Alcohol, Obesity, and Smoking Risk Factors for HCC

BOSTON-Alcohol, obesity,and tobacco are all independent riskfactors for hepatocellular carcinoma(HCC), according to a case-controlstudy presented at the 54th AnnualMeeting of the American Associationfor the Study of Liver Diseases(AASLD abstract 253).Jorge A. Marrero, MD, of the Universityof Michigan Health System,Ann Arbor, found lifetime smokerswere most vulnerable, and suggestedlifetime exposure to more than onerisk factor would significantly raise aperson's risk of liver cancer. "Tobacco,alcohol, and obesity interact synergisticallyto increase the risk of hepatocellularcarcinoma," he said.The study matched 65 consecutiveHCC patients with two control groups:65 patients with cirrhosis but no signsof HCC, and 65 healthy persons withnormal liver tests and no history ofliver disease. Each group had an average age in the mid-50s and more menthan women.The investigators used validatedquestionnaires to gather informationon lifetime tobacco and alcohol use,which were measured in pack-yearsand kilogram-years, respectively. Bodymass index (BMI) was recorded whenthe patients were interviewed.Lifetime exposure to alcohol andtobacco was significantly higher inHCC patients and in cirrhotic patients:73% of the cancer group and 83% ofthe cirrhotic patients, but only 5% ofthe healthy controls, were formerdrinkers; 12% of the cancer patientsand 6% percent of the controls, butnone of the cirrhotic patients, werecurrent drinkers.Only 2% of those with healthy liversreported being current smokers;the same percentage identified themselvesas former smokers. Among HCCpatients, however, 63% said they usedto smoke and 18% were current smokers.In the cirrhotic group, 37% wereformer smokers and 29% continuedto smoke.Significant Predictors for HCCDr. Marrero and his colleagues calculatedthat alcohol intake greater than6 kilogram-years of ethanol (definedas 20 g/d for 15 years) and tobacco usegreater than 15 pack-years were significantpredictors of HCC. The averagetotal alcohol consumption was 34kilogram-years for the cancer patients,24 for the cirrhosis patients, and 5 forthe healthy controls.Cancer patients had double the lifetimetobacco exposure of cirrhotic patients-31 pack-years vs 15. In contrast,the healthy group's exposure was2 pack- years on average. The HCCpatients also smoked longer than thecirrhotic patients (22 years vs 17) anddrank longer (29 years vs 22). Bothgroups had much longer exposuresthan the healthy people.HCC risk increased 2.6-fold withmoderate exposure to tobacco, butshot up 8.2-fold with heavy exposure,Dr. Marrero said. Similarly, the riskincreased almost 3-fold with moderatealcohol consumption, but almost4.5-fold with heavy consumption.Average BMI was 32 for the HCCpatients and 28 for the cirrhosis patients.Among heavy smokers, Dr.Marrero said, HCC risk increased almost5-fold in people with a BMI greaterthan 30. Yet obesity increased riskonly 1.5-fold in people who did notsmoke. While smoking and drinkingtripled risk for lean patients, no significantinteraction was found betweenalcohol by itself and BMI.Dr. Marrero called for prospectivestudies toward developing a methodto stratify cirrhotic patients into highandlow-risk groups for HCC.