The exact causes of ovarian cancer are
not known. However, studies show that the following factors may increase
the chance of developing this disease:
- Family history. First-degree relatives
(mother, daughter, sister) of a woman who has had ovarian cancer are
at increased risk of developing this type of cancer themselves. The
likelihood is especially high if two or more first-degree relatives
have had the disease. The risk is somewhat less, but still above
average, if other relatives (grandmother, aunt, cousin) have had
ovarian cancer. A family history of breast or colon cancer is also
associated with an increased risk of developing ovarian cancer.
- Age. The likelihood of developing ovarian
cancer increases as a woman gets older. Most ovarian cancers occur in
women over the age of 50, with the highest risk in women over 60.
- Childbearing. Women who have never had
children are more likely to develop ovarian cancer than women who have
had children. In fact, the more children a woman has had, the less
likely she is to develop ovarian cancer.
- Personal history. Women who have had breast or
colon cancer may have a greater chance of developing ovarian cancer
than women who have not had breast or colon cancer.
- Fertility drugs. Drugs that cause a
woman to ovulate may slightly increase a woman's chance of developing
ovarian cancer. Researchers are studying this possible association.
- Talc. Some studies suggest that women who have
used talc in the genital area for many years may be at increased risk
of developing ovarian cancer.
- Hormone replacement therapy (HRT). Some
evidence suggests that women who use HRT after menopause may
have a slightly increased risk of developing ovarian cancer.
About 1 in every 57 women in the United States
will develop ovarian cancer. Most cases occur in women over the
age of 50, but this disease can also affect younger women. |
As we learn more about what causes ovarian cancer, we
may also learn how to reduce the chance of getting this disease. Some
studies have shown that breast feeding and taking birth control pills
(oral contraceptives) may decrease a woman's likelihood of developing
ovarian cancer. These factors decrease the number of times a woman
ovulates, and studies suggest that reducing the number of ovulations
during a woman's lifetime may lower the risk of ovarian cancer.
Women who have had an operation that prevents pregnancy
(tubal ligation) or have had their uterus and cervix removed
(hysterectomy) also have a lower risk of developing ovarian cancer.
In addition, some evidence suggests that reducing the amount of fat in the
diet may lower the risk of developing ovarian cancer.
Women who are at high risk for ovarian cancer due to a
family history of the disease may consider having their ovaries removed
before cancer develops (prophylactic oophorectomy). This procedure
usually, but not always, protects women from developing ovarian cancer.
The risks associated with this surgery and its side effects should be
carefully considered. A woman should discuss the possible benefits and
risks with her doctor based on her unique situation.
Having one or more of the risk factors mentioned
here does not mean that a woman is sure to develop ovarian cancer, but the
chance may be higher than average. Women who are concerned about ovarian
cancer may want to talk with a doctor who specializes in treating women
with cancer: a gynecologist, a gynecologic oncologist, or a medical
oncologist. The doctor may be able to suggest ways to reduce the
likelihood of developing ovarian cancer and can plan an appropriate
schedule for checkups.
Detecting Ovarian Cancer
The sooner ovarian cancer is found and treated, the
better a woman's chance for recovery. But ovarian cancer is hard to detect
early. Many times, women with ovarian cancer have no symptoms or just mild
symptoms until the disease is in an advanced stage. Scientists are
studying ways to detect ovarian cancer before symptoms develop. They are
exploring the usefulness of measuring the level of CA-125, a
substance called a tumor marker, which is often found in
higher-than-normal amounts in the blood of women with ovarian cancer. They
also are evaluating transvaginal ultrasound, a test that may help
detect the disease early. The Cancer Information Service can provide
information about this research.
A large-scale study, known as the PLCO
(Prostate, Lung, Colorectal, and Ovarian) Cancer Screening Trial,
is currently evaluating the usefulness of a blood test for the
tumor marker known as CA-125 and a test called transvaginal
ultrasound for ovarian cancer screening. |
Recognizing Symptoms
Ovarian cancer often shows no obvious signs or symptoms
until late in its development. Signs and symptoms of ovarian cancer may
include:
- General abdominal discomfort and/or pain (gas,
indigestion, pressure, swelling, bloating, cramps)
- Nausea, diarrhea, constipation, or frequent urination
- Loss of appetite
- Feeling of fullness even after a light meal
- Weight gain or loss with no known reason
- Abnormal bleeding from the vagina
These symptoms may be caused by ovarian cancer or by
other, less serious conditions. It is important to check with a doctor
about any of these symptoms.
