鐘綠,湯紹輝
低分子量肝素(LMWH)是由普通肝素解聚制備而成的一類分子量較低的肝素的總稱[1]。常見的LMWH有依諾肝素鈉、那屈肝素鈣、達(dá)肝素鈉及亭扎肝素等[2]。LMWH具有很高的抗凝血因子Ⅹa活性和較低的抗凝血因子Ⅱa活性,保留了普通肝素的抗血栓作用而降低了出血的風(fēng)險[3]。目前LMWH廣泛應(yīng)用于預(yù)防與治療肺栓塞(PE)和深靜脈血栓形成(DVT)以及不穩(wěn)定性冠狀動脈疾病、缺血性腦卒中、腎病綜合征等疾?。?-3]。
靜脈血栓栓塞癥(venous thromboembolism,VTE)是惡性腫瘤的常見并發(fā)癥之一,一般包括DVT和PE。惡性腫瘤細(xì)胞表達(dá)組織因子或其他促凝物質(zhì),可直接激活凝血酶原[4]。此外,腫瘤細(xì)胞釋放血管通透因子或血管內(nèi)皮細(xì)胞生長因子,使微血管通透性增加,促凝因子進(jìn)入血管激活全身凝血過程。惡性腫瘤組織壞死后還可產(chǎn)生大量內(nèi)源性和外源性的凝血活酶,促進(jìn)血栓形成[5-7]。因此惡性腫瘤患者凝血系統(tǒng)常被激活而處于高凝狀態(tài),這不僅容易導(dǎo)致VTE的發(fā)生,而且還有利于腫瘤的生長和轉(zhuǎn)移[8]。部分惡性腫瘤患者在疾病的早期即可出現(xiàn)DVT,而到了疾病的進(jìn)展期VTE發(fā)生率明顯升高,但不同類型的惡性腫瘤患者VTE發(fā)生率有明顯差異。研究顯示,腦、卵巢、胰腺、結(jié)腸、胃、肺以及腎臟的惡性腫瘤VTE 發(fā)生率較高[9]。
為了探討LMWH在惡性腫瘤患者中的治療效果,有學(xué)者進(jìn)行了一項臨床隨機(jī)對照試驗(randomized controlled trial,RCT):385例不同類型的進(jìn)展期實體瘤患者(入組時均未發(fā)現(xiàn)血栓事件),隨機(jī)接受12個月的LMWH(LMWH預(yù)防性抗凝組)或者安慰劑(相等量的0.9%氯化鈉溶液,對照組)治療,結(jié)果顯示LMWH預(yù)防性抗凝組患者生存率高于對照組[10]。部分學(xué)者為了進(jìn)一步比較LMWH與其他抗凝藥物在惡性腫瘤合并VTE患者中的治療效果,進(jìn)行了相關(guān)探索。LEE等[11]將惡性腫瘤合并VTE患者進(jìn)行了RCT,該研究結(jié)果表明,對合并有VTE的惡性腫瘤患者,LMWH治療可能帶來一定的生存獲益。但是隨后CONTI等[12]研究結(jié)果顯示,LMWH降低惡性腫瘤合并VTE患者病死率的療效并不優(yōu)于口服抗凝藥物。由此可見,與其他抗凝藥物相比,LMWH的療效優(yōu)勢還存在爭議。鑒于此,本研究運用循證醫(yī)學(xué)方法,充分檢索相關(guān)文獻(xiàn),探討LMWH對惡性腫瘤合并VTE患者生存的影響,為臨床上LMWH在惡性腫瘤患者抗凝治療中的應(yīng)用提供較可靠的證據(jù)。
1.1 檢索策略 采用計算機(jī)檢索PubMed、EMBase、Web of Science、The Cochrane Central Register of Controlled Trials、 中國知網(wǎng)、維普網(wǎng)、萬方數(shù)據(jù)知識服務(wù)平臺等數(shù)據(jù)庫有關(guān)使用LMWH對惡性腫瘤合并VTE患者進(jìn)行抗凝治療的RCT,檢索時間截至2015年2月。英文檢索詞包括low molecular weight heparin、venous thromboembolism、anticoagulants、cancer、malignancy、survival、mortality、effect;中文檢索詞包括低分子量肝素、靜脈血栓、血栓性疾病、抗凝治療、癌癥、惡性腫瘤、生存率、病死率、療效等。對綜述性文獻(xiàn)的參考文獻(xiàn)進(jìn)行二次檢索。
1.2 文獻(xiàn)納入與排除標(biāo)準(zhǔn) 納入標(biāo)準(zhǔn):(1)RCT,設(shè)立平行對照,研究文獻(xiàn)為全文,語種為中文或英文。(2)研究對象:合并有VTE的實體瘤患者。(3)干預(yù)措施:研究組給予LMWH,對照組給予普通肝素、維生素K拮抗劑及其他非低分子量肝素抗凝藥物(Non-LMWH)。排除標(biāo)準(zhǔn):(1)非RCT或Jadad評分<3分的RCT;(2)未提供患者結(jié)局或測量方法的試驗;(3)綜述;(4)重復(fù)報道。
1.3 數(shù)據(jù)提取 提取的數(shù)據(jù)包括發(fā)表信息(第一作者、發(fā)表時間);受試對象(樣本量、性別、年齡、疾病組成);治療方案(研究組和對照組干預(yù)措施、觀察時間、主要觀察結(jié)果)。
