Complex sentence: Those who develop cirrhosis have a 20-fold greater risk of hepatocellular carcinoma, a rate of 1--3% per year, and if this is complicated by excess alcohol the risk becomes 100 fold greater.
Split into simpler sentences: Those who develop cirrhosis have a 20-fold greater risk of hepatocellular carcinoma. If this is complicated by excess alcohol, the risk becomes 100 fold greater.