Association between the low-dose irinotecan regimen-induced occurrence of grade 4 neutropenia and genetic variants of UGT1A1 in patients with gynecological cancers

Association of UGT1A1*6,*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.

Effect of drug metabolizing enzymes and transporters in Thai colorectal cancer patients treated with irinotecan-based chemotherapy

Genetic polymorphisms in drug metabolizing enzymes and drug transporters may affect irinotecan toxicity. Although genetic polymorphisms have been shown to influence the irinotecan toxicity, data are limited in Thai population. Thus, the aim of this study was to assess the allele and genotype frequencies and the relationship between CYP3A4/5, DPYD, UGT1A1, ABCB1, and ABCC2 genetic variations and irinotecan-induced toxicity in Thai colorectal cancer patients. One hundred and thirty-two patients were genotyped, and the effect of genetic variations on irinotecan-induced toxicity was assessed in 66 patients who received irinotecan-based chemotherapy. Allele frequencies of ABCB1 c.1236C > T, ABCB1 c.3435C > T, ABCC2 c.3972C > T, ABCG2 c.421C > A, CYP3A4*1B, CYP3A4*18, CYP3A5*3, DPYD*5, UGT1A1*28, and UGT1A1*6 were 0.67, 0.43, 0.23, 0.27, 0.01, 0.02, 0.64, 0.19, 0.16, and 0.09, respectively. DPYD*2A and DPYD c.1774C > T variants were not detected in our study population. The ABCC2 c.3972C > T was significantly associated with grade 1–4 neutropenia (P < 0.012) at the first cycle. Patients carrying both UGT1A1*28 and *6 were significantly associated with severe neutropenia at the first (P < 0.001) and second (P = 0.017) cycles. In addition, patients carrying UG1A1*28 and *6 had significantly lower absolute neutrophil count (ANC) nadir at first (P < 0.001) and second (P = 0.001) cycles. This finding suggests that UGT1A1*28, *6, and ABCC2 c.3972C > T might be an important predictor for irinotecan-induced severe neutropenia.

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

Background

There are obviously ethnic differences between the UGT1A1 gene polymorphisms. Due to the difference of genetic background and environment, the treatment with colorectal cancer patients of Guangxi Zhuang should not completely follow the Euramerican or Chinese han patients. The study aimed to explore the correlation of UGT1A1 gene polymorphism of Guangxi Zhuang metastatic colorectal cancer (mCRC) with irinotecan -based chemotherapy, in order to develop an individualized irinotecan regimen for mCRC patients of Guangxi Zhuang.

Methods

From June 2013 and June 2015, a total of 406 patients of Guangxi who were histologically diagnosed as metastatic colorectal cancer with 102 patients of this cohort with three generations of Zhuang, and 86 patients that conformed to inclusion and exclusion criteria were competitively enrolled. The distribution of UGT1A1 gene polymorphism was analyzed-retrospectively in all patients. Pyrosequencing method was used to detect the UGT1A1*28 and*6 gene polymorphism in the 86 Guangxi Zhuang mCRC patients. After first-line chemotherapy with FOLFIRI regimen, the relationship between gene polymorphism of UGT1A1 and adverse reactions, and efficacy of Irinotecan were analyzed with χ2 test and Kaplan-Meier method.

Results

UGT1A1*28 wild-type (TA6/6), heterozygous mutant (TA6/7) and homozygous mutant (TA7/7) accounted for 69.8, 30.2 and 0%, respectively. UGT1A1*6 wild type (G/G), heterozygous mutation type (G/A) and homozygous mutant (A/A) accounted for 76.7%, 20.9 and 2.3%, respectively. UGT1A1*28 TA6/7 type could increase the risk of grade 3~4 diarrhea (p = 0.027), which did not increase the risk of grade 3~4 neutropenia (p = 0.092). UGT1A1*6G/A and A/A type could increase the risk of grade 3~4 diarrhea and neutropenia (p = 0.001; p = 0.017). After chemotherapy with FOLFIRI, there was no significant difference in response rate (RR) (p = 0.729; p = 0.745) or in median progression-free survival (mPFS) between the wild-type, mutant treatment of UGT1A1*28 and UGT1A1*6 (7.0 m vs 7.4 m, p = 0.427; 6.9 m vs 7.0 m p = 0.408).

Conclusions

The distribution of UGT1A1*28 and UGT1A1*6 gene polymorphism in Guangxi Zhuang patients were differed from the existing reported of European people and Chinese Han population. The UGT1A1 gene polymorphism with irinotecan chemotherapy-associated diarrhea and neutropenia were closely related. There was no significant association between UGT1A1 gene polymorphism and therapeutic efficacy of irinotecan.

Phase II study of vincristine, actinomycin-D, cyclophosphamide and irinotecan for patients with newly diagnosed low-risk subset B rhabdomyosarcoma: A study protocol

BACKGROUND

Approximately 80% to 90% of patients with low-risk rhabdomyosarcoma can be cured. However, cured patients often face long-term complications associated with the treatment. An important factor in the treatment plan is the dose of cyclophosphamide administered because the dose can have both acute and long-term side effects. It is therefore essential to investigate whether the dose can be reduced without a negative effect on treatment outcome. The ARST0331 trial revealed that drastically reducing the cyclophosphamide dose to 4.8 g/m negatively affected treatment outcomes. The current study aims to determine whether reducing the cyclophosphamide dose to 10.8 g/m while introducing a new drug, irinotecan, can prevent the negative effect on treatment outcome. We also aim to investigate whether the reduced cyclophosphamide dose results in a decrease in infertility, one of the long-term complications of this treatment.

METHODS

The subjects are patients with stage 1 group III rhabdomyosarcoma (excluding those with orbital group III N0 and NX) or patients with stage 3 group I and II low-risk subset B embryonal rhabdomyosarcoma who will alternately undergo VAC 1.2 treatment (vincristine, actinomycin D, cyclophosphamide 1.2 g/m) and VI treatment (vincristine, irinotecan). The effectiveness and safety of this treatment regimen will be assessed. Data will be presented at international conferences and will be published in peer-reviewed journals.

DISCUSSION

This study is significant because it aims to establish that the use of irinotecan in patients with low-risk subset B embryonal rhabdomyosarcoma (aged 30 or younger) allows the dose of cyclophosphamide to be reduced and is associated with few short-term adverse effects and long-term complications. The open-label and single-arm design of this study may be a limitation.

TRIAL REGISTRATION AND ETHICAL APPROVAL

The trial registration number is jRCTs051180200 (Japan Registry of Clinical Trials). The study protocol was approved by the institutional review board at each of the participating centers and the data will be presented at international conferences and published in peer-reviewed journals.