Ovarian cancer

Ovarian cancer is the development of malignant (cancerous) cells in an ovary.


Anatomy
The ovaries are the glands that produce eggs for reproduction and most of the female sex hormones (estrogen and progesterone). These hormones control such physical characteristics as breasts, body shape and body hair. They also play a role in menstrual cycles and pregnancy.
From the ovary, cancer cells can detach and implant on other organs or body parts. The liver, colon (the part of the large intestine that extends from the small intestine to the anus) and diaphragm (the muscle that separates the chest cavity from the abdominal cavity) are often affected. Cancer cells can also enter the lymphatic system (the system that helps protect the body from invasion by bacteria or other organisms) and spread to other more distant organs.


Causes/associated factors
In the United States, more than 25,000 women are diagnosed with ovarian cancer each year. About one of every 70 women will develop ovarian cancer in her lifetime. The condition is most common among Caucasians over age 50, but it can strike women of any race at any age.
The risk of ovarian cancer seems to be related to the number of times you ovulate in a lifetime. The more you ovulate, the greater your risk for ovarian cancer. Factors that suppress ovulation, such as pregnancy and birth control pills, decrease your risk. You face an increased risk of ovarian cancer if you:

have never had biological children
have a family history of ovarian cancer, especially in a close relative, such as your mother, sister or daughter (The risk increases with the number of close relatives affected by ovarian cancer.)
have certain changes in the BRCA1 or BRCA 2 genes (Some changes are also associated with an increased risk of breast cancer.)
You may also have an increased risk if you or a close relative have had breast cancer or colon cancer.

A recent study suggests that taking estrogen replacement therapy for more than 10 years may increase the risk of ovarian cancer.

Taking fertility drugs that stimulate ovulation, eating a diet high in fat or low in vegetable fiber or using talcum powder in the genital area have all been implicated as possible contributors to ovarian cancer. Further research is needed before scientific findings can be determined, however.


Screening
There are no definitive screening tests for ovarian cancer. Regular pelvic exams are currently recommended. Research is underway on blood tests that screen for certain proteins that may help detect ovarian cancer at an early stage. Other research is being done to determine whether existing tests -- such as ultrasound and CA 125 -- could be useful screening tools for women at risk for ovarian cancer.

Signs/symptoms
Ovarian cancer typically has vague symptoms in the early stages, often leading to a later diagnosis and a higher fatality rate. The American College of Obstetrics and Gynecology (ACOG) recently released findings from a new study that identified symptoms of ovarian cancer, including constant bloating, fullness, abdominal or pelvic pressure, unusual fatigue and urination problems. Although these symptoms can appear with many other conditions, they are more constant with ovarian cancer. Additional symptoms identified by other studies include vaginal bleeding, gas, upset stomach, nausea and weight changes. Fluid may accumulate in the abdomen or lungs and cause abdominal swelling or shortness of breath.

Diagnosis
The doctor will do a physical exam, including a pelvic exam and Pap smear (taking a sample of cells from the cervix to screen for cervical cancer). The doctor will also ask questions about your symptoms and medical history. To help the doctor make a diagnosis, you may need one or more of the following tests:
ultrasound (using sound waves to create images of internal body parts)
computed tomography (CT scan; creating a computer-generated, cross-sectional picture of internal body parts)
lower gastrointestinal series (X-rays of the colon and rectum)
intravenous pyelography (IVP, an X-ray of the kidneys and lower urinary tract taken after a dye has been injected into the area)
Your doctor may also order a blood test to measure a substance called antigen 125 (CA 125). This tumor marker is a protein that may be found in elevated levels in the blood of people who have certain types of cancer. Some women who have ovarian cancer have elevated levels of CA 125, but not all. Many other conditions can cause an increase in levels of CA 125, including pregnancy, endometriosis, menstruation or pelvic infections.

A biopsy (taking tissue samples for microscopic examination) is the only way to confirm ovarian cancer. This can be done through laparoscopy, a minor surgical procedure that allows the doctor to view the organs in the abdomen with a laparoscope (a thin tube equipped with a camera lens and light). If your doctor thinks the tumor looks suspicious, it will be removed. The affected ovary and nearby lymph nodes may also be removed. To determine if the cancer has spread, the doctor may examine fluid samples from your abdomen and tissue samples from your diaphragm or other abdominal organs. (This is sometimes referred to as staging the cancer.)


Treatment
Treatment depends on various factors, including how far the cancer has spread, the type of ovarian cancer, and your age and health history. A gynecologic oncologist (a physician who specializes in female reproductive cancer treatment) may recommend surgery, chemotherapy, radiation or a combination of these treatments. Researchers are currently studying new and better ways to treat ovarian cancer, such as vaccines, treatment with hormones and bone marrow and stem cell transplants.
Surgery
Surgical removal of the ovaries, uterus and fallopian tubes is often the initial treatment for ovarian cancer. If you are of childbearing age and would like to remain fertile, the surgeon may remove only the affected ovary if the tumor is small, slow-growing and detected early. If the cancer has spread, the surgeon may remove as much cancerous tissue as possible with a procedure called tumor debulking. This procedure makes subsequent treatment with chemotherapy more effective.

