Fertility preservation in gynecologic malignancies: oncologic safety boundaries, individualized strategies, and reproductive outcomes

Fertility preservation has become an integral component of care for reproductive-aged patients with gynecologic malignancies. However, fertility-sparing treatment should not be equated with maximal organ preservation, and oncologic safety remains the prerequisite for all fertility-preserving strategies. This review summarizes fertility preservation in endometrial cancer, ovarian tumors, and cervical cancer, with particular emphasis on the clinical safety boundaries, selected expanded indications, and reproductive outcomes. For endometrial cancer, fertility-sparing treatment is best established for grade 1 endometrioid carcinoma confined to the endometrium, while selected grade 2 disease or very limited myometrial invasion may be considered only after individualized assessment. Extrauterine disease, high-grade or non-endometrioid histology, and unfavorable molecular features generally argue against conservative treatment. For ovarian tumors, eligibility cannot be defined by the International Federation of Gynecology and Obstetrics (FIGO) stage alone and should instead be determined by the histologic category, substage, tumor differentiation, and adequacy of staging, with substantially different boundaries for borderline ovarian tumors, epithelial ovarian cancer, malignant ovarian germ cell tumors, and sex cord–stromal tumors. For cervical cancer, fertility-sparing surgery is best established in carefully selected node-negative disease ≤2 cm when adequate margins are achievable, whereas tumors >2 and ≤4 cm remain a non-standard setting in which neoadjuvant chemotherapy followed by fertility-sparing surgery may be considered only in highly selected patients at experienced centers. Assisted reproductive technologies and gonadotoxicity reduction strategies, including embryo or oocyte cryopreservation, ovarian tissue cryopreservation, ovarian transposition, radiotherapy dose optimization, and selected pharmacologic ovarian protection, provide additional options when fertility-sparing surgery is inappropriate or insufficient. Overall, fertility preservation in gynecologic oncology is shifting from organ-centered preservation toward individualized, risk-adapted management within clearly defined oncologic boundaries. Future studies should refine the eligibility criteria, standardize the oncologic and reproductive endpoints, and prospectively validate emerging treatment pathways.