Of the top 10 cancers in women, three are to be found in the gynaecologic organs. Some of them can be easily screened or detected early, so it is important for women to keep their genital organs healthy.
This refers to malignant growth arising from the ovaries. The most common ovarian cancers are “epithelial”: They arise from the “skin” (epithelium) of the ovary. The less common ones arise from the “internal parts” of the ovary, either from the egg cells (germ cell tumour) or supporting cells (sex cord/stromal).
There are also extremely rare cancers from the lymph cells of the ovary, known as lymphoma of the ovary.
Ovarian cancer is the fifth most common cancer in Singapore and usually affects older women. Germ cell cancers of the ovary occur more frequently in younger women.
Causes and associations include late pregnancy, early onset of menstruation, later menopause, a family history of ovarian cancer, and endometriosis.
The female reproductive system
The female genital system consists of two main parts: the uterus and the ovaries.
The uterus is divided into the uterine body - the womb, whose main function is holding the baby before it is born - and the uterine cervix, which serves as the entrance or gate to the womb.
The ovaries host ovum or eggs. At regular intervals, they release an ovum which can be fertilised by sperm during sexual intercourse, leading to pregnancy and childbirth.
The lesser-known parts of the female genitalia include the fallopian tubes, which connect the ovaries to the uterus and the vagina. These parts are internal. The external parts consist of the vulva, labia, and clitoris.
Ovarian cancer is rarely genetic, though some families have genetic mutations such as BRCA gene abnormalities or Lynch syndrome. Women who have a first-degree relative (sister or mother) with this disease have 20 times higher risk of developing ovarian cancer.
Ovarian cancers are difficult to prevent or detect early because they rarely have early symptoms or signs.
Symptoms may include tummy discomfort, bloating, and change in bowel habits which tend to signify later ovarian cancer. While a marker in the blood called CA125 is higher in about 80 per cent of patients with epithelial ovarian cancers, it is not always accurate for early diagnosis, as the marker can also be higher in non-cancerous conditions such as endometriosis and appendicitis.
At the moment, there is no widely-accepted and effective screening test for ovarian cancer. However, if you have a strong family history of breast or ovarian cancer, you might want to go for genetic counselling and testing.
If you are slim and experience signs of abdominal bloating and discomfort, go for an ultrasound scan and blood tests to detect early ovarian cancer.
If you have a strong family history of breast or ovarian cancer, see your gynaecologist once every year to get a check-up and an ultrasound.
Women with very strong family history should consider getting a BRCA mutation testing followed by consideration of prophylactic oophorectomy (surgical removal of the ovaries).
This is the most common cancer of the female genital tract in Singapore, and the most common among this affects the lining of the uterus. The less common type takes place in the muscular layer (sarcoma). If found early and treated, the cure rate for uterine cancer is more than 90 per cent.
In Singapore, most cases involve women between 50 and 70 years old.
Women who are obese, have early menarche (first menstrual period) and late menopause, or who are on oestrogen-only hormone replacement therapy may be at higher risk.
While you may have some or all of these risk factors and not get uterine cancer, you should be aware of the symptoms and discuss your concerns with your doctor.
Look out for irregular and abnormal bleeding, especially if it is premenopausal.
It is important to do regular check-ups, including pelvic examinations. About 75 per cent of women diagnosed with uterine cancer have the Stage 1 disease. Of these, 85 to 90 per cent will have no evidence of cancer five years or more after treatment. After surgery, some patients may benefit from adjuvant radiation and chemotherapy.
While there is no simple way to screen for uterine cancer, the key to detecting it at an early stage is looking out for the symptoms, such as irregular and abnormal bleeding, especially when premenopausal.
You can cut your risk of endometrial cancer by keeping an ideal weight and body mass index (BMI). Exercise regularly and keep a low fat diet.
Most cervical cancers arise from the inner lining of the cervix. If exposed to infection from the Human Papillomavirus (HPV), and if the cervix cannot clear the infection over a period of time, the cells lining the cervix may develop pre-cancerous changes called Cervical Intraepithelial Neoplasia (CIN). These turn into cancer cells if left untreated.
Improved education has helped women at higher risk go for screening and get treatment at the CIN stage, so cervical cancer has become less common these days. Most of the time, it occurs in women who do not go for regular screening, and have never done a Pap smear.
Sexual intercourse at an early age, multiple sexual partners, smoking, and a history of sexually transmitted disease can increase the risk of cervical cancers.
There are no symptoms in the early stages. In late stages, typical symptoms include vaginal bleeding after sexual intercourse, abnormal vaginal bleeding between periods, discomfort during sexual intercourse, and foul vaginal discharge.
As cervical cancer can take up to five to 10 years to develop from CIN, screening using regular Pap smears can detect CIN early enough so that it can be managed before it reaches the cancerous stage. It is, therefore, important to go for regular Pap smears.
If you are sexually active, go for Pap smears yearly. However, if you have had three consecutive Pap smears, you can reduce the frequency to every two years.
If you have done an HPV testing on the cervical smear and the results are normal, you can go for Pap smears once every five years.
If you are concerned about a high risk of cervical cancer, consider getting vaccinated before you start any sexual relationship. The earlier the vaccination, the stronger the immune response.
This article is based on information from Dr See Hui Ti’s article, “Tips on maintaining the health of the female reproductive system”, in Singapore Cancer Society’s Cancer Focus Vol 1 2015 issue.