Ovarian cancer

American Joint Committee on Cancer (AJCC) TNM staging system (8th edition)[105]Amin MB, Edge SB, Greene FL, et al, eds. AJCC cancer staging manual, 8th edition. Cham, Switzerland: Springer International Publishing; 2017.

The AJCC staging system describes the extent of disease based on the following anatomical factors: size and extent of the primary tumour (T); regional lymph node involvement (N); and presence or absence of distant metastases (M).

International Federation of Gynecology and Obstetrics staging guidelines[106]Prat J; FIGO Committee on Gynecologic Oncology. Staging classification for cancer of the ovary, fallopian tube, and peritoneum. Int J Gynaecol Obstet. 2014 Jan;124(1):1-5. https://obgyn.onlinelibrary.wiley.com/doi/full/10.1016/j.ijgo.2013.10.001 http://www.ncbi.nlm.nih.gov/pubmed/24219974?tool=bestpractice.com [107]Berek JS, Renz M, Kehoe S, et al. Cancer of the ovary, fallopian tube, and peritoneum: 2021 update. Int J Gynaecol Obstet. 2021 Oct;155 Suppl 1(suppl 1):61-85. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9298325 http://www.ncbi.nlm.nih.gov/pubmed/34669199?tool=bestpractice.com ​​

Stage characteristics:

• Stage I - tumour confined to ovaries or fallopian tube(s)

  • Stage IA - tumour limited to 1 ovary (capsule intact) or fallopian tube; no tumour on ovarian or fallopian tube surface; no malignant cells in the ascites or peritoneal washings

  • Stage IB - tumour limited to both ovaries (capsules intact) or fallopian tubes; no tumour on ovarian or fallopian tube surface; no malignant cells in the ascites or peritoneal washings

  • Stage IC - tumour limited to 1 or both ovaries or fallopian tubes, with any of the following:

    • Stage IC1 - surgical spill

    • Stage IC2 - capsule rupture before surgery or tumour on ovarian or fallopian tube surface

    • Stage IC3 - malignant cells in the ascites or peritoneal washings.

  Note: lymph node dissection is recommended if disease appears to be confined to the ovaries or pelvis, for complete staging.

• Stage II - tumour involves 1 or both ovaries or fallopian tubes with pelvic extension (below pelvic brim) or primary peritoneal cancer

  • Stage IIA - extension and/or implant on uterus and/or fallopian tubes and/or ovaries

  • Stage IIB - extension to other pelvic intraperitoneal tissues.

  Note: lymph node dissection is recommended if disease appears to be confined to the ovaries or pelvis, for complete staging.

• Stage III - tumour involves 1 or both ovaries or fallopian tubes, or primary peritoneal cancer, with cytologically or histologically confirmed spread to the peritoneum outside the pelvis and/or metastasis to the retroperitoneal lymph nodes

  • Stage IIIA1 - positive retroperitoneal lymph nodes only (cytologically or histologically proven):

    • Stage IIIA1 (i) - metastasis ≤10 mm in greatest dimension

    • Stage IIIA1 (ii) - metastasis >10 mm in greatest dimension

  • 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 ≤2 cm in greatest dimension, with or without metastasis to the retroperitoneal lymph nodes

  • Stage IIIC - macroscopic peritoneal metastasis beyond the pelvis >2 cm in greatest dimension with or without metastasis to the retroperitoneal lymph nodes (includes extension of tumour to capsule of liver and spleen without parenchymal involvement of either organ)

  Note: for stages IIIA and IIIB, tumour measurements should be made before debulking procedure, for staging purposes.

• Stage IV - distant metastasis excluding peritoneal metastasis

  • Stage IVA - pleural effusions with positive cytology

  • Stage IVB - parenchymal metastases and metastases to extra-abdominal organs (including inguinal lymph nodes and lymph nodes outside of the abdominal cavity).

Notes:

• Primary site (ovary, fallopian tube, or peritoneum) should be designated where possible. Cases should be listed as 'undesignated' if it is not possible to delineate the primary site clearly

• Histological type should be recorded

• Assignment to stage IIIA1 is based on spread to the retroperitoneal lymph nodes without intraperitoneal dissemination because survival is significantly better in these patients than those with intraperitoneal dissemination

• Retroperitoneal lymph node involvement must be proven cytologically or histologically

• Extension of tumour from omentum to spleen or liver (stage IIIC) should be differentiated from isolated parenchymal metastases (stage IVB).

International Federation of Gynaecology and Obstetrics tumour grades[99]Benedet JL, Bender H, Jones H 3rd, et al. FIGO staging classifications and clinical practice guidelines in the management of gynecologic cancers. FIGO Committee on Gynecologic Oncology. Int J Gynaecol Obstet. 2000 Aug;70(2):209-62. http://www.ncbi.nlm.nih.gov/pubmed/11041682?tool=bestpractice.com

Grade 1: <5% solid tumour growth

Grade 2: >5% solid tumour growth

Grade 3: >50% solid tumour growth

Gynecological Oncology Group classification tumour grades

Grade 1: well differentiated

Grade 2: moderately differentiated

Grade 3: poorly differentiated

Note: the Gynecological Oncology Group (GOG) grading system is based on tumour histology. Different guidelines are applied depending on whether the tumour is serous, endometrioid, mucinous, Brenner's, transitional cell, mixed, or small cell. Clear cell carcinomas are not graded according to the GOG.