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Therapeutic Advances in Medical Oncology 2021Colorectal cancer (CRC) is one of the most common forms of cancer, with an estimated 1.36 million new cases and almost 700,000 deaths annually. Approximately 21% of... (Review)
Review
Colorectal cancer (CRC) is one of the most common forms of cancer, with an estimated 1.36 million new cases and almost 700,000 deaths annually. Approximately 21% of patients with CRC have metastatic disease at diagnosis. The objective of this article is to review the literature on the efficacy and safety of oral drugs available for the treatment of metastatic colorectal cancer (mCRC). Several such drugs have been developed, and fluoropyrimidines are the backbone of chemotherapy in this indication. They exert their antitumour activity by disrupting the synthesis and function of DNA and RNA. Oral fluoropyrimidines include prodrugs capecitabine, tegafur, eniluracil/5-fluorouracil, tegafur/uracil, tegafur/gimeracil/oteracil and trifluridine/tipiracil (FTD/TPI). Oral drugs offer several advantages over injectable formulations, including convenience, flexibility, avoidance of injection-related adverse events (AEs) and, in some circumstances, lower costs. However, oral drugs may not be suitable for patients with gastrointestinal obstruction or malabsorption, they may result in reduced treatment adherence and should not be co-administered with drugs that interfere with absorption or hepatic metabolism. Oral fluoropyrimidines such as capecitabine, as monotherapy or in combination with oxaliplatin, irinotecan or bevacizumab, are as effective as intravenous 5-fluorouracil (5-FU) in first-line treatment of mCRC. Other oral fluoropyrimidines, such as FTD/TPI, are effective in patients with mCRC who are refractory, intolerant or ineligible for 5-FU. In addition, oral fluoropyrimidines are used in adjuvant treatment of mCRC. Regorafenib is an oral multikinase inhibitor used in patients in whom several previous lines of therapy have failed. Frequent AEs associated with oral drugs used in the treatment of CRC include hand-foot syndrome and gastrointestinal and haematological toxicities.
PubMed: 33995592
DOI: 10.1177/17588359211009001 -
The Cochrane Database of Systematic... Jul 2017Patients prefer oral to intravenous (IV) palliative chemotherapy, provided that oral therapy is not less effective. We compared the efficacy and safety of oral and IV... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Patients prefer oral to intravenous (IV) palliative chemotherapy, provided that oral therapy is not less effective. We compared the efficacy and safety of oral and IV fluoropyrimidines for treatment of colorectal cancer (CRC).
OBJECTIVES
To compare the effects of oral and IV fluoropyrimidine chemotherapy in patients treated with curative or palliative intent for CRC.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5), along with OVID MEDLINE, OVID Embase, and Web of Science databases, in June 2016. We also searched five clinical trials registers, several conference proceedings, and reference lists from study reports and systematic reviews. We contacted pharmaceutical companies to identify additional studies.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) comparing oral and IV fluoropyrimidine chemotherapy in patients treated with curative or palliative intent for CRC.
DATA COLLECTION AND ANALYSIS
Three review authors extracted data and assessed risk of bias independently. We assessed the seven domains in the Cochrane 'Risk of bias' tool and three additional domains: schedules of outcome assessment and/or follow-up; use of intention-to-treat analysis; and baseline comparability of treatment arms.
