Review of hepatocellular carcinoma: Epidemiology, etiology, and carcinogenesis.

Since the 1970s, the epidemic of hepatocellular carcinoma (HCC) has spread beyond the Eastern Asian predominance and has been increasing in Northern hemisphere, especially in the United States (US) and Western Europe. It occurs more commonly in males in the fourth and fifth decades of life. Among all cancers, HCC is one of the fastest growing causes of death in the US and poses a significant economic burden on healthcare. Chronic liver disease due to hepatitis B virus or hepatitis C virus and alcohol accounts for the majority of HCC cases. Incidence of nonalcoholic fatty liver disease has been on the risem and it has also been associated with the development of HCC. Its pathogenesis varies based on the underlying etiological factor although majority of cases develop in the setting of background cirrhosis. Carcinogenesis of HCC includes angiogenesis, chronic inflammation, and tumor macroenvironment and microenvironment. There is a significant role of both intrinsic genetic risk factors and extrinsic influences such as alcohol or viral infections that lead to the development of HCC. Understanding its etiopathogenesis helps select appropriate diagnostic tests and treatments.

Cancer review: Cholangiocarcinoma.

Cholangiocarcinoma (CCA) is the most common biliary tract malignancy. CCA is classified as intrahepatic, perihilar or distal extrahepatic; the individual subtypes differ in their biologic behavior, clinical presentation, and management. Throughout the last decades, CCA incidence rates had significantly increased. In addition to known established risk factors, novel possible risk factors (i.e. obesity, hepatitis C virus) have been identified that are of high importance in developed countries where CCA prevalence rates have been low. CCA tends to develop on the background of inflammation and cholestasis. In recent years, our understanding of the molecular mechanisms of cholangiocarcinogenesis has increased, thereby, providing the basis for molecularly targeted therapies. In its diagnostic evaluation, imaging techniques have improved, and the role of complementary techniques has been defined. There is a need for improved CCA biomarkers as currently used ones are suboptimal. Multiple staging systems have been developed, but none of these is optimal. The prognosis of CCA is considered dismal. However, treatment options have improved throughout the last two decades for carefully selected subgroups of CCA patients. Perihilar CCA can now be treated with orthotopic liver transplantation with neoadjuvant chemoradiation achieving 5-year survival rates of 68%. Classically considered chemotherapy-resistant, the ABC-02 trial has shown the therapeutic benefit of combination therapy with gemcitabine and cisplatin. The benefits of adjuvant treatments for resectable CCA, local ablative therapies and molecularly targeted therapies still need to be defined. In this article, we will provide the reader with an overview over CCA, and discuss the latest developments and controversies.