Ovarian cancer is a disease in which normal cells in the ovaries grow rapidly and abnormally, producing tumors.
A woman has two almond-sized ovaries on each side of her uterus. Ovaries produce eggs and the female hormones estrogen and progesterone. Once a month, a single egg is released into a fallopian tube and waits to be fertilized. Cancer occurs when the cells in the ovaries begin to grow abnormally, usually forming a mass.
Cancer can start in an ovary and be contained there. It can also spread to adjacent tissues and even other parts of the body, including the lungs or the liver. When this happens, the cancer is said to metastasize.
Most ovarian cancers (90 percent) begin in the surface or epithelium of an ovary and are called epithelial cell tumors. This type of cancer is found in women who have gone through menopause . Some of these cancers (about 15 percent) are low malignant potential tumors that usually occur in younger women. They are often found early and therefore have good outcomes. Germ cell tumors, those that develop in the egg cells, are rare, comprising about 5 percent of all ovarian cancers and occur in young women and adolescent girls.
Primary peritoneal carcinoma is a related cancer that begins first in the lining of the abdominal cavity or peritoneum. It is linked with ovarian cancer because the cells of the peritoneum and the ovaries are similar, sharing a common embryonic origin.
Though ovarian cancer does occur in young women, it is most often found in women in their 50s. Ovarian cancer is the fifth leading cause of cancer-related death among American women. It has the highest mortality of all female reproductive cancers. White women and those of Ashkenazi (Eastern European) Jewish heritage have higher incidence and mortality rates than women in other ethnic groups. In 2008, the National Cancer Institute estimated nearly 22,000 new cases of ovarian cancer in the United States during that year and over 15,000 deaths.
Causes and symptoms
No known cause has been found for ovarian cancer. However, there are several factors that point to increased risk for the disease. One of the primary factors is age, since there is more incidence of ovarian cancer among menopausal women. A woman's risk increases with age, through a woman's late 70s.
Another important risk factor is having a family history of reproductive cancers. If a woman has a first degree relative (mother, sister, or daughter) who has had cancer of the ovary, breast, uterus, or even colon cancer , she is at risk. If the woman has a second degree relative (grandmother or aunt) with any of these cancers, her risk is still high but not as much as the woman with a first-degree relative.
Women who have never been pregnant, who had their first child after age 30, or who never breastfed their children are at higher risk. Those who have used fertility drugs for a long period of time without becoming pregnant are also at high risk for ovarian cancer.
Women who take hormone replacement therapy with estrogen and progestin for menopause symptoms are at a much higher risk for ovarian cancer than those who do not. A 2006 study revealed that there was a very high risk for the women who take these hormones for five or more years.
Ovarian cancer was once considered to be a silent disease with no symptoms. However, recent surveys of women with this disease have shown that they had presented with symptoms, but their cancer was not investigated by their doctors. One reason is that those early symptoms are often vague and resemble many digestive and urinary disturbances. Early symptoms often are abdominal discomfort such as gas, indigestion, cramps, bloating, and frequent urination. Often this is mistaken for irritable bowel syndrome , a reaction to a disagreeable food, or bladder problems.
Symptoms of advanced ovarian cancer include having a swollen abdomen due to the build up of fluids produced by the tumor, lower leg pain , abdominal pain, changes in bowel or bladder function, swelling in the legs, sudden weight gain or weight loss , painful intercourse, and abnormal vaginal bleeding after menopause. In later stages, the patient may have loss of appetite, swelling in the abdomen, lack of appetite, nausea, fatigue, and pelvic or back pain.
Unfortunately, ovarian cancer is hard to detect. Only about 20 percent of ovarian cancers are found before the cancer has spread to adjacent tissues. In most cases, it is found when the cancer is already in an advanced stage or has metastasized. Diagnosis, for most women, takes about three months, though some women have reported it taking six months or longer. This is of concern because the longer the delay of treatment the more pessimistic the outcome.
A pelvic exam is often done to check for masses within the lower abdomen and pelvis. Early stage ovarian cancers may be too small to be felt. That is why many doctors who suspect ovarian cancer or even benign cysts (non-cancerous tumors) order an ultrasonograph, also called an ultrasound. This test uses sound waves to image the organs within the abdomen. Sometimes masses can be found and measured. For greater detail, many doctors then order a computerized tomography scan, commonly called a CT or CAT scan. For this test, the patient is injected with a dye that allows the organs to be read better by the CT scanner. Some doctors will test the patient's blood for a chemical called cancer antigen-125 (CA-125).