MAIN RESULTS
We included nine RCTs (total of 10,918 participants) that examined treatment with curative intent for CRC with neoadjuvant and/or adjuvant chemotherapy. We included 35 RCTs (total of 12,592 participants) that examined treatment with palliative intent for inoperable advanced or metastatic CRC with chemotherapy (31 first-line studies, two second-line studies, and two studies of first- or second-line chemotherapy). All studies included male and female participants, and no studies included participants younger than 18 years of age. Patients treated with curative intent for CRC with neoadjuvant and/or adjuvant chemotherapy • Disease-free survival (DFS): DFS did not differ between participants treated with oral versus IV fluoropyrimidines (hazard ratio (HR) 0.93, 95% confidence interval (CI) 0.87 to 1.00; seven studies, 8903 participants; moderate-quality evidence).• Overall survival (OS): OS did not differ between participants treated with oral versus IV fluoropyrimidines (HR 0.92, 95% CI 0.84 to 1.00; seven studies, 8902 participants analysed; high-quality evidence).• Grade ≥ 3 adverse events (AEs): Participants treated with oral fluoropyrimidines experienced less grade ≥ 3 neutropenia/granulocytopenia (odds ratio (OR) 0.14, 95% CI 0.11 to 0.16; seven studies, 8087 participants; moderate-quality evidence), stomatitis (OR 0.21, 95% CI 0.14 to 0.30; five studies, 4212 participants; low-quality evidence), and any grade ≥ 3 AEs (OR 0.82, 95% CI 0.74 to 0.90; five studies, 7741 participants; low-quality evidence). There was more grade ≥ 3 hand foot syndrome (OR 4.59, 95% CI 2.97 to 7.10; five studies, 5731 participants; low-quality evidence) in patients treated with oral fluoropyrimidines. There were no differences between participants treated with oral versus IV fluoropyrimidines in occurrence of grade ≥ 3 diarrhoea (OR 1.12, 95% CI 0.99 to 1.25; nine studies, 9551 participants; very low-quality evidence), febrile neutropenia (OR 0.59, 95% CI 0.18 to 1.90; four studies, 2925 participants; low-quality evidence), vomiting (OR 1.05, 95% CI 0.83 to 1.34; eight studies, 9385 participants; low-quality evidence), nausea (OR 1.21, 95% CI 0.97 to 1.51; seven studies, 9233 participants; low-quality evidence), mucositis (OR 0.64, 95% CI 0.25 to 1.62; four studies, 2233 participants; very low-quality evidence), and hyperbilirubinaemia (OR 1.67, 95% CI 0.52 to 5.38; three studies, 2757 participants; very low-quality evidence). Patients treated with palliative intent for inoperable advanced or metastatic CRC with chemotherapy • Progression-free survival (PFS): Overall, PFS was inferior in participants treated with oral versus IV fluoropyrimidines (HR 1.06, 95% CI 1.02 to 1.11; 23 studies, 9927 participants; moderate-quality evidence). Whilst PFS was worse in participants treated with oral compared with IV fluoropyrimidines when UFT/Ftorafur or eniluracil with oral 5-fluorouracil (5-FU) was used, PFS did not differ between individuals treated with oral versus IV fluoropyrimidines when capecitabine, doxifluridine, or S-1 was used.• OS: Overall, OS did not differ between participants treated with oral versus IV fluoropyrimidines (HR 1.02, 95% CI 0.99 to 1.05; 29 studies, 12,079 participants; high-quality evidence). OS was inferior in participants treated with oral versus IV fluoropyrimidines when eniluracil with oral 5-fluorouracil (5-FU) was used.• Time to progression (TTP): TTP was inferior in participants treated with oral versus IV fluoropyrimidines (HR 1.07, 95% CI 1.01 to 1.14; six studies, 1970 participants; moderate-quality evidence).• Objective response rate (ORR): ORR did not differ between participants treated with oral versus IV fluoropyrimidines (OR 0.98, 95% CI 0.90 to 1.06; 32 studies, 11,115 participants; moderate-quality evidence).• Grade ≥ 3 AEs: Participants treated with oral fluoropyrimidines experienced less grade ≥ 3 neutropenia/granulocytopenia (OR 0.17, 95% CI 0.15 to 0.18; 29 studies, 11,794 participants; low-quality evidence), febrile neutropenia (OR 0.27, 95% CI 0.21 to 0.36; 19 studies, 9407 participants; moderate-quality evidence), stomatitis (OR 0.26, 95% CI 0.20 to 0.33; 21 studies, 8718 participants; low-quality evidence), mucositis (OR 0.17, 95% CI 0.12 to 0.24; 12 studies, 4962 participants; low-quality evidence), and any grade ≥ 3 AEs (OR 0.83, 95% CI 0.74 to 0.94; 14 studies, 5436 participants; low-quality evidence). There was more grade ≥ 3 diarrhoea (OR 1.66, 95% CI 1.50 to 1.84; 30 studies, 11,997 participants; low-quality evidence) and hand foot syndrome (OR 3.92, 95% CI 2.84 to 5.43; 18 studies, 6481 participants; moderate-quality evidence) in the oral fluoropyrimidine arm. There were no differences between oral and IV fluoropyrimidine arms in terms of grade ≥ 3 vomiting (OR 1.18, 95% CI 1.00 to 1.40; 23 studies, 9528 participants; low-quality evidence), nausea (OR 1.16, 95% CI 0.99 to 1.36; 25 studies, 9796 participants; low-quality evidence), and hyperbilirubinaemia (OR 1.62, 95% CI 0.99 to 2.64; nine studies, 2699 participants; low-quality evidence).