1.4 質(zhì)量評價 主要根據(jù)Jadad評分標(biāo)準(zhǔn)(總分為5分,≥3分為高質(zhì)量研究),從隨機(jī)方法、盲法以及隨訪3個方面進(jìn)行質(zhì)量評價。
1.5 統(tǒng)計學(xué)方法 采用Cochrane協(xié)作網(wǎng)提供的RevMan 5.0版軟件進(jìn)行數(shù)據(jù)統(tǒng)計分析。采用I2檢驗和P值對納入文獻(xiàn)進(jìn)行統(tǒng)計學(xué)異質(zhì)性分析,當(dāng)P≥0.1和I2≤50%時,表示各研究間無統(tǒng)計學(xué)異質(zhì)性,采用固定效應(yīng)模型進(jìn)行分析;若P<0.1和I2>50%,表示各研究間存在統(tǒng)計學(xué)異質(zhì)性,對異質(zhì)性來源進(jìn)行分析,若異質(zhì)性仍較大,則采用隨機(jī)效應(yīng)模型進(jìn)行分析。分類變量以相對危險度(RR)表示,區(qū)間估計均采用95%可信區(qū)間(95%CI)。以P<0.05為差異有統(tǒng)計學(xué)意義。
2.1 納入文獻(xiàn)情況 共檢索到國內(nèi)外相關(guān)文獻(xiàn)1 566篇,閱讀文獻(xiàn)題目、摘要以及全文后,共29篇[11,13-40]文獻(xiàn)涉及29個RCT納入本研究。共納入4 346例惡性腫瘤合并VTE患者,其中研究組2 175例,對照組2 171例,文獻(xiàn)篩選流程圖見圖1,納入研究的基本特征見表1。
2.2 納入文獻(xiàn)質(zhì)量評價 本研究納入的文獻(xiàn)有2篇[14,28]Jadad 評分為 5 分,有 4 篇[18,29,35,38]Jadad 評分為 4 分,其余試驗[11,13,15-17,19-27,30-34,36-37,39-40]Jadad 評分均為 3 分,均達(dá)到高質(zhì)量文獻(xiàn)標(biāo)準(zhǔn),各納入研究的方法學(xué)質(zhì)量評分詳見表2。
表1 納入文獻(xiàn)的基本特征Table 1 General characteristics of the included studies
表2 納入文獻(xiàn)的質(zhì)量評分Table 2 Jadad scores of the included studies
圖1 納入文獻(xiàn)篩選流程圖Figure 1 Flow chart of literature screening
2.3 Meta分析結(jié)果
2.3.1 病 死 率 27 篇[11,13-29,31-37,39-40]文獻(xiàn)對 比 了 病死率,異質(zhì)性檢驗結(jié)果顯示各研究間無統(tǒng)計學(xué)異質(zhì)性(I2=0,P=0.80),采用固定效應(yīng)模型。Meta分析結(jié)果顯示,研究組與對照組患者病死率比較,差異無統(tǒng)計學(xué)意義〔RR=0.94,95%CI(0.87,1.01),P=0.08,見圖 2〕。
圖2 研究組與對照組患者病死率比較的森林圖Figure 2 Forest plot of the mortality of the study group versus the control group
根據(jù)對照組治療方法分成4個亞組進(jìn)行進(jìn)一步分析,對照組為口服維生素K拮抗劑治療的文獻(xiàn)有9篇[18,20,25-27,32,37,39-40],對照組為普通肝素 + 口服維生素 K 拮抗劑序貫治療的文獻(xiàn)有 11 篇[14,16-17,19,21-24,29,34-35],對照組為LMWH+口服維生素K拮抗劑序貫治療的文獻(xiàn)有5篇[11,28,31,33,36],對照組為普通肝素的文獻(xiàn)有 2 篇[13,15],因其中 1篇[15]治療組和對照組的死亡人數(shù)均為零,故數(shù)據(jù)未能有效合成,未再進(jìn)行亞組分析。3個亞組異質(zhì)性檢驗結(jié)果顯示各研究間無統(tǒng)計學(xué)異質(zhì)性(I2=0,P=1.00;I2=34%,P=0.13;I2=0,P=0.76),均采用固定效應(yīng)模型。Meta分析結(jié)果顯示,研究組與口服維生素K拮抗劑亞組患者病死率比較,差異無統(tǒng)計學(xué)意義〔RR=0.93,95%CI(0.85,1.03),P=0.16,見圖3〕;研究組與普通肝素+口服維生素K拮抗劑序貫治療亞組患者病死率比較,差異無統(tǒng)計學(xué)意義〔RR=0.88,95%CI(0.71,1.08),P=0.23,見圖4〕;研究組與LMWH+口服維生素K拮抗劑序貫治療亞組患者病死率比較,差異無統(tǒng)計學(xué)意義〔RR=0.98,95%CI(0.86,1.11),P=0.75,見圖 5〕。
