About Ovarian Cancer
The ovaries are a pair of almond-shaped organs located in the pelvis on either side of the uterus. They are about 1-1/2 inches long in a young woman, but they shrink to about half their original size after menopause. The function of the ovaries is to produce eggs and female sex hormones; they also regulate the menstrual cycle and pregnancy.
A cancerous tumor that originates in the ovaries is called ovarian cancer. There are many different forms of this cancer, but most types begin in the cells that make up the outer lining of the ovary. These are called epithelial ovarian cancers.
In recent years, research has identified many of the risk factors associated with ovarian cancer. Significant progress has also been made in the treatment of the disease. Although these advances have not yet had a dramatic impact on the cure rate for advanced ovarian cancer, they are helping patients to live longer.
Each year, approximately 25,500 women are diagnosed with ovarian cancer, and 14,500 die of the disease.
Why is ovarian cancer so deadly?
Ovarian cancer accounts for more deaths in the United States than any other gynecologic cancer. Hidden symptoms and a lack of reliable earlydetection tests are to blame. Over 70 percent of all women with ovarian cancer are not diagnosed until the disease has spread beyond the ovary. At this stage, the likelihood of living for five years after diagnosis is between 20 percent and 25 percent. By contrast, at least 90 percent of women who are fortunate enough to have their cancer diagnosed and treated early, when the cancer is still confined to one or both ovaries, will survive for five years or more.
Is ovarian cancer hereditary?
About 5-10 percent of ovarian cancer cases are related to inherited factors. Concern about family history and genetic predisposition to ovarian and breast cancers has been heightened by the recent identification of BRCA1 and BRCA2, the breast-cancer susceptibility genes. Normally, BRCA genes help to prevent cancer, but if a woman inherits a mutated (defective) form, her ovaries and breasts are more susceptible to cancer. In fact, depending on the mutation, women who carry a defective BRCA gene have a lifetime risk of ovarian cancer of about 20 percent. This is dramatically higher than the average woman’s lifetime risk, which is 1.8 percent (about one in 57 women). In addition, ovarian cancer occurs an average of 20 years earlier in BRCA gene-mutation carriers compared to non-carriers.
A woman with two first-degree relatives (a mother, sister or daughter) with breast or ovarian cancer may wish to consult a genetic counselor about testing for the BRCA mutations. Women who test positive for a mutation should consider the various preventive measures available [see question below, “Can I do anything to prevent ovarian cancer?”]. Bear in mind that having only one first-degree relative with ovarian cancer makes the likelihood of carrying a BRCA gene mutation very low. However, ovarian cancer in one first-degree relative does raise a woman’s lifetime risk of the disease from
1.8 percent to about 5 percent.
What are the risk factors associated with ovarian cancer?
The specific causes of ovarian cancer are not known. But every woman who has intact ovaries is at risk for ovarian cancer. The individual level of risk depends on a woman’s family history [see question above,“Is ovarian cancer hereditary?”], age and reproductive history.
Risk increases with age. Ovarian cancer is most common in postmenopausal women, occurring at an average age of 61 years.
Other risk factors include:
- a personal history of breast, uterine, or colon cancer;
- a family history of ovarian, breast, or colon cancer, especially in a mother, sister, or daughter;
- early age at first menstruation (before age 12);
- late age at menopause (after age 52);
- never having children or not having children until late in life (after age 35);
- use of talcum powder in the genital area. (Cornstarch powder is a safe alternative.)
Anything that suppresses ovulation in the premenopausal years reduces ovarian-cancer risk. For example, having more than one full-term pregnancy, breast-feeding, use of oral contraceptives, tubal ligation, and removal of the ovaries all lower a woman’s risk.
Can I do anything to prevent ovarian cancer?
Unfortunately, specific dietary strategies for staving off ovarian cancer have not been proven in research studies. However, healthful living has been linked to a reduction in the risk of all cancers in general. Exercising regularly, eating a diet high in fruits, vegetables, and grains, and not smoking are all protective behaviors. For ovarian cancer specifically, avoiding the use of talcum-based powders in the genital area is also a good idea.
For women considered at particularly high risk – women with two firstdegree relatives with ovarian cancer and women who carry a BRCA gene mutation – some experts recommend regular ultrasonography and CA-125 screening tests, although many early-stage cancers may still be missed. [See question below,“ What diagnostic tests are used to identify ovarian cancer?”]
High-risk premenopausal women should consider taking oral contraceptives. Studies show that the risk of ovarian cancer is reduced by 50 percent in women who take birth-control pills for five years, and by 75 percent in women who take birth-control pills for 10 years or more. For high-risk perimenopausal and postmenopausal women, gynecologists generally recommend preventive removal of the ovaries, called prophylactic oophorectomy (pronounced oh-uh-fuh-REK-tuh-mee). In most cases, high-risk women can safely delay oophorectomy until about age 40, to allow completion of childbearing, because the incidence of ovarian cancer is lower before that age. A high-risk menopausal woman who needs to have abdominal surgery for any reason, even non-gynecological surgery, should discuss prophylactic removal of the ovaries with her surgeon.
