Ovarian Cancer

What is ovarian cancer?

The female reproductive system contains two ovaries on each side of the uterus. The ovaries are where eggs are developed. Ovarian cancer occurs when malignant cell growth affects parts of the ovaries.

What are the different types of ovarian cancer?

There are different types of ovarian cancer classified by the type of cell from which it originates:

• Epithelial ovarian cancer is the most common type of ovarian cancer. It develops from a type of cell that surrounds the exterior of the ovaries.
  
• Germ cell ovarian cancer develops from germ cells that make the eggs.
• Stromal ovarian cancer develops from connective tissue cells that fill the ovaries.

Ovarian Cancer - Prevalence

How common is ovarian cancer?

In Singapore, ovarian cancer is the sixth most common cancer among women. Although it usually occurs in post-menopausal women over the age of 50, ovarian cancer can occur in younger women.

Epithelial ovarian cancer usually affects older women, while germ cell ovarian cancer tends to occur more frequently in younger women.

What are the symptoms of ovarian cancer?

Early-stage ovarian cancer may not cause any noticeable symptoms. Symptoms are usually attributed to other more common conditions and may only be noticed when the cancerous tumour has become quite large.

Some of the symptoms include:

• Constant discomfort or a feeling of ‘pressure’ in the lower abdomen (pelvic area)
• Persistent bloating in the abdomen
• Abdominal swelling
• Quickly feeling full when eating
• Increased urinary frequency
  
• Changes in bowel habits, such as constipation or diarrhoea

When should you see a doctor?

Make an appointment with your doctor if you have any signs or symptoms that worry you.

How is ovarian cancer prevented?

There is no known way to prevent ovarian cancer, but the following factors may reduce risk:

• A healthy lifestyle – a nutritious diet, regular exercise and maintaining a healthy weight
• Oral contraception – taking birth control pills can lower the risk of ovarian cancer. But this must be balanced against the slight increase in breast cancer risk. Discuss with your doctor if this is suitable for you.
• Pregnancy
• Breastfeeding
• Tubal ligation or surgical removal of the uterus (hysterectomy) - these procedures are usually performed for medical reasons and not specifically to reduce the risk of ovarian cancer.
• Risk-reducing surgery for individuals with breast cancer gene (BRCA) mutations - this involves removal of the fallopian tubes and ovaries.

As some of the above measures involve surgery and may carry serious risks or side effects, they cannot be recommended for every woman. It is best to discuss appropriate ways to reduce your individual risk of ovarian cancer with your doctor.

What causes ovarian cancer?

The causes of ovarian cancer are not clear, but there are some known risk factors.

What are the risk factors for ovarian cancer?

• Older age – ovarian cancer is most often diagnosed in women aged 50 years and above. However, younger women can get it too.
  
• Had other cancers – women who have had breast cancer, colon cancer, cancer of the uterus or rectum.
• Family history of ovarian cancer – women who have inherited gene mutations (of breast cancer genes BRCA1 or BRCA2)
• Endometriosis – women who have a painful disorder where the womb lining (or endometrium) is found outside the womb.
• Never having been pregnant – women who have never had children or been pregnant.

How is ovarian cancer diagnosed? 

Initial tests

• Pelvic examination

  Your doctor may feel the ovaries and nearby organs for any lumps or suspicious abnormality.

  

• Ultrasound scan
  

  This is a painless test used to view the structures inside your body. The ultrasound probe may be placed on your abdomen or inside your vagina to scan the ovaries.
  

• Blood test
  

  A blood test may be done to detect a protein called CA-125. The level of CA-125 can be high in women with ovarian cancer. However, other non-cancerous conditions can also cause a high level of CA-125. Thus, this blood test alone is not a conclusive gauge for the diagnosis of ovarian cancer.

Further tests

You may be advised to go for further tests depending on your symptoms and the results of your initial tests.

• Imaging tests

  • CT or MRI scans of the lower abdomen can provide details of the internal organs structure and help to determine the extent of the disease.
  • A chest X-ray may be done to check if the cancer has spread to the lungs.

• Blood test

  • To assess general health and to check if the cancer has affected liver or kidney function.

• Scans of the bowel or urinary tract

  • These tests may be needed if you have symptoms such as constipation or urinary frequency, which may indicate that the cancer has spread to these areas.

• Aspiration of fluid in abdomen

  • If your abdomen is swollen with fluid, a sample of the fluid will be taken and examined under the microscope to look for cancer cells.
    

• Surgery

  • Surgery and a biopsy may be required to determine the extent of the cancer and if it originates from the ovaries.

How is ovarian cancer treated?

Treatment of ovarian cancer usually involves a combination of surgery and chemotherapy. Other treatments such as radiotherapy and target therapy may also be used in certain situations.

An individual with cancer should be assessed by a specialist to determine which modality of treatment is best suited for them.

Surgery

To determine the actual extent of the cancer, surgical exploration or staging is required. During the procedure, the doctor will examine the peritoneum, which is the inner lining of the abdomen. Fluid within the abdomen will be sent for assessment.

In addition to determining the stage of the cancer, the aim of surgery is to remove as much of the cancer as possible. This may include removing of ovaries, fallopian tubes, uterus and surrounding lymph nodes.

Additional treatment following surgery will be determined by the stage of the disease, the grade (aggressiveness) of the disease and the subtype of cancer.

Chemotherapy

For very early-stage disease and non-aggressive types of cancers, further treatment may not be required. But if the cancer is more advanced and aggressive, chemotherapy is the treatment of choice.

Some patients with advanced epithelial ovarian cancer may be given pre-operative chemotherapy to shrink or control the cancer before surgery.

Targeted therapy

There are new targeted drugs which can be used to treat selected cases of epithelial ovarian cancer, including drugs that are administered by drip such as Bevacizumab and oral Olaparib.

How can you prepare for ovarian cancer surgery?

Your surgeon will perform a comprehensive medical work-up including blood tests and scans to see if you are suitable for surgery and advise you on the risks involved. This treatment recommendation is often based on consensus by a group of different specialists' opinions (tumour board) which weighs the pros and cons of every treatment strategy.

Before surgery, the anaesthesia team will also assess your fitness for surgery and advise you on various aspects of general anaesthesia and pain control after surgery.

Specialist nurses will also provide pre-surgery counselling.

What can you expect after ovarian cancer surgery?

After recovering from surgery, you will be given regular outpatient appointments to see your team of doctors. These visits may include blood tests and scans to monitor and check if the cancer recurs.

It is important to follow your doctor's advice, keep to scheduled clinic visits and do the prescribed tests so that timely treatment can be administered if the cancer or other problems arise.