圖3 研究組與口服維生素K拮抗劑亞組患者病死率比較的森林圖Figure 3 Forest plot of the mortality of the study group versus the oral VKA subgroup
根據(jù)研究組LMWH抗凝治療時間長短分成≤3個月亞組及>3個月亞組進(jìn)行進(jìn)一步分析,≤3個月亞組文獻(xiàn)有14篇[13-17,20-21,23,25,31-32,34-35,39],>3 個月亞組文獻(xiàn)有 12 篇[11,18-19,22,24,26-29,33,36-37],其中有 1 篇[40]抗凝治療時間文獻(xiàn)中未提及,未納入亞組分析。2個亞組異質(zhì)性檢驗結(jié)果顯示各研究間無統(tǒng)計學(xué)異質(zhì)性(I2=0,P=0.78;I2=0,P=0.52),均采用固定效應(yīng)模型。Meta分析結(jié)果顯示,≤3個月亞組患者病死率較對照組降低,差異有統(tǒng)計學(xué)意義〔RR=0.89,95%CI(0.80,0.99),P=0.02,見圖6〕;>3個月亞組與對照組患者病死率比較,差異無統(tǒng)計學(xué)意義〔RR=1.01,95%CI(0.91,1.12),P=0.91,見圖7〕。
2.3.2 血栓復(fù)發(fā)率 11 篇[19,22,26,29-32,34-36,38]文獻(xiàn)對比了血栓復(fù)發(fā)率,異質(zhì)性檢驗結(jié)果顯示各研究間無統(tǒng)計學(xué)異質(zhì)性(I2=40%,P=0.08),采用固定效應(yīng)模型。Meta分析結(jié)果顯示,研究組患者血栓復(fù)發(fā)率較對照組降低,差異有統(tǒng)計學(xué)意義〔RR=0.67,95%CI(0.51,0.89),P=0.005,見圖8〕。
2.3.3 大出血發(fā)生率 8 篇[14,19,22,26,31-32,35-36]文獻(xiàn)對比了大出血發(fā)生率,異質(zhì)性檢驗結(jié)果顯示各研究間無統(tǒng)計學(xué)異質(zhì)性(I2=47%,P=0.07),采用固定效應(yīng)模型。Meta分析結(jié)果顯示,研究組與對照組患者大出血發(fā)生率比較,差異無統(tǒng)計學(xué)意義〔RR=0.76,95%CI(0.51,1.13),P=0.18,見圖9〕。
2.3.4 小出血發(fā)生率 6 篇[14,26,31-32,35-36]文獻(xiàn)對比了小出血發(fā)生率,異質(zhì)性檢驗結(jié)果顯示各研究間有統(tǒng)計學(xué)異質(zhì)性(I2=65%,P=0.01),采用隨機(jī)效應(yīng)模型。Meta分析結(jié)果顯示,研究組與對照組患者小出血發(fā)生率比較,差異無統(tǒng)計學(xué)意義〔RR=0.82,95%CI(0.50,1.35),P=0.44,見圖 10〕。
2.3.5 血小板減少癥發(fā)生率 2篇[31,35]文獻(xiàn)對比了血小板減少癥發(fā)生率,異質(zhì)性檢驗結(jié)果顯示各研究間無統(tǒng)計學(xué)異質(zhì)性(I2=0,P=0.51),采用固定效應(yīng)模型。Meta分析結(jié)果顯示,研究組與對照組患者血小板減少癥發(fā)生率比較,差異無統(tǒng)計學(xué)意義〔RR=1.04,95%CI(0.61,1.77),P=0.87,見圖11〕。
圖4 研究組與普通肝素+口服維生素K拮抗劑序貫治療亞組患者病死率比較的森林圖Figure 4 Forest plot of the mortality of the study group versus the sequential treatment with UFH + oral VKA subgroup
圖5 研究組與LMWH+口服維生素K拮抗劑序貫治療亞組患者病死率比較的森林圖Figure 5 Forest plot of the mortality of the study group versus the sequential treatment with LMWH + oral VKA subgroup
圖6 ≤3個月亞組與對照組患者病死率比較的森林圖Figure 6 Forest plot of the mortality of the LMWH treatment time ≤ 3 months subgroup versus the control group
