UGT1A在伊立替康治疗转移性结直肠癌中的疗效与不良反应预测价值

化疗是转移性结直肠癌（mCRC）的主要治疗手段,伊立替康是mCRC的重要药物,但其存在治疗有效率有限、毒副反应个体差异大的问题。因此需要寻找有效的生物学标志物,筛选出对治疗反应性好、耐受性好的个体以指导临床治疗。尿苷二磷酸葡萄糖醛酸转移酶1A（UGT1A）的基因多态性与伊立替康的毒性及疗效均密切相关,但现有研究结果不一致,预测作用存在争议。本文通过Pubmed检索基因多态性与伊立替康相关性的有关文献,综合分析了UGT1A预测伊立替康毒性局限性的原因,可能与人种差异、药物使用剂量不同及与其他化疗药物或靶向药物联合使用有关。UGT1A多位点基因多态性的检测或与羧酸酯酶（CES）、ATP结合盒子（ABC）转运体、CYP3A4、SCOL等多个基因多态性的联合检测可能是提高伊立替康毒性和疗效预测水平的方式之一。     

伊立替康相关不良反应与UGT1A1基因多态性的关系

目的:研究应用伊立替康的不良反应与尿苷二磷酸葡糖醛酸转移酶(UGT)1A1基因TATA盒区域基因多态性的关系。方法:选取2010年10月至2011年8月在我科治疗的患者30例,提取外周血中基因组DNA,测定UGT1A1基因启动子区TATA盒区域中TA序列重复次数;对其中应用伊立替康治疗的23例患者观察相关不良反应,统计分析TA6/TA6、TA6/TA7、TA7/TA7基因型的出现频率及与伊立替康相关不良反应的关系。结果:30例中共检测到UGT1A1纯合子TA6/TA6 23例(76.7%),杂合子TA6/TA7 7例(23.3%),未发现纯合子TA7/TA7型患者。应用伊立替康治疗的患者中杂合子TA6/TA7的Ⅲ-Ⅳ级肠道不良反应发生率高于纯合子TA6/TA6患者(50%vs 6.3%,P<0.05),UGT1A1基因多态性与血液系统毒性未见统计学差异。结论:UGT1A1基因型的检测对伊立替康相关的肠道不良反应有一定预测作用,可为临床制定化疗方案提供参考依据。     

UGT1A1基因型多态性对伊立替康治疗晚期结直肠癌患者疗效和不良反应的影响

目的探讨尿苷二磷酸葡萄醛酸转移酶1A1(UGT1A1)基因多态性对伊立替康治疗晚期结直肠癌患者疗效及不良反应的影响。方法选取2015年2月至2016年12月间新疆维吾尔自治区人民医院收治的62例晚期结直肠癌患者,所有患者均采用伊立替康、亚叶酸钙和氟尿嘧啶(FOLFIRI方案)进行治疗。采用聚合酶链反应(PCR)技术扩增UGT1A1*28、UGT1A1*6基因片段,分析基因型与不良反应及化疗疗效的关系。结果不同年龄、性别、转移数目、癌症类型和分化程度患者不良反应的比较,差异无统计学意义(P>0.05)。UGT1A1*28基因非野生型患者3~4度腹泻比例为38.1%,明显高于野生型患者,差异有统计学意义(P<0.05)。UGT1A1*6基因非野生型患者3~4度中性粒细胞减少比例为77.8%,明显高于野生型患者,差异有统计学意义(P<0.05);双野生型(DW)、单个位点变异型(SV)和双个位点变异型(DV)不良反应的比较,差异无统计学意义(P>0.05);62例患者客观缓解率为40.3%,UGT1A1基因多态性与化疗疗效无明显相关性,差异无统计学意义(P>0.05)。结论 UGT1A1基因型多态性与伊立替康治疗晚期结直肠癌患者不良反应有一定关系,而与化疗疗效无关。     

