Aromatase Inhibitors to Help Treat Breast Cancer
Meet the Latest Hope for Post-Menopausal Breast Tumor Patients
Feb 28, 2009
Some breast cancers express Estrogen receptors or Progesterone receptors and are amendable to hormonal therapy. Tamoxifen, a selective estrogen receptor modulator, has been shown to inhibit the growth of breast cancer by competing with estrogen for its receptors on breast cancer cells. It has been found to be useful in reducing the chance of recurrence and prolonging survival. However, treatment with tamoxifen beyond five years has been shown to offer no additional benefit. It is in fact potentially detrimental to the patient’s health because of its associated increased risks of endometrial cancer, thromboembolic (abnormal clotting) conditions and cerebrovascular diseases (including strokes). These breast cancer sufferers need and await somthing better.
What are Aromatase Inhibitors?
Aromatase Inhibitors are drugs that act by blocking the enzyme aromatase and hence reduce the concentration of estrogen in peripheral tissues. The data from large studies with the newest (often called third generation) Aromatase Inhibitors is showing generally promising results. This data is justifiably starting to cast the third generation Aromatase Inhibitors as the latest hope for post-menopausal breast cancer patients. Their clinical efficacy and safety profile has been so impressive that they have been increasingly used as the standard first-line therapy for metastatic breast cancers. Their use in the adjuvant setting (supplementary to surgery to reduce chance of recurrence) is also on the rise. However, there are still potential hazards and safety issues which need to be addressed before the role of the drugs can be better established. The following issues are often discussed.
Increased Potential Hazards of Aromatase Inhibitors on Bones
From various clinical trials, all third-generation Aromatase Inhibitors have been shown to have adverse effects on bone metabolism, evidenced by more osteoporosis and fractures compared with tamoxifen or placebos.
Reduced Potential Thromboembolic Hazards
Recent clinical trials confirmed increased risk of thromboembolic complications with the use of tamoxifen, as well as a reduced risk with using Aromatase Inhibitors.
Reduced Potential Gynecologic Side Effects
Recent clinical trials comparing use of Aromatase Inhibitors versus use of tamoxifen have shown that the former causes fewer hot flushes, vaginal bleeding, vaginal discharge and endometrial cancer.
Conclusion
The use of Aromatase Inhibitors, compared with using tamoxifen, appears to show improved results and greater patient safety. The best protocl (schedule and duration) to use the new drugs is the subject of many clinical studies being conducted. These trials are likely to help establish the role of Aromatase Inhibitors in the treatment of post-menopausal women with breast cancer.
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