|Ovarian cancer affects the ovaries, which are part of the female reproductive system. The ovaries are located on either side of the uterus. They produce and release eggs (ova), as well as the female hormones estrogen and progesterone.
Throughout our bodies, cells grow and divide to replace old and damaged ones. If a cell’s genetic material is changed or damaged, however, cells may grow in an abnormal, uncontrolled way. When this happens in an ovary, it can cause benign (non-cancerous) cysts or tumours. Sometimes, it creates malignant (cancerous) tumours, which can metastasize (spread) to other tissues.
There are three types of cells in the ovaries: epithelial, germ and stromal. Each type can develop different kinds of cancerous tumours. The most common type of ovarian cancer (90% of cases) is epithelial ovarian cancer. Less common (5% to 10% of cases) is germ cell ovarian cancer, and least common is stromal cell cancer (under 5%).
In Canada, about 2,800 women are diagnosed with ovarian cancer each year – about one in every 71 women. Unfortunately, because the disease is often detected in its later stages, the mortality rate is high: the five-year survival rate is 45%. There is not yet a screening test or a vaccine for ovarian cancer.
Risk factors for germ cell and stromal ovarian cancer are not well understood. We have a better understanding of risk factors associated with the most common type, epithelial ovarian cancer, and tumours of borderline malignancy (epithelial tumours that resemble cancer but have not grown into surrounding tissues). According to the Canadian Cancer Society, these are the known risk factors:
There are a few other possible risk factors, including obesity, endometriosis, using talc on the genitals, and being tall (due to growth and hormones, not height itself). However, their role in ovarian cancer is not yet clear and more research is needed.
There is no definite way to prevent ovarian cancer, but there are some factors that reduce the risk:
Signs and symptoms
In its early stages, ovarian cancer may not cause any signs or symptoms. If it starts to spread, it may cause the following symptoms:
These signs and symptoms are not unique to ovarian cancer, so they may have other causes. However, it’s important to pay attention and see your physician, especially if symptoms are persistent or frequent.
Diagnosing ovarian cancer
There isn’t yet a screening test for ovarian cancer, but your physician may perform these tests:
If your physician has reason to suspect ovarian cancer, he or she may order a biopsy or laparoscopy, which involve removing a small amount of tissue to check for cancerous cells.
Treating ovarian cancer
Once ovarian cancer has been diagnosed, treatment may include surgery to remove the cancerous growth (this is the primary treatment for all types and stages of ovarian cancer); chemotherapy, which uses drugs to kill cancer cells and reduce tumour size; hormonal therapy; and, less frequently, radiation therapy. (Some women also use complementary or alternative therapies – these do not treat the cancer, but may help with symptoms such as fatigue or stress. Always discuss these therapies with a physician.)
When planning treatment, physicians take into account the type of tumour, the grade and stage of the cancer (how it looks and behaves, and how much it has progressed), and whether the patient wants to become pregnant in the future.
Life after ovarian cancer
After treatment, women may experience a mixture of physical and emotional challenges. In some cases, women have long-term side effects or physical changes that linger after treatment has ended. It is important to seek supportive care to help manage the adjustment to life after treatment.
Physicians monitor patients closely to check for recurrence of cancer; checkups may include physical exams, bloodwork and imaging tests. In addition to medical care, women may benefit from peer support and professional counselling. For information and resources, including support groups, contact a reputable organization such as the Canadian Cancer Society or Ovarian Cancer Canada.