Ovarian cancer refers to the out-of-control growth of cells in the ovaries, two glands that are essential for sexual reproduction and women’s health. Ovarian cancer affects an estimated 1 in 78 women in the United States. (1)
In the female anatomy, there is one ovary to the left side of the uterus and one to the right that produce eggs (ova) as well as the sex hormones estrogen and progesterone.
If a woman is fertile, her ovaries release eggs into the fallopian tubes, which serve as passageways to the uterus.
Recent research, including a study published in October 2017 in the journal Nature Communications, has suggested that for many women, ovarian cancer originates in the fallopian tubes. This important finding may point the way to new strategies for prevention, early detection, and treatment. (2)
Types of Ovarian Tumors
The ovaries are made up of three types of cells, each of which has the potential to become malignant.
Epithelial ovarian tumors These are by far the most common type of ovarian tumors and the most likely to be malignant. They develop from cells that cover the outside surface of the ovaries.
These tumors can be benign (noncancerous), borderline (low malignant potential), or malignant.
The last group, also called carcinomas, account for between 85 and 90 percent of all ovarian cancers.
Ovarian germ cell tumors These develop in the ova and are usually benign. This category includes a type called a dermoid cyst.
The malignant kind accounts for less than 2 percent of all ovarian cancers.
Ovarian stromal tumors These develop in the structural tissue cells that hold the ovary together and produce estrogen and progesterone.
They make up only about 1 percent of all ovarian cancers.
Signs and Symptoms of Ovarian Cancer
Ovarian cancer is particularly life-threatening because some of its early signs are vague and easy to ignore or blame on other, far less dangerous health conditions. Symptoms often don’t become apparent until the cancer has spread and become difficult to treat.
The following are the most common symptoms of ovarian cancer:
- Pelvic or abdominal pain
- Difficulty eating or feeling full too quickly
- Urinary discomfort — unusual urgency or frequency (3)
Ovarian cancer can also cause fatigue, stomach upset, back pain, pain during sex, constipation, changes in the menstrual cycle, and abdominal swelling accompanied by weight loss.
If any of these symptoms are persistent and unusual for you, it’s important to discuss them with your doctor. The American Cancer Society recommends that women see a doctor as soon as possible if they experience any of these symptoms more than 12 times in a month.
Causes and Risk Factors of Ovarian Cancer
Medical experts don’t know why certain women develop ovarian cancer and others don’t, or why some ovarian cells become cancerous while others don’t.
Still, scientists have identified a number of risk factors for epithelial ovarian cancer. Some appear to have a very small impact, while others are more significant. (4)
- Age Your risk increases the older you are, with most ovarian cancers developing after menopause.
- Being overweight or obese Research has linked obesity to ovarian cancer, though not necessarily the most life-threatening types.
- Pregnancy after 35 Having your first full-term pregnancy after age 35 or never carrying a child to term increases the risk of ovarian cancer.
- Fertility treatments Some studies suggest a connection between in vitro fertilization (IVF) treatment and borderline ovarian tumors, though the evidence is conflicting.
- Post-menopause hormone therapy Hormone therapy undertaken for many years, especially estrogen alone (without progesterone), is associated with increased risk.
- Family history A family history of ovarian cancer, breast cancer, or colorectal cancer raises your risk.
- Genetic inheritance Among the clearest and most serious risks are certain inherited changes (mutations) in genes, passed down through one’s family. This accounts for 5 to 10 percent of ovarian cancers and is caused most notably by mutations in the BRCA1 and BRCA2 genes.
- Smoking Smoking hasn’t been shown to raise overall ovarian cancer risk but it has been linked to an increase in an uncommon type of epithelial tumor called a mucinous carcinoma.
Learn More About Causes of Ovarian Cancer: Common Risk Factors, Genetics and More
How Is Ovarian Cancer Diagnosed?
In diagnosing ovarian cancer, your doctor may initially perform a pelvic exam to look for changes that indicate the presence of a tumor. But smaller cancers may not be discovered through a pelvic exam. Imaging tests, such as ultrasound, computerized tomography (CT) scans, and positron emission tomography (PET) scans, can aid doctors in finding tumors and making an ovarian cancer diagnosis. Analyzing a tissue sample, usually obtained through biopsy (surgery to remove tissue samples for analysis in the lab), is the only way to tell for sure if a mass is cancerous. (5)
Staging ovarian cancer means evaluating how extensive it is in order to come up with the best treatment plan. Staging typically involves biopsy. Doctors will find out the answers to a series of questions about the primary tumor, including whether or not it is confined to the ovary and fallopian tube and how big it is. They will also determine if cancer cells are present in lymph nodes near the ovaries, and they will look for signs that the cancer has spread to tissues or organs further away, such as the brain. An analysis that factors in all these criteria will arrive at a cancer stage between 1 (the earliest stage) and 4 (the most advanced), with substages that provide more detail.
