Treatment of simple and complex endometrial non-atypical hyperplasia with natural progesterone: response rate to different doses.

The aim of this study is to evaluate the response rate to natural progesterone in non-atypical endometrial hyperplasia and to identify the lowest effective dose. A total of 197 patients of childbearing age with simple or complex hyperplasia were retrospectively identified. The women were treated with a cyclic administration of progesterone at different dosages (100 versus 200 versus 300 mg daily). Endometrial biopsies were performed at 6, 12, 18 months. In comparing progesterone to a regimen of no therapy, a significantly higher remission rate was observed in the progesterone group than in the latter (95 versus 75%, p = 0.05 for simple hyperplasia; 89 versus 35%, p<0.001 for complex hyperplasia). Out of 60 women with simple hyperplasia, remission was observed in 9/11 (81.8%), 40/41 (97.5%) and 8/8 (100%) patients treated, respectively, with progesterone 100, 200 and 300 mg daily. Out of 72 women with complex hyperplasia, remission was observed in 3/5 (60%), 49/53 (92.4%) and 12/14 (85.7%) patients treated with progesterone 100, 200 and 300 mg daily, respectively. There was no statistically significant difference in the response rate in the two groups, neither with simple nor with complex hyperplasia. In conclusion, progesterone increased the regression rate of both simple and complex hyperplasia.