AUTHORS' CONCLUSIONS
Results of this review should provide confidence that treatment for CRC with most of the oral fluoropyrimidines commonly used in current clinical practice is similarly efficacious to treatment with IV fluoropyrimidines. Treatment with eniluracil with oral 5-FU was associated with inferior PFS and OS among participants treated with palliative intent for CRC, and eniluracil is no longer being developed. Oral and IV fluoropyrimidines have different patterns of side effects; future research may focus on determining the basis for these differences.
Topics: Administration, Oral; Adult; Antineoplastic Agents; Camptothecin; Capecitabine; Chemotherapy, Adjuvant; Colorectal Neoplasms; Disease-Free Survival; Female; Floxuridine; Fluorouracil; Humans; Injections, Intravenous; Irinotecan; Male; Neoadjuvant Therapy; Organoplatinum Compounds; Palliative Care; Pyridines; Pyrimidines; Randomized Controlled Trials as Topic; Tegafur; Uracil
PubMed: 28752564
DOI: 10.1002/14651858.CD008398.pub2 -
Pharmacogenomics and Personalized... 2020Evolving intensiveness of colorectal cancer (CRC) treatment, including chemotherapeutics and targeted agents associations, in adjuvant and metastatic CRC (MCRC)... (Review)
Review
Evolving intensiveness of colorectal cancer (CRC) treatment, including chemotherapeutics and targeted agents associations, in adjuvant and metastatic CRC (MCRC) settings, increased overall survival (OS) with individual variability of toxicity. Pharmacogenomic guidelines recommended pre-treatment identification of at-risk patients suggesting dose adjustment of fluoropyrimidines based on dihydropyrimidine dehydrogenase (DPYD), and irinotecan on UDP glucuronosyl-transferase 1 family polypeptide A1 (UGT1A1) genetic variants, but they are poorly applied in clinical practice. This review highlighted clinically validated pharmacogenetic markers, to underline the need of their implementation in the multidisciplinary molecular board for individual CRC patients in clinical practice. Five clinically relevant DPYD variants with different prevalence impair enzymatic effectiveness and significantly increase toxicity: c.1236 G>A (c.1129-5923 C>G, HapB3), 4.1-4.8%; c.1679 T>G (DPYD*13), c.1905+1G>A (DPYD*2A), c.2846 A>T, c.2194 A>T (DPYD*6) 1% each. c.1679T>G and c.1905+1G>A are most deleterious on DPD effectiveness, moderately reduced in c.1236/HapB3 and c.2846A>T. Cumulatively, these variants explain approximately half of the estimated 10-15% fluoropyrimidine-related gastrointestinal and hematological toxicities due to DPD. Prevalent UGT1A1 gene [TA]TAA promoter allelic variant UGT1A1*28, characterized by an extra TA repeat, is associated with low transcriptional and reduced enzymatic effectiveness, decreased SN38 active irinotecan metabolite glucuronidation, vs wild-type [A(TA)6TAA]. Homozygote UGT1A1*28 alleles patients are exposed to higher hematological and gastrointestinal toxicities, even more than heterozygote, at >150 mg/m dose. Dose reduction is recommended for homozygote variant. Wild-type alleles patients could tolerate increased doses, potentially affecting favorable outcomes. Implementation of up-front evaluation of the five validated variants and *28 in the multidisciplinary molecular tumor board, also including CRC genetic characterization, addresses potential treatments with fluoropyrimidines and irinotecan associations at proper doses and schedules, particularly for early CRC, MCRC patients fit for intensive regimens or unfit for conventional regimens, requiring treatment modulations, and also for patients who experience severe, unexpected toxicities. Integration of individual evaluation of toxicity syndromes (TS), specifically limiting TS (LTS), an innovative indicator of toxicity burden in individual patients, may be useful to better evaluate relationships between pharmacogenomic analyses with safety profiles and clinical outcomes.
