Breast cancer is the most common cancer to affect women. It occurs most often in women over 50 years…
What is ovarian cancer?
The ovaries are the pair of small glands in females that produce eggs and female sex hormones. Ovarian cancer occurs when abnormal cells grow uncontrollably in one or both of the ovaries. The exact cause of this abnormal growth is unclear.
The cause of ovarian cancer, as with other cancers, is damage to cellular DNA. This damage results in uncontrolled cell growth, which leads to a cancer forming. Cancers can invade nearby tissue, or cancerous cells can break off and spread throughout the body via the bloodstream or lymphatic system. The exact causes of this cellular damage in the ovaries are not known.
Risk factors for ovarian cancer include:
Women over 50 years of age are at a greater risk of developing ovarian cancer.
Genetics and family history
Women who have inherited an abnormal BRCA1 or BCRA2 gene have a greater risk of developing ovarian or breast cancer. Women with more than one relative in their family affected by ovarian cancer may be at increased risk of having inherited a genetic mutation. They can discuss having genetic testing and counselling with their doctors.
In endometriosis, the tissue normally lining the inside of the uterus can also grow in other areas, such as the ovary, bladder or bowel. Endometriosis in the ovaries can lead to an increased risk of a certain type of ovarian cancer.
Smoking, obesity and high-fat diets all increase the risk of developing ovarian cancer.
Not having children is associated with a small increase in the risk. This is attributed to the ovaries not having a restful period normally experienced during child-bearing.
Epithelial ovarian cancer
This is the most common type of ovarian cancer. It begins in the cells that make up the outer layer of the ovaries (epithelium).
This is a type of epithelial tumour that is not aggressive and generally has good treatment outcomes.
Sex cord stromal cell ovarian cancer
This is a rare type of ovarian cancer that originates in the ovary cells that produce hormones (stromal cells).
Germ cell ovarian cancer
This is a rare type of ovarian cancer that originates in the germ cells that then mature into eggs.
Stages of ovarian cancer
Treatment outcomes can vary greatly, depending on the stage of cancer. Cancer is staged according to its size and location and whether it has spread to nearby or distant lymph nodes or organs throughout the body.
The cancer is only in the ovaries.
The cancer has spread to nearby organs in the pelvis.
The cancer has spread outside the pelvis, and/or to surrounding lymph nodes.
The cancer has spread to the lungs and other areas outside the abdomen.
Signs and symptoms
Ovarian cancer can present with vague symptoms, which can commonly affect women throughout their life. Therefore, a high degree of suspicion is needed to detect the cancer in the early stages. Symptoms can include:
- Abdominal pain, swelling and bloating;
- Frequent urination, and;
- Constantly feeling full.
Methods for diagnosis
A doctor may feel for any masses within a woman's abdomen and perform a vaginal examination to assess her pelvic organs. Often there are no findings on examination, especially in the early stages of the condition.
A blood sample will be tested for CA125, a protein that is often produced in elevated amounts in women with ovarian cancer.
A doctor may organise an abdominal or transvaginal ultrasound to visualise the woman's internal pelvic organs. During the abdominal ultrasound she will lie down in a chair and a hand-held device will be moved over her abdominal area. During a transvaginal ultrasound, the doctor or radiographer will insert this device into the woman's vagina. This is preferable as it produces a better image of the uterus and ovaries.
Computerised tomography (CT) scan
CT can help to further identify the site and size of any abnormal lesions, found on ultrasound.
Magnetic resonance imaging (MRI)
An MRI can be used to accurately assess the spread of the ovarian cancer, if present, within the pelvis.
Positron emission tomography (PET)
PET requires an injection with a radioactive label, or a tracer, to be first administered. When combined with a CT scan, it produces images to assess the size, location and spread of a cancer. It is often used to help monitor response to treatment.
Like the PET scan, the bone scan involves an injection of radioactive material. It is used to determine if the cancer has spread to the bones.
A laparoscopy involves a small incision being made in the abdomen so a camera can be inserted to view the internal organs. It can be used to plan a surgery, or to help perform a biopsy.
The only way to definitively diagnose ovarian cancer is to perform a biopsy of the suspect tissue. The sample will be sent to the pathologist for examination under a microscope.
