Epidemiologic Study of Hepatocellular Carcinoma in the US

Inclusion Criteria for HCC cases:

* a diagnosis of primary liver cancer (excluding secondary tumors)
* a diagnosis of hepatocellular carcinoma if histology is available (excluding those diagnosed in intrahepatic bile duct, bile canals, biliary passages, canaliculi, gall duct and gallbladder)
* a diagnosis of hepatocellular carcinoma with or without microscopic evaluation (including those diagnosed with clinical evidence, lab tests and direct visualization or radiographic and other imaging evidence)
* a histology of primary hepatocellular carcinoma when the patients had a prior diagnosis of other forms of cancer (excluding those who had no histological diagnosis of hepatocellular carcinoma while having a prior history of other cancer;
* age at diagnosis between 35 and 84 years
* living in Connecticut, New Jersey, New York, or Hawaii for at least a year as regular residents.

Exclusion Criteria for HCC cases:

* uncertain diagnoses or classification of malignancy, such as unknown origin
* a diagnosis of primary tumors in other organs, not in the liver
* unable to communicate well enough in English or Spanish
* having medical conditions, such as mental disorders, that prevent the subject from providing reasonably comprehensible information or from being able to give informed consent.
* diagnosed at age \<35 years or \>84 years
* temporary residents of New Jersey, Connecticut, New York, or Hawaii

Inclusion Criteria for control subjects:

* age between 35 and 84 years
* living in New Jersey or Connecticut for at least a year as regular residents
* able to communicate well in English or Spanish
* having no medical conditions, such as mental disorders, that prevent them from providing adequately comprehensible information
* potential subjects with a previous history of cancer are eligible.

Exclusion Criteria for control subjects:

* age \< 35 years or \> 84 years
* temporary residents of New Jersey or Connecticut
* unable to speak English or Spanish
* cannot provide adequately comprehensible information