Axillary lymph node failure in patients treated with accelerated partial breast irradiation

Area of Science:

• Oncology
• Radiation Oncology
• Surgical Oncology

Background:

• Limited data exist on axillary failure (AF) risk following accelerated partial breast irradiation (APBI).
• Assessing AF and regional lymph node failure (RNF) is crucial for breast cancer treatment efficacy.
• Understanding risk factors for these failures can optimize patient selection and outcomes.

Purpose of the Study:

• To determine the rate of axillary failure (AF) and regional lymph node failure (RNF) in patients treated with accelerated partial breast irradiation (APBI).
• To identify clinical, pathological, and treatment-related factors associated with the occurrence of AF and RNF after APBI.
• To compare the observed rates of AF and RNF with those typically seen after whole-breast irradiation.

Main Methods:

• A retrospective analysis of 534 early-stage breast cancer patients treated with APBI.
• Inclusion criteria: invasive breast cancer or ductal carcinoma in situ.
• Variables analyzed: patient age, tumor location, tumor size, grade, ER status, margin status, lymph node status, hormone therapy, and chemotherapy.

Main Results:

• The 5-year actuarial rate of axillary failure (AF) was 0.19%.
• Three patients (0.56%) developed regional lymph node failure (RNF), with a 5-year actuarial rate of 0.37%.
• No analyzed variables were associated with an increased risk of AF, though patient numbers for specific analyses were small.

Conclusions:

• Accelerated partial breast irradiation (APBI) is associated with low rates of axillary failure (AF) and regional lymph node failure (RNF).
• The observed rates of AF and RNF appear comparable to those after whole-breast irradiation.
• No specific patient or treatment factors were identified as significantly increasing the risk of AF after APBI in this cohort.