Cervical cancer refers to cancer of the cervix, which is the lower part of the uterus that bridges the uterus to the vagina. It is the eighth most common type of cancer globally, and the fourth most common type to occur among women (after breast cancer, colorectal cancer and lung cancer). According to a scientific study carried out in 2018, cervical cancer had an estimated age-standardised incidence rate of 13.1 per 100,000 women.
There are usually no observable symptoms in the early stages of cervical cancer. However, as the cancer progresses, a woman may observe one or more of the following symptoms:
- abnormal vaginal bleeding between periods, after intercourse or after menopause
- unusual vaginal discharge that may be watery or bloody and may have a foul odour
- pain and discomfort during intercourse
- pelvic or lower back pain
If the cancer progresses to the point where it spreads out of the cervix, further symptoms such as the following may be observed:
- severe pain in the side or back (usually caused by kidney failure)
- severe vaginal bleeding
- urinating or defaecating more often than usual
- urinary or bowel incontinence
- bloody urine
- swelling of one or both legs
As with most cancers, a late detection implies that the cancer is likely to have spread to other parts of the body. As such, organ and body function of the respective areas may be affected. Some complications that may occur include:
- severe pain, if the cancer has spread to muscles, bones, nerve endings
- kidney failure, as the cancer may cause a build-up of urine in the kidneys
- blood clotting, as cancer sometimes makes blood ‘stickier’ and large tumours could press on veins and hamper blood flow
- bleeding, mostly from the vagina, rectum or in urine
- fistula (rare), which develops as a channel between the bladder and vagina (occasionally rectum and vagina), causing frequent vaginal discharge
Complications could also arise as side effects of treatment. These may include:
- onset of early menopause, if ovaries have been surgically removed or damaged by radiotherapy
- narrowing of vagina, as a result of radiotherapy
- lymphoedema (build-up of fluid in tissue), if pelvic lymph nodes have been removed
- vomiting, diarrhoea, loss of appetite, hair fall, frail skin associated with chemotherapy
About 99% of cervical cancer cases are caused by the Human Papilloma Virus (HPV), which is a group of over 100 different viruses. While around 15 of these are considered high-risk for cervical cancer, the strains HPV 16 and HPV 18 are what cause the majority of disease. Hence, although most women (and their partners) might invariably be infected with HPV at some point in their lives, only a few infections lead to the incidence of cervical cancer.
The virus is usually spread via sexual intercourse/activity, but can also spread via skin contact of the genital areas.
HPV works by bringing the normal functioning of the cells that they invade to a halt, resulting in mutations. This then causes the cells to reproduce uncontrollably, leading to the formation of a malignant tumour.
The following factors are believed to increase the risk of cervical cancer in women:
- smoking (increases risk by two-fold)
- being immunocompromised
- exposure to the hormonal miscarriage prevention drug diethylstilbestrol (DES) while in the mother’s womb
- having many partners
- early sexual activity or having children before the age of 17 years
- pre-existing sexually transmitted infections (STIs)
The initial screening for cervical cancer usually involves one of the following:
- Pap smear test – this involves obtaining a sample of cells (by ‘scraping’) from the cervix and studying them for cancerous or abnormal/pre-cancerous cells
- HPV DNA test – this involves testing a sample of cells taken from the cervix for the presence of high-risk HPV strains
If cancer is suspected, the patient is then usually subjected to a thorough examination by means of colposcopy, where a small microscope with a light will be used to examine the cervix closely. A biopsy is also often carried out at the same time.
Further testing with blood tests, X-rays and scans may be carried out to ascertain the level of spread and what other organs have been affected.
These would then make it possible to establish which stage the cