CYP2D6基因多态性在乳腺癌中的价值

细胞色素P450(cytochrome P450,CYP450)酶系属于单加氧酶,是一种以血红素为辅基的b族细胞色素超家族基因代谢酶,因其还原态的吸收峰在450 nm处而命名。CYP450具有解毒作用,通常可将脂溶性有毒物质代谢为水溶性物质,使有毒物质排出体外。CYP2D6是CYP450家族中的一员,是一种重要的参与外源性物质在体内代谢的酶。研究[1]表明,CYP2D6     

乳腺癌患者CYP2D6基因多态性与他莫昔芬疗效关系的研究进展

摘 要：乳腺是女性激素的靶器官,雌激素与乳腺癌的发病密切相关,内分泌治疗是乳腺癌重要的治疗手段。对于雌激素受体（estrogen receptor,ER）阳性的患者,他莫昔芬（tamoxifen,TAM）是重要的内分泌治疗药物。但是TAM抗肿瘤作用微弱,需要经过体内代谢才能更好发挥作用。CYP2D6是TAM正常代谢的关键酶,具有多种基因多态性。CYP2D6基因多态性是否会影响TAM疗效,既往研究存在较大争议。该文回顾相关文献,就CYP2D6基因多态性与TAM疗效关系的进展作一综述。     

CYP2D6基因多态性与乳腺癌内分泌治疗

CYP2D6是细胞色素P450的一种同工酶,代谢许多临床常用药物。其基因的多态性可以影响他莫昔芬的代谢,从而导致携带不同基因型的乳腺癌患者对他莫昔芬的反应性不同。本文简要综述了CYP2D6基因多态性与他莫昔芬代谢和疗效的关系,药物间的相互作用对他莫昔芬代谢的影响,以及针对不同患者选择个体化内分泌治疗方案。     

乳腺癌患者CYP2D6基因多态性与他莫昔芬代谢相关性研究

目的 探究乳腺癌患者CYP2D6基因多态性与他莫昔芬药物代谢产物浓度之间的关系。方法 收集2010年1月—2012年12月我院乳腺癌患者的外周血样本,检测CYP2D6基因上rs16947,rs1065852和rs28371725三种单核苷酸多态性(Single nucleotide polymorphism,SNP)位点的基因型及他莫昔芬代谢产物在血液中的浓度。应用非参数检验中的独立样本Kruskal-Wallis检验进行统计学分析。结果 CYP2D6基因上rs16947位点不同基因型携带者间他莫昔芬代谢产物4-OH-N-D-TAM和4'OH-N-D-TAM在血液中的浓度具有统计学差异(P=0.049),表明CYP2D6基因上的rs16947位点影响他莫昔芬药物在人体内的代谢。结论 乳腺癌患者CYP2D6基因rs16947位点的基因型与部分他莫昔芬代谢产物的血液浓度有关。     

CYP2D6与他莫昔芬疗效相关性的研究进展

CYP2D6是一种重要的P450系氧化代谢酶,是他莫昔芬在体内代谢成更强抗雌激素作用代谢产物endoxifen的重要代谢酶,因此,强代谢乳腺癌患者服用他莫昔芬后引起明显的潮热症状,而潮热症状的发生与他莫昔芬疗效正相关。除了CYP2D6基因多态性可能影响他莫昔芬体内的代谢外,帕罗西汀（paroxetine）可竞争性抑制CYP2D6对他莫昔芬的代谢,使乳腺癌患者对他莫昔芬疗效明显降低。     

CYP2D6基因型多态性及其对他莫昔芬治疗的影响研究进展

他莫昔芬(Tamoxifen,TAM)是雌激素受体(estrogen receptor,ER)阳性乳腺癌患者的标准辅助内分泌治疗药物。肝细胞色素P450 2D6(cytochromeP450 2D6,CYP2D6)是一种重要的代谢酶,在TAM代谢过程中发挥关键作用。CYP2D6编码基因具有多态性,不同等位基因型的乳腺癌患者CYP2D6代谢酶的活性存在较大差异,对TAM治疗的反应亦不同。研究表明,CYP2D6突变会导致TAM的活性抗肿瘤成分endoxifen的血药浓度明显降低,但其是否影响TAM的治疗疗效尚未得出一致结论。我国人群中常见的CYP2D6基因突变有别于其他人种,具有明显的地域差异。全文综述国内外CYP2D6基因型多态性分布,并结合回顾性及前瞻性临床试验分析CYP2D6基因型多态性对TAM疗效及患者预后的影响,旨在指导我国乳腺癌患者TAM个体化用药。     

