Methods of ovarian suppression used in the UK

Luteinizing hormone-releasing hormone agonists in premenopausal hormone receptor-positive breast cancer

Ovarian function suppression for the treatment of premenopausal breast cancer was first used in the late 19th century. Traditionally, ovarian function suppression had been accomplished irreversibly via irradiation or surgery, but analogues of the luteinizing hormone-releasing hormone (LH-RH) have emerged as reliable and reversible agents for this purpose, especially the LH-RH agonists. Luteinizing hormone-releasing hormone antagonists are in earlier stages of development in breast cancer and are not currently in clinical use. Luteinizing hormonereleasing hormone agonists act by pituitary desensitization and receptor downregulation, thereby suppressing gonadotrophin release. Limited information is available comparing the efficacies of the depot preparations of various agonists, but pharmacodynamic studies have shown comparable suppressive capabilities on estradiol and luteinizing hormone. At present, only monthly goserelin is Food and Drug Administration-approved for the treatment of estrogen receptor-positive, premenopausal metastatic breast cancer in the United States. Luteinizing hormone-releasing hormone agonists have proven to be as effective as surgical oophorectomy in premenopausal advanced breast cancer. They offer similar outcomes compared with tamoxifen, but the endocrine combination appears to be more effective than LH-RH agonists alone. In the adjuvant setting, LH-RH agonists versus no therapy reduce the annual odds of recurrence and death in women aged>50 years with estrogen receptor-positive tumors. Luteinizing hormone-releasing hormone agonists alone or in combination with tamoxifen have shown disease-free survival rates similar to chemotherapy with CMF (cyclophosphamide/methotrexate/5-fluorouracil). Outcomes of chemotherapy with or without LH-RH agonists are comparable, though a few trials favor the combination in young premenopausal women (aged<40 years). Adjuvant LH-RH agonists with or without tamoxifen might be as efficacious as tamoxifen alone, and the additional benefit from chemotherapy is unclear. Adequately powered studies are now studying the relative merits of combining adjuvant tamoxifen or aromatase inhibitors with ovarian function suppression, the additional benefits of adding ovarian function suppression to chemotherapy, and the need for adjuvant chemotherapy for women treated with combined ovarian function suppression and anti-estrogen therapy.

Adjuvant ovarian suppression versus chemotherapy for premenopausal, hormone-responsive breast cancer: quality of life and efficacy tradeoffs

PURPOSE

Recent clinical trials suggest that adjuvant ovarian suppression may be an equally effective and less toxic alternative to systemic chemotherapy in premenopausal women with hormone-responsive breast cancer. We used a decision-analytic framework to evaluate tradeoffs between efficacy and quality of life in the choice between these treatments.

PATIENTS AND METHODS

We used a Markov state-transition model to simulate clinical practice in a cohort of 40-year-old premenopausal women with newly diagnosed, hormone-responsive early breast cancer. We assessed three adjuvant treatments: chemotherapy, surgical ovarian suppression, and medical ovarian suppression. Outcomes were recurrence-free, overall, and quality-adjusted survival. Quality-adjusted survival reflected effects of cancer, treatment-related side effects, and menopausal symptoms.

RESULTS

Assuming equal efficacy, ovarian suppression was superior to chemotherapy when the relative utility of chemotherapy side effects compared with ovarian suppression side effects was less than 0.95. Results were sensitive to assumptions about the likelihood, duration and consequences of treatment-induced menopause. Treatment choice was affected by a 7% proportional increase in the efficacy of one therapy relative to the others, independent of other factors.

CONCLUSION

If adjuvant chemotherapy and ovarian suppression have similar efficacy, then there may be a subgroup of women for whom quality-of-life considerations dominate the choice of treatment. However, small differences in the relative efficacy of these therapies have a substantial impact on treatment choice, regardless of side effects and menopausal transitions.

Ovarian ablation as a treatment for breast cancer

Ovarian ablation is an effective treatment for premenopausal women with hormone receptor positive breast cancer. It can be achieved permanently by surgery or radiotherapy and reversibly by LhRH agonists. This paper discusses the evidence that it is an effective adjuvant therapy and defines the place of oophorectomy in the management of such patients. The achievement of an amenhorreic state is important and chemotherapy may well exert some of its effects by causing ovarian suppression. The use of LhRH agonists in managing such patients is discussed.

Ovarian ablation in the adjuvant treatment of premenopausal and perimenopausal breast cancer

BACKGROUND

Ovarian ablation has been employed in the treatment of breast cancer for many decades and, more recently, its value as an adjuvant treatment for premenopausal women with early-stage disease has been clearly demonstrated. This review examines the different methods of achieving ovarian ablation and assesses the relevance of ovarian suppression as a treatment aim.

METHODS

Medline searches were used to identify recent key articles relating to the adenoma-carcinoma sequence. Further relevant articles were obtained by manual scanning of the reference lists of selected papers.

RESULTS AND CONCLUSION

Ovarian ablation has historically been achieved by surgical or radiological intervention. Although beneficial in premenopausal disease, these methods produce permanent ablation that results in a premature menopause, which may be associated with long-term adverse events. A series of trials have recently demonstrated the benefits of luteinizing hormone releasing hormone (LHRH) agonists, such as goserelin and leuprorelin, as adjuvant treatment for premenopausal hormone-sensitive disease. LHRH agonists produce a reliable suppression of ovarian oestrogen production of equivalent efficacy to adjuvant chemotherapy in hormone-sensitive disease. Effective ovarian suppression is marked by amenorrhoea, but studies have suggested that permanent amenorrhoea is not necessary to confer benefit in the treatment of early breast cancer. LHRH agonists therefore represent a beneficial therapeutic option for premenopausal patients with hormone-sensitive early disease.