The relationship between UGT1A1 gene polymorphism and irinotecan effect on extensive-stage small-cell lung cancer

Association of UGT1A1*6, UGT1A1*28, or ABCC2 c.3972C>T genetic polymorphisms with irinotecan-induced toxicity in Asian cancer patients: Meta-analysis

Effects of UGT1A1*6 and UGT1A1*28 genetic polymorphisms on irinotecan-induced severe toxicities in Asian cancer patients are inconclusive. Also, ABCC2 c.3972C>T may affect toxicity of irinotecan. The aim was to assess the aggregated risk of neutropenia or diarrhea in Asian cancer patients taking irinotecan and inherited UGT1A1*6, UGT1A1*28, or ABCC2 c.3972C>T genetic variants. A PubMed literature search for eligible studies was conducted. Odds ratios (ORs) were measured using RevMan software where p values <0.05 were statistically significant. Patients that inherited both UGT1A1*6 and UGT1A1*28 genetic variants (heterozygous: UGT1A1*1/*6 + *1/*28 and homozygous: UGT1A1*6/*6 + *28/*28) were significantly associated with increased risk of neutropenia and diarrhea compared to patients with UGT1A1*1/*1 (neutropenia: OR 2.89; 95% CI 1.97-4.23; p < 0.00001; diarrhea: OR 2.26; 95% CI 1.71-2.99; p < 0.00001). Patients carrying homozygous variants had much stronger effects in developing toxicities (neutropenia: OR 6.23; 95% CI 3.11-12.47; p < 0.00001; diarrhea: OR 3.21; 95% CI 2.13-4.85; p < 0.00001) than those with heterozygous variants. However, patients carrying the ABCC2 c.3972C>T genetic variant were not significantly associated with neutropenia (OR 1.67; 95% CI 0.98-2.84; p = 0.06) and were significantly associated with a reduction in irinotecan-induced diarrhea (OR 0.31; 95% CI 0.11-0.81; p = 0.02). Asian cancer patients should undergo screening for both UGT1A1*6 and UGT1A1*28 genetic variants to reduce substantially irinotecan-induced severe toxicities.

UGT1A1 Gene Polymorphisms in Patients with Small Cell Lung Cancer Treated with Irinotecan-Platinum Doublet Chemotherapy and Their Association with Gastrointestinal Toxicity and Overall Survival

BACKGROUND

Irinotecan (CPT11) is an important drug for small cell lung cancer (SCLC) chemotherapy (CTx). UDP-glucuronosyltransferase 1A1 (UGT1A1) polymorphisms can influence CPT11-related toxicity. This study aimed to assess prevalence of UGT1A1 polymorphisms and their association with clinical outcomes in patients with SCLC on CPT11-CTx.

METHODS

An observational cohort of treatment-naïve patients with SCLC was given CPT11-platinum doublet at a referral center in North India over 3 years. Clinical outcomes assessed were hematological and gastrointestinal toxicity (Common Terminology Criteria for Adverse Events, version 3.0), response rates (RECIST), and overall survival (OS). Peripheral blood was drawn from all enrolled patients just prior to CPT11-CTx initiation, and genomic DNA was isolated. Genotyping was done by polymerase chain reaction (PCR)-restriction fragment length polymorphism for UGT1A1*7, UGT1A1*6, and UGT1A1*27 and by PCR-DNA sequencing for UGT1A1*28. Patients were classified as homozygous wild-type (WT/WT), heterozygous mutant (WT/M), or homozygous mutant (M/M) for each polymorphism assessed.

RESULTS

Of 140 patients enrolled, no mutant alleles were found for UGT1A1*27 or UGT1A1*7. Frequency of UGT1A1*6 polymorphisms (n = 111) was 89.2% for WT/WT, 8.1% for WT/M, and 2.7% for M/M. For UGT1A1*28 (n = 102), this was 41.2% for WT/WT, 43.1% for WT/M, and 15.7% for M/M. UGT1A1*6 WT/WT patients tolerated >95% predicted CPT11 dose more frequently (59.6% vs. 25.0% in WT/M-M/M combined group; p = .026). The UGT1A1*6 WT/M-M/M group also experienced severe (grade ≥3) diarrhea (41.7% vs. 17.2% in WT/WT; p = .044) and mucositis (41.7% vs. 8.1% in WT/WT; p = .005) more frequently. On multivariate logistic regression analysis, UGT1A1*6 WT/M-M/M status was the only variable associated with occurrence of both mucositis (odds ratio [OR], 10.4) and severe diarrhea (OR, 4.8). UGT1A1*28 WT/M-M/M patients had better OS (320 days [95% confidence interval, 203-437] vs. 216 days [95% confidence interval, 140-292] in WT/WT group; p = .047). On multivariate Cox proportional hazards analysis, UGT1A1*28 WT/M-M/M status was independently associated with better OS (hazard ratio, 0.35), whereas lack of objective radiological response, moderate/heavy smoking, and increasing age were associated with worse OS.

