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.
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
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.
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
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)
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.