Polymorphisms in the UGT1A1 gene predict adverse effects of irinotecan in the treatment of gynecologic cancer in Japanese patients

Role of Genetic Polymorphisms in Drug-Metabolizing Enzyme-Mediated Toxicity and Pharmacokinetic Resistance to Anti-Cancer Agents: A Review on the Pharmacogenomics Aspect

The inter-individual differences in cancer susceptibility are somehow correlated with the genetic differences that are caused by the polymorphisms. These genetic variations in drug-metabolizing enzymes/drug-inactivating enzymes may negatively or positively affect the pharmacokinetic profile of chemotherapeutic agents that eventually lead to pharmacokinetic resistance and toxicity against anti-cancer drugs. For instance, the CYP1B1*3 allele is associated with CYP1B1 overexpression and consequent resistance to a variety of taxanes and platins, while 496T>G is associated with lower levels of dihydropyrimidine dehydrogenase, which results in severe toxicities related to 5-fluorouracil. In this context, a pharmacogenomics approach can be applied to ascertain the role of the genetic make-up in a person's response to any drug. This approach collectively utilizes pharmacology and genomics to develop effective and safe medications that are devoid of resistance problems. In addition, recently reported genomics studies revealed the impact of many single nucleotide polymorphisms in tumors. These studies emphasized the importance of single nucleotide polymorphisms in drug-metabolizing enzymes on the effect of anti-tumor drugs. In this review, we discuss the pharmacogenomics aspect of polymorphisms in detail to provide an insight into the genetic manipulations in drug-metabolizing enzymes that are responsible for pharmacokinetic resistance or toxicity against well-known anti-cancer drugs. Special emphasis is placed on different deleterious single nucleotide polymorphisms and their effect on pharmacokinetic resistance. The information provided in this report may be beneficial to researchers, especially those who are working in the field of biotechnology and human genetics, in rationally manipulating the genetic information of patients with cancer who are undergoing chemotherapy to avoid the problem of pharmacokinetic resistance/toxicity associated with drug-metabolizing enzymes.

Molecular, cellular and systemic aspects of epithelial ovarian cancer and its tumor microenvironment

Ovarian cancer encompasses a heterogeneous group of malignancies that involve the ovaries, fallopian tubes and the peritoneal cavity. Despite major advances made within the field of cancer, the majority of patients with ovarian cancer are still being diagnosed at an advanced stage of the disease due to lack of effective screening tools. The overall survival of these patients has, therefore, not substantially improved over the past decades. Most patients undergo debulking surgery and treatment with chemotherapy, but often micrometastases remain and acquire resistance to the therapy, eventually leading to disease recurrence. Here, we summarize the current knowledge in epithelial ovarian cancer development and metastatic progression. For the most common subtypes, we focus further on the properties and functions of the immunosuppressive tumor microenvironment, including the extracellular matrix. Current and future treatment modalities are discussed and finally we provide an overview of the different experimental models used to develop novel therapies.

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.

UGT1A1 polymorphism has a prognostic effect in patients with stage IB or II uterine cervical cancer and one or no metastatic pelvic nodes receiving irinotecan chemotherapy: a retrospective study

Background

Uridine diphosphate glucuronosyltransferase 1 family polypeptide A1 (UGT1A1) is a predictive biomarker for the side-effects of irinotecan chemotherapy, which reduces the volume of tumors harboring UGT1A1 polymorphisms. We aimed to determine whether UGT1A1 polymorphisms can predict progression-free survival in patients with local cervical cancer treated with irinotecan chemotherapy.

Methods

We retrospectively analyzed the data of 51 patients with cervical cancer treated at a single institution between 2010 and 2015. All patients were diagnosed with 2009 International Federation of Gynecology and Obstetrics (FIGO) stage IB1, IB2, IIA, or IIB squamous cell carcinoma, underwent radical hysterectomy, and received irinotecan chemotherapy as neoadjuvant and/or adjuvant treatment. All patients were examined for irinotecan side effects using UGT1A1 tests. Conditional inference tree and survival analyses were performed considering the FIGO stage, age, the UGT1A1 status, and the number of metastatic lymph nodes to determine primary factors associated with progression-free survival.