UGT1A1*28基因多态性与晚期结直肠癌伊立替康化疗疗效及不良反应的关系

目的:尿苷二磷酸葡糖醛酸转移酶1A1(uridine-diphosphoglucuronosyl transferase 1A1, UGT1A1)作为伊立替康重要的药物代谢酶,其基因多态性可显著影响该酶的活性.本研究旨在观察UGT1A1*28基因多态性与晚期结直肠癌伊立替康化疗疗效和不良反应之间的关系.方法:回顾性研究64例接受伊立替康/氟尿嘧啶一线化疗的晚期结直肠癌患者.从患者外周血白细胞中提取DNA,应用直接测序法检测UGT1A1*28 TATA盒基因序列,并分析基因多态性与化疗不良反应和近期疗效的关系.结果: 51例(79.7%)患者的UGT1A1*28基因启动子区TA序列重复6次,为纯合野生型(TA)6/(TA)6;10例(15.6%)患者的基因型为TA序列重复6次和7次的杂合型(TA)6/(TA)7;3例(4.7%)患者的TA序列重复7次,为纯合突变型(TA)7/(TA)7.UGT1A1*28非野生型的基因多态性可增加患者发生Ⅲ度以上腹泻的风险(38.5% vs 9.8%,P=0.035);UGT1A1*28非野生型基因患者接受伊利替康化疗时,需要下调剂量的比率明显高于野生型基因者(46.2% vs 15.7%,P=0.046).64例患者中28例(43.8%)化疗有效,其中UGT1A1*28野生型基因者22例,非野生型基因者6例,2组的反应率差异无统计学意义(46.2% vs 43.1%,P=0.845).结论:在应用伊立替康化疗的患者中,UGT1A1*28基因启动子区TATA盒基因多态性(TA)6/(TA)7或(TA)7/(TA)7基因型可增加晚期结直肠癌患者接受伊立替康化疗后,发生Ⅲ度以上腹泻的风险,但不影响化疗的近期疗效.     

尿苷二磷酸葡醛酰转移酶1A1基因多态性与伊立替康治疗广泛期小细胞肺癌不良反应的相关性

目的 研究尿苷二磷酸葡醛酰转移酶(UGT) 1A1基因多态性与伊立替康方案治疗广泛期小细胞肺癌患者不良反应的关系.方法 采用聚合酶链反应法扩增目的基因片段,直接测序法对UGT1 A1基因多态性进行检测,观察并记录化疗中出现的不良反应及疗效,比较不同基因型患者使用伊立替康不良反应的发生率.结果 58例广泛期小细胞肺癌患者中,UGT1A1* 28野生型45例(77.6％),UGT1 A1 *93野生型40例(69.0％),UGT1A1* 60野生型38例(65.5％),UGT1 A1* 93和UGT1 A1* 60基因突变分别有18例(31.0％)和20例(34.5％).UGT1A1* 28基因型中,TA5突变8例(13.8％),TA7突变5例(8.6％).TA5突变型中≥3级腹泻5例,≥3级白细胞和中性粒细胞减少各3例;UGT1 A1* 93突变型中,≥3级腹泻7例,≥3级白细胞减少6例,≥3级中性粒细胞减少4例.结论 TA5突变型、UGT1A1*93突变型均增加腹泻和≥3级白细胞和中性粒细胞减少的风险,而UGT1 A1(*28、*93、*60)野生型和UGT1 A1* 60突变型未增加药物不良反应的风险.     