CONCLUSION

UGT1A1*6 and UGT1A1*28 polymorphisms were associated with increased gastrointestinal toxicity and improved OS, respectively, in North Indian patients with SCLC receiving CPT11-CTx.

IMPLICATIONS FOR PRACTICE

UGT1A1 gene polymorphisms are known to influence irinotecan-related toxicity. In this prospective cohort study of patients with small cell lung cancer receiving first-line irinotecan-platinum chemotherapy, the prevalence of UGT1A1*6 polymorphisms was found to be 10.8% UGT1A1*6 and 58.8% UGT1A1*28 homo/heterozygous mutant, respectively. UGT1A1*6 homo/heterozygous mutant status was associated with severe diarrhea and mucositis. UGT1A1*28 homo/heterozygous mutant status was independently associated with improved overall survival.

In vitro inhibition of human UDP-glucuronosyltransferase (UGT) 1A1 by osimertinib, and prediction of in vivo drug-drug interactions

Osimertinib is the only third-generation epidermal growth factor receptor tyrosine-kinase inhibitor (EGFR-TKI) approved by Food and Drug Administration (FDA). This study aimed to know the inhibitory effect of osimertinib on human UDP-glucosyltransferases (UGTs) and human liver microsomes (HLMs), as well as to identify its potential to cause drug-drug interaction (DDI) arising from the modulation of UGT activity. High inhibitory effect of osimertinib was shown towards UGT1A1, 1A3, 1A6, 1A7, 1A8, 1A10, 2B7 and 2B15. Especially, osimertinib exhibited competitive inhibition against UGT1A1 with a K_i,u of 0.87 ± 0.12 μM. It also noncompetitively inhibited SN-38 glucuronidation in pooled HLMs with a K_i,u of 3.32 ± 0.25 μM. Results from quantitative prediction study indicated that osimertinib administered at 80 mg/day may result in a 4.83 % increase in the AUC of drugs mainly metabolized by UGT1A1, implying low risk of DDI via liver metabolism. However, the ratios of [I]_gut/K_i,u are much higher than 11 in HLMs and recombinant UGT1A1, indicating a risk for interaction in intestine. The effects of osimertinib on intestinal UGT should be paid more attention on to avoid unnecessary clinical DDI risks.

Treatment Outcomes of 9,994 Patients With Extensive-Disease Small-Cell Lung Cancer From a Retrospective Nationwide Population-Based Cohort in the Korean HIRA Database

To investigate the efficacy of irinotecan-based (IP) and etoposide-based (EP) platinum combinations, and of single-agent chemotherapy, for treatment of extensive-disease small cell lung cancer (ED-SCLC), we performed a large-scale, retrospective, nationwide, cohort study. The population data were extracted from the Health Insurance Review and Assessment Service of Korea database from January 1, 2008, to November 30, 2016. A total of 9,994 patients were allocated to ED-SCLC and analyzed in this study. The primary objectives were to evaluate the survival outcomes of systemic first-line treatments for ED-SCLC. For first-line treatment, patients who received IP showed a better time to first subsequent therapy (TFST) of 8.9 months (95% confidence interval [CI], 8.50–9.40) than those who received EP, who had a TFST of 6.8 months (95% CI, 6.77–6.97, P < 0.0001). In terms of overall survival (OS), IP was superior to EP (median OS, 10.8 months; 95% CI, 10.13–11.33 vs. 9.5 months; 95% CI, 9.33–9.73; P < 0.0001). Taken together, in the Korean population, first-line IP combination chemotherapy had significantly favorable effects on OS and TFST.

