Carcinosarcoma of the Endometrium-Pathology, Molecular Landscape and Novel Therapeutic Approaches

Endometrial carcinosarcoma (ECS) is a rare and aggressive histological subtype of endometrial cancer that is associated with a dismal prognosis. It is a biphasic metaplastic carcinoma with a monoclonal origin comprising epithelial and mesenchymal components. The ECS originates from the epithelial components of the tumor, which undergoes an epithelial-to-mesenchymal transition. Approximately half of patients are diagnosed at the early stage of the disease, whereas the other half are diagnosed at the advanced stage. More than one-third of women present with metastatic lymph nodes, and approximately 10% will have distant metastases. Therefore, ECS is the deadliest type of endometrial cancer compared to other high-grade endometrial carcinomas. Surgical resection with adjuvant therapy remains the standard of care in most cases. The rarity of this disease hinders conducting prospective clinical trials to establish the optimal treatment regimens and increase overall survival. There are no specific guidelines for managing these rare and aggressive tumors despite the increasing interest in ECS in the gynecologic oncology community. The present review focuses on all new insights into ECS regarding its epidemiology, pathology, prognosis, and treatment. Furthermore, the molecular characteristics and new treatment regimens for primary (early and advanced stages) and recurrent ECS are discussed in detail.