HONG KONG - Hong Kong’s elderly hepatitis B virus (HBV) carriers are advised to seek regular anti-viral treatment, which case research announced on Thursday by the University of Hong Kong (HKU) has shown to cut the incidence of liver cancer by more than a quarter.
The largest-ever research project studied 26,000 HBV patients treated in Hospital Authority out-patient clinics from 1999 to 2012.
The anti-viral drug treatment – which has been commonly prescribed for patients infected with HBV since the 1990s – was found to reduce the overall liver cancer incidence in Hong Kong by 25 to 30 percent.
Liver cancer is currently the third-deadliest cancer in Hong Kong, behind lung cancer and colon cancer. It is the fourth most common cancer in the city.
Currently about 8 percent of Hong Kong’s seven million-strong population carries HBV. Among them, a quarter will develop liver cirrhosis or even liver cancer. Four in every five of the 1,500 liver-cancer fatalities are HBV carriers.
In general, the HBV treatment over the 14-year study period achieved widespread success in lowering the number of liver-cancer cases among all age groups, but not in patients aged 65 or over, who, as researchers said, had shown far less motivation in seeking help and receiving HBV treatment from clinics.
Every year, the city records about 1,700 new liver-cancer cases, of which 75 percent are male, with average age of 60 to 65.
Walter Seto Wai-kay, clinical associate professor at the Department of Medicine at the University of Hong Kong said most elderly patients had limited knowledge of HBV and were less vigilant to threats posed by the disease because they show no symptoms. This has made them more prone to liver-cancer risk.
“In view of this, we called on the senior HBV-infected individuals to come to the clinics more often and take the medication regularly, in order to prevent the liver cancer from affecting them,” said Seto.
Researchers noted that awareness and the habit of seeking regular clinic treatment boosted the efficacy of the treatment. The discovery was based on the fact that the cancer incidence for male HBV-carriers aged 55 to 64, who have a high treatment prescription rate and clinic attendance rate, was reduced 24 percent after using antiviral treatment. In the meantime, the incidence was lowered 8.5 percent among females of the same age group under the same treatment.
Seto attributed the difference between men and women to the high rate of HBV infection among men.
“The reason for the gender difference which has prevailed in the HBV infection is still inconclusive. Some studies have associated the disparity to the female hormones, which might act as a protective shield against HBV virus,” Yuen said when asked about the underlying reason for the gender difference.