Long-term incidence of hepatocellular carcinoma after hepatitis B surface antigen seroclearance.

Abstract

Risk of hepatocellular carcinoma (HCC) decreases following hepatitis B surface antigen (HBsAg) seroclearance. We examined HCC incidence in patients with chronic hepatitis B (CHB) who cleared HBsAg compared to general population. All adults with CHB who cleared HBsAg between 2000-2022 were identified using a territory-wide database in Hong Kong. Annual HCC incidences were estimated and compared to general population. Age- and sex-specific population statistics were retrieved from the Hong Kong Cancer Registry and Census and Statistics Department. Of 13,379 patients with HBsAg seroclearance (mean age 59.7±13.7 years, 59.8% males, 14.6% cirrhosis), 274 (2.0%) developed HCC at a median of 5.6 (IQR 3.1-9.8) years. Annual HCC incidence (95% CI) was 0.43% (0.22%-0.73%) and 0.62% (0.50%-0.76%) among patients with cirrhosis aged <50 years and ≥50 years at HBsAg seroclearance, respectively. In patients without cirrhosis who cleared HBsAg before age 50, the annual HCC incidence was 0.03% (95% CI 0.01%-0.06%), comparable to 0.03% in general population. Annual HCC incidence of male patients without cirrhosis aged <40 and 40-49 years at HBsAg was 0.02% (95% CI 0.002%-0.08%) and 0.09% (0.03%-0.19%), respectively. No HCC cases occurred during 15 years of follow-up among 1,317 female patients without cirrhosis aged <50 years at HBsAg loss; the annual HCC incidence was 0.06% (95% CI 0.02%-0.13%) among those aged 50-59 years. Patients with CHB who clear HBsAg at younger ages, particularly men <40 years and women <50 years without cirrhosis or additional risk factors, have very low HCC risk and may not require routine surveillance.