ESTRO 2024 - Abstract Book

S1505

Clinical - Lower GI

ESTRO 2024

the multivariate analysis, it was determined that Stage III disease had a negative impact on LC (p=0.0046), while positive nodal staging (p=0.0336) and the use of 5FU (p=0.0291) were correlated with DMFS. Among patients who received two cycles of mitomycin, 45% experienced Grade≥2 neutropenia and 27% experienced Grade≥2 thrombocytopenia. On the other hand, those who received only one cycle had lower rates of these toxicities, at 18% and 9%, respectively. Patients treated with capecitabine had higher rates of Grade≥2 thrombocytopenia (22%) and proctitis (22.4%) compared to those treated with 5FU, which exhibited rates of 0% and 3.6%, respectively.

Conclusion:

We can say that toxicity of the treatment is more correlated with the individual characteristics of the patients rather than the duration of treatment with mitomycin and did not impact on the excellent oncological outcome. We can even consider capecitabine could as an alternative drug in treatment regimens, as it shows comparable, or potentially even better, outcomes when compared to 5FU. However, it is important to note that the use of capecitabine comes with a higher burden of toxicities.

Keywords: Anal Canal Cancer; Radiotherapy, Chemotherapy

1136

Digital Poster

Electron beam radiotherapy for the management of perianal malignancies

Lars Ulrik Fokdal 1,2 , Bjarke Mortensen 1 , Lars Henrik Jensen 1,2 , Lars Bundgaard 3 , Sean Patrick McIlroy 1 , Birgitte Mayland Havelund 1 1 Vejle Sygehus, Department of Oncology, Vejle, Denmark. 2 University of Southern Denmark, Department of Regional Health Research, Odense, Denmark. 3 Vejle Sygehus, Department of Surgery, Vejle, Denmark

Purpose/Objective:

Perianal malignancies (PM) is a heterogenous group of rare neoplasms that comprise 3-4% of all anal malignancies. The most common PM includes squamous cell carcinoma (SCC), Bowen's disease (BD), and perianal Paget's disease (PPD). Curative treatment of PM include surgery or radiotherapy (RT), and the treatment choise should be balanced between the chance for local control and the risk for toxicity, including preservation of the anal sphinter.

During the last decade selected patients with PM have been treated with electron beam RT at our institution. The present study evaluates this strategy with assessment of disease outcomes and morbidity after RT.

Material/Methods:

Patients diagnosed with PM and treated with electron beam RT in our department from 2012 to 2022 were included in the study. Clinical information regarding diagnosis, patient demographics, treatments, and outcomes were retrospectively extracted from medical records and analysed descriptively. Local control (LC) and survival was analysed using Kaplan-Meier statistics.