ESTRO 2025 - Abstract Book

S566

Clinical - Breast

ESTRO 2025

3243

Poster Discussion Preoperative chemoradiation in breast cancer patients, A prospective single arm phase II feasibility study.ClinicalTrials.gov ID: NCT06631066 Marwa Mohammed Rostom 1 , Yasser Anwar Abdelazim 1 , Omar Zakaria Youssef 2 , Ayman Abdelsamea Gaber 3 , Khaled Omar Alhameedy 2 , Medhat Mohamed El Sebaie 1 1 Radiation Oncology, National Cancer Institute, Cairo, Egypt. 2 Surgizal Oncology, National Cancer Institute, Cairo, Egypt. 3 Medical Oncology, National Cancer Institute, Cairo, Egypt Purpose/Objective: To evaluate the feasibility and safety of applying chemoradiation concurrently in neoadjuvant settings in terms of both radiation toxicity and surgical outcomes. Material/Methods: It is a prospective single-arm study that enrolled patients who were diagnosed with pathologically proven breast cancer and staged as locally advanced disease. The patients are discussed in multidisciplinary meeting and planned to receive neoadjuvant concurrent chemoradiation (in the form of Adriamycin (80 mg/m 2 ) and Cyclophosphamide (600 mg/m 2 ) followed by Taxol weekly (80 mg/m 2 ) or every 21 days (175mg/m 2 ) with Antiher2 either Herceptin or Herceptin/Perjeta whenever indicated). Radiation therapy is given with 4 th or 5 th week Taxol (or the beginning of the 2 nd cycle) to the whole breast and regional lymphatics (4005 gray in 15 fractions and boost to the tumor 10 gray in 5 fractions in patients younger than 50 years old/ grade III tumors) followed by surgery (mastectomy with or without reconstruction or breast conservative surgery) 6-8 weeks after end of radiation therapy. The patients were followed up weekly during radiation therapy, before surgery and up to two months after surgery. Both radiation induced dermatitis and postoperative complications were recorded. Results: A total of 80 patients were included in the study. Toxicity from radiotherapy in the form of radiation dermatitis was observed in 56 patients (70%) in total, where 41 (51%), 12 (15%), and 3 (3.75%) patients showed grades 1, 2, and 3 dermatitis, respectively, with no patients suffering from grade 4. Only 22 of our patients (27.5%) did not suffer from radiation dermatitis. All patients with dermatitis were treated with conservative measures. The total rate of postoperative complications was 10% (n=8). Only 5 patients suffered from postoperative surgical site infection, and only 3 patients (3.75%) had postoperative skin necrosis. Regarding the pathological response to this approach 37 patients (46.25%) achieved a complete response. Conclusion: This study showed that neoadjuvant chemoradiation is feasible and safe without unacceptable radiation induced toxicity or surgical complications. References: El-Sabawi B, Sosin M, Carey JN, et al. Breast reconstruction and adjuvant therapy: a systematic review of surgical outcomes. J Surg Oncol. 2015;112:458-464. Iyer P, Radhakrishnan V, Balasubramanian A, et al.Study of pathological complete response rate with neoadjuvant concurrent chemoradiation with paclitaxel in locally advanced breast cancer. Indian J Cancer 2020;57:428-434. Bhattacharyya T, Sharma SC, Yadav BS, et al. Outcome of neoadjuvant chemotherapy in locally advanced breast cancer: A tertiary care centre experience. Indian J Med Paediatr Oncol 2014;35:215-220. Keywords: Preoperative, surgical morbidity.