Other chemoprevention agents

Daily use of tamoxifen, a selective estrogen receptor modulator, typically for 5 years, has been demonstrated to reduce the risk of developing breast cancer in high-risk women by about 50%. Cis-retinoic acid also has been shown to reduce risk of second primary tumors among patients with primary head and neck cancer. Finasteride, a 5-alpha reductase inhibitor, has been shown to lower the risk of prostate cancer. Other examples of drugs that show promise for chemoprevention include COX-2 inhibitors (which inhibit a cyclooxygenase enzyme involved in the synthesis of proinflammatory prostaglandins).