What is ovarian cancer?
Ovarian cancer, also known as cancer of the ovaries, is a type of cancer that affects females. It refers to several types of cancer that can develop in the ovaries (the organs that store eggs and are connected to the womb), as well as cancer of the fallopian tubes or tissues in the abdomen.
While it is not the most common type of cancer in women, ovarian cancer has a higher mortality (death) rate than other cancers of the female reproductive system. This may be because symptoms of ovarian cancer are not always obvious, leading to late diagnosis. The prognosis (outlook) tends to be better the earlier the cancer is detected.
This type of cancer mostly affects women over the age of 50, and the average age at diagnosis is 63. Every year, more than 20 000 women in the United States are diagnosed with ovarian cancer; in Europe this number is closer to 65 000.
Treatment depends on the type of ovarian cancer and stage of diagnosis, but typically involves a combination of surgery and chemotherapy. Recovery rates tend to be better in cases where the cancer is diagnosed early, and where the woman is younger than 40.
Types of ovarian cancer
Epithelial ovarian tumors
These comprise the vast majority (about 90 percent) of malignant ovarian cancers. Epithelial ovarian tumors develop in the epithelium, which is the thin layer of tissue covering the ovaries. These most often occur in women over the age of 50. There are several subtypes of epithelial tumors.
Not all epithelial tumors are cancerous (called malignant, or carcinomas). Many epithelial tumors are benign, having less of a tendency to spread.
Some epithelial tumors are called borderline ovarian tumors, or tumors of low malignant potential (LMP tumors); these fall between benign and malignant. They tend to affect younger women, and have a better prognosis (outlook).
Germ cell tumors
Cancerous germ cell tumors account for only a small percentage of malignant ovarian cancers. They are most common in women under 35, and tend to have a good prognosis. The tumors, of which there are six different types, develop from the cells that form eggs. They are typically detected as a painful abdominal mass that gets bigger quickly.
Cancerous stromal tumors also account for just a small percentage of ovarian cancers. Stromal tumors form in the connective tissue cells, which keep the ovary intact and produce female hormones. Most cases are diagnosed early and tend to have a good prognosis.
Stromal tumors, of which there are several different types, can produce sex hormones, causing symptoms that include:
- Unexplained vaginal bleeding
- Precocious breast development in young girls
And, in some cases:
- An absence of menstruation
- Increased growth of facial and body hair
Small cell carcinoma of the ovary
This is a rare type of cancerous tumor that mostly affects young women. There are several different kinds of small cell carcinoma of the ovary.
Sometimes, other types of cancer spread from elsewhere in the body to the ovaries. Examples include cancer of the breast, uterus, cervix and gastrointestinal tract. These types of tumors are called metastatic tumors.
Symptoms of ovarian cancer
Early signs and symptoms of ovarian cancer may be vague and similar to those found in many gastrointestinal conditions, such as irritable bowel syndrome (IBS). This can make the cancer difficult to recognize.
However, symptoms caused by ovarian cancer are typically persistent and represent a change from normal. If a person experiences any unexplained symptoms, it is advisable that they consult a healthcare practitioner, preferably a gynecologist (a doctor specializing in the female reproductive system), without delay.
- Bloating and swelling of the abdomen (stomach)
- Pain or discomfort in the abdominal (stomach) or pelvic area
- Difficulty eating, or feeling full soon after beginning a meal
- Needing to urinate more urgently or often than usual
Many people with ovarian cancer experience non-specific gastrointestinal symptoms for a period of at least three months.
- Indigestion (dyspepsia)
- Feeling full quickly (early satiety)
- Swelling of the abdomen (belly)
- Increase in circumference of the abdomen
- Back pain
- Pain during sex
- Unexplained vaginal bleeding or discharge
- Menstrual changes
- Unexplained weight loss
Symptoms of granulosa cell tumors
A granulosa cell tumor (GCT), a type of stromal tumor of the ovary, may have signs and symptoms that are different from the above. These tumors typically present as large masses, which may be palpable.
Abdominal pain or discomfort, and unexplained bleeding from the vagina in older people, are among the more common symptoms of GCTs. However, symptoms differ according to the lifestage of a person and may include the following:
- In postmenopausal people (those who have experienced menopause): Vaginal discharge, breast tenderness, cancer of the uterus, in rare cases development of male traits like male-pattern hair growth or facial hair (caused by elevated testosterone levels).
- In premenopausal people (those who have not experienced menopause): Irregular, unusually heavy or absent periods, abdominal swelling (increased girth) – often with a mass that can be felt, in some cases development of male traits like male-pattern hair growth or facial hair (caused by elevated testosterone levels).
