Post-Mastectomy Radiation Therapy for T2N0 Hormone-Positive Breast Cancer

Guideline-Based Recommendations

The National Comprehensive Cancer Network recommends that post-mastectomy radiation therapy may be considered optional for T2N0 breast cancer, but should be strongly considered if additional high-risk features are present, including medial tumor location, young age, high grade, lymphovascular invasion, close/positive margins, or aggressive biology (high Ki-67, HER2-positive despite hormone receptor positivity) 1, 2
The European Society for Medical Oncology guidelines note that PMRT should be considered for T2 or greater medially located tumors showing signs of biological aggressiveness 3, 4, 5

The ESMO guidelines specifically identify high-risk features that favor radiation in T2N0 disease, including receptor-negative status, grade 3 histology, high proliferation activity (Ki-67), young age, and medial tumor location 3, 4, 5
The presence of three or more high-risk features, such as tumor size ≥2 cm, lymphovascular invasion, grade 2-3 histology, age <50 years, close/positive margins, and medial tumor location, increases the risk of locoregional recurrence 3, 4, 5

The patient's hormone receptor-positive status is a favorable factor, and the ESMO risk stratification table classifies node-negative, hormone receptor-positive patients with pT ≤2 cm as low risk (<10% 10-year recurrence) if other favorable features are present 3, 4, 5
However, T2 tumors (>2 cm) automatically place patients in at least intermediate risk (10-50% recurrence) 3, 4, 5