Letrozole as second-line hormonal treatment for recurrent low-grade endometrial stromal sarcoma: A case report and review of the literature.

Low-grade endometrial stromal sarcoma (LGESS) is a rare malignancy. The tumor is reportedly responsive to hormonal therapy, most commonly with medroxyprogesterone acetate (MPA), but the effectiveness of aromatase inhibitors for recurrent LGESS remains unclear. The present study reports a case of stage IC LGESS presenting with abnormal uterine bleeding, and also provides a review of the literature. Following a total abdominal hysterectomy and bilateral salpingo-oophorectomy, MPA therapy was initiated; treatment was successful, but discontinued 19 months later due to disruptive side effects. A further 2 months later, the patient presented with recurrent disease and received chemotherapy. MPA treatment was restarted with a partial response. A second recurrence, 4 years later, presented with lung and para-aortic lymph node metastases. The patient responded to treatment with the aromatase inhibitor letrozole. The patient has since exhibited stable disease and remained free of symptoms for 7 years. This case suggests that aromatase-inhibitor treatment may be effective for recurrent LGESS as a second-line treatment.