Aromatase inhibitors continue their ATAC on tamoxifen

The breast cancer drug tamoxifen, the best-known and most widely prescribed anticancer drug in the world, is facing a stiff challenge from an exciting group of compounds called aromatase inhibitors. ‘Tamoxifen is under threat,’ says Anthony Howell, Professor of Medical Oncology at Manchesterʹs Christie Hospital, and Principal Investigator of the largest breast cancer trial ever undertaken. The initial results of this trial suggest that for postmenopausal women, the aromatase inhibitor anastrozole (Arimidex®) is more successful than tamoxifen as an adjuvant (i.e. treatment given to patients after surgery to prevent their cancer returning). ‘If this result holds up, which I think it will undoubtedly, tamoxifen will be ousted from its first-line setting for postmenopausal women,’ he says.