Types of treatment
Treatment will vary according to the type and stage of the cancer.
A range of surgeries are available to treat ovarian cancer, including the following:
- Salpingo-oophorectomy - the removal of the ovary and fallopian tube;
- Radical hysterectomy - this is the removal of the ovaries as well as the uterus and cervix;
- Omentectomy - this is the removal of the protective fatty tissue (omentum) that covers the abdominal organs;
- Lymphadenectomy - the removal of the lymph nodes, and;
- Colectomy - the removal of part or all of the bowel (if the cancer has spread into that region).
Other therapies can be used in addition to surgical treatments, to further improve treatment outcomes. They may be given before surgery (neoadjuvant therapy) and/or after surgery (adjuvant therapy). When given before surgery, they aim to reduce the size, and therefore stage, of the cancer. When given after surgery, they aim to help prevent the cancer returning. These non-surgical treatments include chemotherapy, radiotherapy and hormone therapy.
Occasionally, these therapies may be used if individuals are not suitable for surgical treatment. Often, in these situations, the aim of treatment is to control symptoms, and not necessarily for cure. The treatment options and aims can differ based upon the individual, the stage and type of cancer. A doctor can help explain this information in more detail.
Chemotherapy works by damaging cancer cells and stopping their reproduction. Various medications can be used, which can be administered intravenously or orally. They are often given in cycles, with intervening rest periods, to help reduce toxic side effects. Side effects occur because chemotherapy can also affect healthy cells. A doctor will monitor their patient's dosage carefully to achieve an optimum therapeutic effect.
A doctor might suggest intraperitoneal chemotherapy. This is where the medication is delivered straight into the abdominal cavity through a tube, rather than intravenously. Its suitability depends on the outcome of surgery.
In this type of therapy, focused X-rays from an external beam radiation source are applied to the area where the cancer is located. Radiotherapy can be used alone, or in addition to surgery and/or chemotherapy.
Hormone therapy works to add, block or remove hormones from the body to slow or stop the growth of cancer cells. This is only used to treat some types of ovarian cancer, such as recurrent epithelial tumours. A doctor will advise if this treatment is appropriate.
Some people diagnosed with cancer seek out complementary and alternative therapies. None of these therapies are proven to cure cancer, but some can help people feel better when used together with conventional medical treatment. It is important to discuss any additional treatments with a doctor before starting them.
Treatment side effects
Side effects from treatment for ovarian cancer include the following:
- Nausea, vomiting and fatigue;
- Altered bowel habits - constipation or diarrhoea;
- Joint and muscle pain - this can occur after a treatment session and can last a few days;
- Temporary hair loss on the head and body from some types of chemotherapy. It may grow back after treatment has ended;
- Tingling in the hands and feet - some chemotherapeutic agents can affect the nerves. It is important to tell the doctor if these symptoms develop;
- Infertility and early menopause - surgical removal of both ovaries ends a woman's chances of becoming naturally pregnant and induces early menopause. Discussion with a fertility specialist may be appropriate prior to surgery in regards to egg harvesting and storage.
Advanced ovarian cancer
In cases of advanced cancer, the cancer can metastasise to other parts of the body through the bloodstream and lymphatic system. The growth of cancer in the organs and other body parts has a destructive effect on their function.
Prognosis varies depending on the type and stage of the cancer.
In Australia, as of 2010, the overall five-year survival rate for ovarian cancer is 43%. For those who survive the first year the survival rate increases to 53% and for those who survive the first five years, the survival rate increases to 79% for the next five years. 
Upon diagnosis, the five-year survival rate is 93% if the cancer is found while it is still confined to the ovaries. If the cancer has spread to nearby surrounding tissue, the five-year survival rate is 39%, or 30% if it has spread further than nearby tissues.  Unfortunately, due to its vague symptoms in its early stages, it is often diagnosed in later stages.
It is important to remember survival rates are only an indication and are based upon the averages of previously-treated patients. It is not an absolute prognosis for an individual. It is often difficult to accurately predict an individual's cure or survival rate. Constant advances in treatment are continually improving these statistics.
There is no proven method of preventing ovarian cancer. There is no screening program for ovarian cancer, as an effective test is not yet available.