Guidelines for the treatment of ovarian cancer, fallopian tube cancer, and primary peritoneal cancer: 2025 edition by the Japan Society of Gynecologic Oncology.

To present the 2025 revision of the Japan Society of Gynecologic Oncology Clinical Practice Guidelines for the treatment of ovarian, fallopian tube, and primary peritoneal cancers, which incorporates recent advances in surgical strategies, molecular diagnostics, and maintenance therapies within the context of the Japanese healthcare system. Clinical questions (CQs) were formulated using the PICO framework. Systematic literature searches were conducted in PubMed, the Japan Medical Abstract Society, and the Cochrane Library (January 2019-December 2023), along with additional manual searches for emerging evidence. Three new systematic reviews addressing minimally invasive surgery, secondary cytoreductive surgery, and lymphadenectomy for malignant germ cell tumors were performed. Evidence levels and recommendation strengths were determined according to the Minds 2020 methodology adapted to the Japanese clinical and insurance environment. Recommendations were formulated using a modified GRADE approach. Final recommendations were established through multidisciplinary consensus voting, with a predefined agreement threshold of 75%. The sixth edition comprises 6 chapters and 49 CQs. Major updates include expanded guidance on homologous recombination deficiency testing and genomic profiling, refined indications for maintenance therapy with poly(ADP-ribose) polymerase (PARP) inhibitors and bevacizumab, clarified recommendations for secondary cytoreductive surgery, updated management of PARP inhibitor-exposed recurrence, and strengthened sections on onco-fertility and palliative care. Transparency was enhanced by disclosing key discussion points and consensus rates for each recommendation. These guidelines define evidence-based standards tailored to Japanese clinical practice while maintaining international relevance. They aim to reduce inter-institutional disparities, optimize patient outcomes, and provide a transparent framework for future therapeutic integration.