What is Ovarian Cancer?

Ovarian cancer refers to malignant growth arising from different parts of the ovaries. (Diagram of anatomy). The ovaries are part of a woman’s reproductive system, where the eggs are developed. Most ovarian cancers are classified as "epithelial" and arise from the surface (epithelium) of the ovary. Other types arise from the egg cells (germ cell tumor) or supporting cells (sex cord/stromal).

How common is Ovarian Cancer?

Ovarian cancer is the 5th commonest cancer in Singapore. There are 280 cases diagnosed yearly based on the Singapore Cancer Registry 2005-2009. It is the second most common female genital tract cancer.

Age of Onset

Epithelial ovarian cancer usually affects older women although it can also happen to younger women. Germ cell cancers of the ovary occur more frequently in younger women.

Causes and Risks

Risk factors associated with ovarian cancer include:-

• late pregnancy
• early onset of menstruation
• late menopause
• never had children-history of breast cancer
• genetic predisposition
• endometriosis

Ovarian cancer is known to run in some families where family members may have increased risk of getting ovarian, breast and endometrial cancer(eg BRCA gene abnormalities) or increased risk of getting endometrial cancer, colorectal cancer in addition to ovarian cancer (Lynch syndrome). In women who have a sister or mother with this disease, the risk of developing ovarian cancer is increased twenty-fold. Ovarian cancer also runs in certain families with a history of breast and colon cancers. There is now evidence to suggest that certain genes are involved in causing these diseases.

Symptoms

Among female genital tract cancers, epithelial ovarian cancers are the most difficult to prevent or cure because they rarely have early symptoms or signs. Symptoms tend to develop only when the cancer is advanced. These symptoms include abdominal swelling and discomfort, bloating or wind, pain, change in bowel habits.

Diagnosis

Although a marker in the blood, called CA-125, is raised in about 80% of patients with epithelial ovarian cancers, it is not always accurate and not adequate for diagnosis of ovarian cancer. It is also raised in non-cancerous conditions, such as endometriosis and appendicitis. The result of elevated CA-125 must therefore be interpreted in the light of other clinical findings. Pelvic ultrasound can help to detect abnormal ovarian cysts. CT scans of the abdomen and pelvis and chest x-rays are also useful in detecting whether are areas of the body is affected. Ultimately an operation or biopsy is required to prove that the cells affected are cancerous and originated from the ovaries.

Treatment of Ovarian Cancer

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 is sent for assessment which involves analysis under a microscope. Besides determining the stage of the cancer, the aim of surgery is to remove as much of the cancer as possible. Often this includes removing ovaries, the uterus and its surrounding lymphatics.

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

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

Prognosis of Ovarian Cancer

Ovarian cancer in the early stage can potentially be cured while those in the late stage of the cancer, permanent cure maybe difficult.

Frequently Asked Questions

Is there a screening test for ovarian cancer?

There is currently no widely accepted and effective screening test for ovarian cancer. However, if there is a strong family of history of breast or ovarian cancer, it may be appropriate for that woman to go for genetic counseling and testing.

This article was originally published in nccs.com.sg