Diagnosing Ovarian Cancer
To help find the cause of symptoms, a doctor evaluates a
woman�s medical history. The doctor also performs a physical exam and
orders diagnostic tests. Some exams and tests that may be useful are
described below:
- Pelvic exam includes feeling the uterus,
vagina, ovaries, fallopian tubes, bladder, and rectum to
find any abnormality in their shape or size. (A Pap test, a
good test for cancer of the cervix, is often done along with the
pelvic exam, but it is not a reliable way to find or diagnose ovarian
cancer.)
- Ultrasound refers to the use of
high-frequency sound waves. These waves, which cannot be heard by
humans, are aimed at the ovaries. The pattern of the echoes they
produce creates a picture called a sonogram. Healthy tissues,
fluid-filled cysts, and tumors look different on this picture.
- CA-125 assay is a blood test used to measure
the level of CA-125, a tumor marker that is often found in
higher-than-normal amounts in the blood of women with ovarian cancer.
- Lower GI series, or barium enema,
is a series of x-rays of the colon and rectum. The
pictures are taken after the patient is given an enema with a white,
chalky solution containing barium. The barium outlines the colon and
rectum on the x-ray, making tumors or other abnormal
areas easier to see.
- CT (or CAT) scan is a series of
detailed pictures of areas inside the body created by a computer
linked to an x-ray machine.
- Biopsy is the removal of tissue for
examination under a microscope. A pathologist studies the
tissue to make a diagnosis. To obtain the tissue, the surgeon
performs a laparotomy (an operation to open the abdomen). If
cancer is suspected, the surgeon performs an oophorectomy (removal of
the entire ovary). This is important because, if cancer is present,
removing just a sample of tissue by cutting through the outer layer of
the ovary could allow cancer cells to escape and cause the disease to
spread.
If the diagnosis is ovarian cancer, the doctor will
want to learn the stage (or extent) of disease. Staging
is a careful attempt to find out whether the cancer has spread and, if
so, to what parts of the body. Staging may involve surgery, x-rays
and other imaging procedures, and lab tests. Knowing the stage
of the disease helps the doctor plan treatment.
Treatment for Ovarian Cancer
Treatment depends on a number of factors, including the
stage of the disease and the general health of the patient. Patients are
often treated by a team of specialists. The team may include a gynecologist,
a gynecologic oncologist, a medical oncologist, and/or a radiation
oncologist. Many different treatments and combinations of treatments
are used to treat ovarian cancer.
- Surgery is the usual initial treatment
for women diagnosed with ovarian cancer. The ovaries, the fallopian
tubes, the uterus, and the cervix are usually removed. This operation
is called a hysterectomy with bilateral salpingo-oophorectomy.
Often, the surgeon also removes the omentum (the thin tissue
covering the stomach and large intestine) and lymph nodes
(small organs located along the channels of the lymphatic system) in
the abdomen.
Staging during surgery (to find out whether the
cancer has spread) generally involves removing lymph nodes, samples of
tissue from the diaphragm and other organs in the abdomen, and fluid
from the abdomen. If the cancer has spread, the surgeon usually
removes as much of the cancer as possible in a procedure called tumor
debulking. Tumor debulking reduces the amount of cancer that will
have to be treated later with chemotherapy or radiation therapy.
- Chemotherapy is the use of drugs to
kill cancer cells. Chemotherapy may be given to destroy any cancerous
cells that may remain in the body after surgery, to control tumor
growth, or to relieve symptoms of the disease.
Most drugs used to treat ovarian cancer are given by
injection into a vein (intravenously, or IV). The drugs can be
injected directly into a vein or given through a catheter, a
thin tube. The catheter is placed into a large vein and remains there
as long as it is needed. Some anticancer drugs are taken by mouth.
Whether they are given intravenously or by mouth, the drugs enter the
bloodstream and circulate throughout the body.
Another way to give chemotherapy is to put the drug
directly into the abdomen through a catheter. With this method, called
intraperitoneal chemotherapy, most of the drug remains in the
abdomen.
After chemotherapy is completed, second-look
surgery may be performed to examine the abdomen directly. The
surgeon may remove fluid and tissue samples to see whether the
anticancer drugs have been successful.
