capecitabine-based adjuvant chemotherapy. Methods A total of 218 patients with CRC who were treated with surgical resection and capecitabine-based adjuvant chemotherapy were included in this study retrospectively. Peripheral blood and peripheral blood mononuclear cell (PBMC) specimen of the patients were collected for the genotyping of TYMP polymorphism and TYMP mRNA expression, respectively. Univariate analysis of genotypes and prognosis was carried out by Kaplan-Meier survival analysis, Cox regression analysis was adopted in multivariate analysis. The mRNA expression of TYMP according to genotype status was analyzed using non-parameter test. Results Prevalence of rs11479 in TYMP among the 218 patients exhibited that minor allele frequency of rs11479 was 0.20 (GG 141 cases, GA 68 cases and AA 9 cases), which was in accordance with Hardy-Weinberg equilibrium (P=0.825). Association analysis suggested that the median disease-free survival (DFS) of patients with GG genotype and GA/AA genotype was 3.1 and 6.1 years, respectively (P=0.004). Furthermore, the median overall survival of patients with GG genotype and GA/AA genotype was 5.0 and 7.0 years, respectively (P=0.033). Multivariate Cox regression analysis exhibited that rs11479 polymorphism was an independent factor for DFS (HR = 1.64, P=0.009). Additionally, of the 65 PBMC specimens, mRNA expression results indicated that patients with GA/AA genotypes conferred significantly higher mRNA expression of TYMP than that of patients with GG genotype (P<0.001). Conclusion Polymorphism rs11479 in TYMP gene might predict the prognosis of patients with CRC who received capecitabine-based adjuvant chemotherapy through mediation of the mRNA expression of TYMP. The conclusion of this study should be validated in prospective clinical trials subsequently.
Collapse
Affiliation(s)
- Xiongjie Jia
- Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, People’s Republic of China
| | - Tao Zhang
- Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, People’s Republic of China
| | - Junjie Sun
- Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, People’s Republic of China
| | - Hengxue Lin
- Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, People’s Republic of China
| | - Tianliang Bai
- Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, People’s Republic of China
| | - Yating Qiao
- Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, People’s Republic of China
| | - Yaxin Li
- Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, People’s Republic of China
| | - Gang Li
- Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, People’s Republic of China
| | - Guicun Li
- Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, People’s Republic of China
| | - Xinyu Peng
- Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, People’s Republic of China
| | - Aimin Zhang
- Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, Baoding, People’s Republic of China
- Correspondence: Aimin Zhang; Xinyu Peng, Department of Gastrointestinal Surgery, Affiliated Hospital of Hebei University, No. 212 Yu-Hua East Road, Baoding City, Hebei Province, People’s Republic of China, Tel +863125983782, Email ;
| |
Collapse
|
2
|
Azwar S, Seow HF, Abdullah M, Faisal Jabar M, Mohtarrudin N. Recent Updates on Mechanisms of Resistance to 5-Fluorouracil and Reversal Strategies in Colon Cancer Treatment. BIOLOGY 2021; 10:854. [PMID: 34571731 PMCID: PMC8466833 DOI: 10.3390/biology10090854] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/04/2020] [Accepted: 08/11/2020] [Indexed: 02/06/2023]
Abstract
5-Fluorouracil (5-FU) plus leucovorin (LV) remain as the mainstay standard adjuvant chemotherapy treatment for early stage colon cancer, and the preferred first-line option for metastatic colon cancer patients in combination with oxaliplatin in FOLFOX, or irinotecan in FOLFIRI regimens. Despite treatment success to a certain extent, the incidence of chemotherapy failure attributed to chemotherapy resistance is still reported in many patients. This resistance, which can be defined by tumor tolerance against chemotherapy, either intrinsic or acquired, is primarily driven by the dysregulation of various components in distinct pathways. In recent years, it has been established that the incidence of 5-FU resistance, akin to multidrug resistance, can be attributed to the alterations in drug transport, evasion of apoptosis, changes in the cell cycle and DNA-damage repair machinery, regulation of autophagy, epithelial-to-mesenchymal transition, cancer stem cell involvement, tumor microenvironment interactions, miRNA dysregulations, epigenetic alterations, as well as redox imbalances. Certain resistance mechanisms that are 5-FU-specific have also been ascertained to include the upregulation of thymidylate synthase, dihydropyrimidine dehydrogenase, methylenetetrahydrofolate reductase, and the downregulation of thymidine phosphorylase. Indeed, the successful modulation of these mechanisms have been the game plan of numerous studies that had employed small molecule inhibitors, plant-based small molecules, and non-coding RNA regulators to effectively reverse 5-FU resistance in colon cancer cells. It is hoped that these studies would provide fundamental knowledge to further our understanding prior developing novel drugs in the near future that would synergistically work with 5-FU to potentiate its antitumor effects and improve the patient's overall survival.
