Symptoms of epithelial ovarian cancer can be easily confused with other health conditions. For this reason, many people don’t receive a diagnosis until the cancer has spread.

About 19,710 women in the United States will receive a diagnosis of ovarian cancer in 2023, according to the American Cancer Society. While ovarian cancer is the fifth most common cause of cancer deaths in women, rates of new diagnoses and deaths have been gradually decreasing.

Most people with ovarian cancer will have a type called epithelial ovarian cancer (EOC). There are several subtypes of EOC.

This article takes a closer look at EOC, its symptoms, and how it’s diagnosed and treated.

EOC is one of the three main types of ovarian cancer. It begins in the cells that line the outside of your ovaries.

EOC is the most common type of ovarian cancer. An estimated 85–90% of ovarian cancers are epithelial.

There are also several subtypes of EOC:

Of these subtypes, serous ovarian cancer is the most common, making up about 52% of all EOC cases. Serous ovarian cancer is further classified as low grade or high grade based on how quickly it’s expected to grow and spread.

Other types of ovarian cancer

In addition to EOC, there are two other types of ovarian cancer, which are much less common.

Germ cell ovarian cancer begins in the cells that produce the eggs used in reproduction. Examples of germ cell tumors include:

Stromal ovarian cancer starts in connective tissue that supports the ovaries and makes the hormones estrogen and progesterone. Granulosa cell tumors are the most common type of stromal ovarian cancer.

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Some people with early stage EOC don’t notice any symptoms. As a result, many EOC cases aren’t diagnosed until they’ve reached more advanced stages.

When symptoms of EOC are present, they can include:

EOC symptoms can be vague and similar to those of other, more common health conditions. The key is to recognize when these symptoms are a significant change from what you typically experience and whether they persist for at least 2 weeks.

If you develop symptoms that are persistent, keep coming back, or are severe, consult your doctor to discuss them. While these symptoms may not be due to EOC, they could indicate another medical issue that needs attention.

How aggressive is epithelial ovarian cancer?

Whether EOC is aggressive depends on the type of EOC you have. There are two types:

  • Type 1 EOC includes:
    • low grade serous ovarian cancer
    • clear cell ovarian cancer
    • mucinous carcinoma
    • endometroid carcinoma
  • Type 2 EOC includes:
    • high grade serous ovarian cancer
    • carcinosarcoma
    • undifferentiated carcinomas

Aside from clear cell ovarian cancer, type 1 cancers are low grade. This means they grow and spread slowly. Type 2 cancers are high grade, which means they are more aggressive and are likely to grow and spread rapidly.

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EOC happens when the epithelial cells of your ovaries begin to grow and divide uncontrollably. This happens due to genetic changes that you may either inherit or acquire during your lifetime.

Some of the known risk factors for EOC are:

The exact treatment for EOC largely depends on the stage of your EOC and whether it’s low grade or high grade.

Other factors that play a role in treatment decisions include:

  • the specific type of EOC you have
  • the genetics of the cancer
  • whether the cancer is newly diagnosed or has returned
  • your age and overall health
  • your personal preference


Surgery to remove the cancer is a big part of EOC treatment. The extent of the surgery depends on how far the cancer has spread at the time of your diagnosis.

Surgery for EOC most often involves removing your uterus, both fallopian tubes, and both ovaries. This is called a hysterectomy with bilateral salpingo-oophorectomy.

If the cancer has spread farther into your abdomen or pelvis, surgeons may remove other tissues as well, including your omentum and parts of other organs, such as your intestines, liver, and bladder.

If you have early stage, low grade EOC and you wish to have children in the future, your care team may give you the option of removing only the affected ovary and fallopian tube to preserve your fertility.


Chemotherapy involves drugs that kill cancer cells or slow down their growth. Platinum-based chemotherapy is often used for EOC. Chemotherapy may be used:

  • before surgery to shrink a tumor
  • after surgery to help kill any remaining cancer cells
  • as the only treatment in cases of advanced cancer or in people who cannot have surgery or choose not to do so

Targeted therapy

Targeted therapy drugs focus on certain aspects of the cancer. They’re more specific than chemotherapy drugs.

Targeted therapy is typically used when EOC is advanced or has returned after treatment. Depending on the drug, targeted therapy may be used alone or in combination with chemotherapy.

Examples of targeted therapy drugs used for EOC include:


Immunotherapy helps boost your immune system’s response to cancer. It’s not a common treatment for EOC, as there are no approved immunotherapies for ovarian cancer.

An immunotherapy drug called pembrolizumab (Keytruda) may be used in some cases when EOC is advanced or has returned after treatment.

The outlook for EOC depends on many factors, including:

  • the stage and grade of the cancer
  • the specific type of cancer
  • the genetics of the cancer
  • how the cancer responds to the recommended treatment
  • whether the cancer returns after treatment
  • your age and overall health

EOC makes up the majority of ovarian cancers. Many times, it isn’t diagnosed until more advanced stages, when it has spread. As a result, the overall outlook can be less favorable.

According to the SEER Database of the National Cancer Institute, the 5-year relative survival rates for ovarian cancer in 2013 through 2019 were:

  • 50.8% overall
  • 92.4% for cancer that was localized to the ovary
  • 72.9% for cancer that had spread regionally
  • 31.5% for cancer that had spread to distant tissues

But keep in mind that cancer survival rates are just statistics. They don’t account for individual factors or recent advances in treatment. Your care team can give you a better idea of your specific outlook.

EOC is the most common type of ovarian cancer. It has several subtypes, with serous ovarian cancer being the most common.

Many people with EOC don’t have symptoms when their cancer is at an early stage. Because of this, EOC is often diagnosed when it’s already advanced. This makes the overall outlook for EOC less favorable.

EOC is typically treated with surgery and chemotherapy, but targeted therapy or immunotherapy may be used if the cancer is advanced or has returned after treatment.