Gilbert's Syndrome, Bilirubin Level and UGT1A1∗28 Genotype in Men of North-West Region of Russia

BACKGROUND/OBJECTIVES

Gilbert's syndrome (GS) is a hereditary pathology that affects approximately 10% of the world's population. In most cases, GS is associated with the UGT1A1∗28 polymorphism of UGT1A1 gene coding the enzyme bilirubin uridine diphosphate glucuronosyltransferase (UGT-1A) which plays a key role in the bilirubin metabolism. The presence of an additional TA repeat in the TATA box of the UGT1A1 gene promoter (the allelic variant of 7TA, abbreviated as UGT1A1∗28) leads to a significant decrease in the enzymatic activity of UGT-1A in the liver and to decrease in glucuronidation process as a consequence. The aim of the study is to estimate the prevalence of the 6TA/6TA, 6TA/7TA, and 7TA/7TA genotypes of UGT1A1 promoter and to analyze the effect of these variants on bilirubin levels in healthy men in North-West Russia and patients with a clinical diagnosis of GS.

METHODS

Genotyping of the UGT1A1 ∗28 (rs8175347) polymorphism was carried out by real-time PCR.

RESULTS

The results obtained indicate an increased probability of GS developing in residents of the North-West region of Russia compared with other representatives of the Caucasians.

CONCLUSIONS

Despite the fact that the level of serum bilirubin increases with the rise in the number of additional TA dinucleotides in the UGT1A1 gene promoter tests of clinical manifestations only (jaundice, fatigue, sleep disturbances, nausea, belching, and so on) and increased bilirubin levels in patients with normal liver function do not allow unequivocally diagnose GS. UGT1A1∗28 genotyping should be used as a prognostic risk factor for such pathology development.

Efficacy and safety of Shengjiang Xiexin decoction in prophylaxis of chemotherapy-related diarrhea in small cell lung cancer patients: study protocol for a multicenter randomized controlled trial

Background

Diarrhea is a common adverse reaction in patients with cancer receiving chemotherapy, for which there is currently no effective method of treatment. Shengjiang Xiexin decoction (SXD), a classic traditional Chinese medicine (TCM) formula, has shown efficacy in alleviating irinotecan-induced diarrhea in preliminary clinical studies. The current study is designed to assess the efficacy and safety of SXD for prophylaxis against irinotecan-induced diarrhea. Additionally, we employ a new approach to analyze and evaluate the data based on the patients’ uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) genotype, which predicts the risk of diarrhea.

Methods and design

A prospective, double-blind, randomized, placebo-controlled trial will be conducted in patients with small cell lung cancer (SCLC) from five hospitals in China. For this study, 100 irinotecan-naïve patients will be randomly allocated to either the SXD or placebo arms in a 1:1 ratio. Stratified randomization will be used to divide subjects by UGT1A1 genotype into groups with differing risk of diarrhea. The trial will consist of two cycles of chemotherapy with 14 days of oral administration of SXD or placebo administered beginning between 3 days before and up to 11 days after initiation of each chemotherapy cycle. The primary study outcome is the incidence of diarrhea. Secondary outcomes include the degree of diarrhea, the degree of neutropenia, the rate of alterations in chemotherapy regimens, the amount of antidiarrheal drug taken, the rate of hospitalization, and evaluation of chemotherapy efficacy.

Discussion

This study is the first to use the UGT1A1 genotype to stratify patients into groups based on their risk of diarrhea, and to provide a complete assessment of chemotherapy-related diarrhea (CRD), including records of diarrhea duration, grading the severity of diarrhea, and evaluating concomitant symptoms. Study results will provide high-level clinical evidence on the use of SXD as prophylaxis for CRD.

Trial registration

Chinese Clinical Trial Register: ChiCTR1800018490. Registered on 20 September 2018. Retrospectively registered. http://www.chictr.org.cn/edit.aspx?pid=25250&htm=4c

Jiawei Xianglian Decoction (JWXLD), a Traditional Chinese Medicine (TCM), Alleviates CPT-11-Induced Diarrhea in Mice

