Rechallenging breast cancer with tamoxifen therapy

Advanced breast cancer which has temporarily responded to a course of tamoxifen (Nolvadex) therapy may show a response a second or third time when rechallenged by the same agent subsequently. The interval between such treatments may be critical for response. The observation also has important implications in the management of recurrence in high risk patients who have received adjuvant therapy which includes tamoxifen, after their primary surgery.