Collapse
Affiliation(s)
- Shamin Azwar
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia; (S.A.); (H.F.S.); (M.A.)
| | - Heng Fong Seow
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia; (S.A.); (H.F.S.); (M.A.)
| | - Maha Abdullah
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia; (S.A.); (H.F.S.); (M.A.)
| | - Mohd Faisal Jabar
- Department of Surgery, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia;
| | - Norhafizah Mohtarrudin
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia; (S.A.); (H.F.S.); (M.A.)
| |
Collapse
|
3
|
Carboxylesterase 1 polymorphisms are associated with clinical outcomes in gastroenteric cancer patients treated with capecitabine. Cancer Chemother Pharmacol 2021; 87:681-687. [PMID: 33586000 DOI: 10.1007/s00280-021-04247-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 02/05/2021] [Indexed: 10/22/2022]
Abstract
OBJECTIVES The aim of this study was to test whether CES1, UMPS, DPYS and TPYS polymorphisms influence the outcomes of gastroenteric cancer patients. METHODS We consecutively enrolled 338 patients who were diagnosed with colorectal and gastric cancer from January 2016 to December 2018 at the Harbin Medical University Cancer Hospital, China. RESULTS We found that the patients with CES1 rs7187684 CC genotype had a higher proportion of stage III-IV and relapse rate significantly compared with CT/TT genotype, and the patients with rs7187684 CC genotype had a higher level of CA199 than CT/TT genotype after adjusted for tumor stage, and medication, age, sex, smoking, and drinking. Moreover, the patients with rs7187684 CC genotype had shorter event-free survival (EFS) than CT/TT genotype, and a significant shorter EFS was also found in the patients with rs2244613 TT genotype than GG or GT genotype. Subset analysis results showed that the male, less-drinking or gastric cancer patients with rs7187684 CC genotype had shorter EFS than the patients with CT/TT genotype. Compared with the patients with CES1 rs2244613 TT genotype, the stage I-II patients with GG/GT genotype had longer progression-free survival (PFS), and the male patients with GG/GT genotype had longer EFS. Multivariate Cox regression analysis showed that stage III-IV and tumor metastasis could reduce the patients' PFS and EFS. CONCLUSIONS The identified CES1 polymorphisms might provide guide for the identification of gastroenteric cancer patients who were likely to benefit from capecitabine-based chemotherapy.
Collapse
|
4
|
Gu J, Li Z, Zhou J, Sun Z, Bai C. Response prediction to oxaliplatin plus 5-fluorouracil chemotherapy in patients with colorectal cancer using a four-protein immunohistochemical model. Oncol Lett 2019; 18:2091-2101. [PMID: 31423282 DOI: 10.3892/ol.2019.10474] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 04/29/2019] [Indexed: 12/13/2022] Open
Abstract
The response of cancer patients to oxaliplatin combined with 5-fluorouracil (5-FU) is difficult to predict. It has been reported that carcinoma-associated fibroblasts (CAFs) could induce AKT and ERK phosphorylation, and upregulate survivin expression in colorectal cancer (CRC) cells, which could lead to oxaliplatin plus 5-FU resistance. A total of 71 patients with advanced CRC (aCRC) treated with oxaliplatin plus 5-FU were included in the present study. These patients comprised 46 chemotherapy responders and 25 non-responders. The expression levels of α-smooth muscle actin (α-SMA), phosphorylated (p)-AKT, p-ERK and survivin were determined by immunohistochemical evaluation of paraffin-embedded samples from patients. A predictive model was established using a Probabilistic Neural Network model. The high expression of α-SMA, p-AKT and survivin in patients with aCRC were associated with oxaliplatin plus 5-FU resistance (P<0.001, P=0.023 and P=0.001, respectively). Furthermore, patients with stage IV CRC exhibiting high expression levels of α-SMA and survivin experienced a reduced progression-free survival time compared with patients with low expressions of α-SMA and survivin (5.5 vs. 15.0 months; 5.5 vs. 15.0 months; P=0.005 and P=0.001, respectively). Stage IV CRC and high survivin expression predicted a reduced overall survival time compared with that for patients with stage IV CRC and low survivin expression (50.0 vs. 15.0 months; P<0.001). Patients with α-SMA, p-AKT, p-ERK and survivin overexpression were more likely to present with intrinsic resistance to the oxaliplatin plus 5-FU regimen (the accuracies of modeling, validation and prediction were 83.7, 92.9 and 85.7%, respectively). In conclusion, the multifactorial predictive biomarker model of α-SMA, p-AKT, p-ERK and survivin expression for patients with aCRC to predict intrinsic resistance to oxaliplatin plus 5-FU regimens is of great efficiency and accuracy. Patients with high expression of this predictive model may be intrinsically resistant to the oxaliplatin and 5-FU regimen.
