Ovarian Cancer: Useful Questions & Answers

1) Is ovarian cancer common in Singapore?

Ovarian cancer is the fourth most common cancer affecting Singapore women today (lung, colorectal, breast, ovary, cervix, stomach, uterus). Ovarian cancer remains the most deadly of the gynaecological cancers. There has been an increase in numbers in Singapore over the past 30 years, and ovarian cancer now surpasses cervical cancer in prevalence. In Singapore, this is one of the few cancers for which Malays have a higher risk (on average, 10% to 20% higher) than Chinese. The continuing poor outcome results from the nonspecific and late clinical presentation of ovarian cancer and the lack of reliable and cost effective methods of early detection.  

The lifetime risk for ovarian cancer is about 1% to 2% 

Risk factors:

Age - The risk of developing ovarian cancer gets higher with age. Ovarian cancer is rare in women younger than 40. Most ovarian cancers develop after menopause. Half of all ovarian cancers are found in women over the age of 63.

No / Fewer pregnancy - Women with few pregnancies or who have never been pregnant are at higher risk.

Obesity - Overall, it does seem that obese women (BMI of minimum 30) do have a higher risk of developing ovarian cancer. A study from the American Cancer Society also found a higher rate of death from ovarian cancer in obese women. The risk was increased by 50% in the heaviest women.

Diet - High fatty diet. A recent study of women who followed a low-fat diet for at least four years showed a lower risk of ovarian cancer.

Family history of ovarian cancer, breast cancer, or colorectal cancer - Ovarian cancer can run in families. Your ovarian cancer risk is increased if your mother, sister, or daughter has (or has had) ovarian cancer. The younger your relative was when she developed ovarian cancer, the higher your risk. The risk also gets higher the more relatives you have with ovarian cancer. Increased risk for ovarian cancer does not have to come from your mother's side of the family - it can also come from your father's side. About 10% to 15% of ovarian cancers result from an inherited tendency to develop the disease. A family history of cancer caused by an inherited mutation (change) in certain genes can increase the risk of ovarian cancer. Some of these genes (named BRCA1 and BRCA2) also increase the risk of breast cancer - so having a family member with breast cancer can increase your risk of ovarian cancer. Another set of genes increases the risk of colon cancer, so women who have colon cancer in their families may have a higher risk of developing ovarian cancer. Many cases of familial epithelial ovarian cancer are caused by inherited gene mutations that can be identified by genetic testing.

Personal history of breast cancer - If you have had breast cancer, you also have an increased risk of developing ovarian cancer. Some of the reproductive risk factors and genes for ovarian cancer may also increase breast cancer risk.

Never taken OCP - Women who have never been on contraceptive pills.

Gynecologic surgery - Tubal ligation (having your "tubes tied") may reduce the chance of developing ovarian cancer by up to 67%. A hysterectomy (removal of the uterus without removing the ovaries) also seems to reduce the risk of getting ovarian cancer by about one-third.]

2) What are the symptoms of ovarian cancer? 

Usually asymptomatic in early stages but can present with: 

·         Feeling of discomfort, bloated feeling in the abdomen

·         Change in bowel habit.

·         Flatulence & indigestion

·         Symptoms related to the kidney or bladder

·         Abnormal vaginal bleeding

·         Pain in the abdomen

·         Enlarged abdomen from the tumour

·         Loss of weight

3) Can ovarian cancer be detected like breast and cervical cancer? 

Although there has been a lot of research to develop a screening test for ovarian cancer, there hasn’t been much success so far. There are two tests that are used most commonly to screen for ovarian cancer. These tests, transvaginal sonography and CA-125, are often offered to women who are at high risk of developing epithelial ovarian cancer, such as those with a very strong family history. For this reason, transvaginal sonography and the CA-125 blood test are not recommended for ovarian cancer screening of women without known strong risk factors. These tests are often done in women at high risk, but it is not known how helpful they are.

4) How can women protect themselves against ovarian cancer? 

There are several ways you can reduce your risk of developing epithelial ovarian cancer. Much less is known about ways to lower the risk of developing germ cell and stromal tumors of the ovaries. 

Oral Contraceptive Pill (OCP) - More recently in January 2008, an important article in The Lancet reported the protective effects of the Pill against ovarian cancer. The background risk of ovarian cancer is 1 in 70. It looked at about 23,000 women with ovarian cancer and 87,000 women without ovarian cancer from 21 countries. One-third in each group had ever taken the Pill before in their life. The mean duration of being on the pill was 4.5 years. Overall, they found that the longer the women were on the Pill, the better their protection against ovarian cancer. If a woman were to take the Pill for 5 years, she reduced her risk of ovarian cancer by 1/3. If she took the Pill for 15 years, she reduced her risk of ovarian cancer by half. The shorter the time of cessation from taking the Pill, the greater the protection persisted. This reduction in risk persisted for more than 30 years even after they had stopped taking the Pill. Although taking OCP is associated with a small increase in the risk of developing breast cancer, this risk is much smaller and exists only while on the pill and just after stopping. Whereas, for ovarian cancer, the protection persists for decades. Overall the benefits of the Pill outweigh the risks. Worldwide, the Pill has already prevented 200,000 ovarian cancers and 100,000 deaths from the disease and with more than 100 million women taking the pill today, it is estimated that it will prevent over 30,000 ovarian cancers per year over the next few decades.