UGT1A1基因多态性与伊立替康治疗结直肠癌不良反应的关系

背景与目的：尿苷二磷酸葡萄糖醛酸转移酶1A1(uridine diphosphoglucu-ronosyltransferase 1A1,UGTlA1)是伊立替康代谢关键酶,其活性受基因多态性影响显著。本研究探讨结直肠癌患者中,UGT1A1*28和UGT1A1*6基因多态性与伊立替康治疗相关不良反应之间的关系。方法：入组2013年4月—2013年12月于复旦大学附属中山医院肿瘤内科接受治疗的消化道恶性肿瘤患者160例。抽提外周血中基因组DNA,分别采用STR方法和Sanger测序法,检测UGT1A1*28和UGT1A1*6基因型,分析UGT1A1基因多态性分布情况。对其中82例化疗方案中含伊立替康的结直肠癌患者进行随访,记录不良反应发生情况和严重程度,比较不同基因型患者之间的差异。结果：160例消化道肿瘤患者中,UTG1A1*28(启动子TATA盒区域TA重复次数)野生型TA6/6124例(77.5%);杂合子TA6/7 33例(20.5%);纯合子TA7/7 3例(2.0%)。UGT1A1*6位点(211G>A)野生型GG 105例(65.6%),杂合子GA 48例(30.0%);纯合子AA 7例(4.4%)。82例化疗方案中含伊立替康的结直肠癌患者中,*28基因型(TA6/7和TA7/7)显著增加发生3级以上中性粒细胞减少的风险(58.3% vs 0.0%,P<0.001),并增加整体不良反应发生率(76.0% vs 45.6%,P<0.001);*6基因型(GA和AA)、年龄、性别、化疗方案和伊立替康相关不良反应发生无显著相关性。结论：接受伊立替康化疗的结直肠癌患者,UGT1A1*28位点多态性显著增加中性粒细胞减少发生的风险,可预测伊立替康引起的骨髓抑制性不良反应,辅助临床选择合适的化疗方案。     

川东北地区人群结直肠癌患者UGT1A1*28基因多态性与伊立替康所致毒副反应的相关性

目的:观察结直肠癌患者UGT1A1*28基因多态性的分布频率,了解UGT1A1*28基因多态性与结直肠癌患者应用伊立替康联合5-氟尿嘧啶化疗毒副反应的相关性。方法:从384例接受伊立替康联合氟尿嘧啶一线化疗的晚期结直肠癌病例中采外周血提取DNA。采用PCR 法扩增目的基因片段,直接测序法分析UGT1A1*28基因多态性。临床观察并评价患者化疗毒副反应分级,统计分析UGT1A1*28基因表型与化疗毒副反应相关性。结果:全部 384例患者 UGT1A1*28基因多态性分布情况:TA6/6野生基因型287例(74.7％),TA6/7杂合基因型73例（19.0％）,TA7/7纯合基因型24例（6.3％）。化疗毒副反应和UGT1A1*28基因多态性进行临床单因素分析显示UGT1A1*28基因纯合型TA7/7、杂合型TA6/7与3-4度白细胞减少、中性粒细胞减少、腹泻、胆红素升高具有明显相关性（P<0.01）,UGT1A1*28基因纯合型TA7/7及杂合型TA6/7患者发生中性粒细胞减少的风险较UGT1A1*28基因野生型TA6/6患者高5.625倍（OR=5.625）。UGT1A1*28基因纯合型TA7/7和UGT1A1*28基因杂合型TA6/7患者发生腹泻的风险较UGT1A1*28基因野生型TA6/6患者高6.778倍（OR=6.778）。结论:UGT1A1*28基因纯合型TA7/7及杂合型TA6/7患者应用伊立替康化疗后发生重度中性粒细胞减少、重度腹泻的风险高于UGT1A1*28基因野生型TA6/6,为临床伊立替康用药选择、剂量调整、毒副反应的提前干预提供理论依据。     