圖7 >3個月亞組與對照組患者病死率比較的森林圖Figure 7 Forest plot of the mortality of the LMWH treatment time > 3 months subgroup versus the control group
圖8 研究組與對照組患者血栓復(fù)發(fā)率比較的森林圖Figure 8 Forest plot of the recurrence rate of VTE in the study group versus the control group
圖9 研究組與對照組患者大出血發(fā)生率比較的森林圖Figure 9 Forest plot of the rate of major bleeding in the study group versus the control group
2.4 敏感性分析與發(fā)表偏倚 針對病死率Meta分析分別采用固定效應(yīng)模型和隨機(jī)效應(yīng)模型進(jìn)行分析,結(jié)果基本一致;除去RR值最大的BREDDIN等[29]研究及RR值最小的PRANDONI等[34]研究,結(jié)果無較大變化,結(jié)論較穩(wěn)定。漏斗圖左右基本對稱,未發(fā)現(xiàn)明顯發(fā)表偏倚(見圖12)。
圖10 研究組與對照組患者小出血發(fā)生率比較的森林圖Figure 10 Forest plot of the rate of minor bleeding in the study group versus the control group
圖11 研究組與對照組患者血小板減少癥發(fā)生率比較的森林圖Figure 11 Forest plot of the rate of thrombocytopenia in the study group versus the control group
圖12 發(fā)表偏倚的漏斗圖Figure 12 Funnel plot of publication bias
3.1 惡性腫瘤與VTE VTE包括DVT和PE,是惡性腫瘤患者常見并發(fā)癥之一,臨床上觀察發(fā)現(xiàn)4%~20%的患者可能發(fā)生VTE,VTE是導(dǎo)致患者預(yù)后差的主要原因之一[4]。腫瘤細(xì)胞通過上調(diào)細(xì)胞因子直接激活凝血酶原,誘導(dǎo)血小板聚集,或者通過調(diào)節(jié)內(nèi)皮細(xì)胞或炎性反應(yīng)從而導(dǎo)致凝血的發(fā)生。此外,惡性腫瘤細(xì)胞過表達(dá)組織因子,進(jìn)一步引起血液高凝,并且增加了腫瘤的侵襲性及促進(jìn)腫瘤性血管生成[41-42]。某些惡性腫瘤的治療方法也可能導(dǎo)致VTE。接受他莫昔芬治療的乳腺癌患者VTE的發(fā)病率可能增加2~5倍,聯(lián)合使用他莫昔芬化療患者VTE的風(fēng)險也明顯增高[43-44]。接受促紅細(xì)胞生成素治療的患者或接受化療及重組人紅細(xì)胞生成素治療的宮頸癌患者,VTE的風(fēng)險也明顯增高[45]。
3.2 惡性腫瘤與抗凝治療 惡性腫瘤的高凝狀態(tài)不但引起患者發(fā)生VTE,而且還促進(jìn)腫瘤的生長、侵襲和轉(zhuǎn)移,常導(dǎo)致患者預(yù)后不良。因此,對一些發(fā)生VTE風(fēng)險高的惡性腫瘤患者實施抗凝預(yù)防與治療,對于改善其預(yù)后意義重大。目前常用的抗凝藥物包括LMWH、普通肝素、維生素K拮抗劑如華法林等。國內(nèi)外多項臨床研究顯示,LMWH抗凝治療可使惡性腫瘤患者生存獲益[46-50]。但也有研究持相反的結(jié)論。如SIDERAS等[51]報道其發(fā)現(xiàn)化療聯(lián)合LMWH組患者生存期并不長于單純化療組。而且,VAN DOORMAAL等[52]的RCT及CONTI等[12]的Meta分析顯示,LMWH在降低合并有VTE的惡性腫瘤患者病死率方面并不優(yōu)于口服抗凝藥物。鑒于目前研究結(jié)果意見并不完全統(tǒng)一,為進(jìn)一步比較LMWH與其他抗凝藥物在惡性腫瘤合并VTE患者中的治療效果,本研究對國內(nèi)外發(fā)表的相關(guān)RCT進(jìn)行Meta分析。
