Slideshow: A Visual Guide to Ovarian Cancer

Current research suggests this cancer begins in the fallopian tubes and moves to the ovaries, the twin organs that produce a woman's eggs and the main source of  the female hormones estrogen and progesterone. Treatments for ovarian cancer have become more effective in recent years, with the best results seen when the disease is found early.

Early ovarian cancer rarely has symptoms. As the disease progresses, some symptoms may appear. These include:

• Bloating or pressure in the belly
• Pain in the abdomen or pelvis
• Feeling full too quickly during meals
• Urinating more frequently

These symptoms can be caused by many conditions that are not cancer. If they occur persistently for more than a few weeks, report them to your health care professional.

A woman's odds of developing ovarian cancer are higher if a close relative has had cancer of the ovaries, breast, or colon. Researchers believe that inherited genetic changes account for 10% of ovarian cancers. This includes the BRCA1 and BRCA2 gene mutations, which are linked to breast cancer.  Women with a strong family history should talk with a doctor to see whether closer medical follow-up could be helpful.

The  strongest risk factor for ovarian cancer is age. It's most likely to develop after a woman goes through menopause. Using postmenopausal hormone therapy may increase the risk. The link seems strongest in women who take estrogen without progesterone for at least 5 to 10 years. Doctors are not certain whether taking a combination of estrogen and progesterone boosts the risk as well.

Obese women have a higher risk of getting ovarian cancer than other women. And the death rates for ovarian cancer are higher for obese women too, compared with non-obese women. The heaviest women appear to have the greatest risk.

There is no easy or reliable way to test for ovarian cancer if a woman has no symptoms. No test has been shown to save lives when used in women of average risk. If you have any symptoms that could be ovarian cancer, your doctor may suggest a rectovaginal pelvic exam, a transvaginal ultrasound, or a CA-125 blood test to help find the cause.

Imaging tests, such as ultrasound or CT scans (seen here), can help reveal an ovarian mass. But these scans can't determine whether the abnormality is cancer. If cancer is suspected, the next step is usually surgery to remove suspicious tissues. A sample is then sent to the lab for further examination. This is called a biopsy. 

The initial surgery for ovarian cancer also helps determine how far the cancer has spread, described by the following stages:

Stage I: Confined to one or both ovaries
Stage II: Spread to the uterus or other nearby organs
Stage III: Spread to the lymph nodes or abdominal lining
Stage IV: Spread to distant organs, such as the lungs or liver

The vast majority of ovarian cancers are epithelial ovarian carcinomas. These are malignant tumors that form from cells on the surface of the ovary. Some epithelial tumors are not clearly cancerous. These are known as tumors of low malignant potential (LMP). LMP tumors grow more slowly and are less dangerous than other forms of ovarian cancer.

Ovarian cancer can be a frightening diagnosis, with five-year relative survival rates that range from 93% to 19% for epithelial ovarian cancer, depending on the stage when the cancer was found. For LMP tumors, the five-year relative survival rates range from 97% to 89%.

Surgery is used to diagnose ovarian cancer and determine its stage, but it is also the first phase of treatment. The goal is to remove as much of the cancer as possible. This may include a single ovary and nearby tissue in stage I. In more advanced stages, it may be necessary to remove both ovaries, along with the uterus and surrounding tissues.

In all stages of ovarian cancer, chemotherapy is usually given after surgery. This phase of treatment uses drugs to target and kill any remaining cancer in the body. The drugs may be given by mouth, through an IV, or directly into the belly (intraperitoneal chemotherapy). Women with LMP tumors usually don't need chemo unless the tumors grow back after surgery.

Researchers are working on therapies that target the way ovarian cancer grows. A process called angiogenesis involves the formation of new blood vessels to feed tumors. A drug called Avastin blocks this process, causing tumors to shrink or stop growing (seen in the illustration here). 

When women have both ovaries removed, they can no longer produce their own estrogen. This triggers menopause, no matter how young the patient. The drop in hormone levels can also raise the risk for certain medical conditions, including osteoporosis. It's vital that women have regular follow-up care after being treated for ovarian cancer.

Women may find that it takes a long time for their energy to return after treatments end. Fatigue is a very common problem after treatment for cancer. Beginning a gentle exercise program is one of the most effective ways to restore energy and improve emotional well-being. Check with your health care team to determine which activities are right for you.

Women who have biological children are less likely to get ovarian cancer than women who have never given birth. The risk appears to decrease with every pregnancy, and breastfeeding may offer added protection.

Ovarian cancer is also less common in women who have taken birth control pills. Women who have used the pill for at least five years have about half the risk of women who never took the pill. Like pregnancy, birth control pills prevent ovulation. Some researchers think ovulating less often may protect against ovarian cancer.

Getting your tubes tied, formally known as tubal ligation, may offer some protection against ovarian cancer. The same goes for having a hysterectomy -- removing the uterus.

For women with genetic mutations that put them at high risk for ovarian cancer, removing the ovaries is an option. This can also be considered in women over 40 getting a hysterectomy.

While there is no definitive diet to prevent ovarian cancer, there is evidence that what you eat can make a difference. In one recent study, women who stuck to a low-fat diet for at least four years were less likely to develop ovarian cancer. Some researchers report the cancer is also less common in women who eat a lot of vegetables, but more studies are needed.