Irinotecan (CPT-11) is used for therapy of various cancers. However, it has several serious adverse reactions such as diarrhea which is caused by SN-38, the active form of CPT-11. This study aimed to evaluate the effectiveness of Jiawei xianglian decoction (JWXLD), which has been widely used for the treatment of diarrhea in China. In this study, a mouse model with delayed diarrhea was generated by CPT-11. Real-time PCR and enzyme-linked immunosorbent assay (ELISA) were performed to explore intestinal microflora and inflammatory cytokine. Hematoxylin and eosin (H&E) staining was used to analyze tissue morphology. We found that 0.12, 0.23, and 0.46 g JWXLD significantly reduced the severity of CPT-11-induced diarrhea. The levels of Lactobacillus (Lacto) and Bifidobacterium (Bifid) were significantly downregulated by CPT-11, and these effects can be reversed by JWXLD treatment. Furthermore, JWXLD was observed to decrease the activity of β-glucuronidase (β-GD). Histopathological data showed that CPT-11 induced severe intestinal mucosal injury, which was characterized as grade 6, and JWXLD significantly alleviated the injury. In addition, CPT-11 increased the productions of tumor necrosis factor-alpha (TNF-α), tumor necrosis factor-beta (TNF-β), interleukin-6 (IL-6), and interleukin-1 (IL-1), but decreased interleukin-15 (IL-15), interleukin-7 (IL-7), and uridine diphosphate-glucuronosyltransferase 1A1 (UGT1A1). In conclusion, JWXLD can counteract these effects caused by CPT-11 treatment. JWXLD could alleviate CPT-11-induced diarrhea.

Pharmacokinetic and Pharmacogenetic Markers of Irinotecan Toxicity

BACKGROUND

Irinotecan (IRI) is a widely used chemotherapeutic drug, mostly used for first-line treatment of colorectal and pancreatic cancer. IRI doses are usually established based on patient's body surface area, an approach associated with large inter-individual variability in drug exposure and high incidence of severe toxicity. Toxic and therapeutic effects of IRI are also due to its active metabolite SN-38, reported to be up to 100 times more cytotoxic than IRI. SN-38 is detoxified by the formation of SN-38 glucuronide, through UGT1A1. Genetic polymorphisms in the UGT1A1 gene are associated to higher exposures to SN-38 and severe toxicity. Pharmacokinetic models to describe IRI and SN-38 kinetic profiles are available, with few studies exploring pharmacokinetic and pharmacogenetic-based dose individualization. The aim of this manuscript is to review the available evidence supporting pharmacogenetic and pharmacokinetic dose individualization of IRI in order to reduce the occurrence of severe toxicity during cancer treatment.

METHODS

The PubMed database was searched, considering papers published in the period from 1995-2017, using the keywords irinotecan, pharmacogenetics, metabolic genotyping, dose individualization, therapeutic drug monitoring, pharmacokinetics and pharmacodynamics, either alone or in combination, with original papers being selected based on the presence of relevant data.

CONCLUSION

The findings of this review confirm the importance of considering individual patient characteristics to select IRI doses. Currently, the most straightforward approach for IRI dose individualization is UGT1A1 genotyping. However, this strategy is sub-optimal due to several other genetic and environmental contributions to the variable pharmacokinetics of IRI and its active metabolite. The use of dried blood spot sampling could allow the clinical application of limited sampling and population pharmacokinetic models for IRI doses individualization.

Effects of UGT1A1, CYP3A5 and ABCB1 Genetic Variants on Pharmacokinetics of Antihistamine Drug Mizolastine in Chinese Healthy Volunteers

Mizolastine is a selective histamine H1 receptor antagonist for chronic urticaria or allergic rhinitis. We investigated whether the variant genotypes of metabolic enzymes UGT1A1, CYP3A5 and transporter ABCB1 influence pharmacokinetic phenotype of substrate mizolastine in Chinese volunteers. Genotyping of single nucleotide polymorphisms in UGT1A1*6 (G211A), CYP3A5*3 (A6986G) and ABCB1 (C3435T) was determined by the pyrosequencing method. After a single oral dose of 10 mg mizolastine, the plasma concentrations were measured using validated high-performance liquid chromatography in 24 Chinese healthy volunteers. The results showed that the distributions of wild-type homozygotes and variant allele carriers (the sum of variant heterozygotes and variant homozygotes) were as follows: 17 cases (70.8%) versus seven cases (29.2%) in UGT1A1*6 genotypes, five cases (20.8%) versus 19 cases (79.2%) in CYP3A5*3 genotypes and seven cases (29.2%) versus 17 cases (70.8%) in ABCB1 3435T genotypes, respectively. There were no significant differences in pharmacokinetic parameters of mizolastine between the variant allele UGT1A1*6, CYP3A5*3 and ABCB1 3435T carriers and the wild-type homozygotes, and the ratios were as follows: C_max was 101.03%, 86.02% and 105.78%; T_max was 162.35%, 98.98% and 144.90%; AUC_0-28 was 113.04%, 77.35% and 112.71%; and t_1/2 was 95.77%, 72.40% and 100.97%, respectively. In conclusion, these results suggested that the UGT1A1, CYP3A5 and ABCB1 genetic polymorphisms might be not contributed to the interindividual variation of mizolastine pharmacokinetic phenotype in the Chinese population.

