The female reproductive tract includes the ovaries, fallopian tubes, uterus, cervix, vagina and vulva (See illustration below). Gynaecological cancers are malignant growths that arise from any of the above. Statistics from the Singapore Cancer Registry show that cancers of the uterus, ovary and cervix are the 4th, 5th and 10th top cancers affecting Singapore women between 2011 to 2015.
Illustration showing the female reproductive tract.
Although the locations of the top 3 gynaecological cancers are adjacent to one another. The causes and symptoms of each are very different. The following is some basic information on each of them.
Cervical cancer is the 10th most common cancer among Singapore women. This is unfortunate as cervical cancer is almost always preventable. That is the reason why women are strongly encouraged to have regular pap smears. The purpose of pap smears is to detect pre-cancerous changes in the cervix. If the correct treatment is instituted during the pre-cancerous stage, then cancer of the cervix can be prevented.
The main cause of cervical cancer is Human Papilloma Virus (HPV). There are more than 100 types of HPV. Some types like HPV 16, 18 can cause cancer of the cervix. Most people with HPV infections have no symptoms, and the infection clears spontaneously without treatment. However, in a certain population of people, the HPV infections do not clear and stay within the cells of the body for long periods of time. If a woman infected with high-risk HPV strains like HPV 16, 18 goes undetected and untreated, abnormal cells will grow on the cervix resulting in pre-cancerous and cancerous changes.
Currently there are vaccines available to protect women against the high-risk HPVs that cause cervical cancer.
The classical symptom of cervical cancer is bleeding after sex. Other symptoms include bleeding in between menses or after menopause. Blood-stained, foul-smelling vaginal discharge is another symptom of cervical cancer.
Screening and diagnosis
Pap smear is a simple, painless method of screening for pre-cancerous changes in the cervix If pre-cancerous or cancerous changes are suspected, then test for high-risk HPV and colposcopy would be recommended. Colposcopic examination involves applying special medication to the cervix and examining the cervix with a magnifying glass. Biopsies, or sampling of the cervix, will be done to confirm the diagnosis.
The treatment options for cervical cancer mainly surgery, radiotherapy and chemotherapy.
The risk of cervical cancer can be significantly reduced by getting vaccinated with the HPV vaccine. Having regular pap smears will allow detection of pre-cancerous changes; having the correct treatment at this stage can prevent progression to cancer.
Although ovarian cancer is the 5th most common cancer among Singapore women, it is one of the most lethal. The main reason for that is most patients with ovarian cancers are diagnosed only at late stages. Like most cancers, late diagnosis at advanced stage of the disease usually means lesser chance of cure. Ovarian cancers are usually diagnosed late because symptoms almost always surface late in the disease and lack of screening tests to detect the disease in its early stage.
Causes / risk factors
Unlike cancer of the cervix, there is no known dominant cause of ovarian cancer. However, there are many risk factors which are associated with the development of ovarian cancer. These risk factors include
- Inherited gene mutations
Certain mutations or changes in the genetic make-up can predispose a woman to having ovarian cancer. Most of these mutations are inherited, in other words passed from one generation to another. The gene mutations commonly associated with ovarian cancers are BRCA1 and BRCA2. These two mutations result in higher risk breast cancers. Another inherited syndrome called hereditary non-polyposis colorectal cancer (HNPCC) is associated with increased risk of cancers of the uterine lining (endometrium), colon, ovary, stomach and small intestine. So if one has multiple close family members who have been diagnosed with breast, colon, ovarian or intestinal cancers, testing for these gene mutations are strongly advised.
- Family history
Having a first-degree relative (ie mother, sister or daughter) with ovarian cancer will increase one’s chances of developing ovarian cancer as well. Positive family history of breast or colon cancer is also associated with an increased risk of developing ovarian cancer.
Ovarian cancer is most common amongst women in the 50 to 70 age group.
- Infertility or women who had never been pregnant before.
- Personal history of breast or colon cancer
- Fertility drugs
- Early menarche, ie start having periods before the age of 12
- Late menopause after the age of 52
In many cases, symptoms do not occur until the ovarian cancer is in an advanced stage. Even when present, symptoms of early-stage ovarian cancer are often non-specific and may resemble those of digestive and bladder disorders. It is not unusual for patients to attribute their early symptoms to indigestion and weight gain. The common symptoms of ovarian cancers are abdominal bloating, persistent indigestion, loss of appetite, unexplained weight loss and changes in urinary habits.
Although ultrasound scans of the pelvis and ovarian tumour markers may be useful in detecting ovarian cancer, there is no recommended standard or routine screening test for ovarian cancer for the general public.
Confirmation of ovarian cancer can only be done after the ovary has been surgically removed from the body and studied under a microscope.