乳腺癌患者CYP2D6多态性与Endoxifen血药浓度的相关性分析

目的:研究乳腺癌术后服用他莫昔芬(TAM)辅助治疗绝经前、雌激素受体(ER)阳性患者CYP2D6基因多态性与TAM活性代谢产物Endoxifen血药浓度的相关性,及其与TAM不良反应发生的相关性。方法:57例乳腺癌术后经TAM辅助治疗的患者(绝经前、ER阳性),采用Tetra-primer ARMS PCR检测其CYP2D6基因型,采用LC-MS/MS测定所有患者体内TAM及其活性代谢产物Endoxifen的血药浓度;根据患者自述标记存在治疗不良反应的个体。结果:CYP2D6*10/*10型和*1/*10型受试者体内Endoxifen的血药浓度值分别为(23.55±4.01)和(25.90±3.93)ng/mL,均显著低于*1/*1型受试者(34.82±5.95)ng/mL,差异有统计学意义,P<0.01;但*10/*10型和*1/*10型之间Endoxifen的浓度值差异无统计学意义,P>0.05。CYP2D6*1/*1型组自述无任何不良反应的比例(22.2%)低于突变组(62.5%),且差异有统计学意义,P<0.05。结论:CYP2D6基因多态性与Endoxifen血药浓度的差异及TAM治疗不良反应的发生有关;根据CYP2D6基因型,可指导绝经前、ER阳性乳腺癌患者术后的TAM个体化用药。     

新疆地区不同民族激素受体阳性乳腺癌患者CYP2D6基因多态性及拷贝数变异研究

目的:探讨新疆地区不同民族激素受体阳性乳腺癌患者CYP2D6基因多态性及拷贝数变异情况以指导临床合理用药。方法:选取2008年1月1日至2012年12月31日新疆医科大学附属肿瘤医院激素受体阳性乳腺癌患者253例,其中汉族126例、维吾尔族78例和哈萨克族49例,采用TaqMan实时荧光定量PCR技术和AccuCopyTM多重基因拷贝数检测技术进行CYP2D6基因多态性及拷贝数变异检测。结果:97.6%（247/253）的患者都检测到了CYP2D6等位基因多态性或拷贝数变异情况,最常见多态分布CYP2D6等位基因是*1、*2、*10,分布频率分别为0.577、0.320、0.462。CYP2D6的*2、*4、*10等位基因在汉族、维吾尔族及哈萨克族乳腺癌患者中分布频率分别为（0.023 8、0.038 4、0.042 9）、（0.031、0.038、0.163）、（0.635、0.372、0.184）,差异有统计学意义。汉族、维吾尔族、哈萨克族乳腺癌患者CYP2D6代谢表型及拷贝数情况分布差异无统计学意义。结论:在新疆地区汉族、维吾尔族、哈萨克族激素受体阳性乳腺癌患者CYP2D6基因在代谢表型多态性及拷贝数变异情况方面未发现明显的民族差异性,但*2、*4、*10等位基因在不同民族间分布有差异,为他莫昔芬个体化治疗的进一步研究提供了一定依据。     

CYP2D6基因多态性与乳腺癌患者盐酸表柔比星治疗疗效的相关性研究

目的 探讨CYP2D6基因多态性对乳腺癌患者盐酸表柔比星治疗预后的影响.方法 筛选125例雌激素受体阳性的乳腺癌患者,采用常规酚-氯仿法行全血基因组DNA提取,采用TaqMan MGB RT-PCR法进行CYP2D6基因多态性检测,利用分析软件确定各个样本的基因分型结果(C/C:野生型,C/T:突变杂合子,T/T:突变型).结果 125例乳腺癌患者中,野生型46例(36.8％),突变杂合子55例(44.0％),突变型24例(19.2％).不同CYP2D6*10基因突变型患者的盐酸表柔比星不良反应发生率比较,差异无统计学意义(P﹥0.05).T/T组患者的盐酸表柔比星不良反应发生率低于C/C+C/T组.T/T、C/C和C/T组患者的生存时间比较,差异有统计学意义(P﹤0.05),C/C+C/T组患者的生存时间短于T/T组患者,差异有统计学意义(P﹤0.05).肿瘤最大直径为2～5 cm、淋巴结转移个数≥4、孕激素受体(+++)、CYP2D6(C/T)是影响患者生存时间的独立危险因素.结论CYP2D6*10基因多态性与静脉滴注盐酸表柔比星的雌激素受体阳性的乳腺癌患者生存期缩短有相关性.     

