What is Ovarian Cancer?

Risk Factors, Management, and Prevention of Ovarian Cancer

Patient undergoing chemotherapy for ovarian cancer. Credit: Will & Deni Mcintyre / Getty Images

What exactly is ovarian cancer, what types are there and who gets it, what are the causes and symptoms, and how is it treated?

What is Ovarian Cancer?

Ovarian cancer is a disease that affects ovarian tissue in the female reproductive system. The ovaries are responsible for producing eggs (ova) and are also a production site for the hormones estrogen and progesterone.

Ovarian cancer is the 5th most common cause of cancer deaths in women; though it is fairly uncommon, it often goes undetected until it has reached the advanced stages of the disease.

Types of Ovarian Cancer

There are 3 basic categories of ovarian cancer:

  • Epithelial ovarian cancers arise from the layer of cells (the epithelial layer) lining the ovaries and fallopian tubes and accounts for 95% of ovarian cancer.   The risk of this cancer increases with age.
  • Sex-cord stromal tumors arise from the cells that would surround the egg, and are most common around the age of 50. 
  • Germ cell tumors start in the ovarian germ cells - the eggs.  These tumors can occur at any age but are most common between the ages of 10 and 30.  Immature teratomas are one type of these tumors.

Learn more about some of the rare ovarian tumors.

Causes and Risk Factors of Ovarian Cancer

Unfortunately, we cannot pinpoint exactly what causes ovarian cancer, but researchers have identified several known risk factors for it. We know that ovarian cancer most often is diagnosed in women who:

  • Are post-menopausal (at least for the most common type of ovarian cancer.)
  • Were previously diagnosed with breast cancer.  As noted above, women who have had breast cancer may have an increased risk of developing ovarian cancer, and the BRCA1 and BRCA2 mutations which have been on the news described as the "breast cancer genes," can also increase the risk of ovarian cancer.
  • Suffer from obesity.
  • Used Clomid (a fertility drug) for longer than one year
  • Use(d) estrogen replacement therapy
  • Who have not given birth.  Child birth (as well as the use of oral contraceptives) appears to have a protective effect against the development of ovarian cancer.
  • Have a a known inherited mutation of BRCA 1 or 2 gene confirmed through genetic testing

Ovarian Cancer Symptoms

Ovarian cancer is often referred as the "silent killer" because there are no early warning signs, or symptoms aren't noticeable until the advanced stages, when it is less treatable. Early ovarian cancer symptoms are often vague and are commonly chalked up to be related to other, less serious conditions. These include:

  • Changes in bowel habits like constipation or diarrhea
  • Pelvic pain or pressure
  • Frequent urge to urinate

Symptoms of ovarian cancer that usually do not appear until the disease has progressed include:

Persistent symptoms that continue for several weeks need to be reported to your doctor. You should not wait to see if symptoms get better or go away on their own. Seeing your doctor early may lead to an earlier diagnosis.

Diagnosis of Ovarian Cancer

If your doctor discovers an ovarian mass during an exam or suspects an abnormality related to the ovary, a pelvic exam, ultrasound, and CA-125 blood test (a blood test that screens for a protein that is often elevated in the bloodstreams of women with ovarian cancer) are the first steps in making a diagnosis.

An ultrasound can reveal characteristics about masses that may help doctors determine if they are benign cysts or potentially cancerous. During the ultrasound, characteristics about the mass are noted, like appearance, fluid content, solidity, whether it has spread, and if the other ovary also contains a mass. Based on these characteristics, the radiologist assigns a score of the ultrasound that contributes to the risk of malignancy index (RMI).

The RMI is a scoring system that determines the risk of a mass being cancerous. The ultrasound score is combined with a score that evaluates menopause status and the results of the CA-125 tumor marker test. The sum of these numbers reveal the risk that the mass is cancerous. Keep in mind that the RMI only determines the risk of it being cancer, it is not a diagnosis. It may not be used for all types of cancer in helping to make a diagnosis.

A biopsy is necessary to confirm the presence of cancer and involves removing small tissue samples to be evaluated later under a microscope. An ovarian biopsy can be done surgically through a procedure called a laparotomy. During a laparotomy, the surgeon makes an incision into the abdomen and looks for signs of cancer in the abdominal cavity. This includes taking a biopsy or possibly removing an ovary for further evaluation by a pathologist. If cancer is obvious, the surgeon may try to remove as much of it as possible. This is called debulking, and is a common method of treating ovarian cancer.

