Switching to an Aromatase Inhibitor Provides Mortality Benefit in Early Breast Carcinoma Pooled Analysis of 2 Consecutive Trials

BACKGROUND. The superiority of new generation aromatase inhibitors over ta-moxifen in the adjuvant treatment of early breast carcinoma has emerged from several randomized trials. However, until now not all previous studies have shown a mortality benefit. METHODS. A pooled analysis of 2 prospective multicentric trials, sharing the same study design and nearly identical inclusion criteria, was performed. In both trials, women treated previously with tamoxifen for 2 or 3 years were randomly assigned to either continuing tamoxifen for an additional 2 or 3 years or to hav-ing their treatment switched to aminoglutethimide or anastrozole for a compara-ble time period. Mortality was analyzed according to allocated treatment and other patient and tumor variables. The GROCTA 4B trial was supported in part by grants no 92.02298, 99.022275, 94.041242, 95.00473, and 96.00670 from the Italian National Research Council Project ACRO. The ITA trial was funded by AstraZeneca (Basiglio-Italy), which also provided the trial drugs