Ovarian cancer is a group of cancers that can develop in the ovaries, fallopian tubes, or peritoneum.
These cancers can behave differently based on their type, subtype, stage, and other biological features. Understanding these differences can help you make sense of your diagnosis and treatment options.
Reviewed by: Jennifer McClendon, MCHES
Medically reviewed: September, 2026
The ovaries are two small reproductive organs located in the pelvis. One ovary sits on each side of the uterus.
The ovaries release eggs and produce hormones, including estrogen and progesterone. They also contain several cell types that can develop into different ovarian tumors.
The fallopian tubes extend from the uterus toward each ovary. Their fingerlike ends, called fimbriae, sit close to the ovaries.
The peritoneum is a thin tissue that lines the abdominal wall. It also covers many organs within the abdomen.
These structures are closely connected. Understanding their location helps explain where different cancers associated with ovarian cancer can begin.
For many years, ovarian cancer was thought to begin mainly on the surface of an ovary. Research has changed that understanding, especially for high-grade serous carcinoma.
Many high-grade serous cancers appear to begin in cells near the end of a fallopian tube. Cancer cells can later involve the ovary, peritoneum, or other areas of the abdomen.
Other ovarian cancers begin from different cells within the ovary itself. Primary peritoneal cancer begins in the tissue lining the abdominal cavity.
Epithelial ovarian, fallopian tube, and primary peritoneal cancers share many important features. Doctors generally stage and treat these cancers in similar ways.
Learn more about ovarian cancer types and stages.
💡 Understanding ovarian cancer
NOCC’s Animated Patient Guide explains what ovarian cancer is and where different cancers can begin.
It also introduces ovarian cancer types through easy-to-follow animations and expert information.
Normal cells follow signals that control growth, division, repair, and cell death. Cancer can develop when genetic changes interfere with those normal controls.
These changes may allow abnormal cells to keep growing or survive longer than they should. Over time, these cells can form a tumor and invade nearby tissue.
Some genetic changes are inherited from a parent. Others develop during a person’s lifetime and may only be present in cancer cells.
Cancer usually develops after cells collect several changes over time. Researchers continue studying why these changes occur in different ovarian cancer types.
Most ovarian cancers do not have one identifiable cause. Researchers instead study genetic changes and factors that may affect ovarian cancer risk.
Some genetic changes are inherited from a parent. Others develop during a person’s lifetime.
Many factors can influence risk without directly causing ovarian cancer.
A risk factor is something that changes the chance of developing a disease. Having a risk factor does not mean cancer will develop.
Some people with ovarian cancer have few or no known risk factors. Others may have several factors linked with increased risk.
Risk factors can include age, family history, inherited gene variants, endometriosis, and certain reproductive factors.
Some risk factors apply mainly to epithelial ovarian cancer.
Learn more about ovarian cancer risk factors.
Ovarian cancer is relatively rare compared with many other cancers. However, thousands of people are diagnosed in the United States each year.
The National Cancer Institute estimates about 21,010 new ovarian cancer cases in the United States during 2026. Ovarian cancer accounts for about 1% of all new cancer cases.
A person’s individual risk depends on many factors. These can include age, family history, genetics, and medical history.
Learn more about ovarian cancer statistics from the National Cancer Institute.
Some ovarian cancers are linked to inherited gene mutations. BRCA1 and BRCA2 are among the best-known genes associated with ovarian cancer risk.
Lynch syndrome and changes in other genes can also increase ovarian cancer risk. An inherited gene variant can come from either parent.
Having an inherited variant does not mean someone will develop ovarian cancer. It means their risk may be higher than average.
For someone already diagnosed, inherited genetic testing may also provide information that affects treatment. Results can also provide important information for relatives.
Not every genetic change found in ovarian cancer is inherited. Some changes develop only within the tumor and cannot be passed to children.
Learn more about genetic and biomarker testing in ovarian cancer.
Some ovarian cancers can spread within the abdominal cavity. Cancer cells may shed from a tumor and attach to nearby tissues.
Cancer may spread to the peritoneum or organs within the abdomen. It can also grow directly into nearby tissues.
Cancer cells can also travel through lymphatic vessels or the bloodstream. In later stages, cancer may reach areas outside the abdomen.
Where cancer has spread helps determine its stage. Stage provides important information when your health care team develops a treatment plan.
Cancer keeps the name of the place where it started. Ovarian cancer found in another organ is still considered ovarian cancer.
Learn more about ovarian cancer types and stages.
Ovarian cancers are classified by the cells and tissues where they develop. The three main categories are epithelial, germ cell, and sex cord-stromal tumors.
These categories include different subtypes that can behave differently. Knowing the exact type can help your health care team plan treatment.
Epithelial ovarian cancers are the most common category. They develop from epithelial cells associated with the ovaries or fallopian tubes.
High-grade serous carcinoma is the most common ovarian cancer subtype. Other subtypes include low-grade serous, endometrioid, clear cell, and mucinous cancers.
Ovarian germ cell tumors begin in reproductive cells that produce eggs. They occur more often in adolescents and younger adults.
Some germ cell tumors are benign, while others are cancerous. Treatment depends on the exact tumor type and stage.
Sex cord-stromal tumors begin in tissues that support the ovary. These tissues include cells involved in hormone production.
