Context Hepatocellular carcinoma (HCC) has a male predominance and is closely
related to hepatitis B virus (HBV) infection. Hepatitis B virus vaccination
was launched in 1984 in Taiwan for neonates of mothers carrying hepatitis
B e antigen, resulting in a decreased incidence of HCC in children. The effect
on boys vs girls is not known.
Objective To evaluate the association between a HBV vaccination program with incidence
of childhood HCC by sex.
Design and Setting Analysis of data collected from Taiwan's National Cancer Registry System
and the Taiwan Childhood Hepatoma Study Group between 1981 and 1996.
Participants Children aged 6 to 14 years who were diagnosed as having HCC (201 boys
and 70 girls).
Main Outcome Measure Incidence of HCC in boys and girls before and after implementation of
the vaccination program.
Results The boy-girl incidence ratio decreased steadily from 4.5 in 1981-1984
(before the program's introduction) to 1.9 in 1990-1996 (6-12 years after
the vaccination program was launched). The incidence of HCC in boys born after
1984 was significantly reduced in comparison with those born before 1978 (relative
risk [RR], 0.72; P = .002). No significant decrease
in HCC incidence was observed in girls born in the same periods (RR, 0.77; P = .20). The incidence of HCC in boys remained stable
with increasing age, while an increase of HCC incidence with age in girls
was observed. These age and sex effects remained the same regardless of birth
before or after the vaccination program.
Conclusion Our results suggest that boys may benefit more from HBV vaccination
than girls in the prevention of HCC.