ESTRO 2023 - Abstract Book

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ESTRO 2023

A total of twenty-seven patients met the inclusion criteria. Of them, 16 underwent ES (ES group); among the remaining 11, 4 had delayed BC surgery and 7 did not underwent surgery at all. Median age was 60 years (range 39 – 92), and median follow-up was 42 months (range 11 – 128). Cohort characteristics according to the two groups are shown in Table 1. In the ES group (median age 58.5 years), no patients relapsed in the irradiated DM sites, while 5/16 (31.2%) developed further DM in different distant sites; at the last follow-up, all the patients were alive, of whom 8 without disease, 4 with OMBC and 1 with polimetastatic BC. In the DNS group (median age 61.3 years), 4 patients (36.4%) experienced progression in the irradiated sites, eight developed additional DMs in different sites and 3 (27.3%) recurred at both sites. In this second group, at the last follow-up 4 (36.4%) patients resulted dead and 4 patients had multiple metastatic disease.

Conclusion The results of this preliminary analysis suggest that early surgery of the primary tumor seems to achieve better control of the OMBC disease. Additional and increased follow-up data will provide clearer insights into the best clinical management of patients in this setting.

PO-1259 Local recurrence following mastectomy for invasive breast cancer: a single institution experience

A. Swan 1 , C. Bedi 1 , A. Stillie 1

1 Western General Hospital , Edinburgh Cancer Centre, Edinburgh, United Kingdom

Purpose or Objective Adjuvant chest wall radiotherapy (RT) is routinely offered to all patients (pts) with T3 and T4 disease. Historically, radiotherapy was not offered to all pts with high risk T1 and T2 disease and those with N1 disease. This study analyses the incidence and pattern of local recurrence (LR) in a retrospective cohort of pts post mastectomy in a single institution over a three-year period. Materials and Methods The Edinburgh Cancer Centre departmental database was accessed to identify all pts managed surgically, in a single institution, with a mastectomy following a diagnosis of invasive breast cancer from 1st January 2012 to 31st December 2014. The search identified 443 eligible patients. Results The median age of pts at time of surgery was 58 years (range: 34-84). At a median follow up of 90 months, 23 pts (5%) had developed a local recurrence. 35% (n=8) were under 50 years old at the time of recurrence (median age 60, range 36-88). Median duration between diagnosis and recurrence was 20 months with 4 pts having local recurrence within 1 year of diagnosis. At original diagnosis of invasive cancer, 11/23 pts had triple negative disease. 19/23 pts had received chemotherapy (8 neoadjuvant, 9 adjuvant) and the 10/23 ER positive pts all received adjuvant endocrine treatment. 15/23 pts were assessed for post mastectomy RT due to high-risk pathological features (4 or more nodes after axillary clearance (n=3), involved nodes + high risk features (G3, ER negative, HER2 positive) (n=5), T3 or T4 disease (n=6), involved margin (n=1)). Only 11 patients received adjuvant RT, 4 patients did not due to co morbidities (n=2), patient choice (n=1), and recurrence (n=1) prior to starting adjuvant RT. Conclusion The overall LR rate following mastectomy is low at 5% with median 8 year follow up. Those with LR had higher risk disease at diagnosis, which, despite chemotherapy, recurred mostly within 2 years after treatment. Adjuvant chest wall RT following mastectomy improves local control (1) and is now offered in our centre to patients with T3 and T4 disease at