What are the main types of ovarian cancer?
Ovarian tumors are classified based on the type of cell or tissue where they develop.
The three main types are:
- Epithelial ovarian cancers: Begin in epithelial cells (cells that cover the surface of the ovary) associated with the ovaries or fallopian tubes. Most ovarian cancers are epithelial cancers.
- Ovarian germ cell tumors: Begin in the germ cells (reproductive cells) that produce eggs.
- Sex cord-stromal tumors: Begin in stromal cells (ovarian tissue cells) that support the ovary and include cells that produce hormones.
Not every ovarian tumor is cancer. Some tumors are benign, meaning noncancerous, or borderline, meaning they contain abnormal cells but behave differently from invasive ovarian cancer.
The American Cancer Society provides additional information about ovarian tumors and the different types of ovarian cancer.
What is epithelial ovarian cancer?
Epithelial ovarian cancer is the most common category of ovarian cancer.
These cancers develop from epithelial cells associated with the ovaries or fallopian tubes. Cancers that begin in the fallopian tubes or peritoneum, the tissue lining the abdominal cavity, are closely related and are generally staged and treated in similar ways.
There are five subtypes of epithelial ovarian cancer:
Knowing the specific subtype is important because these cancers can behave differently and may respond differently to treatment.
High-grade serous ovarian cancer
High-grade serous ovarian cancer, also called high-grade serous carcinoma or HGSC, is the most common ovarian cancer subtype.
Research shows that many high-grade serous cancers begin in cells at the end of the fallopian tube before involving the ovary or other areas of the abdomen.
High-grade serous cancer tends to grow and spread more quickly than low-grade serous ovarian cancer. Treatment commonly includes ovarian cancer surgery and chemotherapy.
Genetic testing for an inherited mutation and tumor biomarker testing may also identify information that can help guide treatment.
Learn more about genetic testing for an inherited mutation and tumor biomarker testing in ovarian cancer.
Low-grade serous ovarian cancer
Low-grade serous ovarian cancer, also called low-grade serous carcinoma or LGSOC, is a rare type of ovarian cancer.
LGSOC generally grows more slowly than high-grade serous ovarian cancer and is more often diagnosed in younger adults. It also tends to respond differently to standard chemotherapy.
Low-grade and high-grade serous ovarian cancers are considered different diseases rather than different stages of the same cancer.
Depending on the individual diagnosis, treatment may include surgery, hormone therapy, targeted therapy, chemotherapy, or participation in a clinical trial.
Learn more about low-grade serous ovarian cancer and recent treatment advances.
💡 Questions to ask about low-grade serous ovarian cancer
If you have been diagnosed with LGSOC, understanding how this subtype differs from other ovarian cancers can help you prepare for treatment discussions.
NOCC’s Questions to Ask Your Doctor: Low-Grade Serous Ovarian Cancer guide includes questions about diagnosis, stage, pathology, tumor testing, treatment, second opinions, and other aspects of care.
Download the Low-Grade Serous Ovarian Cancer Questions Guide PDF
Endometrioid ovarian cancer
Endometrioid ovarian carcinoma is a less common epithelial ovarian cancer subtype.
It is often associated with endometriosis in some people and may also be connected with inherited conditions such as Lynch syndrome.
Having endometriosis does not mean that you will develop ovarian cancer. The overall risk remains low.
Learn more about endometriosis and other ovarian cancer risk factors.
Clear cell ovarian cancer
Clear cell ovarian carcinoma is another less common epithelial ovarian cancer subtype.
Like endometrioid ovarian cancer, clear cell ovarian cancer has been associated with endometriosis. It has biological characteristics that differ from high-grade serous ovarian cancer and may respond differently to some treatments.
Because clear cell ovarian cancer is less common, discussing treatment with a gynecologic oncologist experienced in your specific subtype may be helpful.
Mucinous ovarian cancer
Mucinous ovarian carcinoma is a rare type of epithelial ovarian cancer.
When a mucinous tumor is found in the ovary, careful pathology review is important because cancers that begin elsewhere in the body, particularly in the gastrointestinal tract, can sometimes spread to the ovary and look similar to a primary mucinous ovarian cancer.
Treatment depends on the stage, pathology findings, and whether the cancer began in the ovary or another part of the body.
What are fallopian tube and primary peritoneal cancers?
Fallopian tube cancer begins in the fallopian tubes, which connect the ovaries to the uterus.
Primary peritoneal cancer begins in the peritoneum, the thin layer of tissue lining the inside of the abdomen and covering many abdominal organs.
Epithelial ovarian, fallopian tube, and primary peritoneal cancers develop in similar tissues and are generally staged and treated in similar ways.
Research has also shown that many cancers once thought to begin in the ovaries, especially high-grade serous cancers, may actually begin in the fallopian tubes.
