What is it?
Cancer of the ovaries is the sixth most common cancer in women. About 7,000 new cases are diagnosed in the UK each year. It is a more frequent cause of death than the more common, but more easily detected, cancers of the uterus and cervix.
Women have two ovaries, located in the lower abdomen above and to either side of the uterus. About the size of apricots, the ovaries are connected to the uterus by fallopian tubes. Ovaries have two main functions. They produce oestrogen and progesterone, hormones which are responsible for the development of the features that distinguish women from men, their secondary sexual characteristics. The ovaries also regulate women’s periods and the development and release of an egg into the fallopian tube once a month during childbearing years.
Ovarian tumours can be either benign or malignant; it is not usually possible to tell them apart until they have been removed unless they have spread to other parts of the body. About 85% of ovarian tumours begin in the cells covering the outside of the ovaries, but they may also arise in the egg-producing cells (germ cells) or more rarely in the tissue that produces oestrogen and progesterone and holds each ovary together. While benign tumours do not spread, cancerous ovarian tumours will do so if left unchecked. They spread first into the tissues around the ovaries, then to the uterus, bladder, rectum, and the lining of the abdomen. Eventually, cancerous cells will reach the lymph nodes and spread throughout the body and invading and damaging other organs, such as the lungs.
The main risk factors for ovarian cancer are increasing age (ovarian cancers are rare before 45 and most occur between 65 and 74) and a family history of ovarian and/or breast cancer. However, less than 10% of ovarian cancer appears to have a family link. Slightly increased risks may be associated with not having children, taking fertility drugs, and with hormone replacement therapy. Slightly decreased risks are associated with having your tubes “tied” (tubal ligation), taking oral contraceptives, having children, and breast feeding.
It is difficult to detect ovarian cancer early – only about 25% of the cancers are found in the easily treatable stage, before they have spread beyond the ovaries. The symptoms of ovarian cancer are subtle and nonspecific. They include abdominal swelling and pain, indigestion, changes in passing urine and bowel habits, bloating and a feeling of pressure in the pelvis, weight changes, and unexplained vaginal bleeding. Since there are many non-cancerous conditions that can also cause these symptoms, it is important to consult your doctor if you are experiencing any symptoms.
At the moment there is no screening test that is accurate and reliable enough to pick up ovarian cancer at an early stage. Before screening for any type of cancer can be carried out, doctors must have an accurate test to use. The test must be reliable in picking up cancers and it must not give false positive results in people who do not have cancer. There is currently a lot of research looking into developing better methods for early detection amongst women without apparent symptoms In the meantime, it is important that women are aware of the symptoms of ovarian cancer.
Testing of symptomatic women includes:
- CA 125 (Cancer antigen 125) measures a protein in the blood that is high in about 80% of those ovarian cancers that are derived from the surface cells. It may be used in with pelvic examination and a transvaginal and/or pelvic ultrasound to help diagnose ovarian cancer. CA 125 however, it is not specific enough to be used as a general screening test: increases in CA 125 levels are present in other cancers, in hepatitis, pelvic inflammatory disease, and endometriosis as well as in early pregnancy and menstruation. It is mainly used as a tumour marker to monitor ovarian cancer treatment and to help detect early recurrence of cancer.
- AFP (Alpha fetoprotein) and hCG (human chorionic gonadotrophin) levels are increased in some ovarian cancers derived from the germ cells, but they are also elevated during pregnancy. If AFP or hCG are increased in a case of ovarian cancer, the tests can be used to monitor treatment and to detect recurrence of cancer.
- BRCA-1 and BRCA-2 are tests for two genetic mutations that have been associated with an increased risk of ovarian and breast cancer. These tests are usually done to screen and/or help diagnose a patient who has a strong family history of breast or ovarian cancer.
Other non-laboratory tests that are used to look for other abnormalities include:
- Ultrasound (pelvic and/or transvaginal) uses sound waves to create a picture of the uterus and ovaries. It can help determine whether an ovarian growth is likely to be a cancer or a fluid-filled cyst.
- CT scan (computerized tomography)
- X-ray of the gastrointestinal tract
When abnormalities are found and ovarian cancer is suspected, surgery is required to confirm the diagnosis. This may be done by or in consultation with a doctor who specializes in cancers of the female reproductive organs, a gynaecologic oncologist. If cancer is found, the grade (how normal or abnormal cells appear under the microscope) and stage (how far the cancer has spread) will be determined and appropriate treatment decided. If cancer is visible during surgery, the ovary containing it is usually removed along with as much as possible of any tumour that has spread beyond the ovaries. It may also be necessary to remove the other ovary, the fallopian tubes, and the uterus.
Follow-up treatment usually involves chemotherapy, sometimes radiation treatments, and some doctors use CA 125, AFP, or hCG to monitor response to treatment and recurrence. Ovarian cancer treatment is constantly evolving. New chemotherapy drugs and biological therapies are being studied for their effectiveness. Your doctor and/or cancer team can help you determine the treatment course that is right for you.