Altekruse Sean F, Petrick Jessica L, Rolin Alicia I, Cuccinelli James E, Zou Zhaohui, Tatalovich Zaria, McGlynn Katherine A
Division of Cancer Control and Population Sciences, National Cancer Institute, Rockville, Maryland, United States of America.
Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, United States of America.
PLoS One. 2015 Apr 2;10(3):e0120574. doi: 10.1371/journal.pone.0120574. eCollection 2015.
Intrahepatic (ICC) and extrahepatic cholangiocarcinomas (ECC) are tumors that arise from cholangiocytes in the bile duct, but ICCs are coded as primary liver cancers while ECCs are coded as biliary tract cancers. The etiology of these tumors is not well understood. It has been suggested that the etiology of ICC is more similar to that of another type of liver cancer, hepatocellular carcinoma (HCC), than to the etiology of ECC. If this is true, geographic incidence patterns and trends in ICC incidence should be more similar to that of HCC than ECC.
To examine this hypothesis, data from the North American Association of Central Cancer Registries Cancer in North America data file were analyzed. Incidence rates and joinpoint trends were calculated by demographic subgroup. County-level incidence rates were mapped.
Overall incidence rates, racial distribution, male:female ratio, and peak ages were more similar between ICC and ECC than with HCC. During 2000-2009, average annual incidence rates of ECC increased. During 2005-2009, average annual ICC incidence rates also increased. High rates for all three cancer sites were found in the Pacific region, particularly Hawaii and Alaska. Rates of ICC and ECC were also high in the Northeast and the upper Midwest, while rates of HCC were high in the South.
Demographic patterns and geographical variation were more closely related between ICC and ECC than HCC, suggesting that the etiology of ICC and ECC may be similar. Increasing rates of both tumors suggest that further etiology studies are warranted.
肝内胆管癌（ICC）和肝外胆管癌（ECC）是起源于胆管上皮细胞的肿瘤，但ICC被编码为原发性肝癌，而ECC被编码为胆道癌。这些肿瘤的病因尚不清楚。有人提出，ICC的病因与另一种肝癌——肝细胞癌（HCC）的病因相比，与ECC的病因更相似。如果这是真的，那么ICC发病率的地理分布模式和趋势应该与HCC比与ECC更相似。
为检验这一假设，分析了北美中央癌症登记协会北美癌症数据文件中的数据。按人口亚组计算发病率和连接点趋势。绘制了县级发病率地图。
ICC和ECC之间的总体发病率、种族分布、男女比例和发病高峰年龄比与HCC之间更相似。在2000 - 2009年期间，ECC的年均发病率有所上升。在2005 - 2009年期间，ICC的年均发病率也有所上升。在太平洋地区，特别是夏威夷和阿拉斯加，这三种癌症的发病率都很高。ICC和ECC在东北部和中西部上游地区的发病率也很高，而HCC在南部地区的发病率很高。
ICC和ECC之间的人口统计学模式和地理差异比与HCC之间的关系更密切，这表明ICC和ECC的病因可能相似。两种肿瘤发病率的上升表明有必要进一步开展病因学研究。
