張 欣, 羅和生
武漢大學(xué)人民醫(yī)院消化內(nèi)科,湖北 武漢 430060
抗VEGF/VEGFR靶向藥物的治療進(jìn)展
張 欣, 羅和生
武漢大學(xué)人民醫(yī)院消化內(nèi)科,湖北 武漢 430060
腫瘤微環(huán)境在腫瘤的起源、生長(zhǎng)和轉(zhuǎn)移中發(fā)揮重要作用,而新生血管是腫瘤生長(zhǎng)和轉(zhuǎn)移所必需的,血管的生成需要大量調(diào)節(jié)血管生成的細(xì)胞因子參加,而血管內(nèi)皮生長(zhǎng)因子(vascular endothelial growth factor,VEGF)是最重要的促血管生成因子。阻斷VEGF通路中某一環(huán)節(jié),均有可能有效地抑制腫瘤血管生成,使腫瘤血管退化脫落,產(chǎn)生抗腫瘤作用。根據(jù)VEGF的調(diào)控特點(diǎn),已出現(xiàn)多種以VEGF/VEGFR為靶點(diǎn)的抗腫瘤血管生成藥物。本文就抗VEGF的靶向藥物治療及特點(diǎn)作一概述。
VEGF/VEGFR;抗腫瘤藥物;治療進(jìn)展
腫瘤微環(huán)境在腫瘤的起源、生長(zhǎng)和轉(zhuǎn)移中發(fā)揮著重要作用[1],1971年,F(xiàn)olkman[2]發(fā)現(xiàn)血管生成在腫瘤生長(zhǎng)過(guò)程中發(fā)揮重要的作用,新生血管是腫瘤生長(zhǎng)和轉(zhuǎn)移的必要條件[3]。此后,血管生成的研究格外受到人們的關(guān)注,而血管內(nèi)皮生長(zhǎng)因子(vascular endothelial growth factor,VEGF)在血管生成過(guò)程中尤為重要。
VEGF具有高度特異性,其家族成員有VEGF-A、VEGF-B、VEGF-C、VEGF-D和胎盤(pán)生長(zhǎng)因子(placental growth factor,PIGF)。VEGF-A能與VEGFR-1和VEGFR-2結(jié)合,可促進(jìn)血管生成,增加血管通透性,這與Roskoski[4]研究一致,同時(shí)還發(fā)現(xiàn)VEGF-A可促進(jìn)內(nèi)皮細(xì)胞增殖遷徙。VEGF-B只能和VEGFR-1結(jié)合,且它的功能還未研究清楚,但有研究指出VEGF-B可能不直接促進(jìn)血管生成,而是血管生成的存活因子[5-6]。VEGF-C和VEGF-D主要與VEGFR-2和VEGFR-3結(jié)合,它們主要促進(jìn)血管生成和淋巴管生成。PIGF和VEGF-B一樣,只與VEGFR-1結(jié)合,它的功能尚不明確,但是越來(lái)越多的證據(jù)指出,PIGF可以促進(jìn)病理性血管生成[7]。有研究[8-12]表明VEGF通過(guò)旁分泌方式與血管內(nèi)皮細(xì)胞上的受體結(jié)合,促進(jìn)腫瘤細(xì)胞的生長(zhǎng)、侵襲和轉(zhuǎn)移,同時(shí)VEGF通過(guò)自分泌功能和腫瘤細(xì)胞表面的受體結(jié)合,促進(jìn)腫瘤細(xì)胞的侵襲和轉(zhuǎn)移。在腫瘤發(fā)生過(guò)程中,存在VEGF表達(dá)過(guò)量,這些過(guò)量表達(dá)的VEGF可誘導(dǎo)產(chǎn)生大量新生血管,而這些血管又為腫瘤轉(zhuǎn)移提供能量[13-14]。VEGFR是VEGF的受體,在正常生理情況下,當(dāng)VEGF與VEGF-R結(jié)合后,活化酪氨酸蛋白激酶信號(hào)系統(tǒng),參與調(diào)控細(xì)胞增殖與分化,VEGFR分為VEGFR-1、VEGFR-2和VEGFR-3,這3種VEGFR具有酪氨酸激酶活性[15-16],VEGFR-1的功能尚不明確,目前知道VEGFR-1具有血管性和非血管性的功能,它不僅能在腫瘤細(xì)胞上表達(dá),同時(shí)也能在單核細(xì)胞和巨噬細(xì)胞上表達(dá)[9,15,17-18],而VEGFR-2主要與VEGF-A結(jié)合促進(jìn)血管增生和增加血管通透性,VEGFR-2不僅在腫瘤細(xì)胞上表達(dá),且具有自分泌功能[15,19];VEGFR-3主要在淋巴細(xì)胞上表達(dá),介導(dǎo)淋巴管的生成[15,17]。
