• Eisen A, Trudeau M, Shelley W, Sinclair S, Breast Cancer Disease Site Group. The role of aromatase inhibitors in adjuvant therapy for postmenopausal women with hormone receptor-positive breast cancer: guideline recommendations. Toronto (ON): Cancer Care Ontario (CCO); 2008 Feb 26. 49 p. (Evidence-based series; no. 1-18). [86 references]

Recommended treatment options for postmenopausal women with hormone receptor-positive early breast cancer:

Available trial evidence supports six adjuvant hormonal therapy options, summarized across four recommendations directly below, for the treatment of the target population. At present, there are no data available to compare between the various adjuvant aromatase inhibitor strategies. Rather, the use of adjuvant aromatase inhibitors has been compared to the standard of five years of adjuvant tamoxifen. Therefore, the decision about which therapy option to consider for patients beginning hormonal therapy should be made on an individual patient basis. Key evidence and qualifying statements in support of the recommendations will follow the recommendations and proceed in a similar order.

1. Adjuvant tamoxifen (20 mg daily for five years) remains an acceptable option for the treatment of women with hormone receptor-positive, early-stage breast cancer.
2. Adjuvant anastrozole (1.0 mg daily for five years) or letrozole (2.5 mg daily for five years) is an acceptable alternative to five years of adjuvant tamoxifen therapy.
3. Adjuvant tamoxifen (20 mg for two to three years) followed by switching to either adjuvant exemestane (25 mg daily, to a total of five years of hormone therapy) or adjuvant anastrozole (1 mg daily, to a total of five years) therapy is also an acceptable alternative to five years of tamoxifen.
4. Adjuvant letrozole (2.5 mg daily for five years) should be considered for women who have completed five years of adjuvant tamoxifen therapy.

Precautions

5. Women receiving aromatase inhibitors should be monitored for changes in bone mineral density.

Predictors of Treatment Response

6. Due to the lack of evidence, no recommendation for the use of aromatase inhibitors based on human epidermal growth factor receptor 2 (HER2)/neu status can be made at this time.

None provided

The recommendations are supported by randomized controlled trials and one meta-analysis.

• Eisen A, Trudeau M, Shelley W, Sinclair S, Breast Cancer Disease Site Group. The role of aromatase inhibitors in adjuvant therapy for postmenopausal women with hormone receptor-positive breast cancer: guideline recommendations. Toronto (ON): Cancer Care Ontario (CCO); 2008 Feb 26. 49 p. (Evidence-based series; no. 1-18). [86 references]

Not applicable: The guideline was not adapted from another source.

2005 Oct 25 (revised 2008 Feb 26)

Program in Evidence-based Care - State/Local Government Agency [Non-U.S.]

The Program in Evidence-based Care (PEBC) is a Province of Ontario initiative sponsored by Cancer Care Ontario and the Ontario Ministry of Health and Long-Term Care.

Cancer Care Ontario
Ontario Ministry of Health and Long-Term Care

Provincial Breast Cancer Disease Site Group

The members of the Breast Cancer DSG disclosed potential conflicts of interest relating to the topic of this practice guideline. Two of the lead authors (A. Eisen, M. Trudeau) reported related research involvement. These authors reported receiving honoraria or consultant fees from pharmaceutical companies that manufacture the aromatase inhibitors covered by this review.

None available

This summary was completed by ECRI on January 24, 2006. The information was verified by the guideline developer on February 23, 2006. This summary was updated by ECRI Institute on July 17, 2008. The updated information was verified by the guideline developer on August 20, 2008.