PubMed: 33235483
DOI: 10.2147/PGPM.S253586 -
Cancer Microenvironment : Official... Apr 2016Thymidine phosphorylase (TP) is a nucleoside metabolism enzyme that plays an important role in the pyrimidine pathway.TP catalyzes the conversion of thymidine to thymine... (Review)
Review
Thymidine phosphorylase (TP) is a nucleoside metabolism enzyme that plays an important role in the pyrimidine pathway.TP catalyzes the conversion of thymidine to thymine and 2-deoxy-α-D-ribose-1-phosphate (dRib-1-P). Although this reaction is reversible, the main metabolic function of TP is catabolic. TP is identical to the angiogenic factor platelet-derived endothelial-cell growth factor (PD-ECGF). TP is overexpressed in several human cancers in response to cellular stressful conditions like hypoxia, acidosis, chemotherapy and radiotherapy. TP has been shown to promote tumor angiogenesis, invasion, metastasis, evasion of the immune-response and resistance to apoptosis. Some of the biological effects of TP are dependent on its enzymatic activity, while others are mediated through cytokines like interleukin 10 (IL-10), basic fibroblast growth factor (bFGF) and tumour necrosis factor α (TNFα). Interestingly, TP also plays a role in cancer treatment through its role in the conversion of the oral fluoropyrimidine capecitabine into its active form 5-FU. TP is a predictive marker for fluoropyrimidine response. Given its various biological functions in cancer progression, TP is a promising target in cancer treatment. Further translational research is required in this area.
PubMed: 26298314
DOI: 10.1007/s12307-015-0173-y -
PloS One 2023Fluoropyrimidine-based regimens have been investigated as the second line chemotherapy in patients with advanced pancreatic cancer refractory to gemcitabine. We... (Meta-Analysis)
Meta-Analysis
Fluoropyrimidine combination therapy versus fluoropyrimidine monotherapy for gemcitabine-refractory advanced pancreatic cancer: A systematic review and meta-analysis of randomized controlled trials.
OBJECTIVES
Fluoropyrimidine-based regimens have been investigated as the second line chemotherapy in patients with advanced pancreatic cancer refractory to gemcitabine. We conducted this systematic review and meta-analysis to evaluate the efficacy and safety profile of fluoropyrimidine combination therapy versus fluoropyrimidine monotherapy in such patients.
METHODS
The databases of MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, ASCO Abstracts and ESMO Abstracts were systematically searched. Randomized controlled trials (RCTs) that compared fluoropyrimidine combination therapy versus fluoropyrimidine monotherapy in patients with gemcitabine-refractory advanced pancreatic cancer were included. The primary outcome was overall survival (OS). Secondary outcomes included progression-free survival (PFS), overall response rate (ORR) and serious toxicities. Statistical analyses were performed by using Review Manager 5.3. Egger's test was performed to assess the statistical evidence of publication bias by using stata 12.0.