因此,根據(jù)VEGF及VEGFR的調(diào)控特點(diǎn),先后出現(xiàn)了多種靶向藥物,這些藥物可阻斷VEGF信號(hào)轉(zhuǎn)導(dǎo)通路中某一環(huán)節(jié),單獨(dú)或聯(lián)合化療產(chǎn)生抗腫瘤作用,抑制腫瘤生長(zhǎng)及轉(zhuǎn)移。
Bevacizumab,商品名Avastin,是第一個(gè)抗腫瘤血管生成藥物,于2004年在美國(guó)批準(zhǔn)上市,已被批準(zhǔn)用于多種實(shí)體瘤,如轉(zhuǎn)移性腎癌、轉(zhuǎn)移性結(jié)直腸癌、非小細(xì)胞肺癌等,目前與化療藥物聯(lián)用作為轉(zhuǎn)移性結(jié)直腸癌的一線治療方案。它是一種重組人VEGF的單克隆抗體,通過(guò)與VEGF-A結(jié)合,干擾VEGF-A與VEGFR-1、VEGFR-2結(jié)合,抑制腫瘤血管生成,從而抑制腫瘤生長(zhǎng)[20]。有Meta分析研究[20]指出,在晚期結(jié)腸癌中,Bevacizumab聯(lián)合化療如FOLFIRI或FOLFOX方案后較單用FOLFIRI或FOLFOX方案能顯著提高OS(HR=0.848,95%CI:0.747~0.963),延長(zhǎng)PFS(HR=0.617,95%CI:0.530~0.719),改善ORR(OR=1.627,95%CI:1.199~2.207;P<0.05)。貝伐珠單抗在晚期大腸癌的二線治療中也獲得了良好的效果,ECOG3200試驗(yàn)[21]顯示貝伐珠單抗聯(lián)合化療與單用化療相比,ORR分別為21.8%和9.2%,PFS分別為7.2個(gè)月和4.8個(gè)月,OS分別為12.9個(gè)月和10.8個(gè)月。
VEGF-Trap,即Aflibercept,商品名Zaltrap,于2012年8月批準(zhǔn)上市,Aflibercept可與VEGF-A、VEGF-B、PLGF-1及PLGF-2結(jié)合,抑制血管內(nèi)皮信號(hào)途徑的信號(hào)轉(zhuǎn)導(dǎo),同時(shí)下調(diào)腫瘤血管基因表達(dá),降低腫瘤血管密度,抑制腫瘤的生長(zhǎng)和轉(zhuǎn)移[22-25],在轉(zhuǎn)移性結(jié)直腸癌、轉(zhuǎn)移性非小細(xì)胞肺癌、轉(zhuǎn)移性胰腺癌的Ⅱ期、Ⅲ期臨床試驗(yàn)中,VEGF-Trap單獨(dú)或聯(lián)合化療使用均取得較滿意的療效[26],VEGF-Trap聯(lián)合FOLFIRI方案治療轉(zhuǎn)移性結(jié)直腸癌的Ⅲ期臨床試驗(yàn)中發(fā)現(xiàn),加用VEGF-Trap能較單用FOLFIRI能顯著延長(zhǎng)患者無(wú)進(jìn)展生存期(progression-free survival,PFS)(6.90vs4.67 個(gè)月)和OS(13.3vs12.06個(gè)月),因而被美國(guó)FDA批準(zhǔn)可用于聯(lián)合FOLFIRI治療預(yù)先接受過(guò)含奧沙利鉑方案化療的轉(zhuǎn)移性結(jié)腸癌患者[27]。在一項(xiàng)VITAL研究中發(fā)現(xiàn),Aflibercept聯(lián)合多西他賽的二線治療方案治療非小細(xì)胞肺癌,雖然OS無(wú)明顯改變,但是PFS(HR=0.82)和RR(response rate,23.3%vs8.9%)較未聯(lián)合使用Aflibercept明顯改善[28]。
有研究發(fā)現(xiàn),VEGFR數(shù)量有限,且易被飽和,對(duì)于VEGF而言,抑制VEGFR能夠更有效地抑制VEGF信號(hào)轉(zhuǎn)導(dǎo)途徑[29]。Ramucirumab(IMC-1121C)是完全人源化的VEGFR2抗體,它在許多腫瘤模型中具有抗腫瘤活性,2014年被美國(guó)FDA批準(zhǔn)上市,可用于治療晚期胃癌或食管胃交界腺癌,目前Ramucirumab聯(lián)合化療治療乳腺癌、非小細(xì)胞肺癌及二線治療轉(zhuǎn)移性結(jié)腸癌仍處于Ⅲ期臨床試驗(yàn)中;IMC-18F1是重組人VEGFR1單克隆抗體,它可以阻斷VEGF-A、VEGF-B、PIGF與VEGFR-1結(jié)合,在體外模型實(shí)驗(yàn)中能阻斷其生物學(xué)活性,同時(shí)表現(xiàn)出抗血管增生、抗增殖活性,除此之外,它還能增強(qiáng)細(xì)胞毒化療藥的抗腫瘤活性[30]。目前該藥仍處于Ⅰ期臨床試驗(yàn),但已取得較為滿意的結(jié)果[31-32]。
