Chemoprevention for breast cancer.

Despite the progress that has been made in breast cancer diagnosis and treatment, this disease is still a major health problem, being the most frequently diagnosed cancer and the first leading cause of cancer death among women both in developed and economically developing countries. In some developed countries incidence rate start to decrease from the end of last millennium and this can be explained, at least in part, by the decrease in hormone replacement therapy use by post-menopausal women. Chemoprevention has the potential to be an approach of utmost importance to reduce cancer burden at least among high-risk populations. Tamoxifen and raloxifene are both indicated for the prevention of breast cancer in women at high risk for the development of the disease, although raloxifene may have a more favorable adverse-effect profile, causing fewer uterine cancers and thromboembolic events. Aromatase inhibitors will most probably become an additional prevention treatment option in the near future, in view of the promising results observed in adjuvant trials and the interesting results of the very recently published first chemoprevention trial using an aromatase inhibitor.(2) Despite impressive results in most clinical trials performed to date, chemoprevention is still not widely used. Urgently needed are better molecular risk models to accurately identify high-risk subjects, new agents with a better risk/benefit ratio and validated biomarkers.