The full FIGO -- International Federation of Gynecology and Obstetrics -- ovarian cancer surgical staging system is based on Roman numerals as well as letters to designate sub-stages. In general, prognosis depends more upon the main Stage. However, the sub-stages can also be important in deciding between treatment recommendations. Read more in the Treatment Options topic on this site.
Stage I - The cancer is limited to the ovaries
IA - Limited to one ovary and the outer ovarian capsule is not ruptured. There is no tumor on the external surface of the ovary and there is no ascites and/or the washings are negative.
IB - Cancer is present in both ovaries, but the outer capsule is intact and there is no tumor on external surface. There is no ascites and the washings are negative.
IC - The cancer is either Stage IA or IB level but the capsule is ruptured or there is tumor on the ovarian surface or malignant cells are present in ascites or washings.
Stage II - Cancer involves one or both ovaries with spread to other pelvic organs or surfaces.
IIA - Extension or implants onto the uterus and/or fallopian tube. The washings are negative washings and there is no ascites.
IIB - Extension or implants onto other pelvic tissues. The washings are negative and there is no ascites.
IIC - Pelvic extension or implants like Stage IIA or IIB but with positive pelvic washings
Stage III - Cancer spread outside the pelvis to the abdominal area, including metastases to liver surface
IIIA - Tumor is grossly confined to the pelvis but with micro-scopic peritoneal metastases beyond pelvis to abdominal peritoneal surfaces or the omentum.
IIIB - Same as IIIA but with macro-scopic peritoneal or omental metastases beyond pelvis less than 2 cm in size
IIIC - Same as IIIA but with peritoneal or omental metastases beyond pelvis, larger than 2 cm or lymph node metastases to inguinal, pelvic, or para-aortic areas.
Stage IV - Metastases or spread to the liver or outside the peritoneal cavity to areas such as the chest or brain.