A malignant smooth muscle tumor accounting for 7-11% of soft tissue sarcomas in adults and 2-4% of such tumors in children.
Leiomyosarcomas make up almost a quarter of all soft tissue sarcomas, among which those located in the uterus are the most common.
locally advanced to metastatic leiomyosarcomas have a poor prognosis.
Usually located in the retroperitoneum, but also associated with peripheral soft tissue and vascular tissue.
About 50% arise in the retroperitoneum/abdomen and include visceral, uterine, and retroperitoneal, with the uterus being the most common location.
Histology ranges from well defined areas of spindle shaped cells to poorly differentiated anaplastic spindle cells.
Systemic therapy with doxorubicin and ifosfamide or decarbazine are the backbone of first line treatment.
First line responses are approximately 15 to 17% with a median progression free survival approximately five months in the median over row survival of approximately 12 months for metastatic disease.
Doxorubicin and trabectedin in first-line therapy is significantly improved in metastatic and unresectable leiomyosarcoma as compared with doxorubicin alone.