Banxia Xiexin Decoction Is Effective to Prevent and Control Irinotecan-Induced Delayed Diarrhea in Recurrent Small Cell Lung Cancer

Background: Irinotecan (CPT-11) can be used as a first-line therapeutic drug against extensive-stage small cell lung cancer (SCLC); it can also be used in second-line treatment for SCLC. CPT-11-induced delayed diarrhea restricts its clinical application. This study aimed to confirm whether Banxia Xiexin decoction was effective in preventing and controlling CPT-11-induced delayed diarrhea. Methods: A total of 27 patients with recurrent SCLC undergoing chemotherapy regimens including CPT-11 were enrolled for the study. UGT1A1*28, UGTlAl*6, ABCB1*2, and SLCO1B1*15 gene polymorphisms were detected. If delayed diarrhea occurred in the first cycle of chemotherapy, Banxia Xiexin decoction was orally administered for 5 consecutive days starting 1 day before the second cycle of chemotherapy to prevent and control the delayed diarrhea. The objective response, overall survival, and toxicity were recorded. Results: Complete response, partial response, and stable disease were observed in none, 6, and 10 patients, respectively. Delayed diarrhea occurred in 6 patients, and 4 of 5 patients were relieved or controlled using Banxia Xiexin decoction. The median overall survival was 6 months. Conclusion: Banxia Xiexin decoction appeared to prevent and control delayed diarrhea induced by CPT-11 in this small observational study, and further study with a larger sample size, including potentially randomized trials, is suggested.

Genetic Association of Drug Response to Erlotinib in Chinese Advanced Non-small Cell Lung Cancer Patients

The efficacy of erlotinib treatment for advanced non-small cell lung cancer (NSCLC) is due to its action as an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). Patients treated with erlotinib experience different drug responses. The effect of germline mutations on therapeutic responses and adverse drug responses (ADRs) to erlotinib in Chinese patients requires elucidation. Sixty Han Chinese advanced non-small cell lung cancer patients received erlotinib monotherapy and, for each participant, 76 candidate genes (related to EGFR signaling, drug metabolism and drug transport pathways) were sequenced and analyzed. The single-nucleotide polymorphisms (SNPs) rs1042640 in UGT1A10, rs1060463, and rs1064796 in CYP4F11, and rs2074900 in CYP4F2 were significantly associated with therapeutic responses to erlotinib. Rs1064796 in CYP4F11 and rs10045685 in UGT3A1 were significantly associated with adverse drug reaction. Moreover, analysis of a validation cohort confirmed the significant association between rs10045685 in UGT3A1 and erlotinib adverse drug response(unadjusted p = 0.015). This study provides comprehensive, systematic analyses of genetic variants associated with responses to erlotinib in Chinese advanced non-small cell lung cancer patients. Newly-identified SNPs may serve as promising markers to predict responses and safety in erlotinib-treated advanced non-small cell lung cancer patients after chemotherapy doublet.

Relationship between UGT1A1*6/*28 gene polymorphisms and the efficacy and toxicity of irinotecan-based chemotherapy

Purpose

A retrospective study was performed to analyze the relationship between uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) *6/*28 gene polymorphisms and adverse reactions associated with irinotecan (CPT-11)-based chemotherapy. The correlation between UGT1A1 polymorphisms and the clinical efficacy of CPT-11 was also analyzed, along with the influence of age and tumor type.

Patients and methods

Patients administered a CPT-11-based regimen in the Beijing Cancer Hospital from April 2015 to September 2016 were included in our study (n=81). Blood samples for detecting UGT1A1 were collected from each patient after various administration regimens.