Once the ovaries are removed, your body's primary source of estrogen is gone. You may experience symptoms of menopause, such as hot flashes and vaginal dryness. To relieve these symptoms, your doctor may recommend hormone replacement therapy. Discuss the risks and benefits of this therapy with your doctor.

Chemotherapy
Chemotherapy for ovarian cancer often involves a combination of anti-cancer medications. Research has shown that using a platinum medication, (Paraplatin or Platinol), a taxane medication (Taxol or Taxotere) or both works best. Other medications may also be used. Chemotherapy is typically given intravenously or orally. Eventually, the medication reaches all areas of your body through your bloodstream. Chemotherapy usually involves a series of outpatient treatments, each separated by a recovery period.

Doctors are studying a new technique called intraperitoneal chemotherapy. With this procedure, which must be done in the hospital, doctors use a catheter (a flexible tube) to put the chemotherapy drugs directly into the abdomen.

An experimental procedure that uses multiple cycles of high-dose chemotherapy followed by peripheral stem cell transfusion is also being studied. Stem cells come from the bone marrow. When given intravenously, these stem cells can make new blood cells to replace those destroyed by chemotherapy.

Chemotherapy affects healthy cells as well as cancer cells, which leaves you susceptible to infections. You may also bruise or bleed more easily and have less energy. Although side effects vary for each person and depend on which drugs you receive, chemotherapy often causes:

hair loss
nausea
vomiting
mouth sores
tingling in your fingers and toes
ringing in your ears
problems with hearing
To relieve the side effects, your doctor may suggest dietary changes or medication. Most side effects gradually resolve after the drugs are stopped and your body recovers. Some chemotherapy drugs cause kidney damage, so your doctor may ask you to drink plenty of fluids or give you fluids through an IV to help prevent problems. Depending on which drugs you receive, chemotherapy may also increase your chances of developing leukemia (cancer of the blood cells) later in life. Be sure to thoroughly discuss the risks and benefits of treatment with your doctor.

Radiation therapy
Radiation therapy (also called radiotherapy) uses high-energy rays to destroy cancer cells and prevent new cells from growing. With external radiation, the doctor sends the rays to the body from a machine. External radiation therapy requires a series of outpatient treatments, often five days a week for about five weeks. With internal radiation, which requires a short hospital stay, the doctor places radioactive material directly into or near the tumor.

You'll probably be extremely fatigued after radiation, especially a few weeks after treatment starts. Adequate rest is important, but your doctor may encourage you to stay as active as possible. The area of skin that's been exposed to radiation may be red, dry, itchy and tender. It may become permanently darkened. Radiation of the lower abdomen may cause nausea, vomiting, diarrhea or painful urination. Because vaginal dryness is another possible side effect, your doctor may recommend limiting sexual activity until your treatment is complete.

Follow-up care
If you've had surgery and chemotherapy, your doctor may recommend another surgery to make sure the treatment was successful. The second surgery allows the doctor to examine the abdomen directly and take tissue and fluid samples. After your treatment is complete, you'll need regular physical and pelvic exams, as well as Pap smears. Your doctor may also recommend periodic chest X-rays, CT scans of your abdomen, blood work and urinalysis. Blood tests to measure levels of CA 125 can also help monitor your response to treatment, as well as screen for possible recurrence once treatment is complete. Generally, CA 125 levels drop when a tumor shrinks. Levels may rise again if a tumor grows or recurs.


Complications
Complications of ovarian cancer and/or treatment may include:
pleural effusion (the accumulation of fluid in the linings of the lungs)
ascites (the accumulation of fluid in the abdominal cavity)
reaction to radiation and/or chemotherapy
intestinal obstruction
fluid and electrolyte imbalance
leg swelling
malnutrition

Pregnancy-specific information
Ovarian cancer during pregnancy is rare because the cancer is more common in women past childbearing age. Pregnancy does not affect the prognosis of ovarian cancer, but it may increase the risk of pregnancy-related complications.

Senior-specific information
Growing older is a risk factor for ovarian cancer. Be sure to see your doctor for regular pelvic exams.

Prevention
Factors that may decrease your risk of developing ovarian cancer include:
having one or more pregnancies (the more pregnancies, the greater the protection)
breastfeeding
taking birth control pills (Being on the pill even three to six months helps decrease the risk, but the protection is greater the longer you're on the pill.)
having a tubal ligation (a surgical procedure that prevents pregnancy by blocking the fallopian tubes)
surgical removal of both ovaries
avoiding talcum powder use in the genital area
having a hysterectomy (surgical removal of the uterus)
eating a diet low in fat and high in vegetable fiber
If you have a family history of breast or ovarian cancer, consult your doctor for regular pelvic exams. Discuss whether genetic testing would be a good idea in your case.