RESULTS
A total of 1183 patients from six randomized controlled trials were included for this analysis. Fluoropyrimidine combination therapy increased ORR [RR 2.82 (1.83-4.33), p<0.00001] and PFS [HR 0.71 (0.62-0.82), p<0.00001], without significant heterogeneity. Fluoropyrimidine combination therapy improved OS [HR 0.82 (0.71-0.94), p = 0.006], with significant heterogeneity (I2 = 76%, p = 0.0009). The significant heterogeneity might have been caused by the different administration regimens and baseline characteristics. Peripheral neuropathy and diarrhea were more common in the regimens containing oxaliplatin and irinotecan, respectively. No publication bias was detected by Egger's tests.
CONCLUSIONS
Compared with fluoropyrimidine monotherapy, fluoropyrimidine combination therapy had a higher response rate and longer PFS in patients with gemcitabine-refractory advanced pancreatic cancer. Fluoropyrimidine combination therapy could be recommended in the second line setting. However, due to concerns about toxicities, the dose intensities of chemotherapy drugs should be carefully considered in patients with weakness.
Topics: Humans; Gemcitabine; Randomized Controlled Trials as Topic; Antimetabolites; Pancreatic Neoplasms
PubMed: 36862702
DOI: 10.1371/journal.pone.0282360 -
International Journal of Molecular... Apr 2015Fluoropyrimidines, the mainstay agents for the treatment of colorectal cancer, alone or as a part of combination therapies, cause severe adverse reactions in about... (Review)
Review
Fluoropyrimidines, the mainstay agents for the treatment of colorectal cancer, alone or as a part of combination therapies, cause severe adverse reactions in about 10%-30% of patients. Dihydropyrimidine dehydrogenase (DPD), a key enzyme in the catabolism of 5-fluorouracil, has been intensively investigated in relation to fluoropyrimidine toxicity, and several DPD gene (DPYD) polymorphisms are associated with decreased enzyme activity and increased risk of fluoropyrimidine-related toxicity. In patients carrying non-functional DPYD variants (c.1905+1G>A, c.1679T>G, c.2846A>T), fluoropyrimidines should be avoided or reduced according to the patients' homozygous or heterozygous status, respectively. For other common DPYD variants (c.496A>G, c.1129-5923C>G, c.1896T>C), conflicting data are reported and their use in clinical practice still needs to be validated. The high frequency of DPYD polymorphism and the lack of large prospective trials may explain differences in studies' results. The epigenetic regulation of DPD expression has been recently investigated to explain the variable activity of the enzyme. DPYD promoter methylation and its regulation by microRNAs may affect the toxicity risk of fluoropyrimidines. The studies we reviewed indicate that pharmacogenetic testing is promising to direct personalised dosing of fluoropyrimidines, although further investigations are needed to establish the role of DPD in severe toxicity in patients treated for colorectal cancer.
Topics: Animals; Antimetabolites, Antineoplastic; Colorectal Neoplasms; Dihydrouracil Dehydrogenase (NADP); Epigenesis, Genetic; Fluorouracil; Gene Frequency; Humans; Polymorphism, Single Nucleotide
PubMed: 25906475
DOI: 10.3390/ijms16048884 -
Journal of Gastrointestinal Oncology Aug 2015Contemporary adjuvant therapy for pancreatic cancer patients following surgical resection includes chemotherapy and chemoradiotherapy. However, the median survival... (Review)
Review
Contemporary adjuvant therapy for pancreatic cancer patients following surgical resection includes chemotherapy and chemoradiotherapy. However, the median survival remains approximately 20 months despite multi-modality treatment using gemcitabine or fluoropyrimidine systemic chemotherapy. Adjuvant randomized trials are currently underway to evaluate cytotoxic combinations found to be active in advanced disease including FOLFIRINOX, gemcitabine/nab-paclitaxel and gemcitabine/capecitabine. Immunotherapy using genetically engineered cell-based vaccines had shown promise in resected pancreatic cancer patients during early phase trials, and algenpantucel-L vaccine is currently being evaluated in adjuvant setting in a randomized trial. This review focuses on novel adjuvant therapies currently in clinical evaluation.
