Fertility-Sparing Management of Atypical Hyperplasia and Endometrial Cancer from the Perspective of Molecular and Hormonal Profiles: A Meta-Analysis-Driven Framework

Background/Objectives: The prognostic and predictive values of biomarkers in fertility-sparing management of atypical hyperplasia (AH) and endometrial cancer (EC) remain ill-defined. We aimed to identify the impact of tumour profiles on oncologic and reproductive outcomes to inform clinical decision-making. Methods: We conducted a systematic review and meta-analysis by searching MEDLINE, PubMed, Embase, Cochrane Library, Scopus, Google Scholar, and ClinicalTrials.gov, up to July 2026. We intended to include comparative studies or clinical trials, in English or French, assessing outcomes according to molecular or hormonal profiles in reproductive-aged women diagnosed with AH or EC. The primary outcome was the best overall complete remission (CR). Pooled odds ratios (ORs) were calculated using a random-effects model with logit transformation and restricted maximum likelihood estimation. Risk of bias was assessed using the Newcastle–Ottawa scale (NOS). The study protocol was registered in PROSPERO (CRD42025632885). Results: Eighteen retrospective studies comprising 965 patients were included. No specific molecular profile (NSMP) tumours demonstrated significantly higher odds of CR (OR 2.04, 95% CI 1.33–3.11). p53-abnormal (p53abn) and deficient mismatch repair (dMMR) tumours were significantly less likely to achieve CR compared to NSMP (OR 3.87, 95% CI 1.80–8.29 and OR 2.48, 95% CI 1.44–4.29, respectively). POLE-mutated (POLEmut) tumours showed CR comparable to NSMP (OR 1.39, 95% CI 0.60–3.24). Progesterone receptor (PR) positivity was strongly associated with CR (OR 7.73, 95% CI 2.77–21.63). Conclusions: NSMP and PR-positivity represented a favourable prognosis and potential prediction of CR. POLEmut tumours demonstrated CR rates comparable to NSMP, whereas p53abn and dMMR demonstrated unfavourable outcomes. These findings support a biologically tailored approach to patient selection for fertility-sparing management.