From the Guidelines
Ovarian cancer is staged using the FIGO staging system, which categorizes the disease into four stages: I, II, III, and IV, based on the extent of tumor spread.
Staging Criteria
The staging criteria are as follows:
- Stage I: Tumor limited to the ovaries, with three subcategories:
- IA: Tumor limited to one ovary; capsule intact, no tumor on ovarian surface, and no malignant cells in ascites or peritoneal washings.
- IB: Tumor limited to both ovaries; capsules intact, no tumor on ovarian surface, and no malignant cells in ascites or peritoneal washings.
- IC: Tumor limited to one or both ovaries with any of the following: capsule ruptured, tumor on ovarian surface, or malignant cells in ascites or peritoneal washings.
- Stage II: Tumor involving one or both ovaries with pelvic extension and/or implants, with three subcategories:
- IIA: Extension and/or implants on the uterus and/or fallopian tubes, with no malignant cells in ascites or peritoneal washings.
- IIB: Extension to and/or implants on other pelvic tissues, with no malignant cells in ascites or peritoneal washings.
- IIC: Pelvic extension and/or implants (stage IIA or IIB) with malignant cells in ascites or peritoneal washings.
- Stage III: Tumor involving one or both ovaries with microscopically confirmed peritoneal implants outside the pelvis, with three subcategories:
- IIIA: Microscopic peritoneal metastasis beyond pelvis (no macroscopic tumor).
- IIIB: Macroscopic peritoneal metastasis beyond pelvis 2 cm or less in greatest dimension.
- IIIC: Peritoneal metastasis beyond pelvis more than 2 cm in greatest dimension and/or regional lymph node metastasis.
- Stage IV: Tumor involving one or both ovaries with distant metastasis, with pleural effusion requiring positive cytologic test results to designate a case to stage IV, and parenchymal liver metastasis equaling stage IV 1. The FIGO staging system has been updated, with changes including the subdivision of old stages IC, IIIA, and IV, and the elimination of old stage IIC, as reported in the 2016 NCCN guidelines for ovarian cancer 1.
Importance of Accurate Staging
Accurate staging is crucial for determining the prognosis and treatment recommendations for ovarian cancer, as emphasized in the 2011 NCCN guidelines for epithelial ovarian cancer 1.
Surgical Staging
Surgical staging is essential for accurate staging, and patients with ovarian cancer should undergo comprehensive surgical staging, including bilateral pelvic and para-aortic node dissection, as recommended in the 2004 study on surgery for ovarian cancer 1.
Imaging Modalities
Imaging modalities, such as CT, MRI, and PET/CT, play a crucial role in detecting and characterizing adnexal masses, staging ovarian cancer, and assessing the resectability of tumors, as discussed in the 2018 ACR Appropriateness Criteria for staging and follow-up of ovarian cancer 1.
From the Research
Staging Criteria for Ovarian Cancer
The staging of ovarian cancer is determined by the extent to which the cancer has spread from its site of origin, with guidelines set by the Fédération Internationale de Gynécologie et d'Obstétrique (FIGO) 2. The key factors in staging ovarian cancer include:
- The histologic type of the cancer, with high-grade serous carcinoma being the most common type 2
- The extent of spread to other gynecologic organs, lymph nodes, and tissues 2
- The presence of cancer in the ovaries, fallopian tubes, and peritoneum, which are now considered collectively in the staging system 3, 4
Surgical Staging
Surgical staging is a critical step in the treatment of ovarian cancer, particularly in early-stage disease 5, 6. The surgical approach may vary, with options including:
- Open abdominal surgery
- Laparoscopic surgery
- Robotic surgery Each approach has its own advantages and disadvantages, with minimally invasive surgery showing a lower rate of complications compared to open abdominal surgery 5
Importance of Accurate Staging
Accurate staging of ovarian cancer is essential for determining the best course of treatment and predicting patient outcomes 2, 6. Proper staging can distinguish between "real" early-stage ovarian carcinoma and "perhaps" early-stage disease, and is an independent prognostic factor for improved disease-free and overall survival in early-stage ovarian carcinoma 6. The FIGO staging system provides a standardized framework for staging ovarian cancer, allowing for more accurate prognostic information and personalized management of the disease 3, 4