基于CYP2D6多态性晚期乳腺癌内分泌解救策略的研究

目的:探讨大剂量托瑞米芬能否克服乳腺癌CYP2D6*10代谢缺陷,为晚期激素受体阳性乳腺癌患者寻求一种廉价有效的解救策略。方法:选取我院2015年1月至2018年6月收治的晚期乳腺癌患者95例,用PCR方法检测CYP2D6基因多态性。对于CYP2D6*10型患者,按照最佳三阶段设计原则,给予托瑞米芬120 mg每天一次。按修订的实体瘤疗效评价标准评价治疗效果。结果:95例晚期乳腺癌患者中,Wt/Wt 型28例（29.5%）,Wt/*10型49例(51.6%),*10/*10型18例(18.9%)。χ2检验显示CYP2D6 基因多态性与年龄、组织类型、Ki67高低、内脏转移、转移数目等均无明显相关性。第二阶段纳入41例患者,疾病稳定患者仅为10例,遂终止研究。*10/*10型患者疾病控制率为33.3%(5/15),Wt/*10型患者疾病控制率为19.2%(5/26)。3例PR患者均来自*10/*10组。中位随访46个月,*10/*10型患者和Wt/*10型患者OS分别为41个月和43个月,无统计学差异,P=0.327。结论:总体而言,在他莫昔芬治疗失败后CYP2D6*10型乳腺癌患者继续用大剂量托瑞米芬来解救获益不明显,但对于CYP2D6*10/*10亚型的患者,托瑞米芬可能有潜在的解救价值。     

Effect of CYP2D6 polymorphisms on breast cancer recurrence

BACKGROUND:

Previous studies evaluating the effect of cytochrome P450 2D6 (CYP2D6) polymorphisms on outcomes of adjuvant tamoxifen therapy have been conflicting due to differences in study design, concomitant medications that alter CYP2D6 metabolism, and tamoxifen adherence.

METHODS:

The authors performed CYP2D6 genotyping from whole blood and fresh frozen tumor samples (n 106) in patients at The University of Texas MD Anderson Cancer Center who were receiving, or had received, tamoxifen as adjuvant therapy for early breast cancer (EBC), using the AmpliChip CYP450 Test. Each patient's medical history was assessed for drugs that affected CYP2D6. Fifty‐five patients who had experienced breast cancer recurrence were matched (by date of diagnosis, menopausal status, clinical stage [TNM Staging System], and race) to patients without recurrence.

RESULTS:

Unadjusted for other patient characteristics, the odds ratio for disease recurrence associated with CYP2D6 functional status was 1.0 (95% confidence interval, 0.35‐2.85). After adjustment for stage, CYP2D6 inhibitors (moderate or strong vs none), and follow‐up time, no significant association was found between CYP2D6 genotype and breast cancer recurrence in patients who were treated with adjuvant tamoxifen for EBC.

CONCLUSIONS:

This case‐control study demonstrated no significant effect of CYP2D6 genotype on risk of recurrence in breast cancer patients who received adjuvant tamoxifen therapy. Cancer 2012;. © 2011 American Cancer Society.     

The relationship between the CYP2D6 polymorphisms and tamoxifen efficacy in adjuvant endocrine therapy of breast cancer patients in Chinese Han population

Variants of the CYP2D6 gene may lead to a poor prognosis of tamoxifen (TAM)‐treated patients. Our study validated the association between the CYP2D6 genotype and outcomes of patients receiving TAM in adjuvant endocrine therapy. A total of 778 breast cancer patients who received adjuvant TAM (n = 325) or aromatase inhibitors (AIs) (n = 453) at the National Cancer Center were analyzed. Nine single nucleotide polymorphisms (SNPs) in the CYP2D6 gene were selected from online databases. The associations of each SNP genotype with disease‐free survival (DFS) and clinicopathological characteristics were analyzed. A total of 167 (21.5%) patients carried the CYP2D6*10 (c.100C>T) T/T genotype. Among the 325 patients who received TAM, the 5‐year DFS rate was considerably lower in CYP2D6*10 T/T genotype patients than C/C or C/T patients (54.9% vs. 70.9%, p = 0.007). The T/T genotype for CYP2D6*10 was a significant prognostic marker for DFS in multivariate analysis (hazard ratio = 1.87; p = 0.006). The CYP2D6*10 genotype in women who received AIs was not significantly associated with DFS (p = 0.332). Other SNPs were not related to the survival of patients who received TAM. Our finding showed patients with CYP2D6*10 T/T received less benefit from TAM adjuvant treatment. This conclusion may optimize the individualized treatments for this subgroup of patients.     

