Axillary lymph node clearance in patients with positive sentinel lymph node biopsy

Area of Science:

• Oncology
• Surgical Oncology
• Radiotherapy

Background:

• Adjuvant radiotherapy is standard post-breast surgery.
• Trials are evaluating omission of axillary lymph node clearance (ALNC).
• Sentinel lymph node (SLN) macrometastasis is a key factor.

Purpose of the Study:

• To determine the percentage of patients undertreated if ALNC is omitted.
• To assess understaging for postmastectomy radiotherapy (PMRT) and supraclavicular fossa radiotherapy (SCFRT).
• To evaluate proposed trial inclusion/exclusion criteria.

Main Methods:

• Analysis of 38 women with positive SLN macrometastasis and ALNC.
• Patients received PMRT/SCFRT if ≥4 positive nodes or tumor size ≥5cm.
• Fisher's exact test used to assess significance of omitting ALNC.

Main Results:

• 23.7% of patients with ≥4 positive nodes would not be offered SCFRT and PMRT if trial criteria are followed.
• Excluding multicentric disease reduced undertreatment by 15.7%.
• Significant risk (p=0.0001) of missing patients for radiotherapy.

Conclusions:

• Omission of ALNC poses a significant risk of undertreatment in patients with SLN macrometastasis.
• Tumor multicentricity is crucial for predicting axillary nodal involvement.
• Excluding T2 tumors with multicentricity from trials omitting ALNC may be appropriate.