在VEGF信號(hào)轉(zhuǎn)導(dǎo)通路中,當(dāng)VEGF與VEGF-R結(jié)合后,活化酪氨酸蛋白激酶信號(hào)系統(tǒng),參與調(diào)控細(xì)胞增殖與分化,因此,阻斷酪氨酸蛋白激酶途徑即可有效抑制血管生成,因此酪氨酸激酶抑制劑(TKI)應(yīng)運(yùn)而生,此類藥物有sunitinib(Sutent;輝瑞)、sorafenib(Nexavar;拜耳)和pazopanib(Votrient;GlaxoSmithKline),被美國(guó)FDA批準(zhǔn)用于治療腎癌、胃腸基質(zhì)細(xì)胞癌、胰腺癌、肝細(xì)胞癌[27]。
Regorafenib是PDGF受體、c-kit、FGF受體及3種VEGFR的抑制劑,在惡性膠質(zhì)瘤的模型中,它可抑制腫瘤生長(zhǎng)和微血管的密度,同樣在乳腺癌和腎癌模型中,它也表現(xiàn)出抗腫瘤的特性[33]。目前,Regorafenib被FDA批準(zhǔn)用于三線或四線治療轉(zhuǎn)移性結(jié)腸癌。
由于VEGF-C、VEGF-D負(fù)責(zé)調(diào)控淋巴管的生成,因而出現(xiàn)針對(duì)鼠抗人VEGF-D單克隆抗體,抑制腫瘤淋巴管的生成,目前該種單克隆抗體仍處于實(shí)驗(yàn)階段,在多種小鼠荷瘤實(shí)驗(yàn)中證實(shí)有效,但仍需進(jìn)一步論證。
沙利度胺(Thalidomide,Thd)又名反應(yīng)停,曾作為鎮(zhèn)靜劑治療妊娠嘔吐,但由于其導(dǎo)致胎兒畸形而退出市場(chǎng),但在研究其致畸原因時(shí)發(fā)現(xiàn),沙利度胺可抑制妊娠初期胎兒某些器官的血管生成,造成畸形,有學(xué)者在沙利度胺干擾斑馬魚(yú)胚胎的發(fā)育過(guò)程中發(fā)現(xiàn),沙利度胺可下調(diào)VEGF受體neuropilin-1和FLK-1,從而抑制血管生成[34]。因此,現(xiàn)有多種惡性腫瘤化療方案聯(lián)合沙利度胺治療,取得良好的療效。在卡培他濱聯(lián)合沙利度胺治療進(jìn)展期HCC(肝癌)的臨床試驗(yàn)中,可提高患者中位總生存期和中位無(wú)進(jìn)展生存期[35]。在Ⅱ、Ⅲ期的非小細(xì)胞肺癌不能手術(shù)的患者中,采用吉西他濱+卡鉑(GC)方案聯(lián)合沙利度胺治療,治療前后均檢測(cè)血清血管生成素、VEGF,發(fā)現(xiàn)治療后檢測(cè)指標(biāo)最高下降達(dá)70%[36]。
miRNA是進(jìn)化上保守的一類非編碼小分子RNA,能夠通過(guò)與靶基因3’-UTR結(jié)合來(lái)參與mRNA的降解或阻礙mRNA的翻譯,進(jìn)而導(dǎo)致相關(guān)基因表達(dá)水平的下降[38]。Di Bernardini等[38]研究發(fā)現(xiàn)通過(guò)構(gòu)建熒光素酶報(bào)告基因,使得miRNA-21的模擬物可與VEGFA、VEGFB的3’UTG結(jié)合,然后抑制VEGFA、VEGFB的表達(dá),進(jìn)而抑制血管生成。因此,miRNA也成為抗腫瘤血管生成的新研究熱點(diǎn)。
腫瘤血管生成是一個(gè)極其復(fù)雜的過(guò)程,這個(gè)過(guò)程中需要有大量的細(xì)胞因子參與,干擾或阻斷其中的某一環(huán)節(jié)都有可能有效地抑制腫瘤血管生成。而VEGF可促進(jìn)血管生成,在惡性腫瘤的轉(zhuǎn)移過(guò)程中有重要作用,因此,將有更多的抗血管生成的靶向藥物被研發(fā)出來(lái),它們與傳統(tǒng)化療聯(lián)合,有望對(duì)進(jìn)展期、復(fù)發(fā)難治及轉(zhuǎn)移的惡性腫瘤提供新的治療途徑。
[1]Fukumura D, Jain RK. Tumor microenvironment abnormalities: causes, consequences, and strategies to normalize [J]. J Cell Biochem, 2007, 101(4): 937-949.
[2]Folkman J. Tumor angiogenesis: therapeutic implications [J]. N Engl J Med, 1971, 285(21): 1182-1186.
