The liver labyrinth

摘要

The slimy-smooth, dark-red exterior of a healthy liver yields few clues about its complex nature. This 1.5-kilogram lump of tissue is so good at recovering from injury that it requires as little as one-quarter of its original bulk to fully regenerate. But the organ has its limits. Constant cell damage, such as that caused by a fatty diet, necessitates constant repair, providing the perfect setting for malignancy. Researchers are beginning to unravel how the transition to cancer occurs, with the aim of, eventually, finding more-effective ways to prevent it. The body needs fat for hormone production, vitamin transport and insulation, and the liver stores and breaks it down in a tightly regulated process. The accumulation of too much fat, however, can result in (fatty liver disease, and in some people this can develop into a condition called non-alcoholic steatohepatitis (NASH), in which sections of the liver become inflamed. NASH can be accompanied by scar tissue (fibrosis) that becomes thick and hard (cirrhosis), and a few cases (2-5% each year) progress to the most common form of liver cancer, hepatocellular carcinoma (HCC).