Ovarian cancer is the most common gynaecologic cancer in Singaporean women. It is also the 5th leading cause of cancer death in Singaporean women. Ovarian cancer is also the deadliest of all the gynaecologic cancers. However, if ovarian cancer is found and treated early the chance of a complete cure is good, with 90-95% of women living 5 years or more after treatment.
What is ovarian cancer?
Our bodies are made up of tissues and tissues in turn are made up of groups of healthy cells. In ovarian cancer, the cells of the ovary become abnormal and behave abnormally. These abnormal cells begin to grow uncontrollably. Sometimes these changes reverse themselves when the body's repair mechanisms kick in. Sometimes these changes cannot be reversed or repaired and the abnormal cells grow into tumors.
These tumors may then shed cancer cells which drift throughout and lodge themself in the abdomen. These tumor cells then grow where they lodge and eventually cause damage to surrounding normal tissues and organs. This process of cancer spread is known as metastasis. This also explains why ovarian cancer spreads so quickly and widely in the abdomen once an ovarian cancer has grown outside the ovary.
Ovarian cancer can affect any organ in the abdomen, most often affecting the intestines and bowels. Women who have ovarian cancer that has spread in the abdomen usually complain of bloating or feel that their bellies are getting larger; this is due to the large amount of fluid that is produced by the ovarian cancer that collects in the abdomen causing discomfort and decreasing the intestine's ability to digest and absorb nutrients from food.
There are many types of ovarian cancer with the 3 most common types being:
- Germ Cell.
- Sex Cord-Stromal.
Epithelial cancers of the ovary are the most common with about 90% of all ovarian cancers being of the epithelial type. Epithelial ovarian cancer develops when the cells that line the surface of the ovary undergo cancerous change. Most women who develop epithelial type ovarian cancer are over 40 years of age.
Germ cell tumors make up about 5% of all ovarian cancers. Germ cell cancers develop when the cells that develop into eggs become abnormal and develop cancerous change. These cancers tend to occur more frequently in young women, usually in their 20s.
Sex Cord- Stromal tumors are rare cancers that arise from the connective tissue of the ovary.
Who is at risk for Ovarian Cancer?
The risk for ovarian cancer increases with age with the age of peak incidence of the most common type of ovarian cancer (epithelial ovarian cancer) being between age 50 and 75.
How frequently a woman releases eggs from her ovaries will affect her risk of developing epithelial ovarian cancer. Women who ovulate more often will have a higher risk of developing epithelial ovarian cancer as compared to women who ovulate or release eggs less often. This finding is borne out by research that shows that women who have been pregnant more, who breastfeed for longer and women who use oral contraceptive pills are less likely to develop epithelial ovarian cancer in their lifetimes.
Factors that increase a woman's risk of developing epithelial ovarian cancer include:
- A family history of breast, ovarian or colon cancer.
- A personal history of breast cancer.
- Young age at menarche or start of menstruation, especially when coupled with late menopause (after age 50).
- Age more than 30 at time of first pregnancy.
- A history of fertility drug use.
Some women may have a familial form of ovarian cancer. 5-10% of women with ovarian cancer carry certain genes which run in the family. Some of the more common cancer genes associated with ovarian cancer are BRCA1 and BRCA2. A woman with BRCA1 will have a 45% lifetime risk of getting ovarian cancer whereas a woman with BRCA2 will have a 25% lifetime risk of ovarian cancer. A blood test is usually done to determine if a woman is carrying either of these genes. If you are concerned about whether you might be at risk of carrying or are carrying cancer genes, please consult your healthcare provider who will be glad to counsel you about your risks and options for testing and refer you to a cancer genetics specialist if necessary.
Symptoms of Ovarian Cancer
Although the symptoms associated with ovarian cancer are often vague and can be associated with other benign or non-cancerous conditions, a woman should consult a doctor if they have the following symptoms:
- Pain or pressure in the pelvic area or back
- Indigestion, gas, and bloating that cannot be explained
- Abnormal vaginal bleeding
- Pain or swelling of the abdomen
- Increase in abdominal size
- Increased urges to urinate or changes in bowel habits
- Feeling tired
- Weight loss
Are there reliable screening tests that will detect ovarian cancer early?
There are no reliable screening methods for the early detection of ovarian cancer in asymptomatic women. Though far from perfect, women who have a strong family history or are at increased risk for ovarian cancer are encouraged to have regular screening with a blood test (CA125) and transvaginal ultrasonography.
In the general public, for women who are not at increased risk for ovarian cancer, routinely getting a CA125 blood test is NOT recommended. This test is meant to be used in the follow-up of women who already have ovarian cancer and are being treated or followed-up after treatment. In otherwise healthy women with no increased risk, routinely using a CA125 test may result in the woman getting many unnecessary diagnostic procedures which may be expensive and harm a woman's health.
Is there anything I can do to decrease my risk of ovarian cancer?
Research shows that women who have used or are using oral contraceptive pills have a decreased risk of epithelial ovarian cancer. Women who use oral contraceptive pills for as short a time as 12 months can reduce their lifetime risk of epithelial ovarian cancer by 20%. Furthermore, it seems that this protective effect continues to be present years after a woman has stopped using oral contraceptive pills.
Please consult a women's healthcare provider to see if the pills are right for you.
How is Ovarian Cancer treated?
Ovarian cancer is best treated with surgery performed by a gynaecologic oncologist who is a doctor or surgeon specially trained to operate and manage women with cancers of the female reproductive tract.
Ovarian cancer surgery is performed firstly to remove as much of the cancer as possible. Successful surgery for ovarian cancer removes as much cancer as possible leaving no tumor deposit in the abdomen larger than 1cm in size. The second goal of ovarian cancer surgery is see how far the cancer has spread and what organs might be affected by the cancer and lastly to determine if any further treatment after surgery is needed and what form this additional or adjuvant treatment might take. The uterus, both ovaries, all tumor, omentum (which is a fat pad in the abdomen), appendix and sometimes lymph nodes and portions of the lining of the abdomen will be removed in most cases of ovarian cancer surgery. In very young women or women who may want to get pregnant, only the diseased ovary may be removed retaining the uterus and normal-appearing ovary. If you are a woman who needs ovarian cancer surgery, you should consult with your gynecologic oncologist regarding the details of your upcoming operation.
Chemotherapy is usually necessary after all visible tumor has been removed. Whether chemotherapy is necessary and if so what kinds of medicines will be used and how often will depend on the type of ovarian tumor or cancer, how far the cancer has spread (cancer stage), the patient's age and health and what the patient's expectations might be. The most commonly delivered chemotherapy for epithelial ovarian cancer is a combination of 2 medicines, carboplatin and paclitaxel, which are given through an IV drip every 21 days. A total of 6 treatments is the norm.
After completing your treatment, your healthcare team will continue to follow up on your condition with up to 4 visits per year in the first 2 years after treatment. This is because the likelihood of cancer returning after treatment (recurrence) is highest during this period of time. CA125 blood tests and pelvic examinations with CT scans from time to time will allow your healthcare providers to monitor your progress and response to treatment.
Ovarian cancer is the most common and deadliest of the gynaecologic cancers in Singaporean women.
There is no reliable method for detecting ovarian cancer early.
Blood tests for CA125 should not be done for routine screening.
Taking oral contraceptive pills can reduce a woman's lifetime risk for epithelial ovarian cancer.
Treatment for ovarian cancer is a combination of surgery and chemotherapy.
Women with a diagnosis of ovarian cancer should be in the care of gynaecologic oncologist (a gynaecologist with special training and experience in treating women with gynaecologic cancers).