A less invasive surgery, laparoscopic surgery, may also be an option for some women instead of a laparotomy. Laparoscopic surgery involves the surgeon making a small incision into the abdomen. A laparoscope (a fiber optic rod equipped with a light and camera) is inserted through the incision and transmits live video feed to a monitor.

If cancer is confirmed from the biopsy, the stage and grade of ovarian cancer is then determined. For women with suspected advanced stages of ovarian cancer, then additional tests, like imaging tests are required to stage the disease.

Treatment of Ovarian Cancer

Treatment options weigh heavily on the stage and grade of ovarian cancer. There are three primary treatment methods for ovarian cancer: surgery, chemotherapy, and radiation therapy. Surgery combined with chemotherapy is the most common treatment course. Radiation therapy may be used for some women.

Surgery - Debulking or cytoreduction surgery is the primary type of ovarian cancer treatment. The goal of the surgery is to remove as much of the tumor as possible, which in turn, will help increase the effectiveness of chemotherapy.

Ovarian cancer surgery is often a lengthy and very meticulous surgery.  For that reason it is not surprising that studies suggest that surgery performed by a gynecologic oncologist (a specialist in ovarian cancer) may result in better outcomes.  Ask questions.  Getting a second opinion can be extremely important, and many people recommend getting an opinion at a National Cancer Institute designated cancer center.

Chemotherapy - Chemotherapy to treat ovarian cancer helps eliminate cancer cells that remain after surgery. The drugs are delivered either intravenously or directly into the abdominal cavity (intraperitoneal chemotherapy). Chemotherapy may be given before or after surgery. It can also be given alone as palliative chemotherapy, to reduce symptoms but not in an attempt to cure the cancer. How often and how long a person receives chemotherapy is based on their stage of ovarian cancer and other health factors.

Radiation Therapy - Radiation therapy is rarely used to treat ovarian cancer. It may be used to reduce symptoms caused by the cancer.

Coping and Support

A diagnosis of ovarian cancer can be terrifying.  And at the same time you are coping with the emotional roller coast which is cancer, you're being called upon to make critical decisions about your care.  Since studies suggest that people who are actively involved in their care may have a better quality of life, and perhaps even better outcomes, learn how to research your cancer.  Ask a lot of questions, and bring a friend along to ask questions as well.  Strongly consider a second opinion as noted earlier.  And even if you tend to be quiet or shy, learn how to be your own advocate in your cancer care.  As a final tip, some people are mixed on whether or not it helps to look at survival statistics.  If you do, realize that these statistics are compiled based on how well someone did in the past - and often before newer and better treatments became available.

Ovarian Cancer Prevention or Risk Reduction

Like most type of cancer, there are no guaranteed methods of prevention. Several factors reduce our risk:

  • Oral Contraceptive Use: Several studies show that several years of using birth control pills may decrease a woman's risk of ovarian cancer.
  • Childbirth: Giving birth to at least one child may cut the risk of ovarian cancer by 80%. It is not recommended to have children just for the sake of risk reduction though.
  • Tubal Ligation or Hysterectomy: Tubal ligation or a hysterectomy may reduce your risk of ovarian cancer, but these surgeries are never done solely for the purpose of ovarian cancer prevention. They are simply an added benefit of treating another condition.  Learn more about tubal ligation and ovarian cancer.

Some women who are considered to be at higher risk of ovarian cancer choose more drastic methods of prevention. A prophylactic oophorectomy (surgical removal of the ovaries) to prevent ovarian cancer is one method of prevention that may be available to women who are high risk. This option is normally an option for women who have a mutated BRCA 1 or 2 gene, confirmed through genetic testing.

While surgical prevention may drastically cut a woman's risk, a similar type of cancer called primary peritoneal cancer (cancer of the lining of the abdominal cavity), may develop. This type of cancer is rare, but in women with a known mutated BRCA gene, the risk is heightened.


National Cancer Institute. Ovarian, Fallopian Tube, and Primary Peritoneal Cancer – Health Professional Version (PDQ). Accessed 04/17/16. http://www.cancer.gov/types/ovarian/hp

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