In some cases, the doctor may order a biopsy, a small sample of tissue from the suspicious mass. The sample is taken laparoscopically. A laparoscope (a viewing tube with a camera attached to its end) and surgical instruments are inserted through the abdominal wall through small incisions. A slice of tissue is taken for examination under a microscope. Samples of nearby lymph nodes may also be taken. Some physicians may want to remove the affected ovary surgically and then examine samples from it under a microscope. This may mean that the surgeon may have to do another operation in order to remove any other cancer cells that may have spread to other tissues.
Stages of ovarian cancer
There are four stages of this type of cancer. Staging is done after surgical evaluation of the disease has occurred.
- Stage I is the earliest stage. Here the cancer is confined to one ovary or possibly to both.
- Stage II is when the cancer has begun to spread to other locations in the pelvic area, including the uterus or fallopian tubes.
- Stage III is more serious. The cancer has now spread to the peritoneum, the lining of the abdomen or to more lymph nodes in the vicinity of the initial cancer. This is the stage that most ovarian cancers are first diagnosed.
- Stage IV is when the cancer has metastasized beyond the abdomen into other regions of the body, such as the lungs or liver.
How ovarian cancer is treated depends on the type of cancer it is, the size of the tumor, and the stage of the disease. Surgery is usually the first line of treatment. The surgeon tries to remove the entire tumor. Lymph glands and surrounding tissue may also be removed if the cancer has invaded those areas. Often, both ovaries, the uterus, the fallopian tubes, and any adjacent lymph nodes are removed at the same time. If the woman is still in her childbearing years and the cancer seems to be contained in one ovary, the doctor may chose to remove only the affected ovary. This would allow the woman to bear a child if she chose to do so.
Sometimes, the surgeon does a procedure called surgical debulking. This removes as much of the cancer as possible, leaving less than 1 cubic centimeter of tumor tissue in the abdomen. When this is done, other treatment options need to be started in order to attack the remaining cancerous tissue.
Some cancer specialists will recommend chemotheraphy and/or radiation once surgery is done, even if all of the cancer seems to have been removed. Drugs used to treat cancer cells are powerful, indiscriminant chemicals that attack healthy cells as well as cancerous ones. Usually, two drugs are used together, carboplatin (Paraplatin) and paclitaxel (Taxol). This combination reduces tumors in 80 percent of the cases of ovarian cancer where it is used.
These drugs can be injected into a vein, taken by mouth in pill form, or introduced directed into the abdomen by a catheter (intraperitoneal chemotherapy ). Sometimes intravenous and intraperitoneal chemotherapy are used in combination. Women who have intraperitoneal chemotherapy can live a year longer than women who just have the cancer drugs injected into a vein.
Radiation treatments involve using x rays or gamma rays to kill cancer cells. The tumor area is targeted very carefully so only a small area is under attack. However, the radiation does penetrate healthy tissue to get to the cancer and therefore can suffer damage.
Both radiation and chemotherapy have unpleasant side effects. Both cause nausea and vomiting, diarrhea , loss of appetite, weight loss, fatigue, and hair loss. There is abdominal pain and the risk of infection with intraperitoneal chemotherapy.
Mind/body techniques have proven helpful in cancer treatment since Dr. Michael Samuel's work with visualization in the 1960s where children were taught to meditate on images, such as bullets or arrows, destroying cancer cells. That kind of positive mindset has helped many cancer patients endure treatment and keep up a fighting spirit. Visualization is still a viable alternative tool to use with conventional cancer treatment. Equally, meditation, guided imagery, prayer , therapeutic touch, energy work such as Reiki, and massage have been helpful in coping with cancer. Gentle movement activities such as yoga and t'ai chi are also stress relieving and keep the patient active.
Other treatments such as vitamins , herbal supplements, and Chinese herbal medicines can be tried. These treatments, however, should be discussed with the patient's doctor because some of these ingredients may interfere with medications that the patient is taking.
It is very important to eat a balanced diet during cancer treatment and recovery. Though chemotherapy often produces nausea and vomiting, it is crucial that women with ovarian cancer continue to eat nutritious meals. Good nutrition can help women cope with the side effects of cancer treatments and may help boost their immune systems and keep them active. Also, eating protein-rich foods help build and repair tissues of the body.
Chemotherapy can make food taste unpleasant or bland. Women undergoing treatment may also find that their attitudes about food may change. One day, something might not taste good, but it might be delicious a few days later. Women should keep food available, especially fruit and protein foods, and eat smaller amounts more frequently. They should also pack each bite with more calories. For example, putting chopped nuts over a salad or a serving of a casserole can add nutrients and calories into even small bites of food.