What are the symptoms of ovarian cancer?
When an ovarian tumor develops and grows, it takes up extra space in the abdominal cavity, potentially causing vague feelings of bloating or discomfort. These symptoms can easily be attributed to gastrointestinal problems, menstrual changes, weight gain or other minor conditions. This is why ovarian cancer has earned its reputation as a “silent” disease – the symptoms are so mild and ambiguous that they are easily ignored.
If any of the following symptoms persists for more than a few weeks, it could be an early sign of ovarian cancer:
- Feelings of abdominal bloating or swelling;
- General discomfort in the pelvic area;
- Loss of appetite or feelings of fullness, even after a light meal;
- Gastrointestinal symptoms, such as gas, indigestion and nausea;
- Change in bowel movements and urination;
- Abnormal vaginal bleeding;
- Pain during sexual intercourse;
- Unusual fatigue.
See your doctor to investigate the cause of any persistent symptoms.
What diagnostic tests are used to identify ovarian cancer?
To investigate the cause of any symptoms, the first step is a pelvic examination, in which the doctor feels the ovaries, fallopian tubes, uterus, vagina, rectum, bladder and lower abdomen for any growths. Tests for gastrointestinal problems may be ordered next, but two specific tests for ovarian cancer should also be performed.
The first test is a transvaginal pelvic ultrasound, in which high-frequency sound waves are used to produce computer images of the vagina, uterus, ovaries, fallopian tubes and bladder. Ultrasound can often differentiate between malignant (cancerous) tumors and benign (noncancerous) growths, such as ovarian cysts.
The second test is a CA-125 blood test.CA-125 is a tumor marker – a substance often found to be at elevated levels in the blood when cancer is present in the body. Although an increased level of CA-125 frequently indicates cancer, the test is not precise.CA-125 levels may also be high in women who have benign ovarian conditions and in women who are ovulating.What’s more, not all women with ovarian cancer have elevated CA-125. Increased levels are present only in about 80 percent of women with advanced ovarian cancer and 50 percent of women with early-stage disease.
Results of these two tests suggest whether ovarian cancer is likely to be present, but neither test is accurate enough to make a definitive diagnosis. Only surgery to explore the ovaries and other organs in the abdomen can tell for sure if ovarian cancer is present. Of the women who undergo exploratory surgery for ovarian cancer, less than 20 percent are diagnosed with the disease.
What are the stages of ovarian cancer?
The initial surgery used to diagnose ovarian cancer also involves staging. Examination of the fluid and tissue samples removed during surgery (biopsy samples) indicates the type of cancer cells present and how far the cancer has spread. Staging determines whether more extensive surgery or other treatments may be needed.
The four basic stages of ovarian cancer are:
Stage I: Cancer growth is limited to one or both ovaries.
Stage II: Cancer has spread beyond the ovary, but is limited to the pelvic cavity (uterus, fallopian tubes or other structures in the pelvis).
Stage III: Cancer is found in one or both ovaries, in the pelvis and also in the abdominal cavity and/or nearby lymph nodes.
Stage IV: Cancer has spread outside the ovary and abdomen (called distant metastases) or to the liver.
How is ovarian cancer treated?
As with all cancers, treatment depends on the stage of the disease and the patient’s overall health. There are two main treatment approaches.
Surgery to remove the cancerous growth(s) is the primary method of treatment and is performed at the same time as the initial, diagnostic surgery. Both ovaries, the fallopian tubes, the uterus and the cervix are usually removed. The surgeon may also remove the omentum, a thin layer of fatty tissue covering the stomach and large intestine.
If cancer is found at an early stage in a young woman, fertility-sparing treatment, in which only the affected ovary is removed, is sometimes possible.
Most ovarian cancers have reached Stage III by the time they are detected, but the chances of longer survival with good quality of life have greatly improved, thanks to recent advances in chemotherapy. Chemotherapy is used immediately following surgery to kill any cancer cells that may remain in the body. Research completed in only the past few years has shown that a six-week treatment course of a two-drug combination of paclitaxel (Taxol) and intravenous platinum [carboplatin (Paraplatin) or cisplatin (Platinol)] is the most effective initial therapy.
Other chemotherapy drugs and varying drug combinations are used to treat cancers that are resistant to standard chemotherapy as well as any cancer recurrences. Radiation therapy is not routinely used but may help to relieve pain in late-stage ovarian cancer.
Recent research has reported promising results for several new treatment drugs, particularly doxorubicin (Doxil), topotecan (Hycamtin), and gemcitabine (Gemzar). Clinical trials of these drugs and others, including trastuzumab (Herceptin), the first of a new class of drugs known as monoclonal antibodies, vaccines, and hormonal agents such as tamoxifen (Nolvadex), are now under way.