Does survival increase in metastatic breast cancer with recently available anticancer drugs?

ABSTRACT

Metastatic breast cancer (MBC) is incurable in most cases. While multiple treatments are available, the median survival is still approximately 2 years. We planned to assess the apparent impact of taxanes and aromatase inhibitors (letrozole, anastrozole, and exemestane) on the survival of 857 MBC patients for more than 30 years. Patients classed into decades by metastatic disease onset date did not survive significantly longer in recent years. This does not exclude some marked improvements with time 1) in the same period, the disease-free interval for MO patients increased progressively and significantly with time; 2) the overall relapse ratio in MO patients was 20% lower in the 1990-2000 decade compared with 1980-1990; 3) since 1995, treatment for metastasis has been significantly lighter with periods of chemotherapy separated by hormonotherapy or observation in the case of negative receptors. Analyzing individual therapies, availability of taxanes since 1994 did not result in a significant increase of the overall survival. Conversely, receiving hormonotherapy was an important prognostic factor of the overall survival. Three groups were classified according to hormone therapy group 1--tamoxifen, group 2--aromatase inhibitors, group 3--a combination of tamoxifen then aromatase inhibitors. The combination of tamoxifen then aromatase inhibitors favored a survival improvement from metastasis appearance to death compared with aromatase inhibitors alone and with tamoxifen alone. The sequential treatment of tamoxifen then aromatase inhibitors is presently discussed as a possible standard when used as adjuvant treatment. This sequential effect could also constitute a valuable concept for metastatic patients.