Results

Colorectal cancer patients with the UGT1A1*6 mutant genotype had a significantly higher risk of severe delayed diarrhea than that of wild-type individuals when administered a CPT-11 dose ≥130 mg/m² (P=0.042); the same phenomenon was observed when the UGT1A1*6 and UGT1A1*28 mutant genotypes were considered together (P=0.028). However, in lung cancer patients administered a low dose of CPT-11, UGT1A1*6/*28 variants were not significantly associated with severe neutropenia or delayed diarrhea. Furthermore, adult patients with the UGT1A1*6 mutation were more likely to develop severe delayed diarrhea than did wild-type adults (P=0.013); however, the difference was not significant in elderly patients. No significant differences in tumor response were found among the different genotypes (P>0.05).

Conclusion

Thus, age and tumor type influence our ability to predict adverse reactions based on UGT1A1 gene polymorphisms in cancer patients. Further, UGT1A1 gene polymorphisms are not correlated with the efficacy of CPT-11-based regimens.

UGT1A1*6 polymorphisms are correlated with irinotecan-induced neutropenia: a systematic review and meta-analysis

Irinotecan (IRI) chemotherapy toxicities can be severe, and may result in treatment delay, morbidity and in some rare cases death. Neutropenia is a life-threatening side effect of irinotecan, and UDP glucuronosyltransferases (UGTs) gene polymorphisms could predict the side effects in cancer patients and then reduce IRI-induced toxicity by preventative treatment or a decrease in dose. Both UGT1A1*6 and *28 were reliably demonstrated to be risk factors for IRI-induced neutropenia, with tests for both polymorphisms potentially being particularly useful in Asian cancer patients. However, some researchers reported that UGT1A1*6 could predict IRI-induced toxicities in Asian populations, controversial conclusions still remained. Thus, the association between UGT1A1*6 polymorphisms and IRI-induced severe toxicity in cancer patients is still needed to be explored. Therefore, this study aims to investigate the association between UGT1A1*6 polymorphisms and IRI-related severe neutropenia in cancer patients on a large scale. A total of 12 studies that included 746 wild genotype (G/G) cases and 394 variant genotype (G/A and A/A) cases were included on the basis of inclusion criteria. Then we assessed the methodologies quality; odds ratio (OR), risk difference (RD) and 95% confidence intervals (95% CI) were used to assess the strength of association. Overall, an increased risk of severe neutropenia in cancer patients with UGT1A1*6 polymorphisms was found. Patients with recessive models (GA + AA vs. GG) of UGT1A1*6 showed an increased risk (OR 2.03, 95% CI 1.54-2.68; RD = 0.11, P < 0.001). Specifically, the heterozygous variant of UGT1A1*6 showed an increased risk (OR 1.83, 95% CI 1.36-2.46; RD = 0.09, P < 0.001), and homozygous mutation showed also high risk (OR 2.95, 95% CI 1.83-4.75; RD = 0.18, P < 0.001) for severe neutropenia. Subgroup meta-analysis revealed that for patients harboring both heterozygous and homozygous variants, cancer types, low dose of IRI and the duration of treatment also presented comparably increased risk in suffering severe neutropenia. As for country, in China and Japan, there was a statistically increased severe neutropenia with variant genotype of UGT1A1*6 (China: GA + AA vs. GG, OR 1.83, 95% CI 1.28-2.59; RD = 0.08, P = 0.001; Japan: GA + AA vs. GG, OR 2.39, 95% CI 1.45-3.92; RD = 0.15, P = 0.001). In conclusion, in this meta-analysis, the UGT1A1*6 polymorphisms were associated with an increased risk of IRI-induced neutropenia in cancer patients, and increased incidences of severe neutropenia could be correlated with diverse regions, cancer type, low dose of IRI and the duration of treatment.