Without an operation, the diagnosis can only be suspected. The diagnosis can be suspected from
- Physical examination
- On physical examination, a growth or mass may be felt in the lower abdomen. In late stages, the abdomen may be distended.
- Ultrasound scan of the pelvis
Ultrasound scan may reveal the presence of large tumours arising from the ovaries
- Ovarian tumour markers
These are blood tests that may be raised in the presence of certain ovarian cancers. However, these tests are not 100% accurate as they may remain normal despite the presence of ovarian cancers. Some non-cancerous conditions like endometriosis and pelvic inflammatory disease may cause elevated levels as well. Examples of these blood tests include CA125, Alpha Feto-Protein, Carcinoembryonic antigen (CEA) and beta –Human Chorionic Gonadotrophin (bHCG).
- Computed Tomography (CT) & Magnetic Resonance Imaging (MRI)
Like ultrasound scan, these are imaging techniques that allows the internal organs to be examined. Compared to ultrasound scans, CT and MRI allow the organs to be seen in greater details.
- Positron Emission Tomography scan (PET scan)
This scan uses a special dye that has radioactive tracers which are injected into a vein in the arm. When highlighted under a PET scanner, these tracers may identify areas in the body which may be affected by abnormalities like cancer.
Treatment of ovarian cancer usually involves a combination of surgery and chemotherapy.
Women at high risk of developing ovarian cancer such as those with strong family history or women carrying BRCA1 or BRCA2 mutation should consider having a cancer risk assessment by their health professional and advice on options available to reduce the risk of ovarian cancer.
Use of oral contraceptive pills, pregnancy and breastfeeding has been shown to reduce risk of ovarian cancer.
Uterine cancer refers to endometrial cancer or cancer that arises from the lining of the uterine cavity. The incidence of uterine cancer has been increasing over the last couple of decades. To date, it is the most common gynaecological cancer amongst Singapore women. Fortunately, most patients with uterine cancers have symptoms like abnormal vaginal bleeding in early stages of the disease, hence a significant portion of are diagnosed early.
Causes / Risk Factors
Normally, a healthy woman has the right balance of two female hormones – estrogen and progesterone. When a woman’s hormones are imbalanced such that there is excessively high levels of estrogen and inadequate progesterone, the chances of endometrial cancer developing is much higher.
Factors that increase levels of estrogen in the body include:
- Women with infrequent ovulation. Typically, infrequent ovulation translates to infrequent menstruation. The classical example of women with infrequent ovulation is women with polycystic ovarian syndrome (PCOS).
- Women who are obese or have high body mass index. Being obese increases the levels of estrogen in the body.
- Women on estrogen-only replacement therapy (ERT). ERT stimulates the growth of the lining of the womb and increases the risk of endometrial cancer.
- Women with ovarian tumours that secretes estrogen.
Other risk factors for endometrial cancers include:
- Women on tamoxifen therapy for breast cancer.
- Personal history of breast cancer or ovarian cancer.
- Diabetes Mellitus
- Women who did not bear children
The majority of symptoms of endometrial cancer involve abnormal vaginal bleeding, for example:
- Prolonged periods
- Intermenstrual bleeding or bleeding between periods
- More frequent vaginal bleeding or spotting during the years leading up to menopause (perimenopause)
- Post menopausal bleeding or bleeding after the time of menopause
- Blood-stained , watery vaginal discharge
- Symptoms that may be felt in late stages of the disease include pelvic pain, pain during intercourse and unexplained weight loss.
Screening & diagnosis
Currently, there is no reliable and cost-effective test to screen for endometrial cancer. However, women who experience abnormal vaginal bleeding are advised to consult their gynaecologists who may do the following tests:
- Ultrasound scan of the pelvis
This imaging modality allows the doctor to assess the thickness of the inner lining of the uterus. If thicker than expected, the rsik of endometrial cancer is higher.
This is a procedure where a small camera is inserted into the uterine cavity to examine the inner lining. Abnormal growths, if any, will be detected and can be biopsied under direct visual guidance.
- Dilation and curettage (D & C)
D&C is procedure in which tissue is scraped from the lining of the womb and examined for cancer cells.
If discovered early and the endometrial cancer is confined to the uterus, surgical removal of the uterus, fallopian tubes and ovaries often offers cure.
Other modalities of treatment that may be used for endometrial cancers include hormonal therapy, radiotherapy and chemotherapy.
Factors that can maintain the balance of estrogen and progesterone will help to prevent endometrial cancers. These include:
- Cyclical hormonal treatment with oral contraceptive pills or progestogen for women who have infrequent ovulation.
- Maintaining a healthy weight
- Controlling diabetes
All women are at risk for gynecologic cancers. Although the risk generally increases with age, there are other risk factors peculiar to the various cancers. When gynaecologic cancers are found early, treatment is most effective and cure is possible.