原发性肝癌论文：循环DNA和HBV-DNA载量与原发性肝癌的相关性探讨

原发性肝癌论文：循环 DNA 和 HBV-DNA 载量与原发性肝癌的相关性探讨【中文摘要】当前,原发性肝癌(primary hepatic cancer, PHC)是消化系统最常见的恶性肿瘤之一,且病死率高,其中 90%为肝细胞癌(Hepatocellular Carcinoma, HCC)。原发性肝癌与乙型病毒性肝炎(viral hepatitis type B,简称乙肝)关系密切,特别是转为慢性肝炎后肝脏的纤维化是原发性肝癌的发病基础。我们知道,全世界乙型肝炎病毒携带者大约有 2.8 亿,其中我国约占到一半。目前我国有乙肝患者 3000 多万,乙型肝炎病毒(hepatitis B virus, HBV)感染作为原发性肝癌最常见的主要病因,已被流行病学研究所肯定。原发性肝癌患者确诊后,大多数生存期不到 1 年主要是因为患者就诊时多数已进入疾病晚期。当前,甲胎蛋白(alpha-fetoprotein, AFP)是原发性肝癌早期诊断最常用的肿瘤标志物(Tumor Mark, TM)。然而,AFP阳性的原发性肝癌患者约占所有原发性肝癌患者的 65%,还有相当数量的患者缺乏有效的早期诊断及预后指标。循环 DNA (circulating DNA)是存在于各种体液如血液、脑脊液及滑膜液中的一种胞外DNA。Mandel 和 Metais 早在 1947 年就发现了存在于体液中的循环核酸,1977 年 Leon 等人首次报道了肿瘤患者血浆中的 DNA 含量远远高于正常人群。在此之后,大量关于人类各种类型肿瘤,如肝癌、肺癌、乳腺癌、消化道肿瘤、前列腺癌、卵巢癌等的研究均显示肿瘤患者血浆中的 DNA 含量有不同程度的升高。并且血浆 DNA 水平与肿 瘤临床的相关性研究结果表明,血浆 DNA 水平的高低不但能够提示肿瘤的存在,而且与患者的临床分期、是否存在淋巴结转移、肿瘤瘤体大小及预后相关,可作为肿瘤早期诊断、预后及疗效判断的良好指标。另外,循环 DNA 测定具有价格便宜、标本采集方便快捷、创伤性小等优点,还可以考虑将其作为筛查肿瘤性疾病的实验室指标,只不过特异性稍差一些。但是,当前原发性肝癌的肿瘤标志物大多是蛋白类物质,循环 DNA 的研究将为肝癌肿瘤标志物研究开拓一条新的途径。乙型病毒性肝炎(viral hepatitis type B,简称乙肝)是我国流行最为广泛、危害性最严重的一种传染病。HBV-DNA 载量的多少,反映了病毒在机体内的复制情况,人们常常认为与机体的免疫状况有关,往往忽略一个最基本的问题,就是病毒复制的场所在肝脏纤维化后随着病程的进展而不断减少。随着肝硬化的不断进展,少量病毒的复制即可引起肝脏严重的炎性病变,持续的炎性刺激可不断加重肝脏的纤维化,形成恶性循环,最终诱发原发性肝癌(PHC)。检测血浆 DNA 和 HBV-DNA载量在乙型病毒性肝炎炎肝硬化后不同时期的水平,探讨两者联合检测在原发性肝癌预防、早期诊断、病情转归及预后中的价值。方法用 QRT-PCR 方法随访检测 HBsAg 阳性且经彩色 B 超诊断为肝硬化的患者,每三个月检测一次患者的血液循环 DNA 和 HBV-DNA 载量,直到经临床症状、彩色 B 超、CT 诊断为原发性肝癌为止。结果在 PHC 中,血浆 DNA 60.2±9.5ng/ml,健康对照组 20.2±3.4ng/ml,两组差异有统计学意义(P<0.01)；而 HBV-DNA 载量,在 PHC 确诊时多数处于较低水平,78%105copies/ml,与 PHC 确诊前差异有统计学意义(P<0.01)。 PHC 未发生淋巴结转移者循环 DNA 51.2±7.9ng/ml,淋巴结转移者循环 DNA 73.9±10.7ng/ml,两者差异有统计学意义(P<0.05)；而 HBV-DNA 载量有无淋巴结转移无明显差异结论联合检测血液循环 DNA 和HBV-DNA 载量,在原发性肝癌预防、早期诊断、病情进展及预后中的价值明显,且方法简单,易于开展。【英文摘要】Background:At present, the primary hepatic cancer(PHC) is one of the most common malignancies in the digestive system, and high mortality,90 percent of the primary hepatic cancer is hepatocellular carcinoma (HCC). There is a close relationship between the primary hepatic cancer and the viral hepatitis type B. Especially the liver fibrosis is the foundation of PHC after it turn to chronic hepatitis. As we know,the hepatitis B virus carriers more than 280 million all over the world, the numbers accounts for about half in China. At present our country has more than 30 million patients with viral hepatitis type B. Hepatitis B virus infection as the most common and main cause of the primary hepatic cancer has been assured by epidemiological studies. The surial of most patients with the primary hepatic cancer after diagnosis less than one year,the main reason is that many patients has attended into the later. At present, AFP is the most widely used tumor markers of PHC early diagnosis.However, AFP positive PHC patients accounted for about 65% of all PHC patients, there are still many patients lack of effective early diagnosis and prognosis index.The circulating DNA is a kind of extracellular DNA present in various body fluids,for example the blood, cerebrospinal fluid and synovial fluid. As early as 1947 Mandel and Metais have found circulating nucleic acid exists in body fluids. In 1977 Leon, et al. who first reported that the plasma DNA content of patients with tumor is higher than normal. After that, a lot of studies about all human tumour types, including liver cancer, lung cancer, breast cancer, gastrointestinal tumors, prostate cancer, ovarian cancer showed that the plasma DNA content of patients with tumor have different levels elevated. And the correlation studies of plasma DNA level and oncology clinic show that the plasma DNA level of high and low not only can signal the existence of the tumor, and the clinical stages, and whether there is a lymph node metastasis, tumor size and prognosis were related, but also can be used for good judgment index of cancer early diagnosis, prognosis and curative effect.In addition, circulating DNA detection have an advantage of price is lower, specimens for convenient, minimally invasive, it can be considered as a cancer screening index, but the specificity is poorer. At present, however, almost of the liver cancer markers is protein. The research of the tumor circulating DNA will be alternate a new way for tumor markers.The viral hepatitis type B is the most wide and serious harm infectious disease in our country. HBV-DNA load can reflect the appropriateness of the virus in the body, people often think that the virus copy related with the bodys immune status,but often ignore the most fundamental question that the place of the virus copies constantly decline with the development of course after the liver fibrosis. With the development of the liver fibrosis, a small amount of virus copies can cause serious li