Collapse
Affiliation(s)
- Junjie Gu
- Department of Medical Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Dongcheng, Beijing 100730, P.R. China
| | - Zhe Li
- Department of Medical Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Dongcheng, Beijing 100730, P.R. China
| | - Jianfeng Zhou
- Department of Medical Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Dongcheng, Beijing 100730, P.R. China
| | - Zhao Sun
- Department of Medical Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Dongcheng, Beijing 100730, P.R. China
| | - Chunmei Bai
- Department of Medical Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Dongcheng, Beijing 100730, P.R. China
| |
Collapse
|
5
|
p53 expression status is associated with cancer-specific survival in stage III and high-risk stage II colorectal cancer patients treated with oxaliplatin-based adjuvant chemotherapy. Br J Cancer 2019; 120:797-805. [PMID: 30894685 PMCID: PMC6474280 DOI: 10.1038/s41416-019-0429-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/26/2019] [Accepted: 03/01/2019] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND We attempted to elucidate whether p53 expression or TP53 mutation status was associated with cancer-specific survival in adjuvant FOLFOX-treated patients with stage III or high-risk stage II colorectal cancer (CRC). METHODS We analysed CRCs (N = 621) for the presence of TP53 alterations and for p53 expression, using targeted resequencing and immunohistochemistry. CRCs were grouped into four subsets according to the p53 expression status, which included p53-no, mild, moderate and strong expression. RESULTS The distributions of CRCs were 19.85, 11.05, 17.7% and 51.5% in the p53-no, mild, moderate and strong expression groups, respectively. Cases in the p53-mild to moderate expression group were associated with a more frequent proximal location, undifferentiated histology, lower N category, extraglandular mucin production, microsatellite instability, CIMP-P1, CK7 expression and decreased CDX2 expression compared with those of cases of the p53-no expression and p53-strong expression groups. According to survival analysis, the p53-mild expression group showed a poor 5-year relapse-free survival (hazard ratio (HR): 2.71, 95% confidence interval (CI) = 1.60-4.60, P < 0.001) and poor 5-year cancer-specific survival (HR: 2.90, 95% CI = 1.28-6.57, P = 0.011). CONCLUSIONS p53-mild expression status was found to be an independent prognostic marker in adjuvant FOLFOX-treated patients with stage III and high-risk stage II CRC.
Collapse
|
6
|
Zhang S, Tan IB, Sapari NS, Grabsch HI, Okines A, Smyth EC, Aoyama T, Hewitt LC, Inam I, Bottomley D, Nankivell M, Stenning SP, Cunningham D, Wotherspoon A, Tsuburaya A, Yoshikawa T, Soong R, Tan P. Technical reproducibility of single-nucleotide and size-based DNA biomarker assessment using DNA extracted from formalin-fixed, paraffin-embedded tissues. J Mol Diagn 2015; 17:242-50. [PMID: 25746798 DOI: 10.1016/j.jmoldx.2014.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 12/02/2014] [Accepted: 12/05/2014] [Indexed: 02/07/2023] Open
Abstract
DNA extracted from formalin-fixed, paraffin-embedded (FFPE) tissues has been used in the past to analyze genetic polymorphisms. We evaluated the technical reproducibility of different types of assays for gene polymorphisms using DNA extracted from FFPE material. By using the MassARRAY iPLEX system, we investigated polymorphisms in DPYD (rs1801159 and rs3918290), UMPS (rs1801019), ERCC1 (rs11615), ERCC1 (rs3212986), and ERCC2 (rs13181) in 56 FFPE DNA samples. By using PCR, followed by size-based gel electrophoresis, we also examined TYMS 5' untranslated region 2R/3R repeats and GSTT1 deletions in 50 FFPE DNA samples and 34 DNAs extracted from fresh-frozen tissues and cell lines. Each polymorphism was analyzed by two independent runs. We found that iPLEX biomarker assays measuring single-nucleotide polymorphisms provided consistent concordant results. However, by using FFPE DNA, size-based PCR biomarkers (GSTT1 and TYMS 5' untranslated region) were discrepant in 32.7% (16/49, with exact 95% CI, 19.9%-47.5%; exact binomial confidence limit test) and 4.2% (2/48, with exact 95% CI, 0.5%-14.3%) of cases, respectively, whereas no discrepancies were observed using intact genomic DNA. Our findings suggest that DNA from FFPE material can be used to reliably test single-nucleotide polymorphisms. However, results based on size-based PCR biomarkers, and particularly GSTT1 deletions, using FFPE DNA need to be interpreted with caution. Independent repeated assays should be performed on all cases to assess potential discrepancies.
