2026-10-14T05:14:26Z https://api.figshare.com/v2/oai

oai:figshare.com:article/33942034 2026-09-19T09:56:50Z category_7 portal_147 item_type_3 month_year_09_2026

Supplemental Material for: EBV-Negative MSI-High Nasopharyngeal Carcinoma Treated With Toripalimab and Radiation: A Case Report figshare admin karger (2628495) Emily Ritsema (25075600) Ben Yan (25075603) Medicine Medicine <p dir="ltr">Introduction: Nasopharyngeal carcinoma (NPC) is most commonly associated with Epstein-Barr virus (EBV), whereas EBV-negative NPC is less common and biologically heterogeneous. Hypermutated phenotypes defined by microsatellite instability-high (MSI-high) status and high tumor mutational burden (TMB) are rare in NPC, and their therapeutic implications remain incompletely defined.</p><p dir="ltr">Case Presentation: An 82-year-old woman with no prior tobacco history presented with recurrent epistaxis and progressive right-sided nasal obstruction and was found to have EBV-negative, p16-negative nonkeratinizing squamous cell carcinoma of the nasopharynx. Following progression on platinum-based chemotherapy, she was treated with palliative-intent radiation therapy and toripalimab. Comprehensive tumor profiling demonstrated MSI-high status, a TMB of 35.87 mutations/Mb, and alterations involving MSH3, BRCA2, PIK3CA, ATM, CDKN2A, MTAP, and CCND1. Follow-up imaging demonstrated substantial reduction in tumor burden, with resolution of presenting symptoms and continued clinical disease control at last follow-up.</p><p dir="ltr">Conclusion: This case highlights an uncommon EBV-negative NPC molecular phenotype characterized by MSI-high status, markedly elevated TMB, and DNA damage response alterations. Because radiation therapy and toripalimab were administered during the same treatment period, their independent contributions to the observed clinical and radiographic improvement cannot be determined. Comprehensive genomic profiling may nevertheless identify clinically relevant molecular features and broaden therapeutic options in selected patients with EBV-negative, atypical, or treatment-refractory NPC.</p> 2026-09-19T09:56:50Z Dataset Dataset 10.6084/m9.figshare.33942034.v1 https://figshare.com/articles/dataset/Supplemental_Material_for_EBV-Negative_MSI-High_Nasopharyngeal_Carcinoma_Treated_With_Toripalimab_and_Radiation_A_Case_Report/33942034 CC BY 4.0