Progestin therapy for obese women with complex atypical hyperplasia: levonorgestrel-releasing intrauterine device vs systemic therapy.

BACKGROUND: Though hysterectomy remains the standard treatment for complex atypical hyperplasia, patients who desire fertility or who are poor surgical candidates may opt for progestin therapy. However, the effectiveness of the levonorgestrel-releasing intrauterine device compared to systemic therapy in the treatment of complex atypical hyperplasia has not been well studied.
OBJECTIVE: We sought to examine differences in treatment response between local progestin therapy with the levonorgestrel-releasing intrauterine device and systemic progestin therapy in women with complex atypical hyperplasia.
METHODS: This single-institution retrospective study examined women with complex atypical hyperplasia who received progestin therapy between 2003 and 2018. Treatment response was assessed by histopathology on subsequent biopsies. Time-dependent analyses of complete response and progression to cancer were performed comparing the levonorgestrel-releasing intrauterine device and systemic therapy. A propensity score inverse probability of treatment weighting model was used to create a weighted cohort that differed based on treatment type but was similar with respect to other characteristics. An interaction-term analysis was performed to examine the impact of body habitus on treatment response, and an interrupted time-series analysis was employed to assess if changes in treatment patterns correlated with outcomes over time.
RESULTS: A total of 245 women with complex atypical hyperplasia received progestin therapy (levonorgestrel-releasing intrauterine device n = 69 and systemic therapy n = 176). The mean age and body mass index were 36.9 years and 40.0 kg/m2, respectively. In the patient-level analysis, women who received the levonorgestrel-releasing intrauterine device had higher rates of complete response (78.7% vs 46.7%; adjusted hazard ratio, 3.32; 95% confidence interval, 2.39-4.62) and a lower likelihood of progression to cancer (4.5% vs 15.7%; adjusted hazard ratio, 0.28; 95% confidence interval, 0.11-0.73) compared to those who received systemic therapy. In particular, women with class III obesity derived a higher relative benefit from levonorgestrel-releasing intrauterine device therapy in achieving complete response compared to systemic therapy: class III obesity, adjusted hazard ratio 4.72, 95% confidence interval 2.83-7.89; class I-II obesity, adjusted hazard ratio 1.83, 95% confidence interval 1.09-3.09; and nonobese, adjusted hazard ratio 1.26, 95% confidence interval 0.40-3.95. In the cohort-level analysis, the obesity rate increased during the study period (77.8% to 88.2%, 13.4% relative increase, P = .033) and levonorgestrel-releasing intrauterine device use significantly increased after 2007 (6.3% to 82.7%, 13.2-fold increase, P < .001), both concomitant with a higher proportion of women achieving complete response (32.9% to 81.4%, 2.5-fold increase, P = .005).
CONCLUSION: Our study suggests that local therapy with the levonorgestrel-releasing intrauterine device may be more effective than systemic therapy for women with complex atypical hyperplasia who opt for nonsurgical treatment, particularly in morbidly obese women. Shifts in treatment paradigm during the study period toward increased levonorgestrel-releasing intrauterine device use also led to improved complete response rates despite increasing rates of obesity.