The impact of CYP2D6-predicted phenotype on tamoxifen treatment outcome in patients with metastatic breast cancer

Background:

Cytochrome P450 2D6 (CYP2D6) has a crucial role in the metabolic conversion of tamoxifen into the active metabolite endoxifen. In this cohort study, the effect of CYP2D6-predicted phenotype, defined as the combined effect of CYP2D6 genetic variation and concomitant use of CYP2D6-inhibiting medication, on time to breast cancer progression (TTP) and overall survival (OS) in women who use tamoxifen for metastatic breast cancer (MBC) was examined.

Methods:

We selected patients treated with tamoxifen (40 mg per day) for hormone receptor-positive MBC from whom a blood sample for pharmacogenetic analysis (CYP2D6*3, *4, *5, *6, *10 and *41) was available. Patient charts (n=102) were reviewed to assess TTP and OS, and to determine whether CYP2D6 inhibitors were prescribed during tamoxifen treatment.

Results:

OS was significantly shorter in patients with a poor CYP2D6 metaboliser phenotype, compared with extensive metabolisers (HR=2.09; P=0.034; 95% CI: 1.06–4.12). Co-administration of CYP2D6 inhibitors alone was also associated with a worse OS (HR=3.55; P=0.002; 95% CI: 1.59–7.96) and TTP (HR=2.97; P=0.008; 95% CI: 1.33–6.67) compared with patients without CYP2D6 inhibitors.

Conclusion:

CYP2D6 phenotype is an important predictor of treatment outcome in women who are receiving tamoxifen for MBC. Co-administration of CYP2D6 inhibitors worsens treatment outcome of tamoxifen and should therefore be handled with care.     

CYP2D6基因多态性对他莫昔芬及托瑞米芬代谢和疗效影响的研究进展

他莫昔芬和托瑞米芬均为选择性的雌激素受体调节剂,通过竞争性结合雌激素受体发挥抗癌作用,是绝经前乳腺癌最常用的辅助内分泌治疗药物,能够显著降低乳腺癌患者的复发和死亡风险。多项研究发现CYP2D6*10基因的突变会影响他莫昔芬的代谢导致预后不良。而托瑞米芬的代谢受CYP2D6基因多态性的影响较小,治疗乳腺癌的疗效与他莫昔芬相当,甚至优于他莫昔芬。本文就CYP2D6基因多态性与两种内分泌药物代谢和疗效的相关性研究作系统阐述。     

Relationships between CYP2D6 phenotype, breast cancer and hot flushes in women at high risk of breast cancer receiving prophylactic tamoxifen: results from the IBIS-I trial

Background:

Several studies have reported discordant results regarding the impact of the CYP2D6 phenotype on both the effectiveness and the degree of endocrine symptoms associated with tamoxifen. Other studies have suggested that menopausal symptoms may be a predictive factor to tamoxifen response.

Methods:

We investigated the relationship between the CYP2D6-predicted phenotype and tamoxifen response in a nested case–control study among women from the International Breast cancer Intervention Study (IBIS-I), which evaluated tamoxifen in the preventive setting.

Results:

In this retrospective analysis of the tamoxifen-treated women in the IBIS-I study, 9 women (16.6%) who developed oestrogen receptor-positive invasive breast cancer had a 2D6 poor or intermediate metaboliser phenotype compared with 45 (20.6%) controls. Adjusted matched logistic regression revealed no significant difference between cases and controls for extensive vs intermediate metaboliser phenotype (OR=0.81 (0.30–2.23), P=0.7) or extensive vs poor metaboliser phenotype (OR=1.02 (0.31–3.32), P=0.9). Controls in the tamoxifen group with a poor metaboliser phenotype developed nonsignificantly fewer hot flushes compared with those with an extensive metaboliser phenotype (OR=0.40 (0.12–1.31)), but those with the intermediate phenotype developed nonsignificantly more hot flushes (OR=1.38 (0.58–3.29)) in an unadjusted analysis.

Conclusion:

Data from the preventive IBIS-I study did not support an association between the CYP2D6 phenotype and breast cancer outcome or the development of endocrine symptoms in tamoxifen-treated women.     

新疆汉族与维吾尔族乳腺癌CYP2D6和CYP2C19基因多态性差异研究

目的 探讨新疆汉族与维吾尔族绝经前乳腺癌患者CYP2D6和CYP2C19基因频率分布及他莫昔芬代谢类型以指导临床合理用药.方法 选取2011-06-01-2013-12-01新疆医科大学附属肿瘤医院绝经前激素受体阳性乳腺癌患者中汉族125例和维吾尔族121例,对CYP450中常见突变位点利用TaqMan(R)-MGB技术进行基因检测并确定他莫昔芬代谢类型.结果 CYP2D6(* 1/* 10)、CYP2D6(* 10/* 10)及CYP2C19(* 1/*1)基因型在汉族、维吾尔族两组患者中表达差异有统计学意义,x2值分别为1.123、9.746和5.935,P值分别为0.029、0.002和0.015;而CYP2D6(* 1/*5)、CYP2D6(* 5/*5)、CYP2D6(* 5/* 10)、CYP2C19(* 3/*3)基因型在两组患者中均无表达,差异无统计学意义,P＞0.05.两组中CYP2D6(* 1/*1)、CYP2C19(* 1/*2)、CYP2C19(* 2/*2)、CYP2C19(* 1/*3)和CYP2C19(* 2/*3)基因型差异无统计学意义,P＞0.05.汉族患者他莫昔芬快、中、慢代谢型者比例分别为72.0％、24.0％和4.0％,维吾尔族分别为76.9％、17.4％和5.7％,P＞0.05.结论 汉族、维吾尔族乳腺癌患者中CYP2C19*2、CYP2C19*3基因频率均差异无统计学意义;而CYP2D6* 10等位基因的频率差异有统计学意义;他莫昔芬的代谢类型均以快代谢类型为主,两组之间差异无统计学意义.     

Impact of CYP2D*6 in the adjuvant treatment of breast cancer patients with tamoxifen

Biotransformation of tamoxifen to the potent antiestrogen endoxifen is performed by cytochrome P450 (CYP) enzymes, in particular the CYP2D6 isoform. CYP2D6*4 is one of the most frequent alleles associated with loss of enzymatic activity. The incidence of CYP2D6*4 among Caucasians is estimated up to 27%, while it is present in up to 90% of all poor metabolizers within the Caucasian population. The hypothesis under question is whether the presence of one or two non-functioning (null) alleles predicts an inferior outcome in postmenopausal women with breast cancer receiving adjuvant treatment with tamoxifen. The numerous existing studies investigating the association of CYP2D6 with treatment failure in breast cancer are inconsistent and give rather conflicting results. Currently, routine CYP2D6 testing among women with breast cancer is not recommended and the significance of CYP2D6 phenotype in decision making regarding the administration of tamoxifen is unclear. The present study summarizes current literature regarding clinical studies on CYP2D6*4, particularly in terms of response to tamoxifen therapy and breast cancer outcome.     

Association of genetic variation in tamoxifen-metabolizing enzymes with overall survival and recurrence of disease in breast cancer patients

Summary Tamoxifen has been a mainstay of adjuvant therapy for breast cancer for many years. We sought to determine if genetic variability in the tamoxifen metabolic pathway influenced overall survival in breast cancer patients treated with tamoxifen. We examined functional polymorphisms in CYP2D6, the P450 catalyzing the formation of active tamoxifen metabolites, and UGT2B15, a Phase II enzyme facilitating the elimination of active metabolite in a retrospective study of breast cancer patients. We also examined whether the combination of variant alleles in SULT1A1 and UGT2B15 had more of an impact on overall survival in tamoxifen-treated patients than when the genes were examined separately.We conducted a retrospective study using archived paraffin blocks for DNA extraction and data from pathology reports and hospital tumor registry data for information on clinical characteristics, treatment, and outcomes (162 patients receiving tamoxifen and 175 who did not). Genotypes for CYP2D6 and UGT2B15 were obtained and Cox proportional hazards modeling was performed.After adjusting for age, race, stage of disease at diagnosis, and hormone receptor status, we found no significant association between CYP2D6 genotype and overall survival in either group of breast cancer patients. Tamoxifen-treated patients with UGT2B15 high activity genotypes had increased risk of recurrence and poorer survival. When UGT2B15 and SULT1A1 ‘at-risk’ alleles were combined, women with two variant alleles had significantly greater risk of recurrence and poorer survival than those with common alleles. These studies indicate that genetic variation in Phase II conjugating enzymes can influence the efficacy of tamoxifen therapy for breast cancer.