Overcoming immune-resistance in laryngeal cancer: a case report of the abscopal effect and nivolumab beyond progression.

The abscopal effect is defined as the systemic regression of distant neoplastic lesions induced by localized treatment. Although the first case reports date back to the beginning of the twentieth century, it remains a very rare event. In recent years, research and reporting on the subject has increased thanks to the development of new immune-checkpoint inhibitors (ICIs) and stereotactic body radiotherapy, as a consequence of molecular and clinical synergism. This work describes an extremely particular presentation of metastatic laryngeal cancer, with mediastinal abdominal nodes and bone progressive disease after PD-1 inhibitor failure, which resulted in reductions of bone pain and abdominal and thoracic lymphadenopathies and an improvement in clinical conditions after treatment with concurrent palliative radiotherapy on the bulky mediastinal node and ICI beyond progression, configuring an important abscopal response.