Fertility-Preserving Therapy May Impair Endometrial Function and IVF Success After Endometrial Cancer: Study

In order to evaluate the exact effects of previous neoplasms on the following pregnancy outcomes, scientists have conducted a cohort study in a high-throughput tertiary referral center with the collection of data in the period from January 1, 2020, till December 31, 2024. The case group was comprised of women of reproductive age with documented complete remission of either early-stage IA endometrial carcinoma or endometrial intraepithelial neoplasia. In order to avoid possible confounding factors, a 1:1 propensity score–matched case-control study design was applied, comparing those patients with an infertile control group that suffered from simple tubal or male factor infertility.

The matched cases and controls had an identical distribution according to maternal age, BMI, and type of infertility, providing a final sample size of 252 participants (126 paired subjects). All cases and controls were exposed to the same standardized protocol of the artificial cycle for endometrial preparation with programmed oral estrogen before receiving a good-quality blastocyst transfer. The main criteria of outcomes that would be evaluated included the rates of pregnancy and live birth in the first frozen-thawed embryo transfer cycle as well as long-term cumulative pregnancy rate.

Key findings:

• The longitudinal matched cohort study recruited an overall cohort of 252 patients, including 126 females with a past diagnosis of successfully treated endometrial lesions and 126 healthy participants.
• In the initial frozen-thawed embryo transfer cycle, the study group revealed a significantly lower clinical pregnancy rate of 37.3% (47 out of 126 patients) than that recorded among healthy patients of 61.1% (77 out of 126 patients) (P < .001).
• The live birth rate in the first cycle was cut in half, as only 23.8% (30 out of 126 patients) became pregnant in contrast with 47.6% (60 out of 126 patients) of healthy participants (P < .001).
• Female patients with neoplastic lesions needed more days for estrogenic preparations before being ready for transfers (median of 14 vs. 12 days for the control group, respectively; P < .001).
• Although needing additional preparation time and having increased serum estradiol concentrations, the study group had significantly decreased endometrial thickness before starting progesterone administration (P < .001).
• Long-term Kaplan–Meier analysis showed a significantly lower cumulative live-birth rate across successive cycles in the study group, yielding a clear hazard ratio of 0.60 (95% Confidence Interval [CI], 0.40–0.89, P = .012).
• Within the oncofertility cohort, a prolonged time to complete remission exceeding 6 months was independently associated with a 50% reduction in the odds of achieving a clinical pregnancy (Odds Ratio 0.50, 95% CI, 0.30–0.85, P = .011).

In summary, remission of endometrial carcinoma using fertility-sparing treatment techniques does not imply endometrial functionality due to endometrial dysplasia and the inability to achieve a successful pregnancy rate. The results clearly indicate the need for endometrial preservation during cancer therapy. This important scientific work is a much-needed eye-opener for contemporary reproductive medicine, demonstrating the fact that elimination of abnormal cells alone will not result in a healthy pregnancy.

Reference:

Cheng, Xinghan MD; Zhang, Duoduo MD; Gan, Jingwen MD; Tao, Tao MD; Zhou, Yuanzheng MD; Cao, Dongyan MD; Gui, Ting MD; Peng, Peng MD. Frozen–Thawed Embryo Transfer Outcomes After Fertility-Sparing Treatment for Endometrial Carcinoma. Obstetrics & Gynecology ():10.1097/AOG.0000000000006329, May 28, 2026. | DOI: 10.1097/AOG.0000000000006329