An Overview of Ovarian Cancer

Symptoms, Causes, Diagnosis, and Treatment

Chemotherapy for ovarian cancer
Patient undergoing chemotherapy for ovarian cancer. Credit: Will & Deni Mcintyre / Getty Images


Ovarian cancer has been coined the "silent killer" due to its lack of symptoms until the condition is fairly advanced. What do you need to know about the symptoms, risk factors, diagnosis, and treatment of ovarian cancer? The average lifetime risk of developing this cancer is 1.6 percent, but since the disease often goes undetected until it reaches the advanced stages, it is the fifth most common cause of cancer-related deaths in women.

The female reproductive system consists of the vagina, the cervix (the lower portion of the uterus), the uterus, two fallopian tubes, and two ovaries. The ovaries are roughly the size of an almond, and are responsible for the development and release of an egg with each cycle. they are also responsible for the production of the hormones estrogen and progesterone. Ovarian cancer actually usually begins in the part of the fallopian tube closest to an ovary and then spreads to that ovary. These cancers may also sometimes begin in the peritoneum, the membranes the surround the contents of the abdomen, and then spread to an ovary. For that reason, ovarian cancer, cancer of the fallopian tubes, and primary peritoneal cancer are often grouped together when discussing these cancers.


There are 3 basic categories of ovarian cancer (though there are more than 30 subtypes). These different types may be treated in different ways, have a different prognosis, and occur in women of different ages in general.

The main types of ovarian cancer include epithelial ovarian tumors, stromal cell tumors, and germ cell tumors.

Epithelial ovarian tumors arise from the layer of cells (the epithelial layer) lining the ovaries and fallopian tubes and account for 90 to 95 percent of ovarian cancers. The risk of these cancers increases with age, and most people are postmenopausal when diagnosed.

The most common subtypes include endometrioid, mucinous, and serous tumors, with the majority being serous. Mucinous and endometrioid tumors are more common in women under the age of 40. 

Stromal tumors can be either benign or malignant and begin in the stroma (the tissue which surrounds the egg and holds the ovaries together). These are in turn broken down into several subtypes, including granulosa cell tumors that are aggressive in the juvenile form (found between birth and age 20) but usually non-aggressive in the adult form, and Sertoli cell tumors.

Germ cell tumors can also be either benign or malignant, and are the most common form of ovarian cancer in those under 30. The most common age of diagnosis is between the ages of 10 years and 30 years. These tumors begin in the reproductive cells (the egg), and account for around 3 percent of ovarian cancers. Germ cell tumors are often diagnosed in the early stages but tend to grow rapidly. A few of the subtypes include dysgerminomas, endodermal sinus tumors, and immature teratomas

Small cell carcinoma of the ovary is uncommon, making up only 0.1 percent of ovarian cancers.


The symptoms of ovarian cancer are often subtle and vague in the early stages of the disease, and are often attributed to other, less serious conditions.

Even though around 80 percent of these cancers are already at an advanced stage when diagnosed, recent research has found four symptoms that are common in the earlier stages. These include:

  • Changes in bowel habits like constipation or diarrhea
  • Pelvic pain or pressure
  • A frequent need to urinate or urinary urgency
  • Bloating or abdominal swelling

Symptoms of ovarian cancer that often do not appear until the disease has progressed include:

  • Pain during sexual intercourse
  • Persistent fatigue
  • Abdominal weight gain or fluid build-up (ascites)
  • Constipation
  • Sudden unexplained weight gain or unintentional weight loss

    Symptoms due to hormones produced by the tumor (estrogen or testosterone):

    • Masculinization with a deepening of the voice and facial hair (usually associated with sex cord-stromal tumors)
    • Precocious puberty (early onset puberty in young girls)
    • Abnormal uterine bleeding, such as postmenopausal bleeding or bleeding between periods

