Long lasting response with trabectedin monotherapy in relapsed metastatic mesenchymal chondrosarcoma.

Background: Mesenchymal chondrosarcoma is an exceedingly rare malignancy, accounting for around 5% of all patients with chondrosarcoma. It is a translocation-related sarcoma that tends to have both local and distant recurrences. Surgery is the mainstay of treatment in localised cases however treatment of advanced cases remains a challenge. The rarity of the disease precludes dedicated clinical trials and hence guidelines for its management are not well defined. The dearth in literature makes it pertinent that the cases treated with newer therapies must be reported to contribute to existing knowledge.

Case presentation: We hereby report a case of a 39-year old male without any comorbidity presenting with pelvic pain and was diagnosed as mesenchymal chondrosarcoma of the pelvis. He underwent an initial curative resection followed by a disease-free interval of 7 months. Subsequently, he was treated with pulmonary metastatectomy and local debulking surgery at time of initial relapse. He was then exposed to multiple lines of palliative chemotherapy, which limited our treatment options upon subsequent disease progression. Based on recent data, the patient was given trabectedin monotherapy as fourth line chemotherapy. He tolerated the therapy well and attained a progression-free survival of 12 months, which is an impactful figure in relapsed setting in this patient population.

Conclusion: This report aims to present a comprehensive review into available and newer treatment choices for mesenchymal chondrosarcoma, and to highlight trabectedin monotherapy as a possible therapeutic option for mesenchymal chondrosarcoma in the relapsed setting.