Latest studies fail to show that tamoxifen prevents breast cancer

Attempts to map out the role of tamoxifen for the prevention of breast cancer were set back last week when two new European studies failed to show that prophylactic treatment is beneficial in high risk women.

These latest findings contradict those of a US trial which was halted in April on the strength of interim results showing that the incidence of breast cancer was 45% lower among women taking tamoxifen than among those taking placebo (18 April, p 1187). It will be 2005 before we know the true value of tamoxifen and other antioestrogens, predict UK experts. Only when results from ongoing European trials are combined in a meta-analysis will it become clear whether this preventive treatment can save lives and which women are most likely to benefit from early intervention.

Commenting on his group's study results, Dr Trevor Powles, head of the breast unit at the Royal Marsden Hospital, London, said that it was not a surprise …