尿苷二磷酸葡萄糖醛酸转移酶1A1~*6和尿苷二磷酸葡萄糖醛酸转移酶~*28基因多态性与伊立替康疗效及不良反应的关系

目的观察尿苷二磷酸葡萄糖醛酸转移酶1A1(UGT1A1*)6和UGT1A1*28基因多态性与伊立替康化疗疗效及不良反应之间的关系。方法采用外周静脉血DNA抽提、聚合酶链反应(PCR)扩增和焦磷酸测序方法分析UGT1A1*6和UGT1A1*8基因型,收集72例2010年1月至2013年12月间接受伊立替康治疗的晚期恶性肿瘤患者的临床资料,观察患者用药期间的药物不良反应及化疗疗效,分析基因多态性与化疗不良反应及近期疗效的关系。结果 72例恶性肿瘤(结直肠癌、小细胞肺癌)患者中,UGT1A1*6野生型G/G 40例(55.6%),杂合突变型G/A 21例(29.2%),纯合突变型A/A 11例(15.2%);UGT1A1*28野生型(TA)6/(TA)651例(70.8%),杂合突变型(TA)6/(TA)720例(27.8%),纯合突变型(TA)7/(TA)71例(1.4%)。UGT1A1*6突变型患者(G/A和A/A)3~4级腹泻和3~4级中性粒细胞减少的发生率分别为65.6%和43.7%,野生型(G/G)分别为30.0%和17.5%,差异均有统计学意义(均P<0.05)。UGT1A1*28突变型患者[(TA)6/(TA)7和(TA)7/(TA)7]3~4级腹泻的发生率(42.9%)高于野生型(17.6%,P<0.05)。各组之间近期化疗疗效差异无统计学意义(P>0.05)。结论 UGT1A1*6突变型患者应用伊立替康化疗发生3级及以上中性粒细胞减少及迟发性腹泻的风险增加,而UGT1A1*28突变型患者发生3级以上迟发性腹泻的风险增加,UGT1A1各基因型之间疗效无明显差异,通过检测UGT1A1基因多态性能够合理选择应用伊立替康。     

UGTIA1基因多态性与IP方案治疗小细胞肺癌毒性和疗效相关性分析

目的：探讨尿苷二磷酸葡萄糖转移酶1A1（UGTIA1）基因多态性与伊立替康联合顺铂（IP方案）治疗广泛期小细胞肺癌的不良反应和疗效相关性。方法：选取中国医学科学院肿瘤医院2009-01-01-2012-12-31初治广泛期小细胞肺癌患者48例,采用伊立替康联合顺铂化疗方案,分析其临床治疗效果和不良反应及其与UGT1A1基因多态性的相关性。结果：48例小细胞肺癌患者IP方案化疗后CR3例,PR32例,SD4侧,PD9例,总有效率为73．0％,疾病控制率为81．3％。主要毒副作用为中性粒细胞减少34例,贫血29例,血小板减少14例,恶心呕吐38例,迟发性腹泻26例,便秘15例,脱发5例,乏力38例,转氨酶升高14例,心电图异常9例。UGT1A1＊28基因多态性的分布为TA6／6野生型基因34例,TA6／7杂合突变型基因11例,TA7／7纯合突变型基因3例;UGT1A1＊6基因多态性的分布为G／C野生型基因33例,A／G杂合突变型基因13例,A／A纯合突变型基因2例。UGT1A1基因多态性与临床疗效无明显相关性,P〉0．05。提示UGT1A1突变型基因可增加患者发生迟发性腹泻的风险,而对中性粒细胞减少无影响。Logistic多因素回归分析结果显示,UGT1A1＊28、UGT1A1＊6、ECOG评分和治疗周期数对迟发性腹泻有明显影响;同时ECOG评分和治疗周期数对中性粒细胞减少存在影响。结论：UGT1A1突变基因对患者迟发性腹泻有明显影响,UGT1A1基因多态性检测可为临床应用伊立替康联合顺铂相关不良反应的预测提供依据,对临床用药安全具有重要意义。     