PubMed: 26261729
DOI: 10.3978/j.issn.2078-6891.2015.031 -
The Cochrane Database of Systematic... Oct 2015Colorectal cancer represents 10% of all cancers and is the third most common cause of death in women and men. Almost two-thirds of all bowel cancers are cancers of the... (Review)
Review
BACKGROUND
Colorectal cancer represents 10% of all cancers and is the third most common cause of death in women and men. Almost two-thirds of all bowel cancers are cancers of the colon and over one-third (34%) are cancers of the rectum, including the anus. Surgery is the cornerstone for curative treatment of rectal cancer. Mesorectal excision decreases the rate of local recurrences; however, it does not improve the overall survival of people with locally advanced rectal cancer. There have been significant research efforts since the mid-1990s to optimise the treatment of rectal cancer. Based on the findings of clinical trials, people with T3/T4 or N+ rectal tumours are now being treated preoperatively with radiation and chemotherapy, mainly fluoropyrimidine. However, the incidence of distant metastases remains as high as 30%. Combination chemotherapy regimens, similar to those used in metastatic disease with the addition of oxaliplatin and irinotecan, have been tested to improve the prognosis of people with rectal cancer.
OBJECTIVES
To compare outcomes (including overall survival, disease-free survival and toxicity) between two 5-fluorouracil-containing chemotherapy regimens in people with stage II and III rectal cancer who are receiving preoperative chemoradiation.
SEARCH METHODS
We searched the Cochrane Colorectal Cancer Group Specialised Register (January 2015), the Cochrane Central Register of Controlled Trials (2015, Issue 1), Ovid MEDLINE (1950 to January 2015), Ovid EMBASE (1974 to January 2015) and LILACS (1982 to January 2015). We reviewed the reference lists of included studies, checked clinical trials registers and handsearched relevant journal proceedings. We applied no language or publication restrictions.
SELECTION CRITERIA
Randomised controlled trials (RCTs) comparing single-agent chemotherapy (fluoropyrimidine) versus combination chemotherapy (fluoropyrimidine plus another agent including, but not limited to, oxaliplatin) during preoperative radiochemotherapy in people with resectable rectal cancer.
DATA COLLECTION AND ANALYSIS
Two review authors (HMR, EMKS) independently extracted data and assessed trial quality. When necessary, we requested additional information and clarification of published data from the authors of individual trials.
MAIN RESULTS
We included four RCTs involving 3875 people with resectable rectal cancer. In the preoperative period, the participants of these studies were randomised to receive chemoradiation either with a single fluoropyrimidine agent (capecitabine or 5-fluorouracil) or with a combination of drugs (fluoropyrimidine plus oxaliplatin). The only study that reported overall survival and disease-free survival found no significant differences between the intervention and control groups; we considered this evidence very low quality. For pathological complete response after preoperative treatment (ypCR) there was high quality evidence favouring the intervention group (odds ratio (OR) 1.23, 95% confidence interval (CI) 1.04 to 1.46), but there was also moderate quality evidence suggesting a higher risk for early toxicity in the intervention group (OR 2.07, 95% CI 1.31 to 3.27). Moderate to high quality evidence suggested that the control group had better compliance to radiotherapy (OR 0.32, 95% CI 0.14 to 0.75). There were no significant differences between groups in postoperative mortality within 60 days, postoperative morbidity, resection margins, abdominoperineal resection and Hartmann procedures.
