Reactive oxygen species also cause epigenetic alterations at the sites of DNA repair.While this constant cycle of damage followed by repair can lead to mistakes during repair, which in turn lead to carcinogenesis, this hypothesis is more applicable, at present, to hepatitis C. Chronic hepatitis C causes HCC through the stage of cirrhosis. In chronic hepatitis B, however, the integration of the viral genome into infected cells can directly induce a noncirrhotic liver to develop HCC. Alternatively, repeated consumption of large amounts of ethanol can have a similar effect. The toxin aflatoxin from certain Aspergillus species of fungi is a carcinogen and aids carcinogenesis of hepatocellular cancer by building up in the liver. The combined high prevalence of rates of aflatoxin and hepatitis B in settings such as  China and West Africa has led to relatively high rates of hepatocellular carcinoma in these regions. Other viral hepatitides such as hepatitis A have no potential to become a chronic infection, thus are not related to HCC. Diagnosis
Methods of diagnosis in HCC have evolved with the improvement in medical imaging. The evaluation of both asymptomatic patients and those with symptoms of liver disease involves blood testing and imaging evaluation. Historically, a biopsy of a tumor was required to prove an HCC diagnosis. However, imaging (especially MRI) findings may be conclusive enough to obviate histopathologic confirmation. Screening
HCC remains associated with a high mortality rate, in part because initial diagnosis commonly occurs at an advanced stage of disease.
Modified males raised in a laboratory develop normally as they are supplied with this chemical and can be released into the wild. Their subsequent offspring inherit this trait, but find no tetracycline in their environments, so never develop into adults. References
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External links
"Tetracycline". Drug Information Portal. U.S. National Library of Medicine.