Extrauterine endometrial stromal sarcoma: A systematic review and outcome analysis.

Endometrial stromal sarcoma (ESS) is the second most common uterine mesenchymal neoplasm. ESS can arise from extrauterine locations without any uterine involvement and is called extrauterine ESS (EESS). The epidemiological features of EESS are not well-known. Moreover, the factors affecting its outcome have not been systemically studied. The treatment of EESS closely follows that of uterine ESS, comprised of different combinations of surgical management, hormone therapy, chemotherapy, and radiation therapy. However, the effectiveness of different treatment protocols for EESS has not been studied. Here, we have performed a systematic review of all reported cases of EESS in the English literature. We further performed a meta-analysis of the outcome data and investigated how the patients' age, tumor site, tumor size, and management affect the overall and progression-free survival of the patients. We found that tumor site and mode of treatment significantly affected the overall survival and progression-free survival of the patients. Tumor size significantly affected overall survival but not progression-free survival, while the age at diagnosis did not affect patient outcome. As far as we know, ours is the first systematic study of this rare malignancy with an emphasis on outcome analysis.