UGT1A1基因多态性与伊立替康安全性和有效性的临床研究

  目的  观察57例应用伊立替康治疗进展期消化道肿瘤患者的安全性和有效性。  方法  采用全血基因组DNA提取、PCR法扩增目的基因片段, 直接测序法分析UGT1A1基因多态性, 检测2011年8月至2012年6月在河北医科大学第四医院肿瘤内科住院治疗的57例进展期消化道肿瘤患者应用伊立替康的情况, 观察并记录化疗中出现的不良反应以及疗效。  结果  57例进展期消化道肿瘤患者中, UGT1A1基因启动子区28位点, TA序列6次重复的纯合野生型TA6/6有43例（75.4%）; 基因型为TA序列6次和7次重复的杂合型TA6/7有13例（22.8%）; 基因型为TA序列7次重复的纯合突变型TA7/7有1例（1.8%）。UGT1A1基因启动子区6位点野生型G/G有48例（84.2%）, 杂合突变型G/A有7例（12.3%）, 纯合突变型A/A有2例（3.5%）。在57例采用含伊立替康方案化疗的进展期消化道肿瘤患者中, UGT1A1基因启动子区28位点, TA6/6、TA6/7和TA7/7野生型和突变型发生3级以上中性粒细胞减少者分别为7.0%、14.3%, 发生3级以上腹泻者分别为9.3%、14.3%, 其中纯合突变型仅1例患者, 100%的发生率。UGT1A1基因启动子区6位点, G/G、G/A和A/A野生型和突变型发生3级以上中性粒细胞减少者分别为4.2%、55.6%, 发生3级以上腹泻者分别为12.5%、44.4%, 具有统计学差异。各组之间疗效无统计学差异。  结论  患者UGT1A1*28和UGT1A1*6多态性分布基本一致, UGT1A1*6突变型患者应用伊立替康化疗发生3级以上中性粒细胞减少和腹泻的风险增加, 而UGT1A1*28突变型与以上不良反应并无绝对相关性, UGT1A1各基因型之间疗效无明显差异。能否通过对UGT1A1的筛查, 选择合适患者安全有效的应用伊立替康, 值得临床进一步扩大样本量深入研究。      

Role of UGT1A1*28 and UGT1A1*6 for irinotecan-induced adverse drug reaction

Irinotecan is widely used in the treatment of colorectal, gastric, and lung cancers. However, adverse drug reactions such as severe diarrhea and neutropenia limit the dose of this drug. Irinotecan is metabolized by carboxylesterase to form an active metabolite, 7-ethyl-10-hydroxycamptothecin(SN-38), which in turn is subsequently conjugated by UGT-glucuronosyltransferase 1A1(UGT1A1)to yield an inactive form, SN-38 glucuronide(SN-38 G). The UGT1A1 gene polymorphisms contribute to the individual variation in adverse events among patients administered irinotecan. However, the distribution of polymorphisms shows large interethnic differences. The distribution of UGT1A1*28 greatly differs between Caucasians and Japanese; the frequency of UGT1A1*28 is high in Caucasians, whereas it is low in Asians including Japanese. Recently, it has been demonstrated that genetic variants of UGT1A1*6 in addition to UGT1A1*28 are associated with the occurrence of adverse events in irinotecan chemotherapy in Asians. This review summarizes recent studies to outline the role of UGT1A1*28 and UGT1A1*6 for irinotecan-induced adverse drug reaction in Japanese cancer patients.     

UGT1A1*28 and other UGT1A polymorphisms as determinants of irinotecan toxicity

Irinotecan is a drug commonly used for the treatment of cancer patients, both as a single agent or in combination therapy. Neutropenia and diarrhea are the dose-limiting toxicities. Genetic variations of proteins involved in irinotecan metabolism and transport have been considered in the development of irinotecan toxicity. In particular, polymorphisms affecting UDP-glucuronosyltransferase isoform 1A1 (UGT1A1) expression or activity are being investigated. Among these, UGT1A1*28 has been considered as the major predictive pharmacogenetic marker for severe hematological toxicity (neutropenia). However, translation to clinical practice of UGT1A1*28 testing as a predictive marker of adverse effects needs to be further investigated and the available data are not conclusive in defining a precise genotype-based dosage. Further prospective studies are required to reach a personalization of chemotherapy with irinotecan.     

