【作者】 肖铭甲；

【导师】 高毅；

【作者基本信息】 南方医科大学 ， 临床医学， 2013， 博士

【摘要】 目的胆管癌(包括肝内及肝外胆管癌、胆囊癌、壶腹癌)是一种相对少见但预后极差的恶性肿瘤,目前已经确定的危险因素包括：胆石症(结石为混合性结石风险最高),慢性胆囊炎,肥胖,肝吸虫病,原发性硬化性胆管炎,长期暴露于某些化学毒物(如四氯化碳等)。遗传背景、基因损伤及性别(女性多发)在发病中扮演的角色也有报道。自从1991年发现人类胆道系统内存在螺杆菌以来,不断有文献报道这些螺杆菌可能与人类胆道系统疾病如胆管癌、慢性胆囊炎、胆石症的发生相关,已报道的螺杆菌种属包括幽门螺杆菌(H. pylori),胆汁螺杆菌(H. bilis),肝脏螺杆菌(H. hepaticus)等。螺杆菌感染与胆管癌发生之间的关系仍存在争议,本研究旨在通过检索这一领域的所有文献,进行meta分析以探索二者间的联系。方法首先在PubMed, EMBASE, CNKI数据库进行文献检索,获取所有探讨胆管癌和螺杆菌关系的文献,对检索出的文献进行筛选,确定纳入本次meta分析的文献。我们首先对所有纳入的研究进行了meta分析,之后按照各研究所在国家的地理分布进行亚组分析,最后根据各研究选用的样品和检测方法进行分组,进行亚组分析。我们通过x2检验对纳入研究的异质性进行检验。为评估纳入研究是否存在发表偏倚,我们还进行了Begg法检验和Egger回归分析检验。结果经过检索及筛选,最终有10个病例对照研究(总共418例患者)纳入本次meta分析。这些研究都是在2001年到2012年之间发表。总体分析表明,螺杆菌感染与胆管癌发生有显著关联,总体比值比(cumulative odds ratio, cumulative OR)10.49,95%可信区间(confidence interval, CI)5.90-18.67,所以螺杆菌感染可能是胆管癌发生的危险因素之一。基于各研究发表国家的地理分布进行的亚组分析中,我们把10个研究分为欧洲组(Europe)和亚洲组(Asia),两组分别有4个和6个研究。这种分法不仅是按照地域分布划分,同时也与幽门螺杆菌感染的流行状况相一致,即亚洲地区的感染率高,而欧洲人中感染率相对较低。本亚组分析表明,在欧洲组和亚洲组中,螺杆菌感染都与胆管癌发病显著相关,亚洲组OR8.50,95%CI4.28-16.88,欧洲组OR17.46,95%CI5.92-51.47。所以,无论是在感染率较高的亚洲组国家,还是感染率较低的欧洲组国家,螺杆菌感染都可能是胆管癌的危险因素。另一个基于检测方法和样品种类的亚组分析显示,对使用手术切除组织(新鲜组织或石蜡包埋组织)或胆汁作为实验材料并应用PCR法检测螺杆菌的5个研究进行统计分析,发现胆管癌组的螺杆菌阳性率较对照组高(组织样品：胆管癌组38.89%,对照组3.95%, p<0.0001；胆汁样品：胆管癌组75.18%,对照组20.97%,p<0.00001),0R分别为15.72(95%CI4.79-51.55,p<0.00001)和10.78(95%CI4.87-23.88,p<0.00001)。western blot检测血清内的抗肝脏螺杆菌(H. hepaticus)抗体,胆管癌组的抗体阳性率远高于由胰腺癌患者及正常人组成的对照组,分别为38.89%和11.32%,OR10.78,OR的95%CI为4.87-23.88,p=0.01；细菌培养和免疫组化两种方法均未在任一样品中检测出螺杆菌。4.98(1.40,17.80)纳入的10个研究之间不存在明显的异质性和发表偏倚。敏感性分析显示,当剔除任何一项研究后,剩余9个研究间均未显示不再有异质性,效应量维度也未改变。结论我们的研究表明,螺杆菌感染与胆管癌发病存在正相关性,无论是在全面分析还是基于地区分布的亚组分析中。但是,由于相关研究数量较少、纳入研究的病例数较少,获得更准确结论还需进行大样本量的临床研究。目前仍缺少检测手术切除标本和胆汁标本中螺杆菌存在的标准方案。无论是用手术切除组织还是胆汁作为检测样本,目前PCR是检测其中存在螺杆菌的最有效手段,但因为较高的假阳性率影响了结果的可靠性。组织病理学由于其敏感性较低,只有极个别文献称在胆石症患者的胆囊标本中可观察到螺杆菌，但没有从胆管癌患者的手术标本中发现螺杆菌的报道。尽管细菌培养和鉴定是判断感染存在的金标准,遗憾的是,至今大多数研究未能从肝脏或胆道组织和胆汁中成功培养出螺杆菌,相应的技术还需进一步探索。螺杆菌致胆管癌的机制尚不清楚,长期慢性炎症刺激、信号转导通路被干扰后细胞周期受到干扰是目前最可能的解释。更多还原

【Abstract】 ObjectiveCholangiocarcinoma (including intrahepatic or extrahepatic cholangiocarcinoma, gallbladder cancer, and ampullary carcinoma anatomically) is a common hepato-biliary malignancy with poor prognosis. The main associated risk factors identified so far include cholelithiasis (especially mixed gall stones), chronic infections of the gall bladder, obesity, reproductive factors, diet, hepato-biliary anamolies, and environmental exposure to specific chemicals. Genetic and molecular predisposing factors have also been described recently.Since the discovery of Helicobacter species (H.sp) in human biliary system, the association between H.sp infection and cholangiocarcinoma is under debate. This meta-analysis is aimed to explore this issue.MethodsLiterature search was carried out to identify all eligible articles. We performed overall meta-analysis of all studies included and subgroup analysis based on regional distribution. Subgroup analysis in the light of detection method and specimen was also conducted.ResultsTen case-control studies were included. Overall meta-analysis favored a significant association between H.sp infection and cholangiocarcinoma (cumulative OR10.49,95%CI5.90-18.67). Subgroup analysis based on geographic distribution indicated that H.sp infection may serve as a risk factor not only in a region with high cholangiocarcinoma incidence (Asia, OR8.50,95%CI4.28-16.88) but also in low incidence region (Europe, OR17.46,95%CI5.92-51.47).The other subgroup analysis showed that PCR was the most effective and efficient method to detect H.sp in surgically resected tissue and bile, however, the more convincing methods, immnohistochemistry and bacteria culture failed to investigate the presence of H.sp in any sample.There wasn’t obvious publication bias. And no obvious heterogeneity was detected among the studies (I2=0%, p<0.0001).ConclusionOur meta-analysis revealed a positive association between H.sp infection and cholangiocarcinoma in both overall analysis of all studies and subgroup analysis according to geographic distribution, but further investigations are required. PCR is the most effective and efficient method to detect H.sp colonization in both surgically resected tissue and bile, but the golden standard, culture of H.sp from samples is still unsuccessful and needs more exploration.更多还原