Ovarian cancer refers to any cancerous growth that begins in the ovary.
It is the fifth most common cause of cancer deaths in women and the tenth most common cancer among women in the United States.
Among the gynecologic cancers—those affecting the uterus, cervix, and ovaries—ovarian cancer has the highest rate of deaths.
In 2017, around 22,440 women in the U.S. are expected to receive a diagnosis of ovarian cancer, and around 14,080 are expected to die from this disease.
Fast facts about ovarian cancer
- Around 22,000 Americans receive a diagnosis of ovarian cancer yearly.
- Risk factors for developing ovarian cancer include family history, older age, reproductive history, and obesity.
- Treatment options include surgery, radiotherapy, and chemotherapy.
- If it is diagnosed in the early stages, there is a 94 percent chance of surviving for at least 5 more years.
Pelvic pain can be a sign of ovarian cancer.
Most ovarian cancers start in the epithelium, or outer lining, of the ovary.
In the early stages, there may be few or no symptoms.
Symptoms may resemble those of other conditions, such as premenstrual syndrome (PMS), irritable bowel syndrome (IBS), or a temporary bladder problem.
The main difference between ovarian cancer and other possible disorders is the persistence and gradual worsening of symptoms.
Early symptoms of ovarian cancer may include:
- pain in the pelvis, the lower abdomen, or the lower part of the body
- back pain
- indigestion or heartburn
- feeling full rapidly when eating
- more frequent and urgent urination
- pain during sexual intercourse
- changes in bowel habits, such as constipation
As the cancer progresses, there may also be:
- weight loss
- loss of appetite
If an individual experiences bloating, pressure, or pain in the abdomen or pelvis that lasts for more than a few weeks they should see a doctor immediately
Ovarian cancer happens when cells divide and multiply in an unregulated way. However, exactly why this happens is not clear.
The following risk factors are linked to a higher chance of developing the disease:
Women with close relatives who have had ovarian or breast cancer have a higher risk of developing ovarian cancer, compared with other women.
Genetic screening can determine whether somebody carries certain genes that are associated with an increased risk.
Most cases of ovarian cancer occur after menopause, and especially in women aged over 63 years. It is rare before the age of 40 years.
Women who have had one or more full-term pregnancies, especially before the age of 26 years, have a lower risk. The more pregnancies they have, the lower the risk.
Breastfeeding may also decrease the risk.
Using the contraceptive pill for at least 3 to 6 months appears to reduce the risk. The longer the pill is used, the lower the risk appears to be.
Using an injectible contraceptive hormone, depot medroxyprogesterone acetate (DMPA or Depo-Provera CI), especially for 3 years or more, reduces the risk further.
Infertility or fertility treatment
Fertility drugs have been linked to a higher risk of ovarian cancer, especially in women who used them for more than one year without becoming pregnant. Those who are infertile may also have a higher risk than those who are not, possible due to not carrying a pregnancy.
Women who have received a diagnosis of breast cancer have a higher chance of being diagnosed with ovarian cancer.
For this reason, women who are diagnosed with breast cancer and who test positive for the BRCA1 or BRCA2 gene may opt to have an oophorectomy as preventive therapy.
HRT slightly increases a women’s risk of developing ovarian cancer. The risk appears to increase the longer the HRT continues, and returns to normal as soon as treatment stops.
Androgen therapy, such as the use of the drug, Danazol, may also increase the risk.
Obesity and overweight
Obesity and overweight appear to increase the risk of developing many cancers. Ovarian cancer is more common in women with a body mass index (BMI) of over 30.
Having surgery on the reproductive organs appear to reduce the risk of ovarian cancer. In women who undergo tubal ligation, this may be reduced by up to two thirds. A hysterectomy may reduce the risk by one third.
Women who develop endometriosis have an around 30 percent higher risk of developing ovarian cancer, compared with other women.
If ovarian cancer is diagnosed, the next step is to identify its stage and grade.
The stage of a cancer refers to the cancer’s spread.
There are different ways of staging cancer. The American Cancer Society uses a four-stage system.
Stage 1: Cancer cells affect only the ovary or ovaries and have not spread to another area.
Stage 2: The cancer has affected one or both ovaries and also other organs within the pelvis, such as the uterus, fallopian tubes, bladder, or rectum.
Stage 3: The cancer affects one or both ovaries and either the lining of the abdomen or lymph nodes in the back of the abdomen.
Stage 4: The cancer has spread to other parts of the body, outside the peritoneal cavity. This cavity includes the abdomen and the pelvis. Areas that may now be affected include the liver, spleen, and the fluid around the lungs.
Identifying the stage and grade will help the doctor to decide on the best treatment.
However, the stage and grade of ovarian cancer alone cannot predict how it is going to develop.
A doctor will carry out a pelvic examination and check for any palpable abnormalities in the uterus or ovaries. They will also check the patient’s medical history and family history.