UGT1A1*28 and Other UGT1A Polymorphisms as Determinants of Irinotecan Toxicity

Abstract

Irinotecan is a drug commonly used for the treatment of cancer patients, both as a single agent or in combination therapy. Neutropenia and diarrhea are the dose-limiting toxicities. Genetic variations of proteins involved in irinotecan metabolism and transport have been considered in the development of irinotecan toxicity. In particular, polymorphisms affecting UDP-glucuronosyltransferase isoform 1A1 (UGT1A1) expression or activity are being investigated. Among these, UGT1A1*28 has been considered as the major predictive pharmacogenetic marker for severe hematological toxicity (neutropenia). However, translation to clinical practice of UGT1A1*28 testing as a predictive marker of adverse effects needs to be further investigated and the available data are not conclusive in defining a precise genotype-based dosage.

Further prospective studies are required to reach a personalization of chemotherapy with irinotecan.     

Irinotecan Therapy in a 12-year-old Girl with Recurrent Brain Stem Glioma and without Functional Polymorphisms in UGT1A1 Activity: Case Report

Summary A 10-year-old girl was diagnosed with astrocytoma grade 2. Immuno-chemo-radiotherapy (interferon, ranimustine, and radiation), second-line chemotherapy (carboplatin and etoposide, 7 cycles) and third-line chemotherapy (ifosfamide, carboplatin, and etoposide) was given to treat progressive disease. Finally, irinotecan therapy was initiated and led to dramatic clinical improvement. Irinotecan is metabolized by carboxylesterase to form an active SN-38, which is further conjugated and detoxified by UDP-glucuronosyltransferase (UGT) to yield its β-glucuronide. The polymorphic UGT isoenzyme, UGT1A1 has genetic variants which decrease in SN-38 glucuronidating capacity and could help predict irinotecan-associated toxicity. The patient suffered excessive toxicity with low-dose irinotecan although no functional polymorphism in UGT1A1 was identified. We suggest that irinotecan offers an effective treatment option for children with recurrent brain stem glioma and other genetic variants except UGT1A1 may be a risk factor for irinotecan-induced toxicity.     

Prediction of Response to Irinotecan and Drug Toxicity Based on Pharmacogenomics Test: A Prospective Case Study in Advanced Colorectal Cancer

Background: FOLFIRI regimen, which is composed of 5-FU, Leucovorin, and Irinotecan, is used in the first-line chemotherapy of metastatic colorectal cancer. Irinotecan life threatening toxicity is partly related to cytotoxic drug metabolite which is primarily inactivated by the UGT1A1 enzyme. The primary aim of the present research was to find the correlation between UGT1A1-genotype and clinical toxicity of irinotecan. Methods: In a prospective study from March 2011 to December 2013, all patients with metastatic colorectal cancer who had been referred to Medical Oncology Department of Iran Cancer Institute were genotyped for UGT1A1*28 before the first cycle of chemotherapy. All of the patients signed informed consent and trial approved by Ethics Committee of the Tehran University of Medical Sciences. Reduction of the standard dose of Irinotecan (180 mg/m2 body surface area) was measured based on NCI toxicity criteria after the first cycle of chemotherapy. Patients with previous treatment with Oxaliplatin and fluorouracil (5-FU) in the adjuvant setting and adequate liver, kidney, and heart function were included in the trial. Both synchronous and metachronous metastatic disease were noticeable. Results: A total of 50 patients with median age of 52 years were included. Most (70%) of the patients had more than one site of metastases in peritoneum, liver, and/or lung. Thirty-one patients had UGT1A1*1 normal genotype, 13 were in heterozygote and 6 were in homozygote state ofUGT1A1*28/*28. A clinically relevant increase in early toxicity was found in patients carrying the UGT1A1*28/*28 genotype with odds Ratio (OR) of 2.6 (95%CI 2.5-27.28). Similarly, there was a trend of lower overall survival in homozygote group with an HR (Hazardous Ratio) of 2.76 (95%CI .88-.61). No statistically significant relationship was found between UGT1A1genotypes and response to therapy. Conclusions: UGT1A1 28*/28* is strongly associated with drug’s life-threatening toxicity even in a moderate dose of Irinotecan. On the other hand, UGT1A1 genotype data was not helpful to differentiate response to treatment.     

