ESTRO 2024 - Abstract Book

S499

Clinical - Breast

ESTRO 2024

Purpose/Objective:

Clinical practice has changed since the publication of the ACOSOG Z0011 trial, which found that axillary lymph node dissection (ALND) is unnecessary in breast cancer patients with one or two positive sentinel lymph nodes (SLNs). We analyzed the long-term results of patients treated in our center with radiotherapy of the axillary lymph node levels when lymph node dissection was omitted.

Material/Methods:

The results of the patients treated in our Service from February 2011 to April 2015 with histologically confirmed T1 T2 breast carcinoma, without palpable lymphadenopathy, negative axilla evaluated by ultrasound and positive SLN are analyzed. Women were ineligible if they had 3 or more positive SLNs and were candidates for mastectomy. All women received tangential opposite field radiation therapy to the whole breast, and axillary radiation therapy included levels I and II, but not levels III and IV.

Results:

From 2011 to 2015 we treated 148 patients. The final analysis involved 114 patients with positive sentinel nodes. The average tumor size was 2 cm. The median number of lymph nodes removed was 2 and the sentinel lymph node with metastasis was 1. The phenotype was: Luminal A 48.6%, luminal B her2 – 43%, luminal B her2 + 10.5%, Triple negative 6.1 %, Her2 + without luminal: 1.8%. With a median follow-up of 43 months, no regional recurrence was observed and one recurrence occurred in a different breast quadrant. Disease-free survival at 6 years was 91.2%.

Conclusion:

In patients with breast cancer with metastases in one or two nodes treated with breast-conserving surgery, the use of SLNB and radiotherapy of axillary lymph node levels I and II, avoiding lymphadenectomy, provides excellent locoregional control and survival.

Keywords: radiotherapy, breast, axillary

698

Proffered Paper

Significantly poorer survival in irradiated breast cancer patients with ER negative/low TILs tumors

Demet Özcan 1 , Anders W. Mølby Nielsen 2 , Jan Alsner 2 , Jens Overgaard 2 , Birgitte Vrou Offersen 2,3 , Trine Tramm 1,3

1 Aarhus University Hospital, Pathology, Aarhus, Denmark. 2 Aarhus University Hospital, Experimental Clinical Oncology, Aarhus, Denmark. 3 Aarhus University, Clinical Medicine, Aarhus, Denmark