ESTRO 2024 - Abstract Book

S1504

Clinical - Lower GI

ESTRO 2024

reducing total dose erogated to tumor. Further experiences are needed to find the right strategy to achieve excellence tumor control reducing treatment toxicities.

Keywords: Anal Canal Cancer; Radiotherapy; Chemotherapy

1122

Digital Poster

Chemotherapy regimens with definitive radiotherapy in Squamous Cell Carcinoma of the Anal Canal

Andrea Romei 1 , Sara Lucidi 2 , Daniela Greto 3 , Emanuela Olmetto 4 , Pietro Garlatti 4 , Icro Meattini 5 , Erika Scoccimarro 4 , Giulio Francolini 4 , Luca Visani 4 , Monica Mangoni 5 , Pierluigi Bonomo 4 , Mauro Loi 4 , Anna Peruzzi 4 , Giulio Frosini 5 , Dora Cela 5 , Niccolò Bertini 5 , Lorenzo Livi 5 1 University of Florence, Azienda Ospedaliero Universitaria Careggi, Florence, Italy. 2 University, Azienda Ospedaliero Universitaria Careggi, Florence, Italy. 3 Radiation Oncology Unitof Florence, Azienda Ospedaliero Universitaria Careggi, Florence, Italy. 4 Radiation Oncology Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy. 5 Radiation Oncology Unit, Azienda Ospedaliero Universitaria Careggi, Florence, Italy

Purpose/Objective:

Mitomycin and 5-fluorouracil (5-FU) are two standard used chemotherapeutic agents in combination with radiation therapy for the treatment of anal canal carcinoma. The duration of treatment with mitomycin in anal canal carcinoma is a topic of debate. Phase II trials promote the efficacy and safety of using alternative chemotherapeutic agents, including capecitabine, concurrently with radiation therapy. In our study, we assessed the efficacy, in terms of oncological disease control, and toxicity in patients treated with different chemotherapy regimens in concomitance with radiation therapy.

Material/Methods:

We conducted an analysis on a group of 78 consecutive patients who underwent definitive radiotherapy (RT) alongside concurrent chemotherapy (CT) between the years 2013 and 2023. During the treatment, 25 patients were administered fluorouracil (5FU) at a dose of 1000 mg/m² per day on days 1–4 and 29–32 through a continuous 24-hour intravenous infusion along with RT. Fifty three patients received capecitabine at a dosage of 825 mg/m² twice daily from day 1 to 5 every week. Additionally, patients received either a single intravenous infusion of mitomycin at a dosage of 12 mg/m² on day 1 (with a maximum single dose of 20 mg), or they had a second infusion on day 29. We evaluate local control (LC), distant metastasis-free survival (DMFS), overall survival (OS), and the rate of Grade≥ 2 (G≥2) toxicity, as per the CTCAE version 5.1 guidelines.

Results:

Among the patients in the study 37 had Stage III or higher disease, while 47 patients were diagnosed with node positive disease. Following a median follow-up period of 34 months, it was observed that 9 patients experienced disease progression. The 3-year rates of LC, DMFS and OS were found to be 90%, 88%, and 81%, respectively. In