Significance of Axillary Lymph Node Extranodal Soft Tissue Extension and Indications for Postmastectomy Irradiation

Reviewers: Li Liu, MD
Source: Cancer, 86(7): 1258-1262, October 1999.

Background

Extranodal soft tissue extension (ETE) is associated with decreased survival and increased recurrence rates in patients with breast cancer. However, whether axillary irradiation would improve local control remains uncertain. This study reports on a series of patients assessed for ETE status.

Methods

Mignano and associates reported the outcomes for 487 patients who underwent mastectomy and axillary lymph node dissection for infiltrating (T1-T3) breast carcinoma and did not receive postoperative irradiation. All patients had pathologically confirmed axillary lymph node metastases and negative surgical margins.

Results

• The risk of axillary lymph node recurrence in ETE positive patients was low, even without axillary lymph node irradiation.
• Patients with ETE were at increased risk for chest wall recurrence and/or distant failure.
• Chest wall recurrences were more common than axillary recurrences in patients with ETE.

Discussion

The authors concluded that ETE is not necessarily associated with a significantly increased incidence of axillary recurrence. Therefore, axillary irradiation based on this pathologic finding may not be indicated. Two recent randomized trials have demonstrated that postoperative radiotherapy to the chest wall and regional lymph nodes decreased the risk of locoregional recurrence and was associated with improved survival in high-risk postmenopausal breast-cancer patients after mastectomy and limited axillary dissection. Treatment decision should be made individually with full evaluation of benefit and risk factors.