[3]Folkman J. What is the evidence that tumors are angiogenesis dependent? [J]. J Natl Cancer Inst, 1990, 82(1): 4-6.
[4]Roskoski R Jr. Vascular endothelial growth factor (VEGF) signaling in tumor progression [J]. Crit Rev Oncol Hematol, 2007, 62(3): 179-213.
[5]Olofsson B, Korpelainen E, Pepper MS, et al. Vascular endothelial growth factor B (VEGF-B) binds to VEGF receptor-1 and regulates plasminogen activator activity in endothelial cells [J]. Proc Natl Acad Sci U S A, 1998, 95(20): 11709-11714.
[6]Li X, Lee C, Tang Z, et al. VEGF-B: a survival, or an angiogenic factor? [J]. Cell Adh Migr, 2009, 3(4): 322-327.
[7]Ribatti D. The discovery of the placental growth factor and its role in angiogenesis: a historical review [J]. Angiogenesis, 2008, 11(3): 215-221.
[8]Lu Y, Zhang A, Wang S, et al. Role of vascular endothelial growth factor overexpression in ovarian tumor invasion and mechanism [J]. Zhonghua Fu Chan Ke Za Zhi, 2002, 37(5): 294-297.
[9]Suzuki K, Hayashi N, Miyamoto Y, et al. Expression of vascular permeability factor/vascular endothelial growth factor in human hepatocellular carcinoma [J]. Cancer Res, 1996, 56(13): 3004-3009.
[10]Gadducci A, Viacava P, Cosio S, et al. Vascular endothelial growth factor (VEGF) expression in primary tumors and peritoneal metastases from patients with advanced ovarian carcinoma [J]. Anticancer Res, 2003, 23(3C): 3001-3008.
[11]Ha JL, Zhang ZB. Study on relationship between expression of VEGF and microvascular density in human epithelial ovarian cancer tissue [J]. Journal of Xianning University (Medical Sciences), 2011, 25(4): 296-298.
哈建利,張澤波.卵巢癌組織中VEGF的表達(dá)及其與MVD的關(guān)系[J].咸寧學(xué)院學(xué)報(bào)(醫(yī)學(xué)版),2011,25(4): 296-298.
[12]Lee JS, Kim HS, Jung JJ, et al. Expression of vascular endothelial growth factor in adenocarcinomas of the uterine cervix and its relation to angiogenesis and p53 and c-erbB-2 protein expression [J]. Gynecol Oncol, 2002, 85(3): 469-475.
