Ovarian cancer is cancer of the ovaries. It is related to fallopian tube cancer, which develops in the tubes that lead from the ovaries to the uterus, and peritoneal cancer, which is cancer of the tissues that line the abdomen. These cancers are usually diagnosed at an advanced stage.
Ovarian cancer may not cause symptoms until it has spread.
If doctors suspect ovarian cancer, blood tests, ultrasonography, and magnetic resonance imaging or computed tomography are done.
Usually, both ovaries, both fallopian tubes, and the uterus are removed.
Chemotherapy is often needed after surgery.
(See also Overview of Female Reproductive System Cancers.)
Cancer of the ovaries (ovarian carcinoma) develops most often in women aged 50 to 70 years. In the United States, ovarian cancer is the second most common gynecologic cancer, developing in approximately 1 of 70 women. It is the fifth most common cause of cancer deaths in women and, in the United States, will cause an estimated 19,710 new cases and 13,270 deaths in 2023.
Because cancer of the ovaries and fallopian tubes share many features (symptoms, diagnosis, and treatment), they are usually considered together. Cancer that starts in the fallopian tubes is rare.
Locating the Internal Female Reproductive Organs
There are many types of ovarian cancer. They develop from the many different types of cells in the ovaries. Cancers that start on the surface of the ovaries (epithelial carcinomas) account for more that 90%. Most other ovarian cancers start from the cells that produce eggs (called germ cell tumors) or in connective tissue (called stromal cell tumors). Germ cell tumors usually occur in women younger than 30.
Sometimes cancers from other parts of the body spread to the ovaries.
Ovarian cancer can spread as follows:
Directly to the surrounding area
Through the shedding of cancer cells into the abdominal cavity
Through the lymphatic system to other parts of the pelvis and abdomen
Less often, through the bloodstream, eventually appearing in distant parts of the body, mainly the liver and lungs
Risk Factors for Ovarian Cancer
Factors that increase the risk of ovarian cancer include the following:
Being older (the most important)
Having a first-degree relative (mother, sister, or daughter) who has had ovarian cancer
Not having any children
Having a first child late in life
Starting menstruating early
Having menopause late
Having had cancer of the uterus, breast, or large intestine (colon) or having a family member who has had one of these cancers
Use of oral contraceptives significantly decreases risk.
Approximately 15% of cases of ovarian cancer are related to mutations in the BRCA1 and BRCA2 genes, which are also involved in some breast cancers. When mutations in these genes or other rare gene mutations are involved, ovarian and breast cancers tend to run in families. Such cancers are sometimes called hereditary breast and ovarian cancer syndromes. For women who have a BRCA1 mutation, the lifetime risk of developing ovarian cancer is 20 to 40%. Risk is increased less for women with a BRCA2 mutation. The BRCA1 and BRCA2 genes are more common among Ashkenazi Jewish women than the general population.
Symptoms of Ovarian Cancer
Ovarian cancer causes the affected ovary to enlarge. In young women, enlargement of an ovary is likely to be caused by a noncancerous fluid-filled sac (ovarian cyst). However, after menopause, an enlarged ovary can be a sign of ovarian cancer.
Many women have no symptoms until the cancer is advanced. When symptoms are present, they are general. They include abdominal discomfort, bloating, loss of appetite, an early sense of fullness, a change in bowel habits, and frequent urination.
Eventually, the abdomen may swell because the ovary enlarges or fluid accumulates in the abdomen (called ascites). At this stage, pain in the pelvic area, anemia, and weight loss are common.
Rarely, germ cell or stromal cell tumors produce estrogens, which can cause tissue in the uterine lining to grow excessively and breasts to enlarge. Or these tumors may produce male hormones (androgens), which can cause body hair to grow excessively, or hormones that resemble thyroid hormones, which can cause symptoms of an overactive thyroid gland (hyperthyroidism).
Diagnosis of Ovarian Cancer
Ultrasonography
Sometimes computed tomography or magnetic resonance imaging
Blood tests
Diagnosing ovarian cancer in its early stages is difficult because symptoms usually do not appear until the cancer is quite large or has spread beyond the ovaries and because many less serious disorders cause similar symptoms.
If doctors detect an enlarged ovary during a physical examination or suspect early ovarian cancer based on symptoms, ultrasonography is done first. Sometimes computed tomography (CT) or magnetic resonance imaging (MRI) is used to help distinguish an ovarian cyst from a solid cancerous mass. If advanced cancer is suspected, CT or positive emission tomography (PET) is usually done before surgery to determine extent of the cancer.
If cancer seems unlikely, doctors re-examine the woman periodically.
If doctors suspect cancer or test results are unclear, blood tests are usually done to measure levels of substances that may indicate the presence of cancer (tumor markers), such as cancer antigen 125 (CA 125). Abnormal tumor marker levels alone do not confirm the diagnosis of cancer, but when combined with other information, they can support the diagnosis.
