Vianna, Alberto Pereira de Lima^1*, Uyeda, Mari², Maluf, Gabriel³, Kenupp, Maria Graziela de Fátima Alvarez⁴

^1*Medical Student – Universidad Nacional Ecológica, E-mail: alberto53698@uecologica.edu.bo; ORCID: 0009-006-7702-8716; https://orcid.org/0009-0006-7702-8716

²PhD in Oncology – A.C. Camargo Cancer Center, Pos Doctoral Student – A.C. Camargo Cancer Center, Medical Student – Universidad Nacional Ecológica; E-mail: mari53972@uecologica.edu.bo; ORCID: 0000-0002-9490-6000

³Medical Student – Univerdidad Nacional Ecológica, PhD Student – A.C. Camargo Cancer Center, E-mail: gabriel53977@uecologica.edu.bo; ORCID: 0009-0002-0753-6484

⁴Medical Student – Universidad Nacional Ecológica, E-mail: maria53679@uecologica.edu.bo ; ORCID: 0009-001-3768-9900.

Corresponding author: Uyeda, Mari, PhD in Oncology – A.C. Camargo Cancer Center, Pos Doctoral Student – A.C. Camargo Cancer Center, Medical Student – Universidad Nacional Ecológica. Email: mari53972@uecologica.edu.bo; ORCID: 0000-0002-9490-6000

Citation: Vianna, Alberto Pereira de Lima, Uyeda, Mari, Maluf, Gabriel, Kenupp, Maria Graziela de Fátima Alvarez, (2025). Combination Therapies in Merkel Cell Cancer – Synergy between Immunotherapy and Radiotherapy. J Oncol Res Case Rep. 2(1),1-5.

Copyright: © 2025, Vianna, Alberto Pereira de Lima, et al., This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited.

Abstract

Introduction: Merkel cell cancer (MCC) is a rare and aggressive skin cancer, often associated with Merkel cell polyomavirus (MCPyV) infection and prolonged exposure to ultraviolet radiation. Due to its high recurrence rate and metastatic potential, innovative therapeutic strategies have been explored to improve clinical outcomes. The combination of immunotherapy and radiotherapy (RT) has shown promise, taking advantage of the ability of immunotherapy to stimulate the immune system and the efficacy of RT in localised tumour destruction. Methodology: This study is based on a review of the scientific literature, analysing articles published between 2005 and 2024 in databases such as PubMed, Scopus and Web of Science. Studies that investigated the EFFICACY of immunotherapy combined with RT in treating MCC, considering clinical, biological and therapeutic aspects, were included. The selection of articles followed strict criteria, prioritising research with significant samples and well-established methodologies. Results: The data analysed indicate that immunotherapy, especially immune checkpoint inhibitors such as avelumab and pembrolizumab, effectively activates the immune system against tumour cells. When combined with RT, a synergistic effect is observed, where radiation-induced tumour destruction can increase the release of tumour antigens, enhancing the immune response. Clinical studies suggest that this combined approach improves overall survival and reduces the rate of disease recurrence. Discussion: The combination of immunotherapy and RT in MCC represents a significant advance in the treatment of this aggressive neoplasm. RT acts directly to reduce tumour burden, while immunotherapy stimulates the immune system to recognise and eliminate remaining malignant cells. However, challenges such as immune-mediated side effects, tumour resistance, and the need for personalised protocols still need to be overcome. Future studies should focus on optimising the dose and therapeutic sequence, in addition to identifying predictive biomarkers for better patient selection. Conclusion: The synergy between immunotherapy and RT in MCC has shown promising results, improving treatment response and increasing patient survival. The integration of these approaches may represent a new paradigm in oncology, allowing for more effective and personalised treatments. However, additional research is needed to refine protocols and minimise adverse effects, ensuring that this strategy is widely applicable in clinical practice.

Keywords: Merkel cells, Immunotherapy, Combined radiotherapy, Skin cancer, Targeted therapy.