本研究根據(jù)循證醫(yī)學(xué)原則,制定嚴(yán)格的納入標(biāo)準(zhǔn),充分檢索文獻(xiàn),選擇高質(zhì)量(Jadad評分≥3分)的RCT進(jìn)行Meta分析,以期更為客觀地評價LMWH在惡性腫瘤合并VTE患者中的療效,得出如下幾方面結(jié)果。第一,研究組降低惡性腫瘤合并VTE患者的病死率與對照組(應(yīng)用維生素K拮抗劑、普通肝素、普通肝素或LMWH+口服維生素K拮抗劑序貫治療)相比無差異;根據(jù)對照組治療方式不同分為口服維生素K拮抗劑、普通肝素、普通肝素+口服維生素K拮抗劑序貫治療及LMWH+口服維生素K拮抗劑序貫治療4個亞組(其中普通肝素亞組數(shù)據(jù)未能有效合成,未再進(jìn)行亞組分析),結(jié)果顯示研究組在降低惡性腫瘤合并VTE患者的病死率方面與各個亞組相比均無差異;根據(jù)LMWH抗凝治療時間長短分成≤3個月亞組及>3個月亞組,結(jié)果顯示,≤3個月亞組降低惡性腫瘤合并VTE患者的病死率優(yōu)于對照組,>3個月亞組降低惡性腫瘤合并VTE患者的病死率與對照組相比無差異。本結(jié)果與CONTI等[12]的報道類似,其研究顯示LMWH在降低惡性腫瘤合并VTE患者病死率方面與口服抗凝藥物相似:但是,本研究的發(fā)現(xiàn)與AKL等[50]的結(jié)果不一致,其研究顯示LMWH在降低惡性腫瘤合并VTE患者病死率方面優(yōu)于普通肝素+口服維生素K拮抗劑序貫治療。造成差異的原因可能與AKL等[50]納入的RCT較少(僅9篇,而本研究納入11篇)相關(guān)。第二,研究組的血栓復(fù)發(fā)率低于對照組,與AKL等[50]結(jié)果不一致,AKL等[50]研究顯示在血栓復(fù)發(fā)率方面LMWH與普通肝素+維生素K拮抗劑序貫治療組之間無差異,其原因也可能與本研究納入的RCT較多相關(guān)。第三,研究組與對照組相比,大出血、小出血及血小板減少癥發(fā)生率均無差異。上述結(jié)果提示,LMWH是一種治療惡性腫瘤合并VTE患者的有效抗凝藥物,與其他抗凝藥物相比可減少血栓復(fù)發(fā)率;短期(≤3個月)治療可改善這類患者生存狀態(tài),其療效優(yōu)于維生素K拮抗劑、普通肝素、普通肝素或LMWH+口服維生素K拮抗劑序貫治療,長期治療效果(>3個月)及大出血、小出血、血小板減少癥發(fā)生率與維生素K拮抗劑、普通肝素、普通肝素或LMWH+口服維生素K拮抗劑序貫治療類似。
但是,本研究存在一些不足:(1)納入的文獻(xiàn)中沒有亞洲主要國家論文(如中國);(2)各研究的治療時間不一致,跨度大(10 d~6個月);(3)各研究的腫瘤類型不一致,差異很大,有的研究未說明具體的腫瘤類型,或籠統(tǒng)稱為實體瘤;(4)各研究的腫瘤分期不一致,或者未說明具體的腫瘤分期。但本研究納入研究數(shù)量最多、文獻(xiàn)質(zhì)量均較高、評價指標(biāo)較齊全,所得出的結(jié)論對于臨床上LMWH在惡性腫瘤合并VTE患者中的抗凝治療應(yīng)用具有較重要的指導(dǎo)意義。
作者貢獻(xiàn):湯紹輝進(jìn)行文章的構(gòu)思與設(shè)計,負(fù)責(zé)文章的質(zhì)量控制及審校;鐘綠進(jìn)行研究的實施與可行性分析,數(shù)據(jù)收集、整理,統(tǒng)計學(xué)處理,結(jié)果的分析與解釋,撰寫論文,論文的修訂,對文章整體負(fù)責(zé),監(jiān)督管理。
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[1]徐向東.臨床常用藥物手冊[M].北京:人民軍醫(yī)出版社,2011:158-160.
[2]楊寶峰.藥理學(xué)[M].7版.北京:人民衛(wèi)生出版社,2008:58-59.YANG B F.Pharmacology[M].7th ed.Beijing:People's Medical Pubishing House,2008:58-59.
[3]劉松青.實用藥物手冊[M].成都:四川大學(xué)出版社,2007:132-133.LIU S Q.Practical drug handbook[M].Chengdu:Sichuan University Press,2007:132-133.
[4]KHORANA A A,F(xiàn)RANCIS C W,CULAKOVA E,et al.Thromboembolism is a leading cause of death in cancer patients receiving outpatient chemotherapy[J].J Thromb Haemost,2007,5(3):632-634.DOI:10.1111/j.1538-7836.2007.02374.x.
[5]WAHRENBROCK M,BORSIG L,LE D,et al.Selectin-mucin interactions as a probable molecular explanation for the association of Trousseau syndrome with mucinous adenocarcinomas[J].J Clin Invest,2003,112(6) :853-862.DOI:10.1172/JCI18882.