Results

The tree-structured survival model determined high recurrence-risk factors related to progression-free survival. The most relevant factor was ≥2 metastatic lymph nodes (p = 0.004). The second most relevant factor was UGT1A1 genotype (p = 0.024). Among patients with ≤1 metastatic lymph node, those with UGT1A1 polymorphisms benefited from irinotecan chemotherapy and demonstrated significantly longer progression-free survival (p = 0.020) than those with wild-type UGT1A1.

Conclusions

Irinotecan chemotherapy might be beneficial in patients with cervical cancer, UGT1A1 polymorphisms, and ≤ 1 metastatic lymph nodes.

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.

Molecular mechanisms of drug resistance in ovarian cancer

Ovarian cancer is the most lethal malignancy among the gynecological cancers, with a 5-year survival rate, mainly due to being diagnosed at advanced stages, recurrence and resistance to the current chemotherapeutic agents. Drug resistance is a complex phenomenon and the number of known involved genes and cross-talks between signaling pathways in this process is growing rapidly. Thus, discovering and understanding the underlying molecular mechanisms involved in chemo-resistance are crucial for management of treatment and identifying novel and effective drug targets as well as drug discovery to improve therapeutic outcomes. In this review, the major and recently identified molecular mechanisms of drug resistance in ovarian cancer from relevant literature have been investigated. In the final section of the paper, new approaches for studying detailed mechanisms of chemo-resistance have been briefly discussed.

Combination chemotherapy with irinotecan and gemcitabine for taxane/platinum-resistant/refractory ovarian and primary peritoneal cancer: a multicenter phase I/II trial (GOGO-Ov 6)

PURPOSE

To develop a new therapeutic strategy for taxane/platinum-resistant/refractory ovarian and primary peritoneal cancers, we evaluated the feasibility and efficacy of irinotecan and gemcitabine combination chemotherapy.

METHODS

Patients with taxane/platinum-resistant/refractory cancer received escalating doses of irinotecan and gemcitabine (level 1: 80 and 800 mg/m², respectively; level 2: 100 and 1000 mg/m²) on days 1 and 8 on a 21-day cycle. Genotyping for UGT1A1*6 and *28 polymorphisms was performed for possible adverse irinotecan sensitivity.

RESULTS

A total of 35 patients were enrolled. The recommended dose was defined as 100 mg/m² irinotecan and 1000 mg/m² gemcitabine (level 2). The observed common grade 3/4 toxicities were neutropenia (60%), anemia (17.1%), diarrhea (8.6%), thrombocytopenia (5.7%) and nausea (5.7%). Groups homozygous for UGT1A1*6 or *28 were associated with grade 3/4 neutropenia and diarrhea. Objective responses were 20%, including one complete response and six partial responses. In 29 patients treated with the recommended dose, the median progression-free survival and overall survival were 3.8 months (95% CI 2.1-6.0 months) and 17.4 months (95% CI 9.9-21.9 months), respectively, while the 1-year survival rate was 58.6%.

CONCLUSIONS

Combination chemotherapy with irinotecan and gemcitabine represents a safe and effective treatment combination for taxane/platinum-resistant/refractory ovarian and primary peritoneal cancers.

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.

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.

Phase II and UGT1A1 Polymorphism Study of Two Different Irinotecan Dosages Combined with Cisplatin as First-Line Therapy for Advanced Gastric Cancer

BACKGROUND

We investigated the efficacy and safety of biweekly irinotecan and cisplatin (IP) as first-line treatment in advanced gastric cancer patients.

METHODS

Irinotecan 125 mg/m2 on day 1 and cisplatin 60 mg/m2 on day 2 were administrated every 14 days. UGT1A1*28/*6 and toxicities were analyzed.

RESULTS

Forty-one eligible patients were enrolled. Fifteen patients, who were defined as the high-dose group, received starting doses of irinotecan 125 mg/m2. Twenty-six patients, who were defined as the low-dose group, received starting doses of irinotecan 80 mg/m2 and cisplatin 50 mg/m2. The response rate was 53.3% in the irinotecan high-dose group and 53.8% in the irinotecan low-dose group. The most common grade 3/4 toxicity was neutropenia (68.3%). No significant difference in grade 3/4 neutropenia was found between patients with the wild-type genotype and those with variant genotypes for UGT1A1*28 or UGT1A1*6.

CONCLUSIONS

The combination of biweekly irinotecan 80 mg/m2 and cisplatin 50 mg/m2 was active and tolerable. The role of the UGT1A1 genotype in clinical toxicity of an IP regimen requires further investigation.