Learn More About the Stages of Ovarian Cancer
Genetic testing allows women who believe they are at high risk of ovarian cancer to confirm whether or not they have inherited a mutation (such as BRCA1 or BRCA2) that makes them especially vulnerable.
A genetic counselor can talk about the pros and cons of testing and put any potential findings into context before arranging for a laboratory analysis of DNA from a saliva or blood sample.
Women can also take inexpensive at-home genetic tests that bypass genetic counseling. Yet while these tests are more accessible, they are not as inclusive or reliable as tests administered by a professional, and making sense of their findings without help from an expert who understands what the results do and don’t mean, and who can offer informed advice about next steps, is difficult.
Learn More About Genetic Testing and Ovarian Cancer
Learn More About Diagnosing Ovarian Cancer: Tests and Screenings, Early Diagnosis, and Your Doctors
Prognosis of Ovarian Cancer
Ovarian cancer poses an outsize threat because it tends to be detected only after it has moved beyond the ovaries to other parts of the body.
Roughly 8 in 10 women are diagnosed after ovarian cancer has spread to nearby lymph nodes or metastasized to other organs or tissues.
In general, the later ovarian cancer is diagnosed, the harder it is to treat.
While women diagnosed with early-stage ovarian cancer have a five-year relative survival rate of about 92 percent, the five-year relative survival rate for all stages is only 47 percent. (6)
Duration of Ovarian Cancer
The length of time women live with ovarian cancer will depend on the type, stage, treatments, and other factors.
Nearly half of women with ovarian cancer are still alive at least five years after being diagnosed with the disease. (7)
If you have ovarian cancer, you’ll likely need to see your doctor frequently for follow-up visits and tests.
Treatment and Medication Options for Ovarian Cancer
Ovarian cancer treatment almost always starts with surgery. Most women who are diagnosed with ovarian cancer will have an operation to remove the tumor, or at least as much of it as possible.
If the cancer is diagnosed early (as is the case for only 2 women in 10), the operation may be limited to removal of the ovaries and fallopian tubes, a procedure called a bilateral salpingo-oophorectomy, as well as the uterus (a hysterectomy). Depending on the cancer and the stage, some women who want to preserve their fertility may be able to keep one ovary and fallopian tube, and their uterus.
More extensive surgery may be necessary for cancers that have spread, assuming the patient is healthy enough to withstand it.
Surgery is important for staging the cancer — determining how advanced it is in order to settle on the best treatment and make a prognosis.
Post-surgery, many patients are treated with numerous rounds of chemotherapy, which involves administering drugs (typically two used in combination) that kill cancer cells. Sometimes patients will receive chemotherapy before and after surgery, to first shrink the tumor before it is surgically removed. Except for early-stage cancers, chemotherapy is almost always part of the treatment plan.
For advanced ovarian cancers, doctors may also turn to targeted therapy. This type of next-generation medication works by homing in on specific characteristics of cancer cells, disrupting their inner workings and causing them to die, while sparing healthy cells.
For instance, the targeted drug Avastin (bevacizumab) attacks cancer by targeting a protein in malignant cells that enables them to form new blood vessels they need to grow. (8)
Alternative and Complementary Therapies
Some women with ovarian cancer turn to alternative therapies to ease their symptoms and side effects.
Common therapies include:
- Herbs or oils
Always talk to your doctor before trying an alternative treatment.
Additionally, patients with ovarian cancer may benefit from palliative care. This approach can provide relief from the physical and emotional impacts of cancer. Palliative care can be given along with standard cancer treatments. When combined with appropriate therapies, people who choose palliative care may feel better and live longer. (9,10)
Learn More About Treatment for Ovarian Cancer: Medication, Alternative and Complementary Therapies, Surgery Options, and More
Prevention of Ovarian Cancer
Scientists continue to look for ways to reduce a woman’s risk of developing ovarian cancer.
For now, they have identified two protective factors:
- Pregnancy and breastfeeding Women who become pregnant before age 26 and carry to term are at lower risk, with each subsequent full-term pregnancy diminishing the risk further. Breastfeeding has an effect too, perhaps because it prevents ovulation. The risk for cell mutation, which can lead to cancer, is greater the more you ovulate. (11,12)
- Birth control Women who have used oral contraceptives are at lower risk. So are women who’ve had a tubal ligation (had their fallopian tubes tied) or used an intrauterine device (IUD) for a short time. Women who’ve had a hysterectomy (removal of the uterus) also see their ovarian cancer risk drop by a third. (4)
Complications of Ovarian Cancer
Women with ovarian cancer may experience complications related to treatments or the disease itself.