[6]BOCCACCIO C,SABATINO G,MEDICO E,et al.The MET oncogene drives a genetic programme linking cancer to haemostasis[J].Nature,2005,434(7031):396-400.DOI:10.1038/nature03357.
[7]DVORAK H F,QUAY S C,ORENSTEIN N S,et al.Tumor shedding and coagulation[J].Science,1981,212(4497):923-924.DOI:10.1186/s12885-017-3442-y.
[8]AMIRKHOSRAVI A,MEYER T,AMAYA M,et al.The role of tisseactor pathway inhibitor in tumor growth and metstasis[J].Semin Thromb Hemost,2007,33(7):643-652.DOI:10.1177/1010428317712592.
[9]STEIN P D,BEEMATH A,MEYERS F A,et al.Incidence of venous thromboembolism in patients hospitalized with cancer[J].Am J Med,2006,119(1):60-68.DOI:10.1016/j.amjmed.2005.06.058.
[10]AGNELLI G,GUSSONI G,BIANCHINI C,et al.Nadroparin for the prevention of thromboembolic events in ambulatory patients with metastatic or locally advanced solid cancer receiving chemotherapy:a randomized,placebo controlled,double-blind study[ J ].Lancet Oncol,2009,10(10):943-949.DOI:10.1016/S1470-2045(09)70232-3.
[11]LEE A Y,RICKLES F R,JULIAN J A,et al.Randomized comparison of low molecular weight heparin and coumarin derivatives on the survival of patients with cancer and venous thromboembolism[J].J Clin Oncol,2005,23(10):2123-2129.DOI:10.1200/JCO.2005.03.133.
[12]CONTI S,GUERCINI F,IORIO A.Low-molecular-weight heparin and cancer survival:review of the literature and pooled analysis of 1,726 patients treated for at least three months[J].Pathophysiol Haemost Thromb,2003,33(4):197-201.
[13]DUROUX P,NINET J,BACHET P,et al.A randomised trial of subcutaneous low molecular weight heparin (CY 216) compared with intravenous unfractionated heparin in the treatment of deep vein thrombosis.A collaborative European multicenter study[J].Thromb Haemost,1991,65(3):251-256.
[14]HULL R D,RASKOB G E,PINEO G F,et al.Subcutaneous lowmolecular-weight heparin compared with continuous intravenous heparin in the treatment of proximal-vein thrombosis[J].N Engl J Med,1992,326(15):975-982.DOI:10.1056/NEJM199204093261502.
[15]LOPACIUK S,MEISSNER A J,F(xiàn)ILIPECKI S,et al.Subcutaneous low molecular weight heparin versus subcutaneous unfractionated heparin in the treatment of deep vein thrombosis:a Polish multicenter trial[J].Thromb Haemost,1992,68(1):14-18.
[16]PRANDONI P,LENSING A W,BüLLER H R,et al.Comparison of subcutaneous low-molecular-weight heparin with intravenous standard heparin in proximal deep-vein thrombosis[J].Lancet,1992,339(8791):441-445.
[17]SIMONNEAU G,CHARBONNIER B,DECOUSUS H,et al.Subcutaneous low-molecular-weight heparin compared with continuous intravenous unfractionated heparin in the treatment of proximal deep vein thrombosis[J].Arch Intern Med,1993,153(13):1541-1516.
[18]LINDMARKER P,HOLSTR?M M,GRANQVIST S,et al.Comparison of once-daily subcutaneous Fragmin with continuous intravenous unfractionated heparin in the treatment of deep vein thrombosis[J].Thromb Haemost,1994,72(2):186-190.
[19]PINI M,AIELLO S,MANOTTI C,et al.Low molecular weight heparin versus warfarin in the prevention of recurrences after deep vein thrombosis[J].Thromb Haemost,1994,72(2):191-197.
[20]KOOPMAN M M,PRANDONI P,PIOVELLA F,et al.Treatment of venous thrombosis with intravenous unfractionated heparin administered in the hospital as compared with subcutaneous lowmolecular-weight heparin administered at home.The Tasman Study Group[J].N Engl J Med,1996,334(11):682-687.DOI:10.1056/NEJM199603143341102.
[21]LEVINE M,GENT M,HIRSH J,et al.A comparison of lowmolecular-weight heparin administered primarily at home with unfractionated heparin administered in the hospital for proximal deep-vein thrombosis[J].N Engl J Med,1996,334(10):677-681.DOI:10.1056/NEJM199603143341101.
[22]DAS S K,COHEN A T,EDMONDSON R A,et al.Low-molecular-weight heparin versus warfarin for prevention of recurrent venous thromboembolism:a randomised trial[J].World J Surg,1996,20(5):521-526.DOI:10.1186/1471-2407-13-284.
