Ovarian cancer

Synonyms

1

Overview

Ovarian cancer is a cancer that begins in an ovary. It results in abnormal cells that have the ability to invade or spread to other parts of the body. When this process begins, symptoms may be vague or not apparent, but they become more noticeable as the cancer progresses. These symptoms may include bloating, pelvic pain, and abdominal swelling, among others. Common areas to which the cancer may spread include the lining of the abdomen, lining of the bowel and bladder, lymph nodes, lungs, and liver.

The risk of ovarian cancer increases in women who have ovulated more over their lifetime. This includes those who have never had children, those who begin ovulation at a younger age or reach menopause at an older age. Other risk factors include hormone therapy after menopause, fertility medication, and obesity. Factors that decrease risk include hormonal birth control, tubal ligation, and breast feeding. About 10% of cases are related to inherited genetic risk; women with mutations in the genes BRCA1 or BRCA2 have about a 50% chance of developing the disease.
The most common type of ovarian cancer, comprising more than 95% of cases, is ovarian carcinoma. There are five main subtypes of ovarian carcinoma, of which high-grade serous is most common. These tumors are believed to start in the cells covering the ovaries, though some may form at the Fallopian tubes. Less common types of ovarian cancer include germ cell tumors and sex cord stromal tumors. A diagnosis of ovarian cancer is confirmed through a biopsy of tissue, usually removed during surgery.

Screening is not recommended in women who are at average risk, as evidence does not support a reduction in death and the high rate of false positive tests may lead to unneeded surgery, which is accompanied by its own risks. Those at very high risk may have their ovaries removed as a preventive measure. If caught and treated in an early stage, ovarian cancer may be curable. Treatment usually includes some combination of surgery, radiation therapy, and chemotherapy. Outcomes depend on the extent of the disease and the subtype of the cancer present. 

Symptoms

Many people with early ovarian cancer have no signs or symptoms of the condition. When present, symptoms are often nonspecific and blamed on other, more common conditions. Some people with ovarian cancer may experience the following:

  • Bloating
  • Difficulty eating or feeling full
  • Pelvic or lower abdominal pain
  • Back pain
  • Abnormal vaginal bleeding
  • Digestive symptoms such as nausea and vomiting; constipation; indigestion; and/or acid reflux
  • Weight loss or weight gain
  • Increased urinary frequency or urgency
  • Tiredness
  • Shortness of breath

Causes

Most cases of ovarian cancer occur sporadically in people with little to no family history of the condition. They are due to random changes (mutations) that occur only in the cells of the ovary. These mutations (called somatic mutations) accumulate during a person's lifetime and are not inherited or passed on to future generations.

Prevention

There's no sure way to prevent ovarian cancer. But certain factors are associated with lower risk:

  • Use of oral contraceptives, especially for more than 10 years
  • Previous pregnancy
  • History of breast-feeding
  • Daily use of aspirin

People with a significant family history for ovarian cancer are often referred to a genetic counselor to see if they should be tested for BRCA mutation.

Diagnosis

If ovarian cancer cancer is suspected based on the presence of certain signs and symptoms, the following tests and procedures may be recommended:

  • Physical evaluation and pelvic exam to check for signs of ovarian cancer (i.e. lumps or swelling) and to examine the size, shape and location of the ovaries
  • Ulrasound and other imaging studies to look for abnormal growths 
  • Blood tests such as a CA-125 assay which may be elevated in people with ovarian cancer
  • A biopsy of the tumor is the only way to confirm a diagnosis of ovarian cancer

Further, stages of ovarian cancer include:

  • Stage I. Cancer is found in one or both ovaries.
  • Stage II. Cancer has spread to other parts of the pelvis.
  • Stage III. Cancer has spread to the abdomen.
  • Stage IV. Cancer is found outside the abdomen.

 

Prognosis

The long-term outlook (prognosis) for women with ovarian cancer depends on many factors including the subtype of cancer and the stage at which the cancer is diagnosed. In general, epithelial ovarian cancers (the most common subtype) are often associated with a worse prognosis than more rare subtypes such as germ cell and stromal ovarian tumors.

Because early stages of ovarian cancer are often not associated with any specific signs or symptoms, many cases are, unfortunately, diagnosed at a later and less treatable stage. Late stage ovarian cancers are generally associated with a poor prognosis. For example, 5-year survival rates for women diagnosed with stage I ovarian cancer range from 79-87%, while the 5-year survival rates for women diagnosed with stage IV ovarian cancer are approximately 11%.

Treatment

The best treatment options for ovarian cancer depend on many factors including the subtype and stage of the condition. In general, treatment may include a combination of the following:

  • Surgery to remove the ovaries, the fallopian tubes, the uterus, and/or other structures in the belly (pelvis).
  • Chemotherapy
  • Radiation therapy
  • Targeted therapy (such as monoclonal antibody therapy)
     

Surgery
Treatment generally involves removing both ovaries, the fallopian tubes, the uterus as well as nearby lymph nodes and a fold of fatty abdominal tissue (omentum) where ovarian cancer often spreads. Your surgeon also will remove as much cancer as possible from your abdomen.

Less extensive surgery may be possible if your ovarian cancer was diagnosed at a very early stage. For women with stage I ovarian cancer, surgery may involve removing one ovary and its fallopian tube. This procedure may preserve the ability to have children.

Chemotherapy
After surgery, you'll likely be treated with chemotherapy to kill any remaining cancer cells. Chemotherapy drugs can be injected into a vein or directly into the abdominal cavity or both. Chemotherapy may be used as the initial treatment in some women with advanced ovarian cancer.

Approved targeted therapies

  • Doxorubicin HCL liposome (Doxil) -  FDA-approved indication: Treatment of metastatic carcinoma of the ovary in patients with disease that is refractory to both paclitaxel- and platinium-based chemotherapy regimens. Refractory disease is defined as disease that has progressed while on treatment, or within 6 months 
  • Amifostine (Ethyol) - FDA-approved indication: To reduce the cumulative renal toxicity associated with repeated administration of cisplatin in patients with advanced ovarian cancer. 
  • Altretamine (Hexalen) - FDA-approved indication: Single agent palliative treatment of patients with persistent or recurrent ovarian cancer following first-line therapy with a cisplatin and/or alkylating agent based combination. 
  • olaparib (Lynparza) - FDA-approved indication: Use of as monotherapy for patients with deleterious or suspected deleterious germline BRCA mutated (as detected by an FDA-approved test) advanced ovarian cancer who have been treated with three or more prior lines of chemotherapy 
  • Satumomab pendetide (Oncoscint CR/OV ) - FDA-approved indication: For determining the extent and location of extraphepatic malignant disease in patients with known colorectal and ovarian cancer.