Correlation between UGT1A1 gene polymorphism and irinotecan chemotherapy in metastatic colorectal cancer: a study from Guangxi Zhuang

Meta-analysis revisiting the influence of UGT1A1*28 and UGT1A1*6 on irinotecan safety in colorectal cancer patients

Aim: To evaluate the association between irinotecan safety and the UGT1A1 gene polymorphism in colorectal cancer (CRC) patients.Materials & methods: The studies were systematically searched and identified from three databases (PubMed, Embase and The Cochrane Library) until 28 February 2023. The relationships were evaluated using pooled odds ratio (OR).Results: A total of 30 studies out of 600 were included, comprising 4471 patients. UGT1A1*28 was associated with a statistically significant increase in the OR for diarrhea (OR: 1.59, 95% CI = 1.24-2.06 in the additive model; OR = 3.24, 95% CI = 2.01-5.21 in the recessive model; and OR = 1.95, 95% CI = 1.42-2.69 in the dominant model) and neutropenia (OR = 1.70, 95% CI = 1.40-2.06 in the additive model; OR = 4.10, 95%CI = 2.69-6.23 in the recessive model; and OR = 1.93, 95% CI = 1.61-2.31 in the dominant model). Subgroup analysis indicated consistent associations in both Asian and non-Asian populations. UGT1A1*6 was associated with a statistically significant elevation in the OR for diarrhea (only in the recessive model, OR = 2.42; 95% CI = 1.14-5.11) and neutropenia (across all genetic models).Conclusion: The UGT1A1*28 and UGT1A1*6 alleles might be a crucial indicator for predicting irinotecan safety in CRC.

A phase-II study based on dose adjustment according to UGT1A1 polymorphism: is irinotecan underdosed in first-line FOLFIRI regimen for mCRC?

PURPOSE

Irinotecan has considerable importance in the treatment of metastatic colorectal cancer (mCRC). UDP-glucoronyltransferase (UGT) 1A1 is responsible for the inactivation of SN-38, a metabolite of irinotecan. Depending on UGT1A1 polymorphism, the activity of the UGT enzyme can be reduced leading to more frequent occurrence of adverse events related to irinotecan. The present study aimed to assess the safety and efficacy of different doses of irinotecan adjusted according to UGT1A1 polymorphism.

METHODS

Thirty-four patients treated with FOLFIRI as first-line treatment for mCRC were included in this study. The irinotecan dosage was adapted on the basis of UGT1A1 polymorphisms: *1/*1 (370 mg/m2); *1/*28 (310 mg/m2), and *28/*28 (180 mg/m2). The incidence of grades 3 and 4 toxicities (neutropenia, febrile neutropenia, and diarrhoea) was recorded. Response was assessed according to the RECIST 1.1 criteria.

RESULTS

On the basis of UGT1A1 genotyping, 20 patients were *1/*1 (58.8%), 12 were *1/*28 (35.3%) and 2 were *28/*28 (5.9%). Seven patients experienced at least one severe toxicity, i.e., 21% of the population, amounting to eleven adverse events. Concerning the response rate, 15 patients (44%) had partial or complete response.

CONCLUSION

This study demonstrates that mCRC patients treated with FOLFIRI can tolerate a higher dose of irinotecan than the standard dose, i.e., > 180 mg/m2, on the basis of their UGT1A1 genotype, without increased toxicities.

TRIAL REGISTRATION

NCT01963182 (registered on 16/10/2013, Clermont-Ferrand, France).