Learn more from the American Cancer Society about ovarian, fallopian tube, and primary peritoneal cancers.
What are germ cell and sex cord-stromal ovarian tumors?
Germ cell and sex cord-stromal tumors are much less common than epithelial ovarian cancers.
Ovarian germ cell tumors
Ovarian germ cell tumors begin in the reproductive cells that produce eggs. They occur more often in adolescents and young adults.
Some germ cell tumors are benign, such as most mature teratomas, also called dermoid cysts. Others are cancerous.
Malignant germ cell tumors include:
- Dysgerminoma
- Immature teratoma
- Yolk sac tumor
- Mixed germ cell tumors
Because these cancers often affect younger people, fertility preservation may be an important part of treatment planning.
The National Cancer Institute provides additional information about ovarian germ cell tumors.
Sex cord-stromal ovarian tumors
Sex cord-stromal tumors begin in tissues that support the ovary and include cells that produce hormones.
Cancerous stromal tumors can include:
- Granulosa cell tumors
- Sertoli cell tumors
- Sertoli-Leydig cell tumors
Some stromal tumors are benign.
Because these tumors may produce hormones, they can sometimes cause symptoms related to changes in estrogen or androgen levels.
Treatment depends on the specific tumor type, stage, age, fertility goals, and other individual factors.
What about rare ovarian cancer subtypes?
Some ovarian cancers are much less common and may have certain features and treatment considerations that differ from the more common ovarian cancer types.
Examples include ovarian carcinosarcoma and small cell carcinoma of the ovary, hypercalcemic type.
If you have been diagnosed with a rare ovarian cancer, ask whether your care team has experience treating your specific subtype and whether a second opinion or consultation with a specialist may be helpful.
Learn more in NOCC’s Rare Ovarian Cancer Subtypes: What Patients Need to Know.
What does the stage of ovarian cancer mean?
Cancer stage describes where the cancer is located and how far it has spread.
Ovarian, fallopian tube, and primary peritoneal cancers are generally staged from Stage I through Stage IV.
In general:
- Stage I: Cancer is limited to the ovaries or fallopian tubes.
- Stage II: Cancer has spread within the pelvis.
- Stage III: Cancer has spread outside the pelvis into the abdomen and/or nearby lymph nodes.
- Stage IV: Cancer has spread to distant areas of the body.
Doctors commonly use the FIGO staging system developed by the International Federation of Gynecology and Obstetrics.
Cancer staging can be complex. Your doctor can explain what your specific stage and substage mean for your diagnosis.
The American Cancer Society provides detailed information about ovarian cancer staging.
What is stage I ovarian cancer?
In Stage I ovarian cancer, the cancer is limited to one or both ovaries or fallopian tubes.
Stage I is divided into smaller substages based on whether one or both ovaries or fallopian tubes are involved and whether cancer cells are found on the surface or in abdominal or pelvic fluid.
Cancer is inside one ovary or fallopian tube. The outer surface is not involved, and cancer cells are not found in abdominal or pelvic fluid or washings.
Cancer is inside both ovaries or fallopian tubes. The outer surfaces are not involved, and cancer cells are not found in abdominal or pelvic fluid or washings.
Cancer is in one or both ovaries or fallopian tubes, but the tumor ruptured, cancer is found on the outer surface, or cancer cells are found in abdominal or pelvic fluid or washings.
Stage IC is further divided into IC1, IC2, and IC3 based on when rupture occurred or where cancer cells were found.
What is stage II ovarian cancer?
In Stage II ovarian cancer, cancer has spread from one or both ovaries or fallopian tubes to other tissues or organs within the pelvis.
Cancer has spread to or grown into the uterus, fallopian tubes, and/or ovaries.
Cancer has spread to other nearby pelvic tissues or organs such as the bladder, colon, or rectum.
What is stage III ovarian cancer?
In Stage III ovarian cancer, cancer has spread outside the pelvis to the lining of the abdomen and/or nearby lymph nodes.
Stage III is divided into substages based on where the cancer is found and the size of areas that have spread outside the pelvis.
Cancer has spread to nearby retroperitoneal lymph nodes (pelvic area) but there is no other spread outside the pelvis.
Microscopic cancer is found on the peritoneum outside the pelvis. Cancer may also be present in nearby lymph nodes.
Cancer has visibly spread outside the pelvis, and the areas of spread are 2 centimeters or smaller. Cancer may also be present in nearby lymph nodes.
Cancer has visibly spread outside the pelvis, and at least one area is larger than 2 centimeters. Cancer may also involve nearby lymph nodes or the outer surface of the liver or spleen.
What is stage IV ovarian cancer?
Stage IV ovarian cancer means that cancer has spread to distant areas of the body.
Stage IV ovarian cancer can still be treated. Treatment depends on factors such as the cancer type and subtype, where it has spread, your overall health, previous treatment, and biomarker results.
