The prognosis of ovarian cancer depends on the stage and factors such as the person’s age and general health.
This article will describe the stages of ovarian cancer, treatment options, and survival rates.
Doctors take a range of factors into account when determining the stage of cancer.
The stages of ovarian cancer range from 1–4, depending on the size of the tumor and how far it has spread throughout the body.
A gynecologic oncologist, an expert who specializes in cancer of the reproductive organs, typically performs this staging.
Both the International Federation of Gynecology and Obstetrics and the American Joint Committee on Cancer have developed ovarian cancer staging systems that are very similar.
Both take three factors into account when defining ovarian cancer stages:
- Tumor size: This involves assessing the size of the tumor and whether the cancer has spread beyond the ovaries and fallopian tubes.
- Lymph nodes: This involves checking whether there is cancer in nearby lymph nodes.
- Metastasis: This involves checking whether the cancer has spread to distant parts of the body, such as the lungs, liver, or bones.
Stage 1 cancer
Stage 1 ovarian cancer is in one or both ovaries or fallopian tubes. It has not spread to lymph nodes or distant areas of the body.
In some cases, the cancer develops on the surface of the ovary, or cancerous cells slough off and doctors detect them in abdominal or pelvic fluid.
Stage 1 cancer has three subcategories:
- If the cancer is in one ovary or fallopian tube, the subcategory is 1a.
- If it is in both ovaries or fallopian tubes, the subcategory is 1b.
The subcategory is 1c if the cancer is in one or both ovaries or fallopian tubes and any of the following are true:
- The tissue around the tumor has broken during surgery.
- The cancer is on the outside of an ovary or fallopian tube.
- Cancerous cells appear in pelvic or abdominal fluid.
Stage 2 cancer
Stage 2 ovarian cancer has spread to other pelvic organs, such as the bladder, uterus, rectum, or colon. It has not extended to lymph nodes or areas beyond the pelvis.
Stage 2 cancer has two subcategories:
- 2a: The cancer has extended to the uterus or fallopian tubes, but not to nearby lymph nodes or distant sites.
- 2b: The cancer has spread to nearby pelvic organs, such as the bladder or rectum, but not to nearby lymph nodes or distant sites.
Stage 3 cancer
Stage 3 ovarian cancer is in one or both ovaries or fallopian tubes or the lining of the abdominal cavity, which is called the peritoneum.
It has also spread to nearby pelvic organs and lymph nodes.
Stage 3 cancer has four subcategories:
- 3a1: The cancer has spread beyond the pelvis to the lymph nodes, possibly those near the peritoneum, but not to distant sites.
- 3a2: As above, and the cancer has spread to organs near the pelvis. Microscopic deposits of cancer are present in the abdominal lining.
- 3b: As above, and the deposits in the lining are now visible to the naked eye but smaller than 2 centimeters (cm).
- 3c: As above, but the deposits are larger than 2 cm.
Stage 4 cancer
Stage 4 ovarian cancer has spread to the fluid around the lungs or to the liver, bones, spleen, intestines, or more distant lymph nodes.
Stage 4 cancer has two subcategories:
- 4a: The cancer has spread to the fluid around the lungs, but nowhere else, beyond the abdomen.
- 4b: The cancer has spread to the liver, bones, spleen, intestines, or more distant lymph nodes.
How do doctors determine the stage of cancer?
A doctor may better understand the extent of the cancer’s spread during surgery.
Ovarian cancer staging is important because it helps guide cancer treatment and give a better understanding of the person’s prognosis.
A doctor may stage the cancer at two points:
- Preoperative, clinical staging: This involves using imaging to get an idea of metastasis and develop a preliminary treatment plan. This can be especially useful if a person cannot undergo surgery.
- Surgical staging: During surgery, the surgeon can confirm and better visualize the extent of the cancer’s spread.
To determine how far the cancer has spread, the doctor may take samples from the:
- nearby lymph nodes
- omentum, which is the layer of fatty tissue that covers organs in the abdomen
- peritoneum, the tissue that lines the inside of the abdomen
- ascites, which is a buildup of fluid in the abdomen
In the absence of ascites, doctors may perform peritoneal washing during surgery. This involves washing out the space inside the belly, called the peritoneal cavity.
Doctors may also use imaging tests to assess the size of tumors and whether the cancer has spread beyond its point of origin. Some examples of helpful tests include:
Outlook and survival rates for each stage
Survival rates for ovarian cancer depend on the stage of cancer, among other factors.
The National Cancer Institute’s Surveillance, Epidemiology, and End Results Program (SEER) estimate that there will be 22,530 new cases of ovarian cancer in 2019 in the United States. This would represent 1.3% of all new cancer cases.
SEER also report that 13,980 people will die from ovarian cancer in the country throughout the year, accounting for 2.3% of all deaths from cancer.
Overall, 47.6% of people survive for 5 years after an ovarian cancer diagnosis, based on data from 2009–2015. However, the stage at diagnosis is key.
SEER also tracks ovarian cancer survival based on how far the cancer has spread by diagnosis. It uses three classifications:
- Localized cancer is confined to the ovaries.
- Regional cancer has spread to nearby regions or lymph nodes.
- Distant cancer has spread far beyond the area of origin.
Below are the 5-year survival rates for ovarian cancer by classification:
Doctors classify 59% of ovarian cancer cases as distant at diagnosis.
Grade of cancer
The grade, as well as the stage, of cancer can help the doctor recommend the best course of treatment.
Cancer grade describes how much the cancer cells have mutated, or to what extent they resemble regular cells.
This measure is very important, as it can determine the speed at which the cancer is likely to grow or spread.
Below, we describe treatment options by stage, but bear in mind that the grade of cancer is also a key factor in treatment.
Treatment options at each stage
The treatment for ovarian cancer depends on several factors, including the stage, type, and grade of the cancer, as well as the person’s preferences and general health.
The primary treatment for stage 1 ovarian cancer is surgery to remove the tumor. In many cases, the surgeon removes the ovaries, fallopian tubes, and uterus.
A person may need additional treatment if, after assessing the tumor in a lab, the medical team finds a high grade of cancer. In this case, the doctor may recommend chemotherapy.
A person’s doctor can recommend the best course of treatment.
Treatment typically starts with surgery to remove the:
- fallopian tubes
In order to remove all of the cancer, the surgeon may also need to remove pieces of other organs, such as the intestines or liver.
After surgery, the person will receive chemotherapy. Doctors will monitor the person’s progress with blood testing and imaging.
If the cancer is very advanced, the doctor may recommend neoadjuvant chemotherapy before surgery. This is a recent strategy.
The name “neoadjuvant chemotherapy” simply refers to chemotherapy that doctors administer before surgery, and the purpose is to shrink the tumor. Removing a smaller tumor involves less extensive surgery and less risk.
However, depending on individual factors, the risk of surgery may outweigh the benefits, and doctors may recommend nonsurgical options.
For example, when cancer is stage 4, the person and their doctor may choose palliative treatments, which aim to relieve symptoms and provide comfort.
Ovarian cancer is often difficult to detect in its early stages. The best course of treatment and the prognosis depend on the stage, type, and grade of the cancer at diagnosis.
It is important to remember that survival rates are only estimates. The prognosis depends on factors specific to each person.
The doctor can provide specific information about prognosis and treatment options.