(Reuters Health) - People with advanced cases of nonalcoholic fatty liver disease (NAFLD) may need to be watched for liver cancer, a large U.S. study suggests.

Fatty liver disease is known to be linked with a higher risk of a dangerous liver cancer called hepatocellular carcinoma, or HCC. But doctors haven’t known whether some patients are more at risk than others.

The new study showed that when NAFLD progresses to where patients have liver scarring, or cirrhosis, their risk for HCC is dramatically higher.

NAFLD is the leading cause of chronic liver disease in the U.S., affecting approximately 30 percent of the adult population. Often associated with obesity and diabetes, it involves a build-up of fat in the liver not caused by drinking alcohol.

The findings suggest that people with NAFLD and cirrhosis should be monitored for HCC, the authors write in the journal Gastroenterology.

Among people with less severe NAFLD, the risk of liver cancer was not particularly high.

Therefore, the need for regular monitoring doesn’t apply to everyone with NAFLD, Dr. Talal Adhami told Reuters Health in a phone interview. Adhami, a member of the American Liver Foundation’s National Medical Advisory Committee, was not involved in the study.

In fact, most people with NAFLD never develop cirrhosis. In one earlier study, for example, only 5 percent of people with NAFLD developed liver scarring during roughly eight years of follow-up.

The researchers analyzed Veterans Health Administration data on nearly 300,000 people with NAFLD and a similar number of people with healthy livers who were tracked for an average of 11 years.

Over the course of a year, roughly one case of liver cancer was diagnosed in every 50,000 patients with healthy livers. Not surprisingly, the rate was higher among people with NAFLD: one case of cancer for every 5,000 people.

But for patients with NAFLD and cirrhosis, the risk was markedly higher. Over the course of a year, researchers diagnosed more than 50 cases for every 5,000 patients with advanced liver disease.

The study also found higher rates of HCC in men and older patients, and lower rates in women and patients under age 45. The risk was highest in older Hispanic people and relatively low in African-American adults.

Study leader Dr. Fasiha Kanwal, of Baylor College of Medicine and Michael E. DeBakey Veterans Affairs Medical Center in Houston, Texas, said in a statement the study was the first large, diverse cohort study to quantify the risk of HCC in patients with NAFLD.

“This study gives an idea of whom you need to put on your radar for screening and which other patients have less risk of developing HCC,” Adhami said.

The American Liver Foundation notes on its website that there are no treatments yet for NAFLD. “Eating a healthy diet and exercising regularly may help prevent liver damage from starting or reverse it in the early stages,” the group says. People with NAFLD should also see a doctor who specializes in the liver; lose weight, if they are overweight or obese; lower their cholesterol and triglycerides; control their blood sugar levels; and avoid alcohol.

SOURCE: bit.ly/2LR3hgR Gastroenterology, online August 23, 2018.