Tumor Mutational Burden Guides Therapy in a Treatment Refractory

Gynecologic carcinosarcomas, previously known as malignant mixed Müllerian tumors, are uncommon malignancies that demonstrate an aggressive biology and lack a standard therapeutic approach. Molecular analyses have revealed recurrent alterations in chromatin remodeling genes, but clinical support for therapeutic significance is lacking. We prospectively identified a patient with refractory uterine carcinosarcoma whose tumor was subject to molecular profiling at diagnosis and again at radiographic progression. Initial molecular testing did not assess tumor mutational burden, DNA polymerase ɛ ( KEY POINTS: Uterine carcinosarcoma is an uncommon and aggressive histologic variant of endometrial carcinoma with a poor prognosis.Inactivating DNA polymerase ɛ