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Ovarian cancer

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Stages of ovarian cancer

Staging is a way of describing or classifying a cancer based on the extent of cancer in the body. The most common staging system for ovarian cancer is the TNM system. The Union for International Cancer Control (UICC) uses the TNM system to describe the extent of many solid tumour cancers. The TNM system is the basis of the International Federation of Gynecology and Obstetrics (FIGO) staging system.

These systems are used to describe the extent of epithelial, stromal and germ cell ovarian tumours, as well as tumours of borderline malignancy. Ovarian cancer is staged during surgery.

TNM

TNM stands for tumour, nodes, metastasis. TNM staging describes:

  • the size and extent of the primary tumour
  • the number and location of any regional lymph nodes (lymph nodes that are close to the primary site) that have cancer cells in them
  • whether the cancer has spread or metastasized to another part of the body

Primary tumour (T)

TX

Primary tumour cannot be assessed.

T0

There is no evidence of a primary tumour.

T1

The tumour is limited to one or both ovaries.

T1a

The tumour is limited to one ovary, has not grown through the capsule (layer of tissue surrounding the ovary) and is not on the surface of the ovary.

There are no cancer cells in ascitesascitesAbnormal buildup of fluid in the abdomen. or washings of the peritoneumperitoneumThe membrane that lines the walls of the abdomen and pelvis (parietal peritoneum), and covers and supports most of the abdominal organs (visceral peritoneum). taken during surgery (peritoneal washings).

T1b

The tumours are limited to both ovaries, have not grown through the capsule and are not on the surface of the ovaries.

There are no cancer cells in ascites or peritoneal washings.

T1c

The tumour is limited to one or both ovaries with any of the following:

  • The tumour has grown through the ovarian capsule.
  • The tumour has spread to the surface of the ovary.
  • Cancer cells are found in ascites or peritoneal washings.

T2

The tumour is in one or both ovaries and cancer has spread to the pelvis.

T2a

The tumour has spread to the uterus or Fallopian tubes.

There are no cancer cells in ascites or peritoneal washings.

T2b

The tumour has spread to other pelvic tissues.

There are no cancer cells in ascites or peritoneal washings.

T2c

The tumour has spread within the pelvis (T2a or T2b).

There are cancer cells in ascites or peritoneal washings.

T3

The tumour is in one or both ovaries.

There is confirmed spread outside the pelvis to the peritoneum.

T3a

Very tiny (microscopic) tumours have spread to the peritoneum beyond the pelvis (peritoneal metastases).

T3b

The peritoneal metastases are 2 cm or smaller.

T3c

The peritoneal metastases are larger than 2 cm.

Note: If the ovarian tumour has spread to the outer capsule of the liver, the T stage is T3.

Regional lymph nodes (N)

NX

Regional lymph nodes cannot be assessed.

N0

No regional lymph node metastasis.

N1

Regional lymph node metastasis.

Distant metastasis (M)

M0

No distant metastasis.

M1

Distant metastasis (excludes peritoneal metastases).

Note: If the ovarian tumour has spread to the tissues of the liver, it is M1. If there are malignant ovarian cancer cells in the pleural effusionpleural effusionAn abnormal buildup of fluid in the pleural cavity (space between the lungs and the walls of the chest)., it is M1.

Stage grouping for ovarian cancer

FIGO further groups the TNM data into the stages listed in the table below.

FIGO staging – ovarian cancer
FIGO stageTNMExplanation

Stage IA

T1a

N0

M0

The tumour is limited to one ovary. The ovarian capsule is intact.

stage IB

T1b

N0

M0

The tumours are limited to both ovaries. The ovarian capsule is intact.

stage IC

T1c

N0

M0

The tumour is limited to one or both ovaries. It may have grown through the ovarian capsule or spread to the surface of the ovary.

Cancer cells may be present in ascites or peritoneal washings.

stage IIA

T2a

N0

M0

The tumour has spread to the uterus or Fallopian tube(s).

stage IIB

T2b

N0

M0

The tumour has spread to other pelvic organs (such as the bladder or rectum).

stage IIC

T2c

N0

M0

The tumour has spread to any other pelvic organ.

There are cancer cells in ascites or peritoneal washings.

stage IIIA

T3a

N0

M0

There are tiny (microscopic) metastases on the peritoneum outside the pelvis (peritoneal metastases).

stage IIIB

T3b

N0

M0

The peritoneal metastases outside the pelvis are 2 cm or smaller.

stage IIIC

T3c

N0,

N1

M0

The peritoneal metastases outside the pelvis are larger than 2 cm.

The cancer may have spread to the regional lymph nodes.

Any T

N1

M0

The cancer has spread to the regional lymph nodes.

Note: If the cancer has spread to the outer capsule of the liver, the cancer is stage III.

stage IV

any T

any N

M1

The cancer has spread to distant organs (excluding peritoneal metastases, which are stage III).

Note: If the cancer has spread to the tissues of the liver or malignant ovarian cancer cells are found in pleural effusion, the cancer is stage IV.

Recurrent ovarian cancer

Recurrent ovarian cancer means that the cancer has come back after it has been treated. It may recur in the same location as the original cancer or it may recur in another part of the body (metastatic ovarian cancer).

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