TY - JOUR T1 - Response to PD1 inhibition in conventional chondrosarcoma JF - Journal for ImmunoTherapy of Cancer JO - J Immunother Cancer DO - 10.1186/s40425-018-0413-z VL - 6 IS - 1 SP - 94 AU - Michael J. Wagner AU - Robert W. Ricciotti AU - Jose Mantilla AU - Elizabeth T. Loggers AU - Seth M. Pollack AU - Lee D. Cranmer Y1 - 2018/12/01 UR - http://jitc.bmj.com/content/6/1/94.abstract N2 - Background Chondrosarcoma is one of the most common malignant bone tumors in adults. Conventional chondrosarcoma represents around 85% of all chondrosarcomas and is notoriously difficult to treat with chemotherapy.Case presentation We describe a 67-year-old man with metastatic conventional chondrosarcoma who was treated with nivolumab. Treatment was discontinued after restaging showed increased tumor burden, which later proved to be pseudoprogression. The patient restarted nivolumab and continues to have a near complete response.Conclusion Conventional chondrosarcoma may be sensitive to checkpoint inhibitors. Further, this case demonstrates clearly the phenomenon of pseudo-progression in this disease, a factor that must be considered in the design of clinical trials and clinical care. This case supports additional study of immunomodulatory agents in this deadly disease.Abbreviations:CTACancer testis antigenNGSNextGen sequencing ER -