    Causes and Risk Factors

    Unfortunately, we cannot pinpoint exactly what causes ovarian cancer, but researchers have identified several known risk factors for its development. While risk factors are important, it's important to keep in mind that ovarian cancers may occur in people who have no risk factors or family history of the disease, and a high index of suspicious is important if we are to find these cancers at an earlier stage than is now happening. Risk factors include:

    • Age. The risk of epithelial ovarian cancers increases with age and the majority of these cancers are diagnosed after menopause.
    • Caucasian ethnicity.
    • A family history of ovarian cancer, breast cancer, or colon cancer on either side of the family. Having a first degree relative with ovarian cancer (mother, sister, or daughter) is associated with a 5 percent lifetime risk of developing the disease. The risk may be higher if more than one relative is affected.
    • A personal history of breast cancer. 
    • Some gene mutations such as BRCA1 and BRCA2 gene mutations.
    • Obesity.
    • Being tall (5 foot 8 inches or taller).
    • A history of infertility.
    • Unopposed estrogen replacement therapy (estrogen alone without progesterone).

    Factors associated with a lower risk of ovarian cancer include:

    • Having a child before the age of 26.
    • Breastfeeding.
    • Use of oral contraceptives for at least 3 months.
    • Tubal ligation surgery (may reduce the risk by up to 70 percent).
    • Hysterectomy (may reduce risk by up to one-third).
    • Removal of both of the tubes and ovaries (bilateral salpingo-oophorectomy): This reduces the risk of ovarian cancer by 75 to 90 percent, but not completely.

    Ovarian cancer is less common in young women. When it occurs, there is often a family history and it's more likely to be related to hereditary factors such as BRCA mutations. Ovarian cancer is the fifth most common cancer diagnosed during pregnancy and occurs in 1 in 18,000 pregnancies.


    Diagnosing ovarian cancer often requires a combination of imaging and lab tests, as well as having a high index of suspicion. A doctor may make the diagnosis during a routine pelvic exam, or a person may present with symptoms of the tumor or metastases (spread) from the tumor.

    The first test that is usually done is a transvaginal ultrasound. Ultrasound, in particular, can help determine if a mass is a simple cyst, and most likely benign, or solid, and more likely malignant. A blood test called CA-125 may be elevated, but is normal in some people with early ovarian cancer and may be elevated by many other medical conditions. There a number of indices, such as the risk of malignancy index, that may help determine if a biopsy is needed.

    Other imaging tests, such as CT, MRI, and PET scans, along with other blood tests may be ordered, but many of these tests are used primarily to look for any evidence of metastasis (spread) of the cancer.

    A biopsy is needed both to confirm the diagnosis and identify the type. Biopsies are usually performed via a pelvic laparoscopy (a test in which several small incisions are made in the abdomen and an instrument with a camera is inserted to take the biopsy) or laparotomy (open abdominal surgery). Unlike some other areas of the body, a needle biopsy is not usually done as it's thought that the procedure may "seed" or result in the spread of a cancer if one is found. 

    After diagnosis, staging of the tumor is very important in order to determine the most appropriate treatment options. This can be done with a combination of tumor findings on the biopsy sample, and imaging studies, but often requires surgery (removal of the cancer and areas of spread if present) to accurately stage the tumor.


    Treatment options for ovarian cancer depend on the type, stage, and grade of ovarian cancer, as well as other factors such as age and general health. There are three primary treatment methods for ovarian cancer: surgery, chemotherapy, and targeted therapy. Surgery combined with chemotherapy is the most common treatment course for all but the earliest stages of the disease. Radiation therapy is not commonly used, but may be recommended for some women with extensive metastases in their abdomen.


    Surgery may be considered for all stages of ovarian cancer. For very early tumors, especially stromal and germ cell tumors, removal of the ovary and fallopian tube on one side may be done for those who hope to preserve their fertility.

