LATESTBreastCancer Blog: Breast Cancer News (8/24): Aromatase Inhibitors and Tamoxifen:
"When used as adjuvant therapy to prevent recurrence, aromatase inhibitors (AIs) are associated with improvements in disease-free survival, but not overall survival. A review in the Journal of the National Cancer Institute, first published online July 8, examined whether differences in toxicity explain the difference in overall survival. Yesterday, Medical News Today and medpagetoday.com covered the results.
The review included 7 trials and 30,023 patients. Longer use of AIs was associated with increased odds of cardiovascular disease and bone fractures, but decreased odds of venous thrombosis [blood clots] and endometrial cancer. Five years of AIs was associated with an increase in the odds of death without breast cancer recurrence compared to 5 years of tamoxifen or 2-3 years of tamoxifen followed by AIs. However, the difference was not statistically significant.
The authors concluded that when used alone, "cumulative toxicity" of AIs may explain the lack of overall survival benefit despite improvement in disease-free survival. Switching from tamoxifen to AIs "reduces this toxicity and is likely the best balance between efficacy and toxicity."