After the diagnosis of ovarian cancer, doctors determine the stage of cancer to formulate a treatment plan. It helps them understand how  far cancer has spread. If cancer is detected at an early stage, it can be treated successfully. Read on to learn about the different stages of ovarian cancer. 

Stages of ovarian cancer

The stages of ovarian cancer are usually determined using the FIGO (International Federation of Gynaecology and Obstetrics) staging system. Under this system, tests are conducted to measure:

• The size and location of the tumor.
• Whether the tumor has invaded the tissues in and around the ovaries.
• Whether cancer has spread to distant areas of the body (metastasis).

These three factors determine the cancer stage that ranges from Stage 1 to Stage 4, and each stage is divided into sub-stages A, B, and C, except Stage 4. The lower the stage, the lesser is the spread of cancer, whereas higher stages mean that cancer has spread to other organs.

Stage I:

Stage I means the cancer is confined to the ovaries and has not spread.

Stage IA – There is cancer is one ovary

Stage IB – Both the ovaries have cancer

Stage IC – Cancer is in one or both ovaries, and one of the following are also found:

• Cancer is found on the outer surface of one or both ovaries
• The capsule of the ovary has ruptured
• Cancer cells are found in the peritoneal cavity or in fluid washings from the abdomen

Stage II:

In this stage, cancer cells are in either one or both ovaries and has also spread elsewhere into the pelvis.

Stage IIA – Cancer has now reached the Fallopian tubes, the uterus, or both

Stage IIB- Cancer has reached other organs within the pelvis such as the bladder, colon, or rectum

Stage III:

In Stage 3, cancer is either in one or both ovaries and is in the lining of the abdomen and the lymph nodes.

Stage IIIA – Cancer has migrated to the other pelvic organs and to the lymph nodes

Stage IIIB – Cancer inside the peritoneum is 2 centimetres or smaller. It is also found on the outside of the spleen, liver, or in the lymph nodes.

Stage IIIC – Cancer has grown to 2 centimetres or more, and is also found outside the pelvis. It is also on the outside of the spleen, liver, or in the lymph nodes.

Stage IV:

Of all the stages of ovarian cancer, the most advanced is Stage 4, as it is difficult to treat. In this stage, cancer has spread beyond the abdomen to other distant organs such as lungs or tissues inside the liver. Cancer cells present in the fluid around the lungs are also considered as Stage IV ovarian cancer.

The treatment plan for different stages of ovarian cancer differs as per complexities. Usually, the treatment involves surgery to remove the tumor and chemotherapy.