What is the usual cause of death in hepatocellular carcinomas?

This is a good question, because medical newbies and laypeople often simply accept "cancer" as a cause of death.  Of course, having unregulated, poorly differentiated, proliferating cells is one thing, but how do they actually lead to a patient's death?  That depends on the specific tumour.  In the case of the hepatocellular carcinoma (HCC), there are four common causes of death:

• Cachexia - The severe wasting that accompanies cancer has several overlapping causes: stealing away nutrients to fund its own cancerous growth, pressing on gastrointestinal tract structures, inflammatory cytokine release decreasing appetite centrally, etc.  We all know that we can't survive without adequate nutrition for long - cells need energy! - and this is true on a slightly longer timescale in cancers as well. Fundamentally, as horrible as it undeniably is, you can simply starve your cells to death in cancer.


• Liver failure - Although the liver has a large reserve capacity, clearly there must be a point at which too much of the liver has been obliterated by the rapidly growing cancer.  The result is much the same as with other causes of liver failure: glucose instability, hepatic encephalopathy, bleeding diathesis, etc. 
  


• Variceal bleed - If the HCC is large and obstructive enough to cause portal hypertension, oesophageal (and sometimes gastric) varices result, with the ever-present danger of catestrophic rupture.  This danger is of course made more acute if the INR is also prolonged.


• Rupture of the tumour with exsanguination - The tumour can grow so large that, like the varices above, it simply ruptures.  Since tumours contain their own internal network of blood vessels, and since again the INR is often deranged, this can result in rapid exsanguination and death.