Concern about a potentially increased risk of liver cancer associated
to cyproterone acetate (CPA) treatment led to a postmarketing long-ter
m surveillance study with historic accural of four groups of patients
with sexual-hormonal disorders under treatment with CPA. The aim of th
e study was to provide a description of potential ADRs under CPA treat
ment with special emphasis on liver cancer. A long-term follow-up of 2
506 patients was conducted. Six hundred and two persons were followed
up retrospectively for longer than 10 years. In 16,721 patient-years o
f observation after the first CPA dose no malignant liver tumour was o
bserved, whereas six would have been expected in this cohort. Seven in
cident, non-fatal benign liver tumours were found. Altogether 9.6% of
a subset of 1685 patients with reported liver tests had, at some time,
elevated liver enzymes, No cases were reported where CPA therapy had
been discontinued due to severe liver disorder. We concluded from this
active surveillance project, that CPA treatment is probably safe in t
he groups of patients followed up. Even though there was not a single
case of liver cancer detected, the hypothesis of an elevated risk is b
eing tested in an ongoing collaborative European case-control study wh
ich is examining the association of CPA use and primary hepatocellular
cancer. (C) 1997 by John Wiley & Sons, Ltd.