American Society of Clinical Oncology Endorsement of the Cancer Care Ontario Practice Guideline on Adjuvant Ovarian Ablation in the Treatment of Premenopausal Women With Early-Stage Invasive Breast Cancer
Griggs JJ, Somerfield MR, Anderson H, et al.
J Clin Oncol. 2011 Sep 6. [Epub ahead of print]
Article Summary
An ad hoc panel of experts convened by the American Society of Clinical Oncology (ASCO®) reviewed the Cancer Care Ontario guideline on the use of ovarian ablation as adjuvant therapy for premenopausal women with endocrine-sensitive breast cancer. The goal of this exercise was to provide the ASCO® membership access to a high-quality guideline to facilitate clinical decision-making.
The key recommendations are that ovarian ablation is not recommended either as an addition to systemic therapy or as an alternative, and that it should be considered only for patients who refuse or cannot tolerate standard systemic therapy. In addition, the authors urge caution in choosing the method for suppressing ovarian function and recommend, whenever possible, monthly injection of luteinizing hormone-releasing hormone (LHRH) agonists, because this was the mode of administration used in nearly all of the available clinical trials. In addition, they warn that attempting ovarian ablation with LHRH agonists is not always successful.
Viewpoint
For those of us who treat women with breast cancer, this information is helpful. It sets the stage for conversations with patients and reminds us to be cautious in offering therapies that are still unproven. It provides the context for analysis by including a table that provides the complete roster of ongoing clinical trials of ovarian ablation in premenopausal women. Eight national and international trials are listed. Some of these trials are also attempting to tease out the effect of chemotherapy in this patient population, whereas others focus only on the type of endocrine therapy used. Because tamoxifen is the standard of care, it is used alone in 1 treatment arm in 6 of these 8 trials. Two trials (TEXT and PERCHE) provide ovarian ablation to all patients, with random assignment to either tamoxifen or an aromatase inhibitor.
Many reasons can explain the confusion or indecision experienced by oncologists faced with these clinical scenarios. On the one hand, we know that ovarian ablation is effective as the only treatment modality in patients who have no access to other therapies or who simply refuse alternate treatment. We also know that ovarian ablation is "noninferior" to cyclophosphamide, methotrexate, and fluorouracil chemotherapy. However, we do not know whether it adds any benefit to those who will receive modern chemotherapeutic regimens as part of their treatment plan.
Another pressing question is whether to use ovarian ablation for women who remain premenopausal after completing 5 years of adjuvant endocrine therapy with tamoxifen. We know from the MA 17 trial that women who were premenopausal when first diagnosed with breast cancer but who later became menopausal and participated in the study of delayed aromatase inhibition derived as much benefit as those who were older. None of these women received ovarian ablation.
This is a fair and balanced review and a good guideline, and one I plan to share with patients in decision-making. If you plan to offer ovarian ablation to patients, be advised that the guideline favors monthly LHRH injections (instead of the 3-month depot which is more convenient for patients). I would also check circulating estradiol levels (imperfect as they are) and listen for any symptom that indicates that a remnant of functioning ovarian tissue is present.
Abstract