ObjectiveTo assess the endometrial response rates to treatment with the levonorgestrel intrauterine device in post-menopausal women with atypical hyperplasia/endometrial intraepithelial neoplasia and grade 1 endometrioid (AH/EC) endometrial carcinoma who are not surgical candidates. MethodsChart review was undertaken of patients with AH/EC who underwent levonorgestrel intrauterine device insertion by a gynecologic oncologist within two academic health systems between 2002 and 2013. When available, tissue blocks were evaluated with immunohistochemical staining for progesterone receptor expression. ResultsA total of 41 patients received treatment for AH/EC with the levonorgestrel intrauterine device. Follow up sufficient to assess response occurred in 36 women (88%). Complete response was documented in 18 of 36 women (50%), no response in 8 patients (22%), partial response in 3 women (8%) and progression of disease in 7 patients (19%). Four of 18 patients with complete response (22%) later experienced relapse of hyperplasia or cancer. Four patients (10%) died during the study period: none had evidence of metastatic disease and 1 of the 4 woman died of perioperative complications following hysterectomy for stage I disease. Patients responding to treatment had significantly lower progesterone receptor expression on post-treatment biopsies. ConclusionsIntrauterine levonorgestrel is a viable treatment option for post-menopausal women with AH/EC who are poor candidates for standard surgical management. The response rate in this series is similar to published reports in premenopausal patients and includes cases of disease recurrence following conversion to benign endometrium.