Lighter Patients with Liver Cancer Fare Better
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Jot down liver cancer on the list of conditions exacerbated by excess poundage.
That’s the conclusion of Japanese researchers, who found that people who are obese and have hepatitis C virus (HCV)-associated hepatocellular carcinoma have significantly shorter survival than lean patients with liver cancer.
“Obesity may worsen the prognosis of people with hepatocellular carcinoma, and reduction of body weight may improve the clinical course and prognosis of people with HCV by delaying the development of hepatocellular carcinoma,” Toshihiko Mazuta, M.D., and colleagues at Saga Medical School reported at the American Association for the Study of Liver Diseases meeting here.
An estimated 1.5 million people in Japan are infected with HCV, and approximately 30,000 Japanese die from hepatocellular carcinoma annually. More than 80% of the deaths are attributable to HCV-associated liver cancer, Dr. Mizuta said.
Because obesity has been implicated in epidemiological studies as a risk factor for hepatocellular carcinoma, and has been associated with a worse clinical course of HCV, Dr. Mizuta and colleagues decided to look at the influence of body mass index (BMI) on HCV related liver cancer.
They conducted a retrospective study of 150 consecutive patients with hepatocellular carcinoma and HCV antibody positivity. The patients were classified into four groups according to their BMI at time of hepatocellular carcinoma diagnosis: lean, with a BMI
< 22 (57 patients), normal, with a BMI between 22 and 25 (56 patients), overweight, with a BMI 25 and 28, and obese with a BMI >28.
In an interview, Dr. Mizuta noted that although a definition of BMI > 28 as obese differs from that used in the United States (BMI > 30), Japanese people have traditionally been lean, and the comparison is therefore a relative one.
They looked at differences of age, gender, alcohol consumption, smoking (packs/year), diabetes, and hepatic function, as measured by ALT and albumin levels, prothrombin activity, and Child-Pugh class.
They found that lean patients had significantly lower liver enzyme (serum ALT) levels compared with the normal group, but not compared with the overweight or obese cohorts.
When they looked at serum albumin concentration and prothrombin activity, however, they found that levels gradually decreased as BMI increased. For example, albumin concentrations were 3.6 g/dl in lean patients, compared with 3.2 in obese patients. Prothrombin activity declined from 74% among the lightest, patients, to 66% among those who were obese.
In addition, the severity of disease as measured by the ratio of Child-Pugh C class in each group increased in association with BMI. Only 5% of lean patients had Child-Pugh class C disease, compared with 38% of obese patients. "There were no differences in gender, alcohol, smoking, and diabetes among the four groups," added Dr. Mizuta.
They used a Kaplan-Meier analysis to look at the relationship between BMI and cumulative survival rates after treatment for 80 patients with early stage cancer (stage I or II). "The cumulative survival rate of the obese group was significantly lower than that of the other groups," Dr. Mizuta and colleagues noted in this analysis.
In a multivariate analysis, a BMI >
28 proved to be the only independent factor associated with poor prognosis, they found.
“BMI influences the onset age of hepatocellular carcinoma and hepatic function; further, obesity is a poor prognostic factor in patients with HCV -related hepatocellular carcinoma,” they wrote.
Primary source: 2005 AASLD Meeting
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