• Breast Cancer Disease Site Group. Adjuvant systemic therapy for node-negative breast cancer [full report]. Toronto (ON): Cancer Care Ontario (CCO); 2003 May 1 [online update]. 22 p. (Practice guideline report; no. 1-8). [79 references]

Choice of Therapy

• Pre- and postmenopausal women at minimal or low risk of recurrence (<2 cm, well-differentiated, and all other factors favourable or <1 cm, intermediate grade, and all other factors favourable) should receive no adjuvant systemic treatment. They should, however, be made aware that systemic therapy is offered to women at higher risk of recurrence.
• Premenopausal women (age <50 years) at moderate risk of recurrence (1-3 cm and intermediate grade or 2-3 cm and well-differentiated) and with estrogen-receptor-positive tumours should be offered tamoxifen. Chemotherapy added to tamoxifen may provide a modest incremental benefit over tamoxifen alone. This is an ideal situation for a decision aid.
• Premenopausal women (age <50 years) at high risk of recurrence (>3 cm, irrespective of any other factors, or >1 cm with either estrogen-receptor-negative, high grade or lymphatic/vascular invasion) should be offered chemotherapy. There are insufficient data at the present time to recommend the addition of tamoxifen to chemotherapy in this subgroup. If the patient refuses chemotherapy and the tumour is estrogen-receptor-positive, tamoxifen may be considered. There is insufficient data to determine the risk category of a tumour <1 cm in diameter associated with a poor prognostic factor (e.g., grade III, estrogen-receptor-negative, lymphatic/vascular invasion).
• Postmenopausal women (age >50 years) at high risk of recurrence (>3 cm, or >1 cm with high grade or lymphatic/vascular invasion) and with estrogen-receptor-positive tumours should be offered tamoxifen plus chemotherapy. The benefits and risks of additional chemotherapy should be discussed with the patient. If the patient refuses chemotherapy, then tamoxifen alone should be considered. Postmenopausal women at high risk of recurrence and with estrogen-receptor-negative tumours should be offered chemotherapy.
• Postmenopausal women (age >50 years) at moderate risk of recurrence (1-3 cm and intermediate grade, or 2-3 cm and well-differentiated) and with estrogen-receptor-positive tumours should be offered tamoxifen. Chemotherapy added to tamoxifen may provide a modest incremental benefit over tamoxifen alone. This is an ideal situation for the use of a decision aid.

Duration of Tamoxifen

Hormonal therapy should consist of oral tamoxifen 20 mg daily for five years.

Chemotherapy Regimen

Polychemotherapy should reasonably comprise six cycles of cyclophosphamide (oral)/methotrexate/fluorouracil (CMF) or four cycles of doxorubicin/cyclophosphamide (AC).

Process of Decision-making

A patient with node-negative breast cancer should be informed of the availability of adjuvant systemic therapy and should be offered the opportunity of discussing such therapy with an expert clinician. She should be provided with detailed information concerning her risk of recurrence if untreated, the potential efficacy of adjuvant therapy in terms of recurrence and mortality, and the potential side effects of therapy.

None provided

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

• Breast Cancer Disease Site Group. Adjuvant systemic therapy for node-negative breast cancer [full report]. Toronto (ON): Cancer Care Ontario (CCO); 2003 May 1 [online update]. 22 p. (Practice guideline report; no. 1-8). [79 references]

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

1998 Nov 12 (updated online 2003 May 1)

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

The Practice Guidelines Initiative (PGI) is the main project of the Program in Evidence-based Care (PEBC), a Province of Ontario initiative sponsored by Cancer Care Ontario and the Ontario Ministry of Health.

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

Breast Cancer Disease Site Group

Members of the Breast Cancer Disease Site Group disclosed potential conflict of interest information.

None available

This summary was completed by ECRI on August 19, 1999. The information was verified by the guideline developer as of September 17, 1999. This summary was updated by ECRI on December 23, 2002 and April 19, 2004. The information was verified by the guideline developer on April 29, 2004.