A biopsy is done to confirm the diagnosis of ovarian cancer and, if the diagnosis is confirmed, to determine the type of cancer. Doctors examine the ovaries and other organs in the abdomen and pelvis (to check for spread). This procedure is done in one of two ways:
Laparoscopy: Doctors usually use a thin, flexible viewing tube (laparoscope) inserted through a small incision just below the navel, particularly if they think the cancer is not advanced. They use instruments threaded through the laparoscope, sometimes with robotic assistance, to take samples from various other tissues and to examine the ovaries and other organs. The information thus obtained can help doctors determine whether and how far the cancer has spread (its stage). The ovaries can also be removed to treat ovarian cancer using laparoscopy.
Open surgery: If doctors think the cancer may be advanced, they make an incision in the abdomen and directly view the uterus and the tissues around it. They determine the cancer's stage and remove as much of the cancer as possible.
Doctors consider recommending genetic testing for any woman who is diagnosed with ovarian (or fallopian tube) cancer. Doctors also ask about any cancers family members have had. This information can help doctors identify women who are more likely to have a hereditary form of cancer, such as that caused by mutations in BRCA genes.
Staging of ovarian, fallopian tube, and peritoneal cancer
Surgery to stage ovarian and fallopian cancer includes removal of the uterus, ovaries, and fallopian tubes.
Stages are based on how far the cancer has spread. Stages range from I (the earliest) to IV (advanced):
Stage I: The cancer occurs only in one or both ovaries or fallopian tubes.
Stage II: The cancer has spread to the uterus or nearby tissues within the pelvis (which contains the internal reproductive organs, bladder, and rectum) or occurs only on the peritoneum.
Stage III: The cancer has spread outside the pelvis to lymph nodes and/or to other parts of the abdomen (such as the surface of the liver or spleen).
Stage IV: The cancer has spread to distant sites (for example, to the lung).
Treatment of Ovarian Cancer
Usually removal of ovaries, fallopian tubes, and uterus
Removal of all tissue that appears affected (cytoreductive surgery)
Usually chemotherapy
The extent of surgery depends on the type of ovarian and fallopian tube cancer and the stage.
When ovarian and fallopian tube cancers are first diagnosed, they have usually spread throughout the abdomen, so treatment typically involves one of the following:
Surgery to remove as much of the tumor as possible, followed by chemotherapy
Chemotherapy, followed by surgery and more chemotherapy
For most ovarian and fallopian tube cancers, treatment involves removing the ovaries and fallopian tubes (salpingo-oophorectomy) and the uterus (hysterectomy). Laparoscopic surgery or robotic-assisted laparoscopic surgery may be done first to determine whether more extensive surgery is a useful option. If it is not, chemotherapy is started.
When cancer has spread beyond the ovary, nearby lymph nodes and surrounding structures that the cancer typically spreads to are also removed. This approach aims to remove all visible cancer.
If a woman has stage I cancer that affects only one ovary and she wishes to become pregnant, doctors may remove only the affected ovary and fallopian tube.
For more advanced cancers that have spread to other parts of the body, doctors usually remove as much of the cancer as possible to prolong survival. This type of surgery is called cytoreductive surgery. However, depending on where the cancer has spread and how much cancer is present, women may be treated with chemotherapy instead of or before and after surgery.
After surgery, most women with less aggressive stage I epithelial carcinomas require no further treatment. For other stage I cancers or for more advanced cancers, chemotherapy may be used to destroy any small areas of cancer that may remain.
Most women with germ cell tumors can be cured with removal of the one affected ovary and fallopian tube plus a combination of two or more chemotherapy drugs. Radiation therapy is rarely used.
Advanced ovarian cancer usually recurs. So after chemotherapy, doctors typically measure levels of cancer markers (such as CA 125). Cancer marker levels that remain high usually mean that some of the tumor remains.
If the cancer recurs after chemotherapy appeared to be effective, chemotherapy is repeated. Many different chemotherapy drugs or combinations of drugs may be used.
Prognosis for Ovarian Cancer
The prognosis for women with ovarian cancer is based on the stage.
The prognosis is worse when the cancer is more aggressive or when surgery cannot remove all visibly abnormal tissue. Cancer recurs in approximately 70% of women who have had stage III or IV cancer.
Prevention of Ovarian Cancer
There is no screening test for ovarian or fallopian tube cancer. However, some experts believe that if ovarian or breast cancer runs in the family, women should be tested for genetic abnormalities. If first- or second-degree relatives have such cancers, particularly among Ashkenazi Jewish families, women should discuss genetic testing for BRCA abnormalities with their doctors.
Women with certain BRCA gene mutations may be offered the option of having both ovaries and fallopian tubes removed, even when no cancer is present. This approach eliminates the risk of ovarian cancer and reduces the risk of breast cancer.
Did You Know...
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More Information
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
Foundation for Women's Cancer: This web site provides links to information about gynecologic cancers, clinical trials (including finding a trial to participate in), and research. It also offers courses about cancer issues and shares personal stories of women's battle with cancer.
National Cancer Institute: Cancer: Ovarian, Fallopian Tube, and Primary Peritoneal Cancer: This web site provides links to general information about ovarian, fallopian tube, and primary peritoneal cancer, as well as links to information about causes, prevention, screening, treatment, and research and about coping with cancer.
National Cancer Institute: BRCA1 and BRCA2: Cancer Risk and Genetic Testing: This web site provides information about the BRCA genes, the benefits and possible harms of genetic testing, and the implications of having a BRCA mutation.
