Introduction/Background The main goal in fertility-sparing treatment in endometrial cancer, in most cases, is to achieve the pregnancy. Current recommendation advocates for using hysteroscopic resection of focal lesions combined with oral progestogens and levonorgestrel-intra-uterine device as the most effective. However, different modalities have been proved to be successful.

The aim of this study is to present the outcomes of fertility-sparing treatment with megestrol acetate 320 mg daily alone calculated as pregnancy rate and response to treatment.

Methodology Between 2021 and 2022 five women with endometrial cancer grade 1 (3 cases) and 2 (two cases) referred to University Clinical Center in Katowice, Poland, were treated with daily oral dose of 320 mg megestrol acetate. All women were negative for Lynch syndrome and were treated for 6 months after which time hysteroscopy with D&C was performed to confirm the response. If the response was achieved, women were advised to try to censive spontaneously. Live pregnancy rate and response rate was calculated.

Results Complete response was achieved in 3 out of 5 cases. In one woman progression from grade 1 to grade 2 was observed – she was referred for definite hysterectomy with sentinel node biopsy. In this case in pre-operative work-up in pelvic MRI myometrial partial invasion was noted (the patient wished to preserve fertility irrespectively of progression risk). In the second case no response was noted – the patient was also referred for hysterectomy. The rest 3 cases responded well for treatment. Two women conceive spontaneously – however, one miscarried in 7th gestational week, the other is now in 28th gestational age (on May 2023). One is still trying to get pregnant.

Conclusion Fertility-sparing treatment of endometrial cancer, both G1 and G2, with oral megestrol acetate 320 mg daily alone can be effective. Spontaneous pregnancy is possible in some cases.

Disclosures none