Predictors of resolution of complex atypical hyperplasia or grade 1 endometrial adenocarcinoma in premenopausal women treated with progestin therapy

ObjectiveTo identify clinical and pathologic predictors of response to progestin treatment in premenopausal women with complex atypical hyperplasia (CAH) and Grade 1 endometrial adenocarcinoma (Grade 1 EA).MethodsForty premenopausal patients with Grade 1 EA or CAH who underwent progestin therapy for a minimum of 8 weeks were retrospectively identified. Patient characteristics and histopathologic features of pretreatment and first follow-up endometrial specimens were evaluated as predictors of resolution, defined as absence of hyperplasia or carcinoma.ResultsKaplan–Meier analysis indicated 63% resolution at 18 months of follow-up. Multivariate classification analysis showed that resolution rates were higher in individuals with a low pre-treatment qualitative abnormal architecture score and a BMI < 35 (Standardized Resolution Ratio (SRR) = 1.48, p = 0.03). The diagnosis of benign endometrium or simple hyperplasia on the first follow-up specimen was highly predictive of resolution (SRR = 2.25, p = 0.002). Resolution rates were lower among subjects with a high pre-treatment qualitative abnormal architecture score (SRR = 0.37, p < 0.03) and lowest in subjects whose first follow-up specimen showed persistent complexity, atypia, or carcinoma with adjacent stromal decidualization (SRR = 0.24, p = 0.002).ConclusionsClinical and pathologic parameters can predict response to progestin therapy in premenopausal women with CAH and Grade 1 EA. A low likelihood of resolution is predicted by an unfavorable pre-treatment architectural score and lack of pathological response in the first specimen, despite adjacent stromal decidualization.

► Progestin for grade 1 endometrial cancer and CAH—clinical & pathological predictors of resolution.
► 43% resolution at 12 months; 63% resolution at 18 months.
► Lowest resolution rate if no response on 1st follow-up specimen & adjacent stromal decidualization.