Checkpoint blockade immunotherapy for multiple recurrences of radiation-induced maxillary sinus sarcoma: A case report.

BackgroundRadiotherapy has become a fundamental treatment modality of head and neck (HN) malignancies, which provides a chance of long-term survival. However, radiation also amplifies the risk of developing radiation-induced sarcoma (RIS) in the irradiated tissue. Radiation-induced maxillary sinus sarcoma (RIMSS) is an extremely rare and highly lethal malignancy of the HN. RIS is mainly treated with surgery, but the anatomical district and the infiltrative nature of RIS make it challenging to achieve negative margins, resulting in high fatality rate with the mean survival time of approximately one year. Immunotherapy, as an effective treatment option is rapidly evolving for HN tumors. However, checkpoint Blockade Immunotherapy (CBI) combined with chemotherapy as maintenance therapy for RIS of HN is rarely reported.Case presentationThe study presents a 36-year-old female with numerous recurrences of RIMSS, who experienced a dramatic response to checkpoint blockade immunotherapy after rapidly progressing on involved-field radiotherapy and multiple surgeries. After using immunotherapy combined with chemotherapy, the patient had a nearly complete response (CR) and maintained with single-agent programmed cell death 1 (PD-1) inhibitors.ResultsThe patient achieved a durable response, with progression-free survival (PFS) lasting 18 months.ConclusionUsing CBI as maintenance therapy for RIMSS represents a novel treatment option, especially for unresectable patients. Further investigation is warranted to optimize a multimodal treatment and improve response.