Prolonged response to exemestane following multiple surgical resections and hormonal therapies in a patient with recurrent endometrial stromal sarcoma

BACKGROUND: Endometrial stromal sarcomas (ESSs) are rare, indolent tumors with high recurrence rates. Management includes surgery and hormonal therapy given high estrogen and progesterone receptor (ER/PR) expression. CASE: A pre-menopausal patient with stage II ESSs (ER +/PR +) underwent primary surgery followed by adjuvant megestrol. Recurrence in the bladder/upper vagina (ER +/PR −) was diagnosed one year later and treated with anterior pelvic exenteration and adjuvant letrozole. Two years later she recurred and was treated with radical surgery and adjuvant exemestane therapy (tumor ER strongly +/PR +). The patient then had a five-year disease free interval before being diagnosed with her third recurrence (ER +). CONCLUSION: Exemestane treatment for ESSs can lead to a prolonged response, even in the setting of progression after prior aromatase inhibitor treatment.