UGT1A1 polymorphisms with irinotecan-induced toxicities and treatment outcome in Asians with Lung Cancer: a meta-analysis

Previous studies of irinotecan pharmacogenetics have shown that the UGT1A1*28 polymorphism has an effect on irinotecan (IRI)-induced toxicities in Caucasians. Yet compared with the UGT1A1*6 mutation, the UGT1A1*28 occurs at a much lower frequency in the Asians. Whether UGT1A1*6 and UGT1A1*28 are associated with IRI-induced neutropenia, diarrhea and IRI-based chemotherapy tumor response (TR) in Asians with lung cancer remains controversial. In this meta-analysis, we found a higher risk of neutropenia and diarrhea with IRI-based chemotherapy in Asians with lung cancer carrying the UGT1A1*6 polymorphism. However, UGT1A1*28 showed a weak correlation with diarrhea, but no significant correlation with neutropenia. Neither UGT1A1*6 nor UGT1A1*28 is associated with IRI-based chemotherapy TR. These data suggest that the UGT1A1*28 polymorphism may not be a suitable biomarker to predict IRI-induced toxicities and chemotherapy TR in Asians, while UGT1A*6 polymorphism is associated with a higher risk of IRI-induced neutropenia and diarrhea, but not IRI-based chemotherapy TR.

UGT1A1*28 relationship with abnormal total bilirubin levels in chronic hepatitis C patients: Outcomes from a case-control study

Gilbert syndrome (GS) is a frequent benign clinical condition, marked by intermittent unconjugated hyperbilirubinemia, mostly due to the polymorphism uridine diphosphate-glucuronosyltransferase 1A1*28 (UGT1A1*28). Hyperbilirubinemia has been reported in a GS patient undergoing hepatitis C treatment, and other UGT isoforms polymorphisms have been linked to worse outcomes in viral hepatitis. Yet, little is known to GS contributions' to the liver disease scenario. Our aim was to assess UGT1A1 genotypes' frequency in chronic hepatitis C (CHC) patients and correlate with total bilirubin (TB). This is a case-control study in a large tertiary medical center. Cases were CHC patients confirmed by hepatitis C virus (HCV)-polymerase chain reaction. Exclusion criteria were hepatitis B virus or human immunodeficiency virus (HIV) coinfection. Control were healthy blood donors. UGT1A1 promoter region gene genotyping was performed, and bilirubin serum levels were available for HCV patients. Genotypes and alleles frequencies were similar in case (n = 585; P = 0.101) and control groups (n = 313; P = 0.795). Total bilirubin increase was noticed according to thymine-adenine repeats in genotypes (P < 0.001), and the TB greater than 1 mg/dL group had more UGT1A1*28 subjects than in the group with TB values <1 mg/dL (18.3 vs 5.3; P < 0.001). Bilirubin levels are linked to the studied polymorphisms, and this is the first time that these findings are reported in a chronic liver disease sample. Among patients with increased TB levels, the frequency of UGT1A1*28 is higher than those with normal TB. Personalized care should be considered to GS, regarding either abnormal bilirubin levels or drug metabolism.

Predictive Value of UGT1A1*28 Polymorphism In Irinotecan-based Chemotherapy

The UGT1A1*28 polymorphism was suggested to be significantly connected with irinotecan-induced toxicity and response to chemotherapy. However, the results of previous studies are controversial. Hence we carried out a meta-analysis to investigate the effect of UGT1A1*28 polymorphism on severe diarrhea, neutropenia, and response of patients who had undergone irinotecan-based chemotherapy. The PubMed, Web of Science, Wanfang, and CNKI databases were searched for clinical trials assessing the association of UGT1A1*28 polymorphism with severe diarrhea, neutropenia, and response to irinotecan-based chemotherapy. The combined odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the relationship under a fixed- or random-effects model. Fifty-eight studies including 6087 patients with cancer were included. Our results showed that patients carrying the TA6/7 and TA7/7 genotypes had a greater prevalence of diarrhea and neutropenia than those with the TA6/6 genotype (TA6/7+TA7/7 vs. TA6/6: diarrhea, OR = 2.18, 95%CI = 1.68-2.83; neutropenia, OR = 2.15, 95%CI = 1.71-2.70), particularly patients with metastatic colorectal cancer. Stratified analysis showed that Asians with the TA6/7 and TA7/7 genotypes were more likely to have diarrhea and neutropenia, and Caucasians with the TA6/7 and TA7/7 genotypes were more likely to have neutropenia than other groups. However, patients with the TA6/7+TA7/7 genotypes showed a higher response than patients with TA6/6 genotype (OR = 1.20, 95%CI = 1.07-1.34), particularly Caucasians (OR = 1.23, 95%CI = 1.06-1.42) and patients with metastatic colorectal cancer (OR = 1.24, 95%CI = 1.05-1.48). Our data showed that the UGT1A1*28 polymorphism had a significant relationship with toxicity and response to irinotecan-based chemotherapy. This polymorphism may be useful as a monitoring index for cancer patients receiving irinotecan-based chemotherapy.

