The association between parity and hepatocellular carcinoma (HCC) was
studied using a data-base generated by linking 2 Swedish nation-wide r
egistries; the Cancer Registry and the Fertility Registry. Among women
born between 1925 and 1960, 133 patients with HCC recorded in the Can
cer Registry between 1958 and 1984 were compared with 665 age-matched
controls. In this nested case-control study there was no positive asso
ciation between parity, age at first birth or frequency of twinning on
the one hand, and risk of HCC on the other. It appears that the posit
ive association between parity and HCC previously reported is limited
to cases of HCC caused by chronic infection with hepatitis B virus; th
ese cases represent only a small fraction of HCC cases in Sweden. (C)
1993 Wiley-Liss, Inc.