[Current status of breast cancer chemoprevention].
Chemoprevention is defined as the use of natural or synthetic chemical agents to reverse, suppress or prevent carcinogenic progression of invasive cancer. Drugs that act as chemoprevention agents for breast cancer are divided into two major groups: drugs that prevent Estrogen Receptor (ER)-positive breast cancers [selective estrogen receptor modulators (SERM), aromatase inhibitors GnKH agonists and phytoestrogens] and drugs that prevent ER-negative breast cancers [cyclooxygenase-2 (COX-2) inhibitors, retinoids, statins, receptor tyrosine, kinase inhibitors, monoclonal antibody against HER-2 and telomerase inhibitors]. Results from the NSABP Study of Tamoxifen and Raloxifene (STAR), which compared the risk-reducing efficacy as well as toxicity of these two SERMs in a similar high-risk for breast cancer population, showed that Raloxifene is as effective as Tamoxifen in reducing the risk of non-invasive breast cancer (p=.83). It has a statistically significant lower risk of thromboembolic events and cataracts, however a non- statistically significant higher risk of noninvasive breast cancer. Based on promising data involving reduction of contralateral breast cancer risk in adjuvant studies, several aromatase inhibitors, including letrozole, anastrozole and exemestane, are being included in trials to evaluate their efficacy in breast cancer prevention in both case-control and cohort studies As such randomized studies to confirm this efficacy are needed. Positive results of several recent clinical trials for preventing breast cancer in high-risk populations suggest that chemoprevention is a rational and attractive strategy.
Oliveira
Vilmar Marques de
VM
Departamento de Obstetrícia e Ginecologia, Faculdade de Ciências Médicas, Santa Casa de SPSP.
Aldrighi
José Mendes
JM
Rinaldi
José Francisco
JF
D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001141:Aromatase / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000517:prevention & control*; D002986:Clinical Trials as Topic; D005260:Female; D006801:Humans; D011451:Prostaglandin-Endoperoxide Synthases / Q000627:therapeutic use; D020849:Raloxifene Hydrochloride / Q000627:therapeutic use; D012306:Risk; D013629:Tamoxifen / Q000627:therapeutic use
D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen; D020849:Raloxifene Hydrochloride; D001141:Aromatase; D011451:Prostaglandin-Endoperoxide Synthases