[23]Columbus Investigators,BüLLER H R,GENT M,et al.Lowmolecular-weight heparin in the treatment of patients with venous thromboembolism[J].N Engl J Med,1997,337(10):657-662.DOI:10.2147/CEOR.S126379.
[24]SIMONNEAU G,SORS H,CHARBONNIER B,et al.A comparison of low-molecular-weight heparin with unfractionated heparin for acute pulmonary embolism.The THESEE Study Group.Tinzaparine ou Heparine Standard:evaluations dans I'Embolie Pulmonaire[J].N Engl J Med,1997,337(10):663-669.DOI:10.1056/NEJM199709043371002.
[25]GONZALEZ-FAJARDO J,ARREBA E,CASTRODEZA J,et al.Venographic comparison of subcutaneous low-molecular-weight heparin with oral anticoagulant therapy in the long-term treatment of deep venous thrombosis[J].J Vasc Surg,1999,30:283-290.
[26]LOPACIUK S,BIELSKA-FALDA H,NOSZCZYK W,et al.Low molecular weight heparin versus acenocoumarol in the secondary prophylaxis of deep vein thrombosis[J].Thromb Haemost,1999,81(1):26-31.
[27]VEIGA F,ESCRIBá A,MALUENDA M P,et al.Low molecular weight heparin (enoxaparin) versus oral anticoagulant therapy(acenocumarol) in the long-term treatment of deep venous thrombosis in the elderly:a randomised trial[J].Thromb Haemost,2000,84(4):559-564.
[28]LóPEZ-BERET P,ORGAZ A,F(xiàn)ONTCUBERTA J,et al.Low molecular weight heparin versus oral anticoagulants in the long-term treatment of deep venous thrombosis[J].J Vasc Surg,2001,33(1):77-90.
[29]BREDDIN H K,HACH-WUNDERLE V,NAKOV R,et al.Effects of a low-molecular-weight heparin on thrombus regression and recurrent thromboembolism in patients with deep-vein thrombosis[J].N Engl J Med,2001,344(9):626-631.DOI:10.1056/NEJM200103013440902.
[30]MERLI G,SPIRO T E,OLSSON C G,et al.Subcutaneous enoxaparin once or twice daily compared with intravenous unfractionated heparin for treatment of venous thromboembolic disease[J].Ann Intern Med,2001,134(3):191-202.
[31]MEYER G,MARJANOVIC Z,VALCKE J,et al.Comparison of low-molecular-weight heparin and warfarin for the secondary prevention of venous thromboembolism in patients with cancer:a randomized controlled study[J].Arch Intern Med,2002,162(15):1729-1735.
[32]LEE A Y,LEVINE M N,BAKER R I,et al.Low-molecularweight heparin versus a coumarin for the prevention of recurrent venous thromboembolism in patients with cancer[J].N Engl J Med,2003,349(2):146-153.DOI:10.1056/NEJMoa025313.
[33]CESARONE M R,LEDDA A,NICOLAIDES A,et al.Threemonth,outpatient,oral anticoagulant treatment in comparison with low-molecular-weight heparin in cancer patients[J].Circulation,2003,108(17):2875.
[34]PRANDONI P,CARNOVALI M,MARCHIORI A,et al.Subcutaneous adjusted-dose unfractionated heparin vs fixed-dose low-molecular-weight heparin in the initial treatment of venous thromboembolism[J].Arch Intern Med,2004,164(10):1077-1083.
[35]HULL R D,PINEO G F,BRANT R F,et al.Long-term lowmolecular-weight heparin versus usual care in proximal-vein thrombosis patients with cancer[J].Am J Med,2006,119(12):1062-1072.DOI:10.1016/j.amjmed.2006.02.022.
[36]DEITCHER S R,KESSLER C M,MERLI G,et al.Secondary prevention of venous thromboembolic events in patients with active cancer:enoxaparin alone versus initial enoxaparin followed by warfarin for a 180-day period[J].Clin Appl Thromb Hemost,2006,12(4):389-396.DOI:10.1177/1076029606293692.
[37]VON DELIUS S,AYVAZ M,WAGENPFEIL S,et al.Effect of low-molecular-weight heparin on survival in patients with advanced pancreatic adenocarcinoma[J].Thromb Haemost,2007,98(2):434-439.
[38]ROMERA A,CAIROLS M A,VILA-COLL R,et al.A randomised open-label trial comparing long-term sub-cutaneous low-molecular-weight heparin compared with oral-anticoagulant therapy in the treatment of deep venous thrombosis[J].Eur J Vasc Endovasc Surg,2009,37(3):349-356.DOI:10.1016/j.ejvs.2008.11.030.