Polymorphisms of estrogen metabolism-related genes ESR1, UGT2B17, and UGT1A1 are not associated with osteoporosis in surgically menopausal Japanese women

INTRODUCTION

Bilateral salpingo-oophorectomy (BSO) is a risk factor for osteoporosis. Previous studies have reported an association between genetic polymorphisms and the risk of developing osteoporosis. However, the relationship between osteoporosis and genetic polymorphisms in Japanese women treated with BSO is not well understood. To improve the quality of life for post-BSO patients, it is important to determine the genetic factors that influence their risk for osteoporosis. The aim of this study was to investigate the association between gene variations of estrogen metabolism-related genes and osteoporosis in surgically menopausal patients, which may improve their quality of life.

MATERIAL AND METHODS

This study included 203 menopausal women treated with BSO because of gynecologic disorders. One hundred and twenty-six women with artificial (surgical) menopause, who had undergone BSO in the premenopausal period, were compared with 77 women with natural menopause, who had undergone BSO in the postmenopausal period. The women were tested for bone mineral density to diagnose osteoporosis. Polymorphisms of estrogen receptor 1 (ESR1) and UDP-glucuronosyl transferase (UGT) genes UGT2B17 and UGT1A1 were analyzed, and their association with bone mass and osteoporosis was statistically evaluated.

RESULTS

No significant association was found between osteoporosis and polymorphisms in ESR1, UGT2B17, or UGT1A1 in both groups, suggesting that BSO might be a more significant physiological factor in influencing bone mass density compared to genetic variations.

CONCLUSIONS

These results suggest that the ESR1, UGT2B17, and UGT1A1 polymorphisms are not genetic factors affecting osteoporosis in postmenopausal Japanese women.

The efficacy and safety of neoadjuvant chemotherapy in the treatment of locally advanced cervical cancer: A randomized multicenter study

OBJECTIVE

This study sought to evaluate the toxicity and curative effect of irinotecan plus cisplatin neoadjuvant chemotherapy (NACT) for stage Ib2, IIa2, and IIb cervical cancer patients.

METHODS

A total of 219 patients were randomly assigned to two groups: 109 patients were treated with 1-2 cycles of chemotherapy (NACT group), and 110 patients in the control group were treated directly with surgery (DS group). Patients in the NACT group were randomly assigned to two groups: 50 patients were treated with irinotecan plus cisplatin followed by surgery (IP group), and 59 patients were treated with paclitaxel plus cisplatin followed by surgery (TP group). Patients with pathological recurrence risk factors received post-operative radiotherapy.

RESULTS

Survival analysis revealed no significant difference in disease-free survival (DFS) or overall survival (OS) between the NACT and DS groups. Analysis of clinicopathologic factors showed that the lymphovascular space invasion (LVSI) and deep stromal invasion rates were significantly lower in the NACT group. Grade 3/4 neutropenia and grade 3/4 diarrhea were both higher in the IP group than in the TP group. DFS and OS were similar in the IP and TP groups. Univariate analysis showed that LVSI was the only factor associated with DFS.

CONCLUSION

NACT did not improve overall survival but did reduce the number of patients who received post-operative radiotherapy. NACT consisting of irinotecan plus cisplatin for cervical cancer showed similar efficacy and higher toxicity compared with the use of paclitaxel plus cisplatin, although the toxicity was tolerable.

Formulation and evaluation of irinotecan suppository for rectal administration

Irinotecan suppository was prepared using the moulding method with a homogeneous blend. A sensitive and specific fluorescence method was developed and validated for the determination of irinotecan in plasma using HPLC. The pharmacokinetics of intravenous administered and rectal administered in rabbits was investigated. Following a single intravenous dose of irinotecan (50 mg/kg), the plasma irinotecan concentration demonstrated a bi-exponential decay, with a rapid decline over 15 min. C_max, t_1/2, AUC_0–30h and AUC_0-∞ were 16.1 ± 2.7 g/ml, 7.6 ± 1.2 h, 71.3 ± 8.8 μg·h/ml and 82.3 ± 9.5 μg·h/ml, respectively. Following rectal administration of 100 mg/kg irinotecan, the plasma irinotecan concentration reached a peak of 5.3 ± 2.5 μg/ml at 4 h. The AUC_0–30h and AUC_0-∞ were 32.2 ± 6.2 μg·h/ml and 41.6 ± 7.2 μg·h/ml, respectively. It representing ∼50.6% of the absolute bioavailability.