Bilirubin metabolism and UDP-glucuronosyltransferase 1A1 variants in Asians: Pathogenic implications and therapeutic response

In the Asian general population, at least six single-nucleotide variants (SNVs) in the UDP-glucuronosyltransferase (UGT) 1A1 gene have been identified: -3279T>G, -53A(TA)₆ TAA>A(TA)₇ TAA, 211G>A, 686C>A, 1091C>T, and 1456T>G. Each of these six SNVs was observed in at least four ethnic groups of the 12 Asian populations studied. In East Asian populations, the descending frequency of these six SNVs was as follows: -3279G>[-53A(TA)₇ TAA, 211A]>(686A, 1091T)>1456G. Because of the presence of linkage disequilibrium and the expulsion phenomenon, when the SNVs -3279G, -53A(TA)₇ TAA, 211A, and 686A were simultaneously involved, 15 instead of the estimated 81 genotypes were observed. Those carrying 686AA or 1456GG developed Gilbert's syndrome or Crigler-Najjar syndrome type 2. Both -53A(TA)₇ TAA/A(TA)₇ TAA and 211AA are the main causes of Gilbert's syndrome in East Asian populations. In East Asian populations, the 211AA genotype is the main cause of neonatal hyperbilirubinemia, whereas -53A(TA)₇ TAA/A(TA)₇ TAA exerts a protective effect on hyperbilirubinemia development in neonates fed with breast milk. Both 211A and -53A(TA)₇ TAA are significantly associated with adverse drug reactions induced by irinotecan (one of the most widely used anticancer agents) in Asians. However, at least three common SNVs (-3279G, -53A(TA)₇ TAA, and 211A) should be comprehensively analyzed. This study investigated the clinical significance of these six SNVs and demonstrated that examining UGT1A1 variants in Asian populations is considerably challenging.

Predicting drug response and toxicity in metastatic colorectal cancer: the role of germline markers

INTRODUCTION

Despite the introduction of targeted agents leading to therapeutic advances, clinical management of patients with metastatic colorectal cancer (mCRC) is still challenged by significant interindividual variability in treatment outcomes, both in terms of toxicity and therapy efficacy. The study of germline genetic variants could help to personalize and optimize therapeutic approaches in mCRC.

AREAS COVERED

A systematic review of pharmacogenetic studies in mCRC patients published on PubMed between 2011 and 2021, evaluating the role of germline variants as predictive markers of toxicity and efficacy of drugs currently approved for treatment of mCRC, was perfomed.

EXPERT OPINION

Despite the large amount of pharmacogenetic data published to date, only a few genetic markers (i.e., DPYD and UGT1A1 variants) reached the clinical practice, mainly to prevent the toxic effects of chemotherapy. The large heterogeneity of available studies represents the major limitation in comparing results and identifying potential markers for clinical use, the role of which remains exploratory in most cases. However, the available published findings are an important starting point for future investigations. They highlighted new promising pharmacogenetic markers within the network of inflammatory and immune response signaling. In addition, the emerging role of previously overlooked rare variants has been pointed out.

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.

Rapid detection of the irinotecan-related UGT1A1*28 polymorphism by asymmetric PCR melting curve analysis using one fluorescent probe

BACKGROUND

Determination of UGT1A1 (TA)_n polymorphism prior to irinotecan therapy is necessary to avoid severe adverse drug effects. Thus, accurate and reliable genotyping methods for (TA)_n polymorphism are highly desired. Here, we present a new method for polymerase chain reaction (PCR) melting curve analysis using one fluorescent probe to discriminate the UGT1A1*1 [(TA)₆ ] and *28 [(TA)₇ ] genotypes.

METHODS

After protocol optimization, this technique was applied for genotyping of 64 patients (including 23 with UGT1A1*1/*1, 22 with *1/*28, and 19 with *28/*28) recruited between 2016 and 2021 in China-Japan Friendship Hospital. The accuracy of the method was evaluated by comparing the results with those of direct sequencing and fragment analysis. The intra- and inter-run precision of the melting temperatures (T_m s) were calculated to assess the reliability, and the limit of detection was examined to assess the sensitivity.

RESULTS

All genotypes were correctly identified with the new method, and its accuracy was higher than that of fragment analysis. The intra- and inter-run coefficients of variation for the T_m s were both ≤0.27%, with standard deviations ≤0.14°C. The limit of detection was 0.2 ng of input genomic DNA.