[39]VAN DOORMAAL F F,DI NISIO M,OTTEN H M,et al.Randomized trial of the effect of the low molecular weight heparin nadroparin on survival in patients with cancer[J].J Clin Oncol,2011,29(15):2071-2076.DOI:10.1200/JCO.2010.31.9293.
[40]PARK J C,PRATZ C F,TESTFAYE A,et al.The effect of therapeutic anticoagulation on overall survival in men receiving first-line docetaxel chemotherapy for metastatic castration-resistant prostate cancer[J].Clin Genitourin Cancer,2015,13(1):32-38.DOI:10.1016/j.clgc.2014.04.008.
[41]RIKLES F R.Mechanisms of cancer-induced thrombosis in cancer[J].Pathophysiol Haemost Thromb,2006,35(1/2):103-110.DOI:10.1159/000093551.
[42]RAK J,MILSOM C,MAY L,et al.Tissue factor in cancer and angiogenesis:the molecular link between genetic tumor progression,tumor neovascularization,and cancer coagulopathy[J].Semin Thromb Hemost,2006,32(1):54-70.DOI:10.1055/s-2006-933341.
[43]FISHER B,COSTANTINO J,REDMOND C,et al.A randomized clinical trial evaluating tamoxifen in the treatment of patients with node-negative breast cancer who have estrogen-receptor-positive tumors[J].N Engl J Med,1989,320(8):479-484.DOI:10.1056/NEJM198902233200802.
[44]PRITCHARD K I,PATERSON A H,PAUL N A,et al.Increased thromboembolic complications with concurrent tamoxifen and chemotherapy in a randomized trial of adjucant therapy for women with breast cancer.Nathional Cancer Institute of Canada Clinical Trials Group Breast Cancer Site Group[J].J Clin Oncol,1996,14(10):2731-2737.DOI:10.1200/JCO.1996.14.10.2731.
[45]WUN T,LAW L,HARVEY D,et al.Increased incidence of symptomatic venous thrombosis in patients with cervical carcinoma treated with concurrent chemotherapy,radiation,and erythropoietin[J].Cancer,2003,98(7):1514-1520.DOI:10.1002/cncr.11700.
[46]KLERK C P,SMORENBURG S M,OTTEN H M,et al.The effect of low molecular weight heparin on survival in patients with advanced malignancy[J].J Clin Oncol,2005,23(10):2130-2135.DOI:10.1200/JCO.2005.03.134.
[47]顧愛琴,白皓,紀(jì)灝,等.低分子肝素聯(lián)合化療治療非小細(xì)胞肺癌的隨機(jī)研究[J].中國癌癥雜志,2003,3(4):364-366.DOI:10.3969/j.issn.1007-3639.2003.04.026.GU A Q,BAI H,JI H,et al.Randomized study of low molecular weight heparin (LMWH) plus chemtherapy in advanced non-small cell lung cancer[J].China Oncology,2003,3(4):364-366.DOI:10.3969/j.issn.1007-3639.2003.04.026.
[48]LAZO-LANGNER A,GOSS G D,SPAANS J N,et al.The effect of low-molecular-weight heparin on cancer survival.A systematic review and meta-analysis of randomized trials[J].J Thromb Haemost,2007,5(4):729-737.DOI:10.1111/j.1538-7836.2007.02427.x.
[49]劉璠,封辰葉,劉廷威,等.低分子肝素單藥抗凝治療癌癥相關(guān)急性肺血栓栓塞癥療效和預(yù)后分析[J].中國全科醫(yī)學(xué),2014,17(4):422-424.DOI:10.3969/j.issn.1007-9572.2014.04.015.LIU F,F(xiàn)ENG C Y,LIU T W,et al.Outcome and prognosis of patients with cancer-associated acute pulmonary thromboembolism following anticoagulation therapies[J].Chinese General Practice,2014,17(4):422-424.DOI:10.3969/j.issn.1007-9572.2014.04.015.
[50]AKL E A,KAHALE L,NEUMANN I,et al.Anticoagulation for the initial treatment of venous thromboembolism in patients with cancer[J].Cochrane Database Syst Rev,2014,19(6):CD006649.DOI:10.1002/14651858.CD006649.
[51]SIDERAS K,SCHAEFER P L,OKUNO S H,et al.Lowmolecular-weight heparin in patients with advanced cancer:a phase 3 clinical trial[J].Mayo Clin Proc,2006,81(6):758-767.DOI:10.4065/81.6.758.
[52]VAN DOORMAAL F F,COHEN A T,DAVIDSON B L,et al.Idraparinux versus standard therapy in the treatment of deep venous thrombosis in cancer patients:a subgroup analysis of the Van Gogh DVT trial[J].Thromb Haemost,2010,104(1):86-91.DOI:10.1160/TH09-12-0870.