But the dramatic way in which the American National Cancer Institute handled the revelations of its research results - announcing interim, rather than complete findings, and declaring that it would be "unethical" not to offer the drug to women who were taking placebos - was unwise.
In Britain, where prescription drugs are heavily regulated by the Medical Control Agency, they must first pass a series of tests before being released for use. This process lasts between 180 days and two years. For women at risk of breast cancer, this must seem like a cruel and unreasonable delay.
But no drug, however wondrous, is risk-free and women taking Tamoxifen do show increased risk of endometrial cancer and blood-clotting. Comparisons have been made with the demands of Aids sufferers that AZT be given a product licence before the statutory test period had passed. But there is an important difference. People with Aids are already seriously ill. Women prone to breast cancer are not. Prophylactic drugs must be monitored with special care to ensure that they do not increase the chances of those who take them developing other dangerous conditions.
That said, we encourage the MCA to analyse the Tamoxifen tests as quickly as possible. It is already freely available for the treatment of existing cancers, so a good deal of raw data exists. In medicine as elsewhere, people assess the risk differently at different times in their lives and this should be reflected in the decision about its use. Women should certainly be made aware of the life-saving potential of this drug. But they should be fully apprised of the limitations and risks, as well as the hype.