RESUMO
OBJECTIVE: For young women with complex atypical endometrial hyperplasia (CAH) and endometrial cancer (EC) who choose to preserve fertility, progestin therapy is the mainstay of treatment. The objective of this study was to evaluate oncologic and reproductive outcomes associated with progestin therapy among these women from a population-based cancer registry. METHODS: This was a retrospective population-based cohort study of women under age 45 in British Columbia from 2003 to 2015 with CAH or grade I endometrioid EC who used progestins as initial management. Demographics, treatment type, response to treatment, determinants of definitive surgery (hysterectomy), pathologic findings, and obstetrical outcomes were reviewed. RESULTS: There were 50 women under age 45 with CAH (n = 29) and EC (n = 21). Median age at diagnosis was 36 years (range 25-41), and most were nulliparous (88%) with a median BMI of 32.9 (range 21-70). After 6 months of therapy, 58% of women had persistent disease, and only 35% had full resolution at last follow-up (median 23 months). There were 32 women who had a hysterectomy, including 27 because of persistent/recurrent disease, and 5 who chose surgery despite complete response to progestins. The majority of hysterectomy specimens (85%) had minimal or no residual pathology, even among those with disease on preoperative biopsy. Only 10% of women had successful pregnancies. CONCLUSION: There is a moderate to high risk of persistence of CAH or EC on progestin therapy. However, for those undergoing hysterectomy, the vast majority has low-risk disease confined to the endometrium, implying the possibility of further conservative management of persistent disease.