Breast Cancer Treatment (PDQ®): Treatment - Health Professional Information [NCI] - Stage I, II, IIIA, and Operable IIIC Breast Cancer
A single study of more than 300 patients that compared cyclophosphamide, methotrexate, 5-FU, and prednisone (CMFP) with the same chemotherapy regimen plus surgical oophorectomy showed no additional survival benefit from oophorectomy.[Level of evidence: 1iiA] Three trials (including the International Breast Cancer Study Group's trial [IBCSG-VIII] and the Eastern Cooperative Oncology Group's trial [EST-5188]) involving more than 3,000 patients assessed the impact on DFS and OS from the use of an LHRH analogue (in one trial, 50% of the patients had radiation oophorectomy rather than an LHRH analogue) in addition to chemotherapy.[127,129,130][Level of evidence: 1iiA] None of the trials identified a statistically significant benefit in OS or DFS from ovarian suppression.
As an adjuvant strategy, ovarian ablation has also been compared with chemotherapy in premenopausal women. In a direct comparison of surgical or radiation ablation and CMF, DFS and OS rates were identical in 332 premenopausal women with stage II disease.[Level of evidence: 1iiA] A trial of 599 premenopausal node-positive patients found leuprorelin acetate to be similar to CMF with respect to DFS and OS. A Danish trial compared ovarian ablation or suppression to CMF (9 cycles intravenously every 3 weeks) in premenopausal, ER-positive women and found no difference in OS or DFS in the two study groups.[133,134] The study did not have tamoxifen as an adjuvant arm and also did not use taxanes or anthracyclines. Results may have been different with these two contemporary modifications to the study. A trial of CMF versus tamoxifen plus ovarian ablation (e.g., by surgery, radiation therapy, or gonadotropin-releasing hormone [GnRH]) in premenopausal or perimenopausal women with receptor-positive tumors has been reported.[Level of evidence: 1iiA] In this small trial, which did not meet its target accrual, the combination of tamoxifen and ovarian ablation provided comparable DFS and OS rates. In three larger trials in which medical ovarian ablation with goserelin was used, the impact of goserelin alone on DFS was found to be comparable to CMF in the subgroup of ER+ patients,[127,136][Level of evidence: 2Dii] whereas the combination of goserelin and tamoxifen was associated with prolonged DFS compared with CMF alone.[Level of evidence: 1iiDii] Whether tamoxifen or aromatase inhibitors add to ovarian ablation, and the elucidation of the optimal roles for endocrine manipulation and chemotherapy in receptor-positive premenopausal women, require further evaluation. These issues are the subject of several trials.
In summary, the weight of evidence suggests that ovarian ablation should not be routinely added to systemic therapy with chemotherapy and/or tamoxifen.[127,129,130,139] Ovarian ablation alone should not be routinely used as an alternative to any other systemic therapy.[131,132,133,134,139] Further results of research studies prospectively evaluating the role of adjuvant ovarian ablation are awaited.