Collapse
Affiliation(s)
- Shenli Zhang
- Cancer and Stem Cell Biology Program, Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Iain B Tan
- Department of Medical Oncology, National Cancer Centre, Singapore, Singapore
| | - Nur S Sapari
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Heike I Grabsch
- Leeds Institute of Cancer and Pathology, University of Leeds, Leeds, United Kingdom
| | - Alicia Okines
- Department of Gastrointestinal Oncology, Royal Marsden Hospital, Sutton, United Kingdom
| | - Elizabeth C Smyth
- Department of Gastrointestinal Oncology, Royal Marsden Hospital, Sutton, United Kingdom
| | - Toru Aoyama
- Department of Gastrointestinal Surgery, Kanagawa Cancer Center, Yokohama, Japan
| | - Lindsay C Hewitt
- Leeds Institute of Cancer and Pathology, University of Leeds, Leeds, United Kingdom
| | - Imran Inam
- Leeds Institute of Cancer and Pathology, University of Leeds, Leeds, United Kingdom
| | - Dan Bottomley
- Leeds Institute of Cancer and Pathology, University of Leeds, Leeds, United Kingdom
| | - Matthew Nankivell
- Medical Research Council Clinical Trials Unit, University College London, London, United Kingdom
| | - Sally P Stenning
- Medical Research Council Clinical Trials Unit, University College London, London, United Kingdom
| | - David Cunningham
- Department of Gastrointestinal Oncology, Royal Marsden Hospital, Sutton, United Kingdom
| | | | - Akira Tsuburaya
- Gastroenterological Center, Yokohama City University Medical Center, Yokohama, Japan
| | - Takaki Yoshikawa
- Department of Gastrointestinal Surgery, Kanagawa Cancer Center, Yokohama, Japan
| | - Richie Soong
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore; Department of Pathology, National University Health System, Singapore, Singapore
| | - Patrick Tan
- Cancer and Stem Cell Biology Program, Duke-NUS Graduate Medical School, Singapore, Singapore; Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore; Department of Cellular and Molecular Research, National Cancer Centre, Singapore, Singapore; Cancer Therapeutics and Stratified Oncology Group, Genome Institute of Singapore, Singapore, Singapore.
| |
Collapse
|
7
|
Potentially functional SNPs (pfSNPs) as novel genomic predictors of 5-FU response in metastatic colorectal cancer patients. PLoS One 2014; 9:e111694. [PMID: 25372392 PMCID: PMC4221105 DOI: 10.1371/journal.pone.0111694] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 09/29/2014] [Indexed: 12/31/2022] Open
Abstract
5-Fluorouracil (5-FU) and its pro-drug Capecitabine have been widely used in treating colorectal cancer. However, not all patients will respond to the drug, hence there is a need to develop reliable early predictive biomarkers for 5-FU response. Here, we report a novel potentially functional Single Nucleotide Polymorphism (pfSNP) approach to identify SNPs that may serve as predictive biomarkers of response to 5-FU in Chinese metastatic colorectal cancer (CRC) patients. 1547 pfSNPs and one variable number tandem repeat (VNTR) in 139 genes in 5-FU drug (both PK and PD pathway) and colorectal cancer disease pathways were examined in 2 groups of CRC patients. Shrinkage of liver metastasis measured by RECIST criteria was used as the clinical end point. Four non-responder-specific pfSNPs were found to account for 37.5% of all non-responders (P<0.0003). Five additional pfSNPs were identified from a multivariate model (AUC under ROC = 0.875) that was applied for all other pfSNPs, excluding the non-responder-specific pfSNPs. These pfSNPs, which can differentiate the other non-responders from responders, mainly reside in tumor suppressor genes or genes implicated in colorectal cancer risk. Hence, a total of 9 novel SNPs with potential functional significance may be able to distinguish non-responders from responders to 5-FU. These pfSNPs may be useful biomarkers for predicting response to 5-FU.
