Ovarian Cancer: Defining the Disease

Ovarian cancer is a serious disease—you should be educated on what causes this type of cancer and what to look for.

Know the facts

What is ovarian cancer?

Ovarian cancer is a disease in which cells in the ovaries grow out of control and form tumors. Type, subtype, stage, and grade are just a few ways to classify ovarian cancer.


Type and subtype refer to where the first tumor is formed. Knowing this can help health care professionals identify specific characteristics that define the cancer. The 3 types of ovarian cancer are epithelial, germ cell, and stromal.

Epithelial Ovarian Carcinoma

Epithelial ovarian carcinoma originates in the tissue that surrounds the ovaries. This is the most common type of ovarian cancer, accounting for almost 90% of diagnoses.

Subtypes: Serous, Mucinous, Endometrioid, Clear Cell

Germ Cell Tumors

Germ cell tumors start from the cells that produce the eggs. Most of these tumors are benign, but a small number are cancerous.

Subtypes: Dysgerminoma, Endodermal Sinus (Yolk Sac), Choriocarcinoma, Teratoma

Stromal Cell Tumors

Stromal cell tumors develop from tissues that hold the ovary together and those that produce hormones. These types of tumors are rare and can cause vaginal bleeding. Stromal tumors are often found at an early stage, with more than 75% of women surviving long term.

Subtypes: Granulosa Cell, Granulosa-Theca, Thecoma, Fibroma, Sertoli-Leydig Cell


The stage of the cancer refers to how far it has spread from the ovary to other parts of the body. Ovarian cancer is divided into 4 stages. Staging is an important part of the process because accurate staging can help determine treatment.

The cancer is limited to 1 or both ovaries.

  • IA:Cancer cells are found inside a single ovary.
  • IB:Cancer cells are found inside both ovaries.
  • IC:Cancer cells are found inside or outside 1 or both ovaries or in the fluid or washing of the abdominal cavity.

The cancer has spread outside the ovaries and is growing in the pelvis.

  • IIA:Cancer cells have spread to the fallopian tubes, the uterus, or both.
  • IIB:Cancer cells have spread to other tissues in the pelvis, such as the bladder or rectum.

The cancer has spread outside the pelvis and may appear in the lymph nodes of the back of the abdomen.

  • IIIA:Cancer cells appear in samples of tissues taken from the lining of the abdomen.
  • IIIB:Small tumors (2 cm or smaller) are visibly growing in the abdomen.
  • IIIC:Larger tumors (larger than 2 cm) are visible in the abdomen. Additionally, the cancer may have spread to the lymph nodes, but not to the inside of the liver or spleen.

The cancer has spread to more distant organs, such as the liver and lungs. It is important to know that if the cancer appears on the surface of the liver only, and not inside the liver, it is still considered stage III.

  • IVA:Cancer cells are found in the fluid around the lungs.
  • IVB:Cancer has spread to the inside of the spleen or liver, to other lymph nodes, and/or to other organs like the lungs, brain, or skin.


Grade is a way to describe the look of cancer cells when compared with healthy cells.

Grade 1:
Low-grade tumors

Cells look healthy and tend to have a better outlook.

Grade 2:
Intermediate-grade tumors

Cells look and act somewhere in between grade 1 and grade 3.

Grade 3:
High-grade tumors

Cells look less healthy and usually have a worse outlook.


Who can get ovarian cancer?

All women have some risk of developing ovarian cancer during their lifetime. This year alone, more than 22,000 women will learn that they have ovarian cancer. Certain women may have high risk factors, such as inherited mutations or a family history of ovarian cancer.

How is ovarian cancer diagnosed?

Ovarian cancer is difficult to diagnose. Screening tests, such as ultrasounds and computed tomography (CT) scans, show masses around the pelvis, which can suggest ovarian cancer. Removing part of the tumor for testing is the only way to officially diagnose ovarian cancer.

Early diagnosis can lead to better outcomes

Finding ovarian cancer before it spreads is critical—when found early, about 94% of women live longer than 5 years after diagnosis. While there are currently no effective screening tests for ovarian cancer, there are scientific studies in progress to help determine ways to detect ovarian cancer.

Ovarian cancer signs and symptoms

When ovarian cancer causes symptoms, they tend to be symptoms that are more commonly caused by other things, so early detection may be difficult.

Signs and symptoms can include:

Abdominal bloating or swelling

Pelvic pain or discomfort

Changes in bowel habits, such as constipation

A frequent need to urinate

Increased abdominal girth

Weight loss

Persistent indigestion, bloating, or nausea

Back pain

Trouble eating or feeling full quickly