ESTRO 2025 - Abstract Book

S3907

Radiobiology - Microenvironment

ESTRO 2025

Keywords: spatial transcriptomics, lung cancer, immunity

References: This study was funded by the Polish National Agency for Academic Exchange/National Science Centre Poland (grant 2020/39/O/NZ5/01696)

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Digital Poster Impact of antihistamines type 1 and 2 in disease free survival of breast cancer patients Pamela Reyes-Sierra 1 , Cindy Sharon Ortiz-Arce 2 , Alejandra Leticia Hernandez-Ibarra 1 1 Clinical Research, Instituto Mexicano del Seguro Social, Monterrey, Mexico. 2 Head of Clinical Research, Instituto Mexicano del Seguro Social, Monterrey, Mexico Purpose/Objective: Role of antihistamines as modifiers in tumor progression and potential antineoplastic agents has been a subject of study as it has been observed that its use is associated with an increase in survival of cancer patients as well as a reduction in cell migration and the induction of apoptosis (1). In the case of breast cancer, a significant relationship has been established, positively impacting the survival of patients using loratadine and desloratadine, regardless of their age, immunohistochemical status, or stage (2,3). Antihistamines are drugs with a high safety profile, minimal side effects, low cost and easily found in the public health care system. For this reason, we emphasize the importance of studying their potential use as a co-adjuvant in the current treatment regimen for breast cancer. Material/Methods: The present cohort study used the database of public health system hospitals in Mexico to evaluate potential benefit of antihistamines consumption in survival in breast cancer patients. We included patients diagnosed between 2005 and 2024; antihistamine (AH) use was determined based on prescriptions of types 1 or 2 AH for at least 2 continuous months during or after radiotherapy treatment. We included 1256 patients who were divided into two groups, AH consumer group 603 patients and non-consumer group 653 patients. Primary endpoint disease free survival (DFS) by Kaplan-Meier curves and differences between groups was studied with the Log Rank Test using Graph Pad Prism v 10.3. Results: Analizing the data we found a significant benefit in disease free survival for patients who were antihistamine consumers, with a median survival of 184 months months and a Hazard Ratio (HR) of 1.66, 95% Confidence Interval (CI) of 1.21 to 2.28 (Fig 1).