Gynecologic surgery - Although both tubal ligation and hysterectomy may reduce the chance of developing ovarian cancer, experts agree that these operations should only be done for valid medical reasons and not for their effect on ovarian cancer risk.

Genetic testing - a family history of ovarian cancer, including cancer due to BRCA mutation. OCP also seem to reduce the risk for women with BRCA1 and BRCA2 mutations. Research has shown that women who have BRCA gene mutations and have had both their ovaries removed have a substantial reduction in their risk of breast cancer as well as their risk of ovarian cancer. The risk of ovarian cancer is reduced by 85% to 95%, and the risk of breast cancer cut by 50% to 60%.

 

5) Could you elaborate on the key recommendations of The Lancet editorial?

Prof Valarie Beral director of the Cancer Research UK Epidemiology Unit at Oxford University conducted a research study involving: 

·         45 research papers involving 23,000 women with ovarian cancer and 87,000 without ovarian cancer.

·         Overall, 1/3 of all the women had ever used OCP, for 4-5 years on average.

·         The longer women stayed on OCP, the lower their risk of developing the disease.

·         This is regardless of ethnicity, education, age of menarche, parity, FHx breast CA, use of HRT, BMI, alcohol and smoking.

·         This reduction in risk persisted for more than 30 years even after they had stopped taking OCP.

·         It is estimated that:
- women who take OCP for 5 years reduce their risk of getting ovarian cancer by one-third.
- women who take OCP for 15 years reduce their risk of getting ovarian cancer by half.

·         An estimated 300 million women have used the OCP since its introduction in the early 1960s.

·         Although taking OCP is associated with a small increase in the risk of developing breast cancer, this risk is much smaller and exists only while on the pill and just after stopping. Whereas for ovarian cancer, the protection persists for decades.

·         Overall, the benefits of the pill outweigh the risks.

·         Taking the pill for 10 years cuts the risks of ovarian cancer before the age of 75 from 12 per 1000 women to 8 per 1000.

·         It reduces the risk of dying from the disease from 7 per 1000 women to 5 per 1000 before the age of 75.

·         Worldwide, OCP has already prevented 200,000 ovarian cancers and 100,000 deaths from the disease.

·         With more than 100 million women taking the pill today, it is estimated that it will prevent over 30,000 ovarian cancers per year over the next few decades.

6) How does the Pill protect against ovarian cancer? 

Researchers are not sure but postulate that as OCP suppresses ovulation, this may have some protection against neoplastic change.

7) Would you recommend that women go on the Pill to protect themselves against ovarian cancer? If so, how long should they go on the Pill for? Why is this so? 

For women with menstrual problems or who require contraception, the OCP would be an excellent choice as it reduces the risk of ovarian cancer at the same time. This is provided that they have no contraindications -over the age of 35, heavy smoker, obesity (BMI over 35), hypertension, heart disease, breast cancer, deep vein thrombosis, poorly controlled diabetes, liver problems, migraine. 

Women should go on the pill as long as they want, provided they neither have contraindications nor decide to get pregnant. The Faculty of Family Planning and Reproductive Health Care Clinical Effectiveness Unit said that OCP can be used from the first menstrual period to 50 years of age, if there are no risk factors.

8) Would you recommend that the Pill be made available over-the-counter? 

Despite the convincing evidence of ovarian cancer protection, the doctor still needs to take a thorough history and perform a clinical examination to exclude contraindications to taking the OCP. So currently, over the counter availability may not be advisable in the Singapore context.

9) Does the Pill cause any cancers, e.g., breast cancer?

OCP is associated with a small increase risk of breast cancer and is reduced to no increase risk 10 years after stopping OCP. OCP is also associated with a very small increase risk of cervical cancer that increases with increasing duration of use.

 

10) What are some side effects of going on the Pill? 

OCP is safe for the majority of women. Some women do experience nausea, headaches, breast tenderness, weight gain and mood swings when starting the pill, but these undesirable effects will go away after a few cycles. Rare side effects include risks of blood clots in the leg, migraines, stroke and high blood pressure. Those risks are particularly elevated in women in their late 30s and who smoke.

Disclaimer: The information in this website is for general health education only. Please consult a doctor if you have symptoms or questions on medical conditions or illnesses.

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