Surgical management of early stage invasive breast cancer (stage I and II). Provincial Breast Disease Site Group.

GUIDELINE QUESTION

What is the optimal surgical management of early stage invasive breast cancer (stage I and II)? More specifically, what is the relative efficacy (and safety) of breast conservation therapy (lumpectomy with axillary dissection) compared with modified radical mastectomy?

OBJECTIVE

To make recommendations about surgical management and techniques in the treatment of early stage invasive breast disease (stage I and II).

OUTCOMES

Survival, local recurrence (for lumpectomy patients) and quality of life are the primary outcomes of interest.

PERSPECTIVE (VALUES): Evidence was selected and reviewed by 6 members of the Ontario Cancer Treatment Practice Guidelines Initiative, Disease Site Group for Breast Cancer (Breast DSG). Earlier drafts of this evidence-based recommendation have been reviewed, discussed and approved by the Breast DSG, which comprises surgeons, medical oncologists, radiation oncologists, epidemiologists, a pathologist and a medical sociologist. There was no consumer participation in the development of this guideline.

QUALITY OF EVIDENCE

There are 7 randomized controlled trials (RCTs) comparing breast conservation therapy with mastectomy in women with early stage breast cancer.

BENEFITS

In 6 RCTs, no statistically significant differences were detected in survival rate between the mastectomy and conservative therapy (lumpectomy) groups. In 1 RCT, a statistically significant differences was detected in favour of the mastectomy arm; however, this was an early trial with substantial methodologic weaknesses.

HARMS

None.

PRACTICE GUIDELINE

Women with early stage invasive breast cancer (stage I and II) who are candidates for breast conservation therapy (see discussion of technical factors) should be offered the choice of either breast conservation therapy (excision of tumour with clear margins and axillary dissection) or modified radical mastectomy. The choice is an individual one for the patient, and thus she should be fully informed of the options, including the risks and benefits of each procedure. She should be informed that breast irradiation is part of the procedure for breast conservation therapy. In addition, she should be aware of the potential need for further surgery if the margins are positive. For further information about the use of radiotherapy in the management of early stage breast cancer, please refer to the Ontario Cancer Treatment Practice Guidelines Initiative's practice guideline Breast Irradiation in Women with Early Stage Invasive Breast Cancer Following Breast Conserving Surgery.