ESTRO 2024 - Abstract Book

S643

Clinical - Breast

ESTRO 2024

the two institutions: 71 (76.3%) patients out of the 93 patients from that institution received PMRT. cALND did not alter the receipt of RNI to the supraclavicular (95% vs 86%, p=0.43), internal mammary (35% vs 59%, p=0.07) or axillary level II (90% vs 88%, p>0.99) and level III (90% vs 84%, p = 0.71) lymph nodes. Level I axillary lymph nodes were specifically targeted in 77% of patients, but that rate was lower in patients undergoing cALND (45%), as compared to SLNB only (90%; p<0.01). LRR rates were very low in the cohort. There was one in-breast tumour recurrence and one combined axillary and in-breast recurrence in patients receiving PMRT. PMRT did not significantly affect the 5-year LRR (0% vs 0%, p=0.45) and OS (100% vs. 95.5%, p=0.33). 5-year DFS (93.3% vs 80.4%, p=0.01) and distant DFS (93.3% vs 80.4%, p<0.01) were significantly higher in patients that received PMRT, even though this population had a higher burden of nodal disease.