Cervical cancer: Prevent and treat it
Improving awareness of the risks of cervical cancer could see this common woman’s cancer drop out of the Top 10 list.
Cervical cancer is the 10th most common cancer among women in Singapore. But some doctors expect the cancer of the lower part of the uterus, or the womb, to drop out of the top 10 list in the near future, as awareness of the cancer improves and women do more to reduce the risks and detect it early.
After all, cervical cancer is one of the most treatable cancers around. In Singapore, the number of new cases has dropped significantly over the years, which has pushed the ranking of cervical cancer down from fifth to 10th place. Today, some 190 cases are diagnosed every year, and the cancer is often tagged “the 100 per cent preventable cancer”.
What makes this possible is that more women who are at higher risk are doing more to prevent or, at least, reduce their risk, and going for early screening so that they can get treated in the early or even pre-invasive stages.
However, the cancer is preventable, detectable, and treatable only if women know the right thing to do.
Understanding the risks
Cervical cancer is a malignant cancer arising in the tissues of the cervix, which is the organ connecting the uterus and the vagina.
The most common type of cervical cancer, by far, is Squamous Cell Carcinoma (SCC). This develops from infection from the Human Papilloma Virus (HPV), a common virus. Other types, including adenocarcinoma, small cell carcinoma, adenosquamous, adenosarcoma, melanoma and lymphoma, are a lot less common, constituting no more than 20 per cent of all cervical cancers.
There are about 150 types of HPV – a common sexually transmitted infection – but fewer than 20 of them actually cause cervical and other cancers such as those of the vulva, vagina, penis, anus, and back of the throat.
This is how cervical cancer usually comes about: It starts with HPV infection of the cervix which, if it does not clear over a period of time, can trigger abnormal growth in the cells of the inner lining. These cells may then develop pre-cancerous, pre-invasive changes, which are called Cervical Intraepithelial Neoplasia (CIN). If left untreated, the CIN can turn into an invasive cancer.
It needs to be noted, however, that HPV infection does not necessarily lead to cancer. In fact, such infection clears in a large majority – up to 90 per cent – of cases.
Some, however, do result in skin growths on the genitals called genital warts. These can cause some pain and discomfort, but are not cancerous.
Because most cases of cervical cancer involve the HPV, which is transmitted sexually, women who are sexually active are more susceptible to cervical cancer. Those who have many sexual partners, or partners who have many other partners, face a greater risk, while those who start unprotected sexual intercourse before the age of 16 face the highest risk.
Generally, women between the age of 17 and 20 have the highest chance of HPV infection, and most cases of CIN are found in younger women. Those who have a history of sexually transmitted diseases such as herpes and genital warts also have a higher risk.
Smoking can also increase the risk of HPV infection, as can the use of long-term oral contraceptives. Women whose immune system is weak also face greater risk.
Symptoms to look out for
One of the challenges of trying to detect cervical cancer is that there are no symptoms in the early stages. By some estimates, half of all women discover they have cervical cancer only when it is in the advanced stage, when the cancer has spread.
In late stages, typical symptoms include:
- Vaginal bleeding following intercourse or after menopause
- Abnormal vaginal bleeding between periods
- Unusual vaginal discharge that may be heavy or smell foul
- Lower abdominal pain or pain during intercourse
- Back pain
- Painful or difficult urination and cloudy urine
- Chronic constipation and feeling of presence of stool despite having emptied bowels
- Leaking of urine or faeces from the vagina
Because there are no early signs, and some of the above symptoms may be mistaken for other conditions such as yeast infection or urinary tract infection, doctors urge women to go for regular screening.
Prevention through vaccination
While HPV infection cannot be treated, women can reduce the risk of infection and developing HPV-related cancers. One effective way is vaccination.
In particular, two vaccines, Cervarix and Gardasil, have been shown to prevent 70 to 80 per cent of cervical cancer, and are considered safe by the World Health Organization.
Administered in three doses over six months, they have to be administered to young girls – before they start sexual activity – to have maximum effect.
Doctors recommend the vaccines for women between the ages of 9 and 26. But women should seek their doctors’ advice first, to see which vaccine they should take – and whether they should take it at all.
Vaccination, however, does not guarantee that a woman will not get HPV infection or be spared cervical cancer. The vaccines cover only some high-risk types, so women should learn to look out for symptoms and go for regular screening to ensure they can detect the cancer early.
Early detection through screening
One of the most common methods of screening for cervical cancer is the Pap smear. This involves taking a sample of cells from the surface of the cervix during a vaginal examination. This test is quick, simple and painless. Statistics show that timely and regular Pap smears can cut the incidence of cervical cancer by as much as 90 per cent.
It can take up to five to 10 years for CIN to develop into cancer, so regular Pap smears should be done to detect CIN early. This can then be managed before it advances into a cancer.
Women are advised to begin Pap smears early, as soon as they become sexually active. Doctors suggest beginning at the age of 18 and doing a test every year for one to three years. The frequency can then be lowered to every three years.
If a Pap smear reveals that some cells in the cervix are abnormal, further tests may be done. This may include a colposcopy – examining the cervix with a microscope. This procedure is painless and takes just 15 minutes. Doctors may also order a chest X-ray, CT scan, MRI of the abdomen and pelvis, or examination of the pelvis.
If pre-invasive CIN is discovered during screening, the abnormal lining of the cervix can be removed to prevent the cells from turning into cancer. This may be done by local excision techniques such as knife or laser cone biopsies, or ablative techniques such as laser vaporisation or cold coagulation.
If early invasive cancer is discovered, surgery is usually done. This usually involves a hysterectomy, or removal of the uterus along with surrounding tissue and lymph nodes. Radiotherapy and chemotherapy may also be administered. Survival rate for early-stage cervical cancer is very good, with the five-year survival rate reaching as high as 95 per cent.
If the cervical cancer has reached an advanced stage and surgery is not possible, chemoradiotherapy or radiotherapy is usually given. Survival rates for advanced-stage cervical cancer are lower, dropping below 40 per cent for the five-year survival rate.
Written by Kok Bee Eng
Tags: cervical cancer, common cancer, human papillomavirus (HPV) cancer, hysterectomy, pap smears, prevent cancer, squamous cell carcinoma (SCC), vaccination, women (gynaecological) cancer