Collapse
|
8
|
Thymidine phosphorylase gene variant, platelet counts and survival in gastrointestinal cancer patients treated by fluoropyrimidines. Sci Rep 2014; 4:5697. [PMID: 25027354 PMCID: PMC4100023 DOI: 10.1038/srep05697] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 06/23/2014] [Indexed: 02/08/2023] Open
Abstract
The predictive value of thymidine phosphorylase gene variants (TP, also called platelet-derived endothelial cell growth factor) and thrombocytosis were controversial and worthy of further study in gastrointestinal cancer (GIC) patients. We screened all of the common missense single nucleotide polymorphisms (MAF ≥ 0.1) in fluoropyrimidines (FU) pathway genes (including TP, TS, ENOSF1 and DPD). Three of them were selected and genotyped using Sequenom MassARRAY in 141 GIC patients. TP expression was assessed by immunohistochemistry. Our aim was to evaluate the prognostic significance of studied genes and platelet counts in GIC patients. Multivariate analyses indicated in rs11479-T allele carriers, platelet counts negatively correlated to overall survival. In addition, T allele of TP: rs11479 was associated with higher TP expression in cancer tissues. We suggest TP: rs11479 variant combined with platelet counts may be useful prognostic makers in GIC patients receiving first-line FU chemotherapy and thrombopoietin factor should be used with caution in the rs11479 T allele bearing patients.
Collapse
|
9
|
Jennings BA, Loke YK, Skinner J, Keane M, Chu GS, Turner R, Epurescu D, Barrett A, Willis G. Evaluating predictive pharmacogenetic signatures of adverse events in colorectal cancer patients treated with fluoropyrimidines. PLoS One 2013; 8:e78053. [PMID: 24167597 PMCID: PMC3805522 DOI: 10.1371/journal.pone.0078053] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 09/09/2013] [Indexed: 12/18/2022] Open
Abstract
The potential clinical utility of genetic markers associated with response to fluoropyrimidine treatment in colorectal cancer patients remains controversial despite extensive study. Our aim was to test the clinical validity of both novel and previously identified markers of adverse events in a broad clinical setting. We have conducted an observational pharmacogenetic study of early adverse events in a cohort study of 254 colorectal cancer patients treated with 5-fluorouracil or capecitabine. Sixteen variants of nine key folate (pharmacodynamic) and drug metabolising (pharmacokinetic) enzymes have been analysed as individual markers and/or signatures of markers. We found a significant association between TYMP S471L (rs11479) and early dose modifications and/or severe adverse events (adjusted OR = 2.02 [1.03; 4.00], p = 0.042, adjusted OR = 2.70 [1.23; 5.92], p = 0.01 respectively). There was also a significant association between these phenotypes and a signature of DPYD mutations (Adjusted OR = 3.96 [1.17; 13.33], p = 0.03, adjusted OR = 6.76 [1.99; 22.96], p = 0.002 respectively). We did not identify any significant associations between the individual candidate pharmacodynamic markers and toxicity. If a predictive test for early adverse events analysed the TYMP and DPYD variants as a signature, the sensitivity would be 45.5 %, with a positive predictive value of just 33.9 % and thus poor clinical validity. Most studies to date have been under-powered to consider multiple pharmacokinetic and pharmacodynamic variants simultaneously but this and similar individualised data sets could be pooled in meta-analyses to resolve uncertainties about the potential clinical utility of these markers.
Collapse
Affiliation(s)
- Barbara A. Jennings
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
- * E-mail:
| | - Yoon K. Loke
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Jane Skinner
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Melanie Keane
- Norfolk and Norwich University Hospital, Norwich, United Kingdom
| | - Gavin S. Chu
- Norfolk and Norwich University Hospital, Norwich, United Kingdom
| | - Richard Turner
- Norfolk and Norwich University Hospital, Norwich, United Kingdom
| | - Daniel Epurescu
- Norfolk and Norwich University Hospital, Norwich, United Kingdom
| | - Ann Barrett
- Norfolk and Norwich University Hospital, Norwich, United Kingdom
| | - Gavin Willis
- Norfolk and Norwich University Hospital, Norwich, United Kingdom
| |
Collapse
|