Mandelbaum RS, Ciccone MA, Nusbaum DJ, et al. - Researchers undertook this retrospective analysis at a single-institution, to find out how treatment response varies between local progestin therapy with the levonorgestrel-releasing intrauterine device and systemic progestin therapy among women having complex atypical hyperplasia. This study involved 245 women with complex atypical hyperplasia who were treated with progestin therapy (levonorgestrel-releasing intrauterine device n = 69 and systemic therapy n = 176). Via histopathology on subsequent biopsies, the evaluation of treatment response was done. Higher rates of complete response and a lower probability of progression to cancer were observed among women who received the levonorgestrel-releasing intrauterine device vs those who were administered systemic therapy, as shown in the patient-level analysis. Overall, it was inferred that greater effectiveness may be afforded by local therapy with the levonorgestrel-releasing intrauterine device vs systemic therapy for women with complex atypical hyperplasia who preferred nonsurgical management, especially in morbidly obese women. During the study span, shifts in treatment paradigm toward increased levonorgestrel-releasing intrauterine device use resulted in improved complete response rates despite increasing rates of obesity.