What is the role of ovarian ablation in the management of primary and metastatic breast cancer today?

Ovarian ablation has been used for more than a century in the treatment of breast cancer. Methods of irreversible ovarian ablation include surgical oophorectomy and ovarian irradiation. Potentially reversible castration can be accomplished medically using luteinizing hormone releasing hormone (LHRH) analogues. In addition, cytotoxic chemotherapy unpredictably produces amenorrhea and primary ovarian failure in 10%-95% of premenopausal women as a function of patient age, cumulative dose, and the specific agents used. In the metastatic setting, ovarian ablation and tamoxifen monotherapies produce comparable outcomes and may be more effective when used together. While many early adjuvant trials of ovarian ablation were methodologically flawed, a more recent meta-analysis by the Early Breast Cancer Trialists' Collaborative Group of 12 properly designed randomized trials found significantly greater disease-free and overall survival rates for women under the age of 50, regardless of nodal status, receiving ovarian ablation as a single adjuvant therapy. Several important issues regarding the role of ovarian ablation in the treatment of breast cancer remain unresolved. Data suggest that ovarian ablation followed by some years of tamoxifen produces similar results to those seen with adjuvant chemotherapy in women with hormone-receptor positive breast cancer; however, the value of combining these modalities is still unclear. Other areas of ongoing investigation include the appropriate duration of therapy with LHRH analogues in the adjuvant setting, the long-term sequelae of ovarian suppression among young breast cancer survivors, and refinement of the population most likely to benefit from ovarian ablation or suppression.