- In prepubescent children (those who have not yet experienced puberty): Early puberty, and in some cases development of male traits like male-pattern hair growth or facial hair.
In most cases, GCTs are detected at an early stage and the prognosis is good.
Causes of ovarian cancer
The causes of ovarian cancer are not known. However, certain factors are thought to increase a person’s risk of developing the condition.
Ovarian cancer risk factors
- Being over 50
- Having a close relative who has had ovarian cancer, or cancer of the breast, colon, uterus or rectum
- Having an inherited mutation in breast cancer gene 1 (BRCA1) or breast cancer gene 2 (BRCA2) – this is particularly prevalent among Eastern European females and females of Ashkenazi Jewish descent
- Carrying genes linked to hereditary nonpolyposis colorectal cancer (HNPCC), known as Lynch syndrome
- Polycystic ovary syndrome (PCOS)
- Intrauterine devices
- Cigarette smoking
People over the age of 50 and those who have a strong family history of ovarian (or breast) cancer, a BRCA mutation or Lynch syndrome may be encouraged to undergo screening for ovarian cancer.
Diagnosis of ovarian cancer
As the first step, a doctor will need to confirm that the symptoms are not being caused by any other conditions, including uterine fibroids, endometriosis, and gastrointestinal disorders.
A doctor will typically take the person’s medical history and perform a physical examination, including a pelvic examination. If they suspect that ovarian cancer may be present, they will order an ultrasound, computed tomography (CT) scan, or a magnetic resonance imaging scan (MRI) to investigate.
The doctor will also order blood tests to check, among other things, the levels of a substance called cancer antigen (CA) 125. This is a tumor marker that is often found at elevated levels in people with ovarian cancer. However, this test is not totally reliable; certain other conditions, such as endometriosis, can cause the levels to be high, and in some cases of ovarian cancer the levels are not elevated.
If the combined tests suggest that ovarian cancer may be present, it will usually be necessary to undergo surgery to confirm the diagnosis. In a small number of cases, a non-surgical biopsy, where the doctor takes a sample of tissue or fluid with a needle, may be performed.
A pap test, which is used to screen for cervical cancer, usually cannot detect ovarian cancer.
The aim of surgery is to confirm the diagnosis, define the extent of disease, and remove all visible tumor. If ovarian cancer is suspected, the doctor may recommend an exploratory laparotomy or sometimes an exploratory laparoscopy, depending on the age of the person and size of the identified mass, among other factors.
For the highest probability of success, a gynecologic oncologist, a medical professional specializing in the management of cancers of the female reproductive system, should be asked to perform the surgery.
The surgeon will typically make a long incision in the abdomen in order to check the area for any signs of cancer. Where possible, they may take samples of tissue and fluid, which will be closely examined by a specialist while the person is in the operating room. If cancer is strongly suspected or confirmed, the surgeon will remove as much of the cancerous tissue as they can during the same procedure. Called debulking, this may involve removing the uterus, fallopian tubes and one or both ovaries, as well as nearby tissue and organs if the cancer has spread.
If a person is not a good candidate for surgery to remove the bulk of the tumor tissue, a doctor may recommend that they undergo a course of initial chemotherapy to reduce the tumor size, followed by surgery to remove tumor tissue, and further chemotherapy.
In some cases, for instance when the person is young and the likelihood of cancer small, or where a laparotomy cannot be performed, this less-invasive type of surgery may be recommended. The surgeon will typically make a small incision in the abdomen to insert a laparoscope – a flexible tube with a camera on the end – and use this to check for cancer. Tissue and fluid samples can also be taken, and the ovaries removed, if necessary, during the procedure.
- Stage I ovarian cancer: The cancer is at an early stage. Tumors are found in one or both ovaries, and, depending on the advancement of the condition, the ovary or ovaries may have ruptured, there may be tumors on the surface of the ovaries, or the cancer cells may have started spreading within the pelvic area.
- Stage II ovarian cancer: The cancer is still at an early stage, but has spread to other organs in the pelvis, such as the uterus or fallopian tubes. It may also have started spreading outside the pelvic area.
- Stage III ovarian cancer: The cancer is at a more advanced stage. While it may extend to the capsule of the liver and spleen, it has not spread beyond the abdomen and abdominal lymph nodes.
- Stage IV ovarian cancer: The cancer is at a very advanced stage, having spread into other areas such as the liver or lungs.
Staging the cancer helps doctors recommend the most appropriate treatment programme. Generally speaking, the earlier the stage of diagnosis, the higher the likelihood of recovery.
