What is the treatment approach for ovarian cancer according to the 2025 FIGO (International Federation of Gynecology and Obstetrics) staging?

Ovarian Cancer Staging and Treatment According to 2025 FIGO

The 2014 FIGO staging system remains the current standard for ovarian cancer classification, with treatment stratified by stage, histologic subtype, and surgical completeness—there is no separate "2025 FIGO" staging system. 1

FIGO Staging System (2014 - Currently Used)

Stage I: Tumor Confined to Ovaries or Fallopian Tubes

• IA: One ovary/tube, capsule intact, no surface tumor, negative washings 1
• IB: Both ovaries/tubes, capsules intact, no surface tumor, negative washings 1
• IC: Limited to ovaries/tubes with:
  • IC1: Surgical spill 1
  • IC2: Capsule rupture before surgery or surface tumor 1
  • IC3: Malignant cells in ascites/washings 1

Stage II: Pelvic Extension Below Pelvic Brim

• IIA: Extension to uterus/tubes/ovaries 1
• IIB: Extension to other pelvic tissues 1

Stage III: Peritoneal Spread Beyond Pelvis and/or Retroperitoneal Nodes

• IIIA1(i): Positive retroperitoneal nodes ≤10 mm 1
• IIIA1(ii): Positive retroperitoneal nodes >10 mm 1
• IIIA2: Microscopic extra-pelvic peritoneal involvement 1
• IIIB: Macroscopic peritoneal metastasis ≤2 cm 1
• IIIC: Macroscopic peritoneal metastasis >2 cm (includes liver/spleen capsule without parenchymal involvement) 1

Stage IV: Distant Metastasis

• IVA: Pleural effusion with positive cytology 1
• IVB: Parenchymal metastases, extra-abdominal organs, inguinal nodes 1

Treatment by Stage

Early Stage (FIGO I-II)

Surgical Management

Comprehensive staging via midline laparotomy by a gynecologic oncologist is mandatory and includes: 1, 2

• Peritoneal washings with cytology 1
• Complete abdominal cavity inspection and palpation 1
• Bilateral salpingo-oophorectomy 1
• Total hysterectomy 1
• Omentectomy 1
• Appendectomy (for mucinous carcinoma) 1
• Systematic pelvic and para-aortic lymphadenectomy 1
• Biopsies from all visible lesions and peritoneal surfaces 1

Lymphadenectomy can be omitted in low-grade endometrioid or expansile mucinous carcinoma with radiologically/clinically negative nodes (lymph node metastasis rate <1%) 1

Fertility-sparing surgery (unilateral salpingo-oophorectomy with uterine preservation) may be considered for stage IA or IC1-2 with unilateral involvement and favorable histology (low-grade tumors) 1

Adjuvant Chemotherapy Indications

Surgery alone is adequate for: 1, 2

• Stage IA/IB, well-differentiated (grade 1), non-clear cell histology 1

Adjuvant chemotherapy is recommended for: 1, 2

• Stage IA/IB poorly differentiated (grade 3) 1
• Stage IA/IB with clear cell histology 1
• Stage IA/IB with dense adhesions 1
• All grades of stage IC (IC1, IC2, IC3) 1
• All stage IIA disease 1

Chemotherapy regimen: Carboplatin AUC 5-7 ± Paclitaxel 175 mg/m² every 3 weeks for 3-6 cycles 1, 2, 3

Advanced Stage (FIGO IIB-IV)

Primary Treatment Approach

Maximal upfront cytoreductive surgery with goal of no residual disease (R0 resection) is the standard approach when feasible based on preoperative imaging assessment 1, 2

For patients unlikely to achieve complete cytoreduction or with high perioperative risk, neoadjuvant chemotherapy (NACT) followed by interval cytoreductive surgery (ICS) is recommended: 1

• Histologic confirmation via core biopsy strongly preferred 1
• Platinum-taxane doublet for high-grade serous or endometrioid carcinoma 1
• ICS performed after 3-4 cycles of NACT 1
• Total of 6 cycles chemotherapy (NACT + post-ICS) 1

Standard Chemotherapy Regimen

Carboplatin AUC 5-7.5 + Paclitaxel 175 mg/m² IV over 3 hours every 3 weeks for 6 cycles 1, 3

Maintenance Therapy Considerations

Following completion of primary chemotherapy, maintenance options include: 4

• PARP inhibitors (outstanding results in BRCA-mutated and homologous recombination deficient tumors) 4
• Bevacizumab (anti-VEGF antibody) 4
• Combination strategies for specific molecular profiles 4

HIPEC Consideration

For FIGO stage III disease with good performance status and adequate renal function treated with NACT, hyperthermic intraperitoneal chemotherapy (HIPEC) may be offered during ICS through shared decision-making 1

Critical Prognostic Factors

The most important prognostic factor is the extent of residual disease after cytoreductive surgery: 1, 5

• Complete resection (R0): Median survival ~5 years, 2-year survival 80% 5, 6
• Optimal cytoreduction (residual <1 cm): Significantly improved survival 5
• Suboptimal cytoreduction (residual >2 cm): 2-year survival <22% 5

Comprehensive surgical staging upstages 60% of apparent early-stage disease, directly impacting survival outcomes 1

Common Pitfalls to Avoid

• Do not use laparoscopy for staging in suspected ovarian cancer—midline laparotomy remains standard due to increased capsule rupture risk 1
• Do not omit lymphadenectomy in high-grade histologies even in apparent early disease 1
• Do not perform "second-look" surgery after chemotherapy completion in apparent complete remission—no survival benefit demonstrated 1
• Do not use aluminum-containing needles or IV sets with carboplatin—causes precipitate formation and loss of potency 3