Gilbert's Syndrome and irinotecan toxicity: combination with UDP-glucuronosyltransferase 1A7 variants increases risk

BACKGROUND: Gilbert's syndrome is characterized by a functional promoter single nucleotide polymorphism (SNP) of the UDP-glucuronosyltransferase (UGT) 1A1 gene and represents a pharmacogenetic risk factor for irinotecan toxicity, but study data remain controversial. The active CPT-11 metabolite 7-ethyl-10-hydroxycamptothecin is detoxified by several UGT1A proteins, which include UGT1A7 with a high specific activity that may contribute to the risk of irinotecan toxicity in Gilbert's syndrome patients. METHODS: Genotyping of the UGT1A1*28, UGT1A7 N129K/R131K, and UGT1A7-57T/G variants was done in 105 irinotecan-treated patients with metastatic colorectal cancer; adverse events were documented during all 297 treatment cycles and analyzed by Cochran-Mantel-Haenszel, Mann-Whitney, and chi2 tests. RESULTS: The presence of UGT1A7 but not UGT1A1 variants was associated with at least one adverse event. In patients combining all three variants, thrombocytopenia and leukopenia were significantly more frequent. The overall incidence of adverse events was significantly higher (P = 0.0035) in carriers of the UGT1A risk alleles, who also had significantly higher rate of dose reductions. CONCLUSIONS: Irinotecan toxicity is more likely in patients with Gilbert's syndrome carrying the UGT1A1*28 allele combined with reduced function UGT1A7 N129K/R131K and UGT1A7-57T/G SNP. Based on the ability of UGT1A7 to metabolize and eliminate the active irinotecan metabolite 7-ethyl-10-hydroxycamptothecin, the UGT1A1/UGT1A7 SNP combination haplotype appears to be a superior risk predictor than Gilbert's syndrome alone.     

Intérêt du génotypage de l’UGT1A1 dans le cadre du traitement des cancers digestifs par irinotécan

Irinotecan is a cytotoxic agent administered by IV infusion in the treatment of advanced colorectal cancer. Its anticancer activity results from its bioactivation into SN-38 metabolite, which is cleared through glucuronidation by the hepatic enzyme uridine diphosphate-glucuronosyltransferase 1A1 (UGT1A1). In the general population, there is wide inter-subject variability in UGT1A1 enzyme activity related to UGT1A1 gene polymorphisms. The French joint workgroup coming from the National Pharmacogenetic Network (RNPGx) and the Group of Clinical Oncologic Pharmacology (GPCO) herein presents an updated review dealing with efficacy and toxicity clinical studies related to UGT1A1 genetic variants. From a critical analysis of this review it clearly emerges that, for doses higher than 180 mg/m², hematologic and digestive irinotecan-induced toxicities could be prevented in daily clinical practice by generalizing the use of a simple pharmacogenetic test before starting treatment. The clinical relevance of this test is also discussed in terms of treatment efficacy improvement, with the possibility of increasing the irinotecan dose in patients not bearing the deleterious allele. This test involves using a blood sample to analyze the promoter region of the UGT1A1 gene (UGT1A1*28 allele). Best execution practices, laboratory costs, as well as results interpretation are described with the aim of facilitating the implementation of this analysis in clinical routine. The existence of a French laboratories network performing this test in clinical routine makes it possible to generalize UGT1A1 deficiency screening, so as to guarantee equal access to safe treatment and optimized irinorecan-based therapy for the many patients receiving irinotecan-based therapy in advanced colorectal cancer.     

