Positive axillary sentinel lymph node: is axillary dissection always necessary?

Area of Science:

• Oncology
• Surgical Oncology
• Breast Cancer Research

Background:

• Growing interest in omitting axillary dissection (AD) for early breast cancer with positive sentinel nodes (SN), especially with minimal tumor burden (micrometastases or isolated tumor cells).
• Current clinical practice appears to precede definitive evidence, with data suggesting AD is underutilized in cases of positive SN.
• Several clinical trials (IBCSG 23-01, ASCOG Z0011, EORTC AMAROS) are investigating this issue.

Purpose of the Study:

• To evaluate the safety and efficacy of foregoing AD in early breast cancer patients with micrometastases or isolated tumor cells in the SN.
• To compare outcomes of patients who did not undergo further axillary treatment after a positive SN versus those who did.

Main Methods:

• Retrospective analysis of early breast cancer patients with micrometastases or isolated tumor cells in the SN who did not receive further axillary treatment.
• Review of interim results from the ASCOG Z0011 trial, comparing locoregional and regional recurrence rates between patients with positive SN who underwent AD versus those who did not.

Main Results:

• The ASCOG Z0011 interim analysis showed no significant difference in locoregional or regional recurrence between patients with positive SN who received AD and those who did not, after 6.3 years of follow-up.
• The retrospective study found high five-year survival rates and a low cumulative incidence of axillary recurrence in patients foregoing AD with minimal SN involvement.
• These findings support the practice of omitting AD in select early breast cancer cases with limited SN metastasis.

Conclusions:

• Foregoing axillary dissection in early breast cancer patients with minimal sentinel node involvement (micrometastases or isolated tumor cells) is a viable approach, supported by current evidence and retrospective data.
• High survival rates and low axillary recurrence incidence justify the increasing clinical adoption of this strategy.
• Further research, including ancillary analyses of ongoing trials like IBCSG 23-01 and AMAROS, is needed to identify patients at high risk for overt axillary disease who may benefit from elective AD.