Ovarian cancer (staging)

The most commonly adopted ovarian cancer staging system is the FIGO staging system. The most recent staging system is from 2014 :

CT is considered the best imaging modality for staging ovarian cancer. .

  • stage I:  tumor limited to the ovaries
    • stage Ia: 
      • tumor limited to one ovary
      • capsule intact
      • no tumor on ovarian surface
      • no malignant cells in ascites or peritoneal washings
    • stage Ib: 
      • tumor involves both ovaries; otherwise similar to stage Ia
        • capsule intact
        • no tumor on ovarian surface
        • no malignant cells in ascites or peritoneal washings
    • stage Ic: 
      • tumor involves one or both ovaries, with any of the following: 
        • stage Ic1: surgical/intraoperative spill
        • stage Ic2: capsule ruptured before surgery, or tumor on ovarian or fallopian tube surface
        • stage Ic3: malignant cells in the ascites or peritoneal washings

  • stage II: tumor involves one or both ovaries with pelvic extension or primary peritoneal cancer (below pelvic brim)
    • stage IIa: extension or implants on the uterus or fallopian tubes
    • stage IIb: extension to other pelvic intraperitoneal tissues

  • stage III: tumor involves one or both ovaries or fallopian tubes with cytologically or histologically confirmed spread to the peritoneum outside the pelvis and/or metastasis to the retroperitoneal lymph nodes
    • stage IIIa: positive retroperitoneal lymph nodes and /or microscopic metastasis beyond the pelvis:
      • stage IIIa1: positive (cytologically or histologically proven) retroperitoneal lymph nodes only
        • stage IIIa1(i): metastatic retroperitoneal node measuring ≤10 mm
        • stage IIIa1(ii): metastatic retroperitoneal node measuring >10 mm
      • stage IIIa2: microscopic extrapelvic (above the pelvic brim) peritoneal involvement with or without positive retroperitoneal lymph nodes
    • stage IIIb: macroscopic peritoneal metastasis beyond the pelvis up ≤2 cm in greatest dimension, with or without metastasis to the retroperitoneal lymph nodes
      • includes extension of tumor to the capsule of liver and spleen
    • stage IIIc: macroscopic extrapelvic peritoneal metastases >2 cm in greatest dimension, with or without metastasis to the retroperitoneal lymph nodes
      • includes extension of tumor to the capsule of liver and spleen

  • stage IV: consists of distant metastasis, excluding peritoneal metastases, and includes the following:
    • stage IVa: pleural effusion with positive cytology
    • stage IVb: distant metastases
      • parenchymal metastases and metastases to extra-abdominal organs (including inguinal lymph nodes and lymph nodes outside of the abdominal cavity)

Notes:

  • bilateral ovarian tumors may represent stage I disease, but represent metastases in ~30% of patients
  • one of the potential difficulties in differentiating stage II from stage III disease is differentiating between involvement of pelvic and extrapelvic peritoneum
  • the majority of ovarian cancers present as stage III
  • presence of metastatic lymph nodes is important, but the number of nodes does not carry prognostic significance
  • the amount of peritoneal involvement carries prognostic significance, but the 2 cm cut off in the staging system is subjective

See also