Some common complications include: (13)
- Fatigue or weakness
- Gastrointestinal side effects
- Edema (excess fluid buildup)
- Ascites (collections of fluid in the abdominal cavity)
- Anemia (low blood cell counts)
- Bowel or bladder obstruction
- Nutritional problems
- Pleural effusion (a buildup of fluid between the thin membranes that line the lungs and the inside of the chest cavity)
Learn More About the Complications of Ovarian Cancer: How It Affects Your Body in the Short and Long Term
Research and Statistics: Who Has Ovarian Cancer?
The number of women diagnosed with ovarian cancer has significantly decreased over the past 20 years.
A report published in May 2018 by the American Cancer Society found that rates declined 29 percent between 1985 and 2014, and the number of deaths decreased 33 percent between 1976 and 2015. (14)
Today, an estimated 22,240 women develop ovarian cancer each year, and around 14,000 die.
Ovarian cancer accounts for only 2.5 percent of all cancers diagnosed in women, making it relatively rare, yet it is responsible for 5 percent of all cancer-related deaths in women. (6)
Black Americans and Ovarian Cancer
While ovarian cancer is more common in white women, studies show Black American women who have this type of cancer don’t survive as long. Although there have been advances in treatments, not all racial groups have benefited equally when it comes to survival.
For instance, between 1975 and 2016, the five-year survival rate for ovarian cancer increased from 33 percent to 48 percent in white women but decreased from 44 percent to 41 percent in Black women.
Though the exact causes for these disparities aren’t known, some evidence has suggested that socioeconomic factors, such as access to healthcare, may play a role.
Researchers are currently conducting studies to try and understand more about why this discrepancy exists. (1,15)
Related Conditions and Causes of Ovarian Cancer
Some conditions that are related to ovarian cancer include:
Resources We Love
If you or a loved one has been diagnosed with ovarian cancer, or you are concerned about the disease, a number of excellent organizations can help, whether you’re seeking comprehensive, educational information about the condition, emotional support, insight into the latest research, or financial assistance.
American Cancer Society This organization offers everything from information about individual diagnoses and navigating treatment to help finding support groups and rides to treatment.
National Ovarian Cancer Coalition (NOCC) An advocacy organization that offers information about ovarian cancer, recent information about new developments in treatment, and holds events around World Ovarian Cancer Awareness Day.
Ovarian Cancer Research Alliance (OCRA) OCRA supports research and offers information as well as peer support for women going through ovarian cancer.
National Cancer Institute The NCI offers a full suite of information ranging from basic information about individual cancers to new developments in treatment, to finding clinical trials, and information on COVID-19 and cancer.
Learn More About Additional Resources and Support for Ovarian Cancer
Editorial Sources and Fact-Checking
- Key Statistics for Ovarian Cancer. American Cancer Society. January 8, 2020.
- Labidi-Galy SI, Papp E, Hallberg D, et al. High-Grade Serous Ovarian Carcinomas Originate in the Fallopian Tube. Nature Communications. October 23, 2017.
- Signs and Symptoms of Ovarian Cancer. American Cancer Society. April 11, 2018.
- Ovarian Cancer Risk Factors. American Cancer Society. June 9, 2020.
- Tests for Ovarian Cancer. American Cancer Society. April 3, 2020.
- Cancer Stat Facts: Ovarian Cancer. National Cancer Institute Surveillance, Epidemiology, and End Results Program (SEER).
- Stages of Ovarian Cancer. Ovarian Cancer Research Alliance.
- Treating Ovarian Cancer. American Cancer Society.
- Ovarian Cancer: Diagnosis and Treatment. Mayo Clinic. July 25, 2019.
- What Kinds of Cancer Treatment Are There? American Cancer Society. March 31, 2015.
- Breastfeeding Lowers Your Breast Cancer Risk. MD Anderson Cancer Center. October 2014.
- Extended Breastfeeding Reduces Risk of Ovarian Cancer. Ovarian Cancer Research Alliance. January 23, 2013.
- Herrinton LJ, et al. Complications at the End of Life in Ovarian Cancer. Journal of Pain and Symptom Management. September 2007.
- Torre LA, Trabert B, DeSantis CE, et al. Ovarian Cancer Statistics, 2018. CA: A Cancer Journal for Clinicians. May 29, 2018.
- Ovarian Cancer Studies Aim to Reduce Racial Disparities, Improve Outcomes. National Cancer Institute. July 16, 2020.