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Stages and Subtypes

Read about cancer treatment options listed by gene mutation, type of cancer and type of treatment.

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Stages and subtypes of , ovarian and primary peritoneal cancer

Ovarian, , and primary peritoneal cancer are very closely related. Although they each begin in different parts of the reproductive tract, the cells look and behave the same and similar treatments are used for each. Primary peritoneal cancer arises from the lining of the abdomen, also known as the peritoneum.

Subtypes and grades

After surgery confirms cancer, the pathologist looks closely at the type of cells found in the tumor for additional clues on how to best treat it. The subtypes can also be classified as high-grade or low-grade depending on how quickly the cancer cells are growing and dividing and the presence of certain genetic mutations within the tumor. The subtype and grade affect treatment options and prognosis. The most common subtypes of ovarian cancer belong to a group called epithelial cancers, that arise from the outer lining of the ovaries and tubes. These include:

  • Serous 
  • Endometrioid
  • Clear cell
  • Mucinous

High-grade serous are the most common type of ovarian cancer. The following rare subtypes arise from other cells within the ovaries and tubes:

  • Stromal cell 
  • Germ cell
  • Small cell
  • Mixed Mullerian (cancinosarcoma)

Certain subtypes have been linked to specific inherited mutations. Women with  may develop any of the epithelial subtypes listed above. Women with a  or  mutation are most likely to develop high-grade serous subtype (although they may develop any subtype).

Stages of cancer

The  of a cancer refers to whether it has spread beyond the ovaries or tubes, and if it has, the location in the body where it has spread. Measuring the of ovarian cancer helps doctors decide how to treat it. 

The stages of ovarian and cancers are:

  • 1 is confined to the ovary or .
  • 2 is confined to the pelvis.
  • 3 is confined to the upper abdomen.
  • 4 has spread beyond the abdomen.

Stages 3 and 4 are considered advanced ovarian cancer. 

National guidelines recommend that women with certain inherited mutations linked to ovarian cancer undergo surgery to remove their ovaries and to lower their risk for cancer. In some of these women, a pre-cancerous , known as serous tubal intraepithelial carcinoma (STIC), may be found during risk-reducing surgery. Researchers are studying whether additional treatment for people with STIC lesions improves their outcomes.

Doctors may order additional tumor tests to help guide treatment. For some people with advanced cancers, tumor testing can look for further clues to help guide the choice of targeted therapies. 

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The following organizations offer peer support services for people with or at high risk for ovarian cancer:

Last updated January 04, 2024