    Unlike many stage 4 cancers, in which surgery does not make a difference in survival, debulking or cytoreduction surgery does improve survival with advanced ovarian cancers. The goal in this setting is to remove as much of the tumor (and metastases) as possible, in order to increase the effectiveness of chemotherapy. Many people are confused that the "ideal" cytoreduction surgeries do not usually attempt to remove all cancer cells (complete cytoreduction). Instead, an "optimal" cytoreduction surgery is one in which clusters of tumor cells remain, but are less than 1 cm (about half an inch) in diameter.

    Ovarian cancer surgery is often a lengthy and very meticulous surgery.  For that reason, it is not surprising that studies suggest that surgery performed by a gynecologic oncologist (a specialist in gynecological cancer, especially ovarian cancer) may result in better outcomes. Getting a second opinion can be extremely important, and many people recommend getting an opinion at a National Cancer Institute-designated cancer center which has surgeons who specialize in cytoreductive surgery for ovarian cancer.


    Chemotherapy to treat ovarian cancer is used to eliminate cancer cells that remain after surgery, or to reduce the risk of recurrence when no obvious cancer cells remain. The drugs are delivered either intravenously or directly into the abdominal cavity (intraperitoneal chemotherapy). Chemotherapy may be given before or after surgery. It can also be given alone as palliative chemotherapy, to reduce symptoms but not in an attempt to cure cancer. How often and how long a person receives chemotherapy is based on their stage of ovarian cancer and other health factors. The most common chemotherapy regimens for epithelial ovarian cancer use a combination of a platinum drug (such as Platinol or cisplatin) and a taxane (such as Taxol or paclitaxel).

    Targeted Therapy

    Targeted therapies are drugs that target specific pathways in the growth of cancer cells. Since they specifically target cancer cells, and they often (but not always) have fewer side effects than conventional chemotherapy drugs. There are two types of targeted therapies which are used. One type is known as an angiogenesis inhibitor, a drug that inhibits the formation of new blood vessels by tumors (so the tumor can't continue to grow and expand). The other is a category of drugs known as PARP inhibitors, which targets a pathway in cancer cell growth. One of the PARP inhibitors is approved only for women with a BRCA gene mutation, while the other two may be used for women with or without these mutations.

    Clinical Trials

    Clinical trials are in progress studying combinations of the above therapies, as well as newer therapies such as immunotherapy drugs. According to the National Cancer Institute, people who are diagnosed with ovarian cancer should consider taking part in a clinical trial. Some of these trials offer treatments which would otherwise be unavailable outside of a medical research study.


    While the median survival rate for high-grade epithelial ovarian cancer (all stages combined) is 5 years, roughly 15 percent of people will be alive after 10 years. Researchers are now studying these "outliers" in hopes of finding better ways to treat the disease.

    Prognosis for individuals is dependent on many factors, such as the response to treatment and much more. Factors associated with a better prognosis include younger age, lower grade tumors, earlier stage at diagnosis, non-serous types, the absence of ascites (abdominal fluid), and optimal cytoreduction surgery. Having a BRCA mutation doesn't appear to affect survival either way.

    A Word From Verywell

    At the current time, most epithelial ovarian cancers are diagnosed in the later stages of the disease. Since we do not have a screening test, and even screening those at a higher risk does not appear to lower the death rate, it's important for women to be aware of the symptoms and seek medical attention if they should experience any of these signs.

    If you or a loved one have recently been diagnosed with ovarian cancer, you may feel very frightened as you look at the statistics surrounding ovarian cancer. Despite these sobering numbers, however, treatments for the disease are improving as are survival rates, and many clinical trials are in progress today looking for newer and better ways to treat the disease.


    Hoppenot, C., Eckert, M., Tienda, S., and E. Lengyel. Who Are the Long-Term Survivors of High-Grade Serous Ovarian Cancer?. Gynecologic Oncology. 2018. 148(1):204-212.

    National Cancer Institute. Ovarian Epithelial, Fallopian Tube, and Primary Peritoneal Cancer Treatment (PDQ)—Health Professional Version. Updated 01/19/18.