Obviously, the earlier the cancer is found and treated, the better the chances for long-term survival. If ovarian cancer is found early, there is a 90 percent chance of achieving a 5-year survival rate. The rate of survival drops for more advanced ovarian cancer.
Women who have had ovarian cancer may also be at risk for contracting colon or breast cancer . Because it can compromise the immune system , chemotherapy also raises the risk of developing other types of cancers such as leukemia.
There is no way to prevent this disease. However, women can increase their chances of early detection by having yearly pelvic exams, reporting unusual vaginal bleeding or abdominal pain, eating a low-fat diet , and not using talcum powder near the vaginal area. Some women with a strong family history of reproductive cancers might consider genetic counseling and testing to see whether they have mutations in the BRCA1 and BRCA2 genes. If they do, they may wish to discuss having their ovaries removed. This is called prophylactic oophorectomy. Women with the gene mutations and who have their fallopian tubes and ovaries removed lower their risk of having ovarian cancer by 80 percent. Premenopausal women who have their ovaries removed deduce their risk by 95 percent and their risk of having breast cancer by 50 percent.
WHEN TO SEE THE DOCTOR
If a woman has symptoms, she should see the doctor. If the woman has a history of reproductive cancers in her family, she may want to consult a gynecologic oncologist, a specialist in female reproductive cancers, while she is disease free, to discuss her options about screening and treatment options that she might need in the future.
Early detection may still be the ultimate answer for many women. Until recently, there had been no screening test available. Some doctors used the CA-125 assay to screen some women, but it was highly unreliable because it often did not detect early cancers. CA-124 had been used mainly in more advanced cases to determine how well treatment was going and to check for recurrence. Fujirebio Diagnostics in 2008 announced its new HE4 test that is being used in Europe. HE4 can be elevated in women with epithelial ovarian cancers. The HE4 test is used with the CA-125 test to estimate a woman's risk of epithelial ovarian cancer when she presents with a suspicious pelvic mass. The combination of the two tests is an accurate predictor of Stage I ovarian cancer and may prove to be a very useful screening tool.
Until the HE4/CA-125 combination test or another screening test is approved in the US, doctors should pay close attention to any abdominal symptoms in women who have a family history of reproductive cancers. A warning sign should be when a woman reports persistent symptoms or she says they are getting worse. Ordering a simple ultrasound image could save a woman's life by detecting ovarian cancer early.
Benign cysts —Non-cancerous tumors.
Biopsy —A small sample of tissue taken for microscopic analysis.
Ovaries —Small organs beside the uterus that produce eggs and the female hormones estrogen and progesterone.
Gynecologic oncologist —A physician who specializes in the treatment of female reproductive cancers.
Intraperitoneal chemotherapy —Treatment performed by injecting anti-cancer drugs directed into the abdomen by a catheter.
Intravenous chemotherapy —Treatment performed by injecting anti-cancer drugs into a patient's veins.
Laparoscope —A viewing tube with a camera attached to its end that is inserted through the abdominal wall through small incisions.
Metastasize —To spread cancer cells to adjacent tissues or other parts of the body.
Peritoneum —The lining of the abdominal cavity.
Prophylactic oophorectomy —An operation that removes healthy ovaries in order to prevent disease.
Doctors should also be sensitive to the emotional life of the woman who has to cope with ovarian cancer. If the woman is still in her child-bearing years, besides dealing with a life-threatening illness, the woman may also be dealing with the loss of her capability to have a child. Physicians should help the patient find as much information about the disease as she wishes to have, as well as a support group or a therapist who can help her with the emotional turmoil this disease can produce.
“A snapshot of ovarian cancer.” National Cancer Institute report. (December 2007): 1–2
Carter, Ann and Cooper, Phyllis G. “Cancer of the ovary (Senior Health Advisor 2007).” Clinical Reference Systems. (May 31, 2007): NA
“New ovarian cancer test now available in Europe.” Business Wire. (March 4, 2008): NA “Ovarian cancer.” CareNotes. (February 1, 2008): NA
“Ovarian cancer.” www.mayoclinic.com/health/ovariancancer/DS00293
American Cancer Society, 800-227-2345, www.cancer.org.
Women's Cancer Network, 401 N. Michigan Ave., Chicago, IL, 60611, 312-644-6610, www.wcn.org.
Janie F. Franz