AUTHORS' CONCLUSIONS
There was very low quality evidence that people with resectable rectal cancer who receive combination preoperative chemotherapy have no improvements in overall survival or disease-free survival. There was high quality evidence that suggested that combination chemotherapy with oxaliplatin may improve local tumour control in people with resectable rectal cancer, but this regimen also caused more toxicity. The review included four RCTs but only one reported survival; therefore, we cannot make robust conclusions or useful clinical recommendations. The publication of more survival data from these studies will contribute to future analyses.
PubMed: 35658163
DOI: 10.1002/14651858.CD008531.pub2 -
Oncology (Williston Park, N.Y.) Oct 2000Over the past decade, increasing data have emphasized both the importance of dihydropyrimidine dehydrogenase (DPD), the initial, rate-limiting enzyme in the catabolism... (Review)
Review
Over the past decade, increasing data have emphasized both the importance of dihydropyrimidine dehydrogenase (DPD), the initial, rate-limiting enzyme in the catabolism of fluorouracil (5-FU), and its role as a control step in 5-FU metabolism, regulating the availability of 5-FU for anabolism. It is now clear that DPD also accounts for much of the variability observed with therapeutic use of 5-FU, including variabilities in 5-FU levels over a 24-hour infusion, interindividual pharmacokinetics, bioavailability, toxicity, and drug response (resistance). This variability makes effective dosing of 5-FU and related drugs difficult. In order to lessen this variability, and potentially improve 5-FU pharmacology, the pharmaceutical industry has made an effort to develop DPD inhibitors to modulate 5-FU metabolism, which has resulted in the creation of a new subclass of orally administered fluoropyrimidines, known as DPD-inhibiting fluoropyrimidines (DIF). Four drugs--uracil and tegafur (UFT) or the combination of UFT and leucovorin, ethynyluracil (eniluracil), S-1, and BOF-A2--have recently undergone clinical evaluation in the United States. The biochemical basis for using these drugs is reviewed.
Topics: Administration, Oral; Antimetabolites, Antineoplastic; Antineoplastic Combined Chemotherapy Protocols; Biological Availability; Dihydrouracil Dehydrogenase (NADP); Drug Combinations; Drug Resistance, Neoplasm; Fluorouracil; Humans; Leucovorin; Oxidoreductases; Oxonic Acid; Pyridines; Tegafur; Uracil
PubMed: 11098485
DOI: No ID Found -
Frontiers in Pharmacology 2023Fluoropyrimidines are chemotherapeutic agents widely used for the treatment of various solid tumors. Commonly prescribed FPs include 5-fluorouracil (5-FU) and its oral... (Review)
Review
Fluoropyrimidines are chemotherapeutic agents widely used for the treatment of various solid tumors. Commonly prescribed FPs include 5-fluorouracil (5-FU) and its oral prodrugs capecitabine (CAP) and tegafur. Bioconversion of 5-FU prodrugs to 5-FU and subsequent metabolic activation of 5-FU are required for the formation of fluorodeoxyuridine triphosphate (FdUTP) and fluorouridine triphosphate, the active nucleotides through which 5-FU exerts its antimetabolite actions. A significant proportion of FP-treated patients develop severe or life-threatening, even fatal, toxicity. It is well known that FP-induced toxicity is governed by genetic factors, with dihydropyrimidine dehydrogenase (), the rate limiting enzyme in 5-FU catabolism, being currently the cornerstone of FP pharmacogenomics. -based dosing guidelines exist to guide FP chemotherapy suggesting significant dose reductions in defective patients. Accumulated evidence shows that additional variations in other genes implicated in FP pharmacokinetics and pharmacodynamics increase risk for FP toxicity, therefore taking into account more gene variations in FP dosing guidelines holds promise to improve FP pharmacotherapy. In this review we describe the current knowledge on pharmacogenomics of FP-related genes, beyond , focusing on FP toxicity risk and genetic effects on FP dose reductions. We propose that in the future, FP dosing guidelines may be expanded to include a broader ethnicity-based genetic panel as well as gene*gene and gender*gene interactions towards safer FP prescription.
PubMed: 37256234
DOI: 10.3389/fphar.2023.1184523