CONCLUSION

The developed PCR melting curve analysis using one fluorescent probe can provide accurate, reliable, rapid, simple, and low-cost detection of UGT1A1 (TA)_n polymorphism, and its use can be easily generalized in clinical laboratories with a fluorescent PCR platform.

UGT1A Gene Family Members Serve as Potential Targets and Prognostic Biomarkers for Pancreatic Cancer

Background

Pancreatic cancer (PC) is one of the most common cancers worldwide, with high mortality. The UGT1A gene family plays important roles in pharmacology and toxicology, contributing to interindividual differences in drug disposition. However, mRNA expression and prognostic value of the UGT1A gene family in PC have not been identified.

Methods

Oncomine, GEPIA2, DAVID 6.8, Metascape, Kaplan-Meier plotter, cBioPortal, GeneMANIA, TRRUST v2, TIMER, and R software were used in our study.

Results

The transcriptional levels of UGT1A1/3/6/8/9/10 in PC tissues were significantly higher than those in normal tissues. These results were further validated using five pairs of PC tumor tissues and adjacent nontumor tissues. A significant correlation was found between the expression of UGT1A1/6/10 and the pathological stage of PC. PC patients with lower transcriptional levels of UGT1A1/4/5/6/10 were associated with a better prognosis. The differentially expressed UGT1A gene family functions were primarily related to the glucuronidation pathway, cytokine-cytokine receptor interactions, and the ILK signaling pathway. Our data suggest that HNF1A, AHR, and CDX2 are key transcription factors for the UGT1A gene family. Furthermore, the expression levels of UGT1A1/3/8/9/10 were positively correlated with the activities of tumor-infiltrating immune cells, especially B cells. The expression levels of UGT1A6/9 were negatively correlated with macrophage infiltration levels.

Conclusions

These results suggest that the UGT1A gene family could serve as a potential prognostic biomarker and target for PC. However, future studies are required to validate our findings and promote the clinical utility of the UGT1A gene family in PC.

Influence of UGT1A1 *6/*28 Polymorphisms on Irinotecan-Related Toxicity and Survival in Pediatric Patients with Relapsed/Refractory Solid Tumors Treated with the VIT Regimen

Objective

The association between UGT1A1*6/*28 polymorphisms and treatment outcomes of irinotecan in children remains unknown. This retrospective study investigated the influence of UGT1A1*6/*28 polymorphisms on irinotecan toxicity and survival of pediatric patients with relapsed/refractory solid tumors.

Methods

The present study enrolled a total of 44 patients aged younger than 18 years at Sun Yat-sen University Cancer Center between 2014 and 2017.

Results

There were 26 boys and 18 girls; the median age at first VIT course was six years (range: 1-18 years). The tumor types included neuroblastoma (n = 25), rhabdomyosarcoma (n = 11), Wilm's tumor (n = 4), medulloblastoma (n = 2), and desmoplastic small round cell tumor (n = 2). Overall, 203 courses of VIT regimens were prescribed. Neither UGT1A1*6 nor *28 polymorphisms were associated with the incidence rates of severe (grade III-IV) irinotecan-related toxicities, but tended to reduce the patient overall survival (UGT1A1*6, P = 0.146; UGT1A1*28, P = 0.195). Moreover, patients with mutant UGT1A1*6 genotypes were more likely to develop grade I-IV irinotecan-related diarrhea (P = 0.043) and anemia (P = 0.002). Overall, the UGT1A1*28 polymorphism may play a protective role against irinotecan-related diarrhea and abdominal pain.

Conclusion

In relapsed/refractory pediatric solid tumors, the UGT1A1*6 polymorphism was a risk factor of irinotecan-related diarrhea and anemia. The UGT1A1*28 polymorphism may serve a protective role in irinotecan-related abdominal pain and diarrhea. Both mutations had a tendency to be risk factors for survival. Nevertheless, prospective studies are required to verify such conclusions.