Introduction/Background This study investigated the risk factors and therapeutic regimens in refractory endometrial atypical hyperplasia (EAH) and endometrial cancer (EC) patients with fertility-sparing treatment.

Methodology Patients with EAH (n=284) or well-differentiated EC (n=95, FIGO stage IA, without myometrial invasion) were retrospectively included. All patients received progestin therapy combined with hysteroscopy. Therapeutic effects were evaluated by hysteroscopy every three months during the treatment. Profiles of blood glucose levels, sex hormone levels, serum CA-125 and HE4 were tested before progestin treatment, and estorgen receptor (ER)/progesterone receptor (PR) status of lesions were detailly recorded.

Results The median age was 32.0 year-old (range, 20–49 year-old). Totally 354 patients (93.4%) achieved complete response (CR) while 6 patients presented with progressed disease (PD), 5 patients remained no response (NR) and then chose hysterectomy, and 14 patients were still in treatment. We defined refractory patients as: (1) presented PD during fertility-sparing treatment; (2) remained no response (NR) after 6 months of treatment; (3) did not achieve CR after 9 months of treatment. 91 patients were refractory. After adjusting for age and type of fertility-sparing therapies, BMI ≥30 kg/m² (OR, 2.880; 95% CI, 1.354–6.126; P=0.006) and testosterone (T) ≥0.37 ng/ml (OR, 0.448; 95% CI, 0.249–0.805; P=0.007) were significantly correlated with higher risk of refractory disease. After at least 6 months of high-dose progestin treatment, patients who altered to high-dose progestin combined with metformin or Diane-35 combined with metformin may have higher CR rate than those with original regimens (90.9%, 85.7% vs. 61.1%, P=0.132). Diane-35 combined with metformin use up-regulated PR, which in turn may improve treatment efficacy.

Conclusion BMI ≥30 kg/m² and T ≥0.37ng/ml were associated with higher risk of refractory disease. Individualized therapies are needed for refractory patients.

Disclosure Nothing to disclose.