Cancer cells are found in fluid around the lungs. This is called a malignant pleural effusion.
Cancer has spread to the inside of organs such as the liver or spleen, lymph nodes outside the abdominal cavity, or other distant organs or tissues.
How is ovarian cancer stage determined?
Ovarian cancer staging may use information from:
- Imaging tests
- Physical examination
- Biopsy and pathology results
- Surgery
- Lymph node evaluation
- Fluid or washings from the abdomen and pelvis
For many people, the final stage is determined after tissue removed during surgery has been examined by a pathologist.
In some situations, especially when surgery is not performed first, doctors may initially estimate the stage using examination, imaging, and biopsy results.
Learn more about how ovarian cancer is diagnosed and ovarian cancer surgery.
What is the difference between ovarian cancer stage and grade?
Stage and grade describe different characteristics of cancer.
- Stage describes where cancer is located and how far it has spread.
- Grade describes characteristics of the cancer cells when viewed under a microscope and may provide information about how the tumor is likely to behave.
The grading system used depends on the type of ovarian cancer.
For example, high-grade serous carcinoma and low-grade serous carcinoma are biologically different ovarian cancer types. They are not simply different numerical grades of the same cancer.
Some other ovarian cancers may receive a numerical grade based on their pathology.
Your pathology report may include your cancer type, subtype, grade, and other features. Ask your health care provider to explain what these findings mean for you.
Why do ovarian cancer type, stage, and grade matter?
Cancer type, subtype, stage, and grade help your health care team understand the disease and determine which treatments may be appropriate.
Treatment decisions may also depend on:
- Your age and overall health
- Whether surgery can remove all or most visible cancer
- Inherited genetic mutations
- Biomarkers or molecular changes found in the tumor
- Previous cancer treatments
- Fertility considerations
- Your personal goals and preferences
Two people with the same ovarian cancer stage may receive different treatment recommendations because their cancers have different biological features.
Learn more about:
💡 Watch: Understanding ovarian cancer types and stages
NOCC’s You and Ovarian Cancer Animated Patient Guide offers visual explanations of ovarian cancer diagnosis, staging, testing, and treatment.
Explore the Ovarian Cancer Animated Patient Guide
Understanding your diagnosis
Learning the type and stage of ovarian cancer can bring a lot of new information at once. You do not need to understand every medical term immediately.
Ask your health care team to explain your pathology report, stage, tumor testing, and treatment recommendations in a way that makes sense to you. Bringing a written list of questions to appointments can help.
Explore additional information and support:
Frequently asked questions about ovarian cancer types and stages
High-grade serous carcinoma is the most common type of ovarian cancer.
Many high-grade serous cancers are now believed to begin in the fallopian tubes before involving the ovaries or other areas of the abdomen.
No. Low-grade serous and high-grade serous ovarian cancers are biologically different diseases.
Low-grade serous cancer generally grows more slowly and responds differently to treatment. High-grade serous cancer typically grows more quickly and is much more common.
The type describes the kind of cancer and the cells or tissue where it developed.
The stage describes where the cancer is located and how far it has spread.
Both are important when your health care team develops a treatment plan.
No. Most ovarian cysts are not cancer.
Ovarian cysts are fluid-filled sacs that develop in or on an ovary. Many form as part of normal ovulation and go away without treatment.
A health care provider may recommend additional evaluation if a cyst persists, has unusual features on imaging, causes symptoms, or develops after menopause.
Learn more about ovarian cysts, endometriosis, PCOS, and ovarian cancer risk.
Usually, no.
A dermoid cyst is another name for a mature teratoma. Mature teratomas are ovarian germ cell tumors that are usually benign.
An immature teratoma is different. It is a rare malignant germ cell tumor that occurs most often in younger people.
Yes. Stage IV ovarian cancer can be treated.
Treatment is individualized and may include surgery, chemotherapy, targeted therapy, hormone therapy, clinical trials, or other approaches depending on the specific cancer and patient.
A Stage IV diagnosis describes how far cancer has spread. It does not predict exactly how an individual person will respond to treatment.
A pathology report may include:
The type and subtype of ovarian cancer
Tumor grade
Information about the tissue examined
Lymph node findings when applicable
Other characteristics that may help guide treatment
Additional genetic or biomarker testing may provide information that is not included in the initial pathology report.
Ask your health care provider for a copy of your pathology report and to explain any terms you do not understand.
You may also find NOCC’s 11 Questions to Ask Your Doctor When Newly Diagnosed With Ovarian Cancer helpful.
The stage assigned when ovarian cancer is first diagnosed generally remains part of your medical history even if the cancer later grows, spreads, responds to treatment, or returns.
If ovarian cancer comes back after treatment, it is usually described as recurrent ovarian cancer rather than being assigned a new stage.
More information about ovarian cancer types and stages
