RET-mutated recurrent leiomyosarcoma treated with cabozantinib: a case report

We present the case of a 68-year-old man with a recurrence of a high-grade leiomyosarcoma with metastatic disease. Despite initial treatment with liposomal doxorubicin, disease progression was observed after three cycles. A molecular study revealed an activating mutation of the RET gene, and treatment with cabozantinib was started at a dose of 60 mg daily. Five months later, the patient had a partial metabolic response. However, disease progression was documented two months later, and treatment was suspended. This case highlights the clinical activity of cabozantinib as monotherapy after failure of first-line chemotherapy in recurrent high-grade leiomyosarcoma with RET gene mutation.