Some stromal tumors produce hormones that can affect symptoms and treatment decisions.
Learn more about the different types and stages of ovarian cancer.
Ovarian cancer is one of the five main gynecologic cancers. The others are cervical, uterine, vaginal, and vulvar cancer.
Each cancer begins in a different part of the reproductive system. They can also have different symptoms, risk factors, screening approaches, and treatments.
Some cancers associated with ovarian cancer can begin in the fallopian tubes or peritoneum. These cancers are closely related to epithelial ovarian cancer.
Routine screening is available for cervical cancer, but not for ovarian cancer. A Pap test does not screen for ovarian cancer.
Learn more from the Centers for Disease Control and Prevention about gynecologic cancers.
Ovarian cancer symptoms can be subtle and may resemble common digestive or urinary problems. These symptoms often have causes other than cancer.
Common ovarian cancer symptoms include:
Pay attention to symptoms that are new, frequent, persistent, or getting worse. Unusual vaginal bleeding should also be discussed promptly with a health care provider.
Symptoms alone cannot tell you whether you have ovarian cancer. A health care provider can determine whether further evaluation may be needed.
Learn more about ovarian cancer signs and symptoms.
Ovarian cancer can be difficult to detect early because symptoms may be subtle. They can also resemble common digestive, urinary, or gynecologic conditions.
There is also no reliable routine screening test for ovarian cancer in people without symptoms. A Pap test does not screen for ovarian cancer.
Knowing the symptoms can help you recognize changes in your body. Persistent or unusual symptoms should be discussed with a health care provider.
Learn more about ovarian cancer signs and symptoms and ovarian cancer diagnosis.
When ovarian cancer is suspected, evaluation may include an exam, imaging, blood tests, and other testing. These tests can help identify possible causes of symptoms or abnormal findings.
A CA-125 blood test may provide useful information during an evaluation. However, CA-125 cannot confirm or rule out ovarian cancer by itself.
A pathologist usually confirms cancer by examining tissue or cells. Pathology also helps identify the ovarian cancer type and subtype.
Learn more about how ovarian cancer is diagnosed.
Ovarian cancer treatment is individualized. Treatment depends on the cancer type, stage, overall health, and other features of the diagnosis.
Genetic or biomarker testing may also help guide treatment decisions. These tests can identify inherited changes or features within the tumor.
Treatment may include:
Not every treatment is appropriate for every ovarian cancer type. Treatments may also be combined or used at different points in care.
Learn more about ovarian cancer treatment options.
The outlook for ovarian cancer varies from person to person. Stage is important, but it is not the only factor.
Other factors may include:
Two people with the same stage may have different cancers and treatment responses. Your health care team can explain which factors matter most.
Survival statistics describe outcomes among large groups of people. They cannot predict exactly what will happen to one person.
Statistics also reflect people treated during earlier years. Newer treatments may not be fully represented in current survival estimates.
Learn more about ovarian cancer survival statistics from the American Cancer Society.
Ovarian cancer is not one disease. Understanding a diagnosis often means learning several pieces of information together.
Your health care team may discuss:
These details help explain how your cancer may behave. They can also help determine which treatments may be considered.
If you are newly diagnosed, you do not need to learn everything at once. Ask your care team to explain unfamiliar terms.
Explore additional information and support:
No. Ovarian cancer includes several types and subtypes that can develop from different cells and tissues.
These cancers may grow differently or respond differently to treatment. Knowing the exact type is an important part of diagnosis.
Yes. Many high-grade serous cancers appear to begin near the end of a fallopian tube.
Cancer cells may later involve the ovary, peritoneum, or other abdominal tissues.
Learn more about ovarian cancer types and stages.
No. Some ovarian cancers are linked to inherited gene variants, but many are not.
Inherited variants can include changes in BRCA1, BRCA2, and genes associated with Lynch syndrome.
Learn more about genetic and biomarker testing in ovarian cancer.
Most ovarian cysts are not cancer. Many cysts develop as part of normal ovarian function and disappear without treatment.
Some ovarian masses need additional evaluation because of their appearance, symptoms, age, or other factors.
Learn more about ovarian cysts, endometriosis, PCOS, and ovarian cancer risk.
No. A Pap test is used to screen for cervical cancer.
It does not screen for ovarian cancer.
Learn more from the CDC about ovarian cancer screening.
No. Symptoms may be mild, vague, or difficult to recognize.
When symptoms occur, they may resemble common digestive, urinary, or gynecologic conditions.
Learn more about ovarian cancer signs and symptoms.
Yes. Ovarian cancer can spread within the abdomen or to other parts of the body.
Cancer may spread through nearby tissues, abdominal surfaces, lymphatic vessels, or the bloodstream.
Yes. There are several treatments for ovarian cancer.
Treatment depends on the cancer type, stage, biological features, overall health, and other individual factors.
Learn more about ovarian cancer treatment options.
Learn about factors linked with ovarian cancer risk and what may affect your individual risk.
Learn about common ovarian cancer symptoms and when changes should be discussed with a health care provider.
Learn how doctors evaluate possible ovarian cancer and which tests may be used during diagnosis.
© 2026 National Ovarian Cancer Coalition is a 501(c)(3) non-profit organization.