- Radiation therapy, also called
radiotherapy, involves the use of high-energy rays to kill cancer
cells. Radiation therapy affects the cancer cells only in the treated
area. The radiation may come from a machine (external radiation).
Some women receive a treatment called intraperitoneal radiation
therapy in which radioactive liquid is put directly into
the abdomen through a catheter.
Clinical trials (research studies) to
evaluate new ways to treat cancer are an important treatment option for
many women with ovarian cancer. In some studies, all patients receive the
new treatment. In others, doctors compare different therapies by giving
the promising new treatment to one group of patients and the usual
(standard) therapy to another group. Through research, doctors learn new,
more effective ways to treat cancer. More information about treatment
studies can be found in the NCI publication Taking Part in Clinical
Trials: What Cancer Patients Need To Know. NCI also has a Web site at
http://cancertrials.nci.nih.gov that provides detailed information about
ongoing studies for ovarian cancer. Clinical trial information is also
available from the Cancer Information Service by calling 1-800-4-CANCER
(1-800-422-6237).
The NCI's CancerNet� Web site provides
information from numerous NCI sources, including PDQ�, NCI's
cancer information database. PDQ contains information about
ongoing clinical trials as well as current information on cancer
prevention, screening, treatment, and supportive care. CancerNet
also contains CANCERLIT�, a database of citations and abstracts
on cancer topics from scientific literature. CancerNet can be
accessed at http://cancernet.nci.nih.gov on the
Internet. |
Possible Side Effects of Treatment
The side effects of cancer treatment depend on
the type of treatment and may be different for each woman. Doctors and
nurses will explain the possible side effects of treatment, and they can
suggest ways to help relieve problems that may occur during and after
treatment.
- Surgery causes short-term pain and tenderness
in the area of the operation. Discomfort or pain after surgery can be
controlled with medicine. Patients should feel free to discuss pain
relief with their doctor. For several days after surgery, the patient
may have difficulty emptying her bladder and having bowel movements.
When both ovaries are removed, a woman loses her
ability to become pregnant. Some women may experience feelings of loss
that may make intimacy difficult. Counseling or support for both the
patient and her partner may be helpful.
Also, removing the ovaries means that the body's
natural source of estrogen and progesterone is lost, and menopause
occurs. Symptoms of menopause, such as hot flashes and vaginal
dryness, are likely to appear soon after the surgery. Some form of
hormone replacement therapy may be used to ease such symptoms.
Deciding whether to use it is a personal choice; women with ovarian
cancer should discuss with their doctors the possible risks and
benefits of using hormone replacement therapy.
- Chemotherapy affects normal as well as
cancerous cells. Side effects depend largely on the specific drugs and
the dose (amount of drug given). Common side effects of chemotherapy
include nausea and vomiting, loss of appetite, diarrhea, fatigue,
numbness and tingling in hands or feet, headaches, hair loss, and
darkening of the skin and fingernails. Certain drugs used in the
treatment of ovarian cancer can cause some hearing loss or kidney
damage. To help protect the kidneys while taking these drugs, patients
may receive extra fluid intravenously.
- Radiation therapy, like chemotherapy, affects
normal as well as cancerous cells. Side effects of radiation therapy
depend mainly on the treatment dose and the part of the body that is
treated. Common side effects of radiation therapy to the abdomen are
fatigue, loss of appetite, nausea, vomiting, urinary discomfort,
diarrhea, and skin changes on the abdomen. Intraperitoneal radiation
therapy may cause abdominal pain and bowel obstruction (a
blockage of the intestine).
Several NCI booklets, including Chemotherapy and You,
Radiation Therapy and You, and Eating Hints for Cancer Patients,
suggest ways for patients to cope with the side effects they experience
during cancer treatment.
Doctors and nurses will explain the possible
side effects of treatment, and they can suggest ways to help
relieve problems that may occur during and after treatment. |
The Importance of Followup Care
Followup care after treatment for ovarian cancer is
important. Regular checkups generally include a physical exam, as well as
a pelvic exam and Pap test. The doctor also may perform additional tests
such as a chest x-ray, CT scan, urinalysis, complete blood
count, and CA-125 assay.
In addition to having followup exams to check for the
return of ovarian cancer, patients may also want to ask their doctor about
checking them for other types of cancer. Women who have had ovarian cancer
may be at increased risk of developing breast or colon cancer. |