Objectives The role of adjuvant radiation therapy RT in Malignant Phyllodes Tumors of the Breast MPTB is still controversial Our objective was to investigate the role of adjuvant (RT) in MPTB.

Methods Patients diagnosed with MPTB and treated at our institution from January 2010 to December 2019 were reviewed.

Results A total of 23 patients with non metastatic MPTB were included in our study. The median age was 41 years old (18–70 years). All patients underwent primary surgical treatment. Four patients had conserving surgery with clear surgical margins. Definitive mastectomy was carried out in 19 patients (82%). The median pathological tumor size was 12 cm (3- 25cm). Sixteen patients had adjuvant RT. Only one patient with breast conserving surgery had adjuvant RT. Fifteen patients who were treated with mastectomy had adjuvant RT with delivering a dose of 50Gy in 25 fractions over 5 weeks. Adjuvant RT was more indicated for patients with heterologous component (4/7), tumors ≥ 5 cm (14/20); presence of high atypia (15/19),tumoral necrosis (4/5),high mitoses (10/13). Unfortunately, five patients had local recurrence LR, from them two patients had adjuvant radiotherapy (p=0.1). In addition, four patient had distant metastases, from them tow had radiotherapy (p=0.3). The median overall survival was 180 months. Adjuvant RT was not independently associated with improvement in overall survival (P= 0.6).

Conclusions The benefit of Adjuvant radiotherapy for MPTB was not yet clear. Further study was needed to establish the real place of adjuvant RT.