UGT1A1基因不同表型与FOLFIRI方案治疗晚期结直肠癌疗效及毒副反应的相关性

目的:回顾性分析UGT1A1基因不同表型与FOLFIRI方案治疗晚期结直肠癌疗效及毒副反应的相关性。方法:收集贵州医科大学附属肿瘤医院腹部肿瘤科2014年1月至2018年12月收治的临床分期为Ⅳ期结直肠癌或根治性手术后复发转移的晚期结直肠癌患者240例的临床病理资料,所有患者初次行FOLFIRI方案化疗前抽血,提取全血中的DNA,采用PCR技术行UGT1A1基因型检测;接受FOLFIRI化疗方案治疗直至疾病进展或者发生不可耐受的毒性反应。分别采用Binary Logistic Regression模型分析UGT1A1基因不同表型与FOLFIRI化疗疗效的相关性,分解模型及广义估计方程多应变量回归分析UGT1A1基因不同表型与FOLFIRI化疗毒副反应的相关性。结果:本组患者共发现3种UGT1A1基因表型,分别为UGT1A1*1/*1(纯合野生型TA6/6型 188/240 78.3%)、UGT1A1*28/*1(杂合突变型TA6/7型 47/240 19.6%)和UGT1A1*28/*28(纯合突变型TA7/7型 5/240 2.1%)。UGT1A1基因型中TA6/7型TA6/6型相比,FOLFIRI化疗无应答风险增加16%,但无统计学差异;本组转移器官＞2个的患者中TA6/7型和TA6/6型相比,血液学及非血液学毒副反应发生的风险均增加了9.377 3倍（P=0.007 9）,其中消化道毒副反应发生风险增加了42.806 6倍（P=0.025 9）;本组行FOLFIRI化疗≥4周期的患者中,TA6/7型比TA6/6型的患者发生血液学毒性的风险增加了22.324 6倍（P=0.003 5）。结论:TA6/6型为我省结直肠癌患者最为常见的UGT1A1基因表型,而TA7/7型罕见;晚期结直肠癌转移器官数超过2个行FOLFIRI化疗的患者中UGT1A1基因TA6/7型较TA6/6型患者血液学及非血液学毒副反应发生的风险均明显增加,其中消化道毒副反应发生的风险更胜。     

UGT1A1 polymorphism can predict hematologic toxicity in patients treated with irinotecan.

PURPOSE: Irinotecan (CPT-11) is approved in metastatic colorectal cancer treatment and can cause severe toxicity. The main purpose of our study was to assess the role of different polymorphisms on the occurrence of hematologic toxicities and disease-free survival in high-risk stage III colon cancer patients receiving 5-fluorouracil (5FU) and CPT-11 adjuvant chemotherapy regimen in a prospective randomized trial. EXPERIMENTAL DESIGN: Four hundred patients were randomized in a phase III trial comparing LV5FU2 to LV5FU2 + CPT-11. DNA from 184 patients was extracted and genotyped to detect nucleotide polymorphism: 3435C>T for ABCB1, 6986A>G for CYP3A5, UGT1A1*28 and -3156G>A for UGT1A1. RESULTS: Genotype frequencies were similar in both treatment arms. In the test arm, no significant difference was observed in toxicity or disease-free survival for ABCB1 and CYP3A5 polymorphisms. UGT1A1*28 homozygous patients showed more frequent severe hematologic toxicity (50%) than UGT1A1*1 homozygous patients (16.2%), P = 0.06. Moreover, patients homozygous for the mutant allele of -3156G>A UGT1A1 polymorphism showed more frequent severe hematologic toxicity (50%) than patients homozygous for wild-type allele (12.5%), P = 0.01. This toxicity occurred significantly earlier in homozygous mutant than wild-type homozygous patients (P = 0.043). In a Cox model, the hazard ratio for severe hematologic toxicity is significantly higher for patients with the A/A compared with the G/G genotype [hazard ratio, 8.4; 95% confidence interval, 1.9-37.2; P = 0.005]. CONCLUSIONS: This study supports the clinical utility of identification of UGT1A1 promoter polymorphisms before LV5FU2 + CPT-11 treatment to predict early hematologic toxicity. The -3156G>A polymorphism seems to be a better predictor than the UGT1A1 (TA)(6)TAA>(TA)(7)TAA polymorphism.