Sometimes, a medical check-up will reveal an ovarian cyst – a fluid-filled sac either inside or on the ovary. Ovarian cysts are common in females of all age groups, and are usually harmless (benign). They may cause pain and pressure in the pelvic area, but many people experience no symptoms at all. The cysts do not usually cause irregular periods or vaginal bleeding.
The majority of ovarian cysts typically develop during ovulation (the process where an egg is released from the ovary), and disappear on their own within a month or two, without any treatment. However, a very small number of ovarian cysts may be cancerous. If a cyst is particularly large, does not go away, has developed in a pre-pubescent or postmenopausal person, or there is any other cause for concern, a doctor may recommend further scans, blood tests and sometimes surgery to investigate.
Ovarian cancer treatment
Following the surgery, where as much of the cancer as possible will be removed, further treatment may be recommended. The treatment approach will depend on the stage and type of the ovarian cancer, but, except in the very early stages, will typically involve chemotherapy.
In some cases of stage III or stage IV ovarian cancer, doctors may recommend a course of chemotherapy prior to surgery. This is called neoadjuvant chemotherapy.
Chemotherapy for ovarian cancer
Chemotherapy can improve the likelihood of recovery from ovarian cancer. It typically involves the administering of drugs called paclitaxel and carboplatin through the veins, a procedure that is done approximately once every three weeks for up to six cycles. Sometimes, other drugs may be used. The treatment may also be administered directly into the abdominal cavity; this is called intraperitoneal chemotherapy.
The general aims of chemotherapy treatment are to destroy any remaining tumor tissue, and increase the likelihood of recovery.
Chemotherapy can sometimes have unpleasant side-effects such as hair loss, nausea and vomiting, fatigue and pain. A doctor will be able to advise on how best to manage the side-effects, should they occur. For more information, see this resource on chemotherapy side effects.
Also known as radiotherapy, this type of treatment uses X-rays to destroy cancer cells. In the treatment of ovarian cancer, radiation therapy is typically only used in cases where a person does not respond to chemotherapy, or where the cancer is very advanced and it is no longer possible to administer chemotherapy.
While a number of other treatments for ovarian cancer are being explored, further research is needed before they can be recommended. If a person is interested in alternatives to chemotherapy, it is advisable to consult with their healthcare team.
In some cases, it may be possible to participate in a clinical drug trial. More information about trials in the USA can be found on the following websites:
A doctor will be able to advise whether drug trials might be viable options for a particular person.
Recurrent ovarian cancer
After treatment, a person will typically be asked to have follow-up physical examinations, scans and blood tests regularly over a period of at least five years. A doctor will be able to advise on which are necessary, and how frequently these should be done.
If ovarian cancer recurs, the first indications may include abdominal (belly) pain, bloating, back pain, and sometimes a noticeable mass in the pelvis. Blood tests may show elevated levels of tumor markers.
If there are any signs that ovarian cancer has returned, further surgery and/or treatment with chemotherapy (second-line chemotherapy) may be recommended.
Prevention includes regular gynecological checkups. Women with multiple family members who have ovarian, breast or uterine (womb) cancer should discuss testing for the BRCA gene with their doctor. Women with the BRCA gene may consider surgical removal of their ovaries to reduce their risk of ovarian cancer.
Other names for ovarian cancer
- Neoplasm ovary
- Ovarian neoplasms
- Ovarian carcinoma
UpToDate. “Ovarian germ cell tumors: Pathology, clinical manifestations, and diagnosis.” November 30, 2017. Accessed April 12, 2018. ↩
UpToDate. “Sex cord-stromal tumors of the ovary: Granulosa-stromal cell tumors.” July 6, 2017. Accessed April 12, 2018. ↩
North American Journal of Medical Sciences. Ovarian Granulosa Cell Tumor: Clinical Features, Treatment, Outcome, and Prognostic Factors.” March, 2014. Accessed February 3, 2018. ↩ ↩
Medscape. “Granulosa-Theca Cell Tumors Clinical Presentation.” January 15, 2015. Accessed February 3, 2018. ↩
UpToDate. “Patient education: Ovarian cancer screening (Beyond the Basics).” April 22, 2016. Accessed February 17, 2018. ↩ ↩
UpToDate. “Patient education: Ovarian cancer diagnosis and staging (Beyond the Basics).” July 10, 2017. Accessed March 7, 2018. ↩
UpToDate. “Patient education: Ovarian cysts (Beyond the Basics).” September 5, 2017. Accessed March 9, 2018. ↩ ↩ ↩