Background: Intrauterine progesterone therapy potentially provides a simple alternative treatment for women with Stage I Grade I endometrial cancers who are at high risk for surgery. The case histories of four women with early endometrial cancer primarily treated with levonorgestrel intrauterine system (Mirena) are reported and the literature reviewed.
Cases: Four women had Stage I grade 1 endometrial adenocarcinoma with positive progesterone receptor. All were assessed to be in American Society of anaesthesiologists risk class IV. After insertion of mirena intrauterine system, one woman (25%) had complete histological regression of disease within 6 months. One of three women who did not respond to treatment subsequently had a vaginal hysterectomy, which showed endometrial cancer with superficial myometrial invasion.
Conclusion: This report raises doubts about the effectiveness of intrauterine progesterone therapy as a definitive alternative for the treatment of early endometrial cancer.