The 4th edition of the European Code against
Cancer recommends limiting - or avoiding when possible - the use of
hormone replacement therapy (HRT) because of the increased risk of
cancer, nevertheless acknowledging that prescription of HRT may be indicated under certain medical conditions. Current evidence shows that HRT, generally prescribed as menopausal
hormone therapy, is associated with an increased risk of
cancers of the breast, endometrium, and ovary, with the risk pattern depending on factors such as the type of
therapy (oestrogen-only or combined oestrogen-
progestogen),
duration of treatment, and initiation according to the time of menopause. Carcinogenicity has also been established for anti-neoplastic agents used in
cancer therapy,
immunosuppressants, oestrogen-
progestogen contraceptives, and
tamoxifen. Medical use of ionising radiation, an established
carcinogen, can provide major health benefits; however, prudent practices need to be in place, with procedures and techniques providing the needed diagnostic information or therapeutic gain with the lowest possible radiation exposure. For pharmaceutical drugs and medical radiation exposure with convincing evidence on their carcinogenicity, health benefits have to be balanced against the risks; potential increases in long-term
cancer risk should be considered in the context of the often substantial and immediate health benefits from diagnosis and/or treatment. Thus, apart from HRT, no general recommendations on reducing
cancer risk were given for carcinogenic drugs and medical radiation in the 4th edition of European Code against
Cancer. It is crucial that the application of these measures relies on medical expertise and thorough benefit-risk evaluation. This also pertains to
cancer-preventive drugs, and
self-medication with
aspirin or other potential chemopreventive drugs is strongly discouraged because of the possibility of serious, potentially lethal, adverse events.