The following tests are used to help diagnose ovarian cancer:
Blood tests: Checking for elevated levels of a marker called CA-125.
Imaging tests: Transvaginal ultrasound, MRI, or a CT scan might be used.
Laparoscopy: A laparoscope, a thin viewing tube with a camera at the end, is inserted through a small incision in the lower abdomen. This will allow the doctor to see the ovaries and, if necessary, to take a tissue sample
Colonoscopy: If there is constipation or bleeding from the rectum, a colonoscopy may be needed, to examine the large intestine, or colon.
Abdominal fluid aspiration: If the patient’s abdomen is swollen, there may be a buildup of fluid, which can be examined by using a fine needle to remove some fluid through the abdomen.
Biopsy: The usual way to diagnose ovarian cancer is to remove the tumor or part of the tumor to examine for the presence of cancer cells.
Treatment for ovarian cancer may consist of surgery, chemotherapy, radiation therapy, hormone therapy, or targeted therapy. Often more than one treatment is used.
The kind of treatment depends on many factors, including the type of ovarian cancer, its stage and grade, as well as the general health of the patient.
In most cases, surgery is done to remove the cancer. It is often the first option. The extent of the surgery depends on the stage of the cancer.
Salpingo-oophorectomy: Surgery is done to remove the ovaries and fallopian tubes.
Hysterectomy: The surgeon removes the uterus and any surrounding tissue that is affected. If only the uterus is removed, this is a partial hysterectomy. In premenopausal women, menopause will begin immediately after this procedure.
Lymph node dissection: The surgeon removes lymph nodes in the pelvis and near the aorta.
Cytoreductive or debulking surgery: If the cancer has spread beyond the pelvic area, the surgeon will reduce as much cancerous tissue as possible. This may include tissue from the gallbladder and other organs. This procedure can help relieve symptoms and make chemotherapy more effective.
Chemotherapy is the use of certain medications to destroy cancer cells. Cytotoxic medication delivers drugs that are poisonous to cells. These drugs prevent the cancer cells from dividing and growing.
Chemotherapy is used to target cancer cells that surgery cannot or did not remove.
Treatment usually involves 3 to 6 chemotherapy sessions, or cycles. These will be given 3 to 4 weeks apart, to allow the body time to recover. If the cancer returns or begins to grow back again, chemotherapy may be given again to shrink it.
Newer medications can directly target specific pathways or functions in cancer cells. These medications include bevacizumab (Avastin) and olaparib (Lynparza).
Unlike traditional chemotherapy, these drugs limit damage to normal cells. This reduces common side effects.
Chemotherapy targets rapidly dividing cells. Unfortunately, healthy rapidly dividing cells, such as red and white blood cells, and hair follicles may also be affected.
The severity and type of side effects depend on the kind of medication, the number of treatments, and some aspects of the patient and their general health. Side effects can include:
- nausea, vomiting
- hair loss
- loss of appetite
- mouth sores
- infections, because the white blood cell count is low
The damaged healthy cells normally repair themselves rapidly after treatment is over, and the side effects soon disappear.
Followup tests, such as blood tests and imaging scans, will be carried out to determine how well the treatment is working.
If cancer is still present after chemotherapy treatment, doctors will switch to other treatments.
Hormone therapy (HT) may be added to the treatment plan in order to prevent estrogen from reaching the cancer cells.
Cutting off the supply of estrogen slows the growth of the cancer cells.
Hormone therapy may include goserelin (Zolodex), leuprolide (Lupron), Tamoxifen, or an aromtase inhibitor
Radiation is less often used in ovarian cancer treatment. It may be used if there are small traces of cancer in the reproductive system, or to treat the symptoms of advanced cancer.
The surgeon will follow up the treatment to monitor its success. If laboratory tests show that cells are clear of cancer, the cancer is “in remission.”
Successful treatment is possible, but it depends on the stage at which the cancer is diagnosed.
Survival rates for cancer are often measured as the relative likelihood of surviving for 5 years or more after the first diagnosis. The outlook varies depending on the stage:
- At stage I, the 5-year survival rate is 90 percent.
- At stage II, it is 70 percent.
- At stage III, it is 39 percent.
- At stage IV, it is 17 percent.
For this reason, it is important to attend all recommended screening and to seek medical help as soon as any symptoms appear.
There are over 30 types of ovarian cancer, and they are defined by the type of cell in which they start.
These occur in three main groups:
- Epithelial tumors: These grow in the cells lining the surface of the ovary. They are the most common and the most dangerous, occurring in 85 to 90 percent of woman with ovarian cancer.
- Germ cell tumors: This type of tumor occurs in the cells that produce eggs for reproduction. They are often benign, and in the cases where they become cancerous, 90 percent can be cured.
- Primary peritoneal carcinoma: This is similar to epithelial ovarian cancer, but it is not affected by the removal of the ovaries.
The type of ovarian cancer will shape a person’s treatment, symptoms, and likelihood of survival.