People who are cured of hepatitis C virus (HCV) lower their risk of liver cancer, aidsmap reports. However, those who do develop hepatocellular carcinoma (HCC, the most common form of liver cancer) during or shortly after curing the virus may develop more aggressive cases.

Researchers studied a group of 3,075 people with hep C in northern Italy who were treated for the virus between January 2015 and June 2016. They presented their findings at the Annual Meeting of the American Association for the Study of Liver Diseases (AASLD) in Boston.

The participants had moderate or advanced fibrosis (scarring) of the liver. Seventy-two percent had cirrhosis. The study excluded those previously diagnosed with liver cancer and those who had undergone a liver transplant before being treated for hep C.

During an average follow-up of 300 days following the start of hep C treatment, 41 people in the study cohort developed liver cancer, for a rate of 1.64 cases per year for each 100 participants. The rate for those without cirrhosis was 0.23 cases; for those with cirrhosis, it was 1.93 cases per year for each 100 participants.

The researchers compared these rates to the cancer rate seen in the same Italian region among a group with hep C who had not been treated for the virus: 2.8 cases per year for every 100 people.

Thirty-nine percent (16 cases) of the 41 cases of liver cancer among the new study cohort were a relatively aggressive form—a notably high proportion. Such aggressive cases were more likely during the first six months following treatment.

The researchers theorize that changes in the liver following the rapid elimination of the virus during HCV treatment—in the body’s immune and tumor-repression responses—may have facilitated the more rapid growth of already-existing tumors.

To read the aidsmap article, click here.