The impact of the UGT1A1*60 allele on bilirubin serum concentrations

AIM

Identify the functional status of the uridine-diphosphate glucuronyl transferase 1A1 (UGT1A1) -3279T>G (*60) variant.

MATERIALS & METHODS

Retrospective review of clinically obtained serum bilirubin concentrations in pediatric patients to evaluate the association of the UGT1A1 -3279T>G (*60) variant with bilirubin concentrations and assessed linkage disequilibrium of the UGT1A1 -3279T>G (*60) and A(TA)7TAA (*28) variants.

RESULTS

Total bilirubin concentration did not differ between patients who had a UGT1A1*1/*1 diplotype and patients homozygous for the UGT1A1 -3279T>G (*60/*60) variant. Total bilirubin concentration was lower in patients homozygous for the UGT1A1 -3279T>G (*60/*60) variant than in patients homozygous for the UGT1A1 A(TA)7TAA (*28/*28) variant (p < 0.01). The -3279T>G (*60) and A(TA)7TAA (*28) variants were in strong incomplete linkage disequilibrium in both black and white patients.

CONCLUSION

The presence of the UGT1A1 -3279T>G (*60) variant is not associated with increased bilirubin concentrations.

UGT1A1 gene polymorphism is associated with toxicity and clinical efficacy of irinotecan-based chemotherapy in patients with advanced colorectal cancer

OBJECTIVES

To investigate the relationship between uridine diphosphate glucoronosyltransferase 1A1 (UGT1A1)*28/*6 and toxicity and clinical efficacy of irinotecan-based chemotherapy in patients with advanced colorectal cancer (CRC) in Xinjiang Uygur and Han population.

METHODS

A total of 183 patients (Uygur, 114; Han, 69) with advanced CRC who received the irinotecan-based chemotherapy were enrolled in this retrospective analysis. Polymerase chain reaction amplification and direct sequencing method were used for UGT1A1*28 and UGT1A1*6 polymorphism detection. The patients were followed up to analyze the relationship between different genotypes with adverse reactions and the clinical outcome of irinotecan-based chemotherapy.

RESULTS

Significant differences were found in genotype frequencies of UGT1A1*28 and UGT1A1*28/*6 between Uygur and Han (P = 0.02 and P = 0.002). Uygur and Han patients carrying wild UGT1A1*28 and *6 genotypes appeared to have significantly lower diarrhea incidence (I/II and III/IV) than those carrying mutant genotypes (all P < 0.05). In Uygur patients, UGT1A1*28 genotypes were related with objective response rate and disease control rate (P < 0.05). Compared with *1 allele *1/*1, *1 allele *1/*28*1/*28 mutant of UGT1A1*28 was associated with shorter OS in both Uygur and Han ethnicities (all P < 0.05). Compared with double allele variants (DW), single allele variants (SV), and double allele variants (DV) of UGT1A1*28/*6 were associated with shorter overall survival (OS) in Uygur and Han (all P < 0.05). Cox regression analysis revealed factors significantly influencing OS, including UGT1A1*28, UGT1A1*6, combined genotypes and chemotherapy line in Ugyur, and only combined genotypes in Han (all P < 0.05).

CONCLUSION

UGT1A1 gene polymorphism predicts irinotecan-related adverse reactions in advanced CRC patients of Xinjiang Uygur and Han nationality; UGT1A1 gene polymorphism is correlated with efficacy and prognosis in Uygur nationality, but only related to prognosis in Han nationality in irinotecan-based chemotherapy.

Onivyde for the therapy of multiple solid tumors

Drug delivery system based on nanobiotechnology can improve the pharmacokinetics and therapeutic index of chemotherapeutic agents, which has revolutionized tumor therapy. Onivyde, also known as MM-398 or PEP02, is a nanoliposomal formulation of irinotecan which has demonstrated encouraging anticancer activity across a broad range of malignancies, including pancreatic cancer, esophago-gastric cancer, and colorectal cancer. This up-to-date review not only focuses on the structure, pharmacokinetics, and pharmacogenetics of Onivyde but also summarizes clinical trials and recommends Onivyde for patients with advanced solid tumors.