[13]Deng LC, Shen WS, Zhang Y, et al. The effect of chemotherapy on serum VEGF levels in patients with advanced colorectal cancer [J]. Journal of Clinical Medicine in Practice, 2010, 14(5): 90-91, 93.
鄧立春, 沈偉生, 張瑤, 等. 化療對(duì)晚期結(jié)直腸癌患者血清VEGF水平的影響[J]. 實(shí)用臨床醫(yī)藥雜志, 2010, 14(5): 90-91, 93.
[14]Liu JS, Zhu MC. Research progress of RNAi inhibited VEGF expression in tumor therapy [J]. Int J Lab Med, 2011, 32(1): 60-62.
劉津杉, 朱明才. RNAi抑制VEGF表達(dá)在腫瘤治療中的研究進(jìn)展[J]. 國(guó)際檢驗(yàn)醫(yī)學(xué)雜志, 2011, 32(1): 60-62.
[15]Cao Y. Positive and negative modulation of angiogenesis by VEGFR1 ligands [J]. Sci Signal, 2009, 2(59): re1.
[16]Korpanty G, Sullivan LA, Smyth E, et al. Molecular and clinical aspects of targeting the VEGF pathway in tumors [J]. J Oncol, 2010, 2010: 652320.
[17]Takahashi S. Vascular endothelial growth factor (VEGF), VEGF receptors and their inhibitors for antiangiogenic tumor therapy [J]. Biol Pharm Bull, 2011, 34(12): 1785-1788.
[18]Fischer C, Mazzone M, Jonckx B, et al. FLT1 and its ligands VEGFB and PIGF: drug targets for anti-angiogenic therapy? [J]. Nat Rev Cancer, 2008, 8(12): 942-956.
[19]Hamerlik P, Lathia JD, Rasmussen R, et al. Autocrine VEGF-VEGFR2-Neuropilin-1 signaling promotes glioma stem-like cell viability and tumor growth [J]. J Exp Med, 2012, 209(3): 507-520.
[20]Qu CY, Zheng Y, Zhou M, et al. Value of bevacizumab in treatment of colorectal cancer: A meta-analysis [J]. World J Gastroenterol, 2015, 21(16): 5072-5080.
[21]Reddy GK. The addition of bevacizumab to FOLFOX4 prolongs survival in relapsed colorectal cancer: interim data from the ECOG 3200 trial [J]. Clin Colorectal Cancer, 2005, 4(5): 300-301.
[22]Huang J, Frischer JS, Serur A, et al. Regression of established tumors and metastases by potent vascular endothelial growth factor blockade [J]. Proc Natl Acad Sci U S A, 2003, 100(13): 7785-7790.
[23]Byrne AT, Ross L, Holash J, et al. Vascular endothelial growth factor-trap decreases tumor burden, inhibits ascites, and causes dramatic vascular remodeling in an ovarian cancer model [J]. Clin Cancer Res, 2003, 9(15): 5721-5728.
[24]Verheul HM, Hammers H, van Erp K, et al. Vascular endothelial growth factor trap blocks tumor growth, metastasis formation, and vascular leakage in an orthotopic murine renal cell cancer model [J]. Clin Cancer Res, 2007, 13(14): 4201-4208.
[25]Lassoued W, Murphy D, Tsai J, et al. Effect of VEGF and VEGF Trap on vascular endothelial cell signaling in tumors [J]. Cancer Biol Ther, 2010, 10(12): 1326-1333.
[26]Gaya A, Tse V. A preclinical and clinical review of aflibercept for the management of cancer [J]. Cancer Treat Rev, 2012, 38(5): 484-493.
[27]Ciombor KK, Berlin J, Chan E. Aflibercept [J]. Clin Cancer Res, 2013, 19(8): 1920-1925.
[28]Ramlau R, Gorbunova V, Ciuleanu TE, et al. Aflibercept and Docetaxel versus Docetaxel alone after platinum failure in patients with advanced or metastatic non-small-cell lung cancer: a randomized, controlled phase III trial [J].J Clin Oncol, 2012, 30(29): 3640-3647.
[29]Zhu Z, Witte L. Inhibition of tumor growth and metastasis by targeting tumor-associated angiogenesis with antagonists to the receptors of vascular endothelial growth factor [J]. Invest New Drugs, 1999, 17(3): 195-212.
[30]Wu Y, Zhong Z, Huber J, et al. Anti-vascular endothelial growth factor receptor-1 antagonist antibody as a therapeutic agent for cancer [J]. Clin Cancer Res, 2006, 12(21): 6573-6584.
[31]Spratlin JL, Cohen RB, Eadens M, et al. Phase Ⅰ pharmacologic and biologic study of ramucirumab (IMC-1121B), a fully human immunoglobulin G1 monoclonal antibody targeting the vascular endothelial growth factor receptor-2 [J]. J Clin Oncol, 2010, 28(5): 780-787.
[32]Chen C, Yu DC, Teng LS. Development of anti-tumor drugs targeting VEGF/VEGFR: a progress [J]. Chin J Cancer Biother, 2007, 14(3): 291-295, 300.
陳川, 俞德超, 滕理送. 以VEGF/VEGFR為靶點(diǎn)的抗腫瘤藥物的研究進(jìn)展[J]. 中國(guó)腫瘤生物治療雜志, 2007, 14(3): 291-295, 300.
[33]Wilhelm SM, Dumas J, Adnane L, et al. Regorafenib (BAY 73-4506): a new oral multikinase inhibitor of angiogenic, stromal and oncogenic receptor tyrosine kinases with potent preclinical antitumor activity [J]. Int J Cancer, 2011, 129(1): 245-255.
[34]Yabu T, Tomimoto H, Taguchi Y, et al. Thalidomide-induced antiangiogenic action is mediated by ceramide through depletion of VEGF receptors, and is antagonized by sphingosine-1-phosphate [J]. Blood, 2005, 106(1): 125-134.
[35]Ang SF, Tan SH, Toh HC, et al. Activity of thalidomide and capecitabine in patients with advanced hepatocellar carcinoma [J]. Am J Clin Oncol, 2012, 35(3): 222-227.
[36]Dudek AZ, Lesniewski-Kmak K, Larson T, et al. Phase Ⅱ trial of neoadjuvant therapy with carboplatin, gemcitabine plus thalidomide for stages ⅡB and Ⅲ non-small cell lung cancer [J]. J Thorac Oncol, 2009, 4(8): 969-975.
[37]He DL, Xie XM, Liu Y, et al. Preliminary study of microRNA expression in colon cancer drug-resistant cell line LoVo/5-Fu [J]. China Journal of Modern Medicine, 2013, 23(18): 31-35.
何冬雷, 謝小明, 劉玉, 等. 結(jié)腸癌耐藥細(xì)胞株LoVo/5-Fu中microRNA表達(dá)的初步研究[J]. 中國(guó)現(xiàn)代醫(yī)學(xué)雜志, 2013, 23(18): 31-35.
[38]Di Bernardini E, Campagnolo P, Margariti A, et al. Endothelial lineage differentiation from induced pluripotent stem cells is regulated by microRNA-21 and transforming growth factor β2 (TGF-β2) pathways [J]. J Biol Chem, 2014, 289(6): 3383-3393.
(責(zé)任編輯:馬 軍)
The therapy progress of target drugs of anti-VEGF/VEGFR
ZHANG Xin, LUO Hesheng
Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, China
Tumor microenvironment plays an important role in tumor, including the origin, growth and metastasis. And angiogenesis is essential for tumor growth and metastasis, lots of cytokines take part in angiogenesis, and vascular endothelial growth factor (VEGF) is the most important one of them. Blocking the VEGF pathway can inhibit tumor angiogenesis, and improve the degradation of tumor vessel, also produce broad-spectrum anti-tumor effect. According to the characteristics of VEGF regulation, the tumor angiogenesis drugs with VEGF/VEGFR as the target have appeared. The characteristics of target drugs of anti VEGF were summarized in this paper.
VEGF/VEGFR; Anti-tumor drugs; Therapy progress
10.3969/j.issn.1006-5709.2016.03.034
張欣,博士,研究方向:消化道惡性腫瘤。E-mail:katherine1216@163.com
羅和生,博士生導(dǎo)師,教授,研究方向:胃腸動(dòng)力學(xué)、消化道惡性腫瘤。E-mail:xhnk@163.com
R735
A
1006-5709(2016)03-0355-04
2015-05-28