Chang Mei-Hwei
National Taiwan University Hospital, Taipei.
Recent Results Cancer Res. 2009;181:85-94. doi: 10.1007/978-3-540-69297-3_10.
Chronic inflammation caused by persistent infection is closely related to a number of cancers; these include hepatitis B (HBV) or C and hepatoma, human papilloma virus and cervical cancer, and Helicobacter pylori and gastric cancer. The first evidence of cancer prevention by vaccination in humans was provided by HBV vaccination in infants. Chronic HBV is related to approximately 60%-90% of hepatocellular carcinomas (HCC) in adults and nearly 100% of childhood HCC in areas endemic for HBV infection. The first universal HBV vaccination program was launched in Taiwan and has continued for more than 20 years. Three or four doses of HBV vaccine were given to all infants starting from the first week of life. In addition, infants of high-risk mothers (with positive hepatitis B e antigen or high HBsAg titers) were given hepatitis B immunoglobulin within 24 h after birth. At 20 years after the launch of the HBV vaccination program in Taiwan, chronic HBV infection (HBsAg seropositive) rates in the general population below 20 years of age have revealed a remarkable reduction from 10%-17% before the vaccination program to 0.7%-1.7% after the program. HCC incidence rate in children 6-14 years old also fell from 0.52-0.54 to 0.13-0.20 per 100,000 (R.R. = 0.25-0.36). HCC prevention failure is mainly related to vaccine failure to prevent chronic HBV infection. The causes of vaccine failure have included intrauterine infection, vaccine escape mutants, genetic hyporesponsiveness, and poor compliance. Future efforts to reduce vaccine failure will improve the efficacy of liver cancer prevention by HBV vaccination. The experience of HCC prevention by HBV immunization may be applied to the prevention of other infection-related cancers.
持续性感染引起的慢性炎症与多种癌症密切相关；这些癌症包括乙型肝炎（HBV）或丙型肝炎与肝癌、人乳头瘤病毒与宫颈癌，以及幽门螺杆菌与胃癌。人类通过接种疫苗预防癌症的首个证据是婴儿接种乙肝疫苗提供的。慢性HBV感染与成人中约60%-90%的肝细胞癌（HCC）以及HBV感染流行地区近100%的儿童HCC有关。首个全民乙肝疫苗接种计划在台湾启动，并持续了20多年。从出生第一周起，所有婴儿都接种三剂或四剂乙肝疫苗。此外，高危母亲（乙肝e抗原阳性或乙肝表面抗原滴度高）的婴儿在出生后24小时内接种乙肝免疫球蛋白。在台湾启动乙肝疫苗接种计划20年后，20岁以下普通人群中的慢性HBV感染（乙肝表面抗原血清阳性）率已显著下降，从接种计划前的10%-17%降至计划后的0.7%-1.7%。6-14岁儿童的HCC发病率也从每10万人0.52-0.54降至0.13-0.20（相对危险度=0.25-0.36）。HCC预防失败主要与疫苗未能预防慢性HBV感染有关。疫苗失败的原因包括宫内感染、疫苗逃逸突变体、遗传低反应性和依从性差。未来减少疫苗失败的努力将提高乙肝疫苗接种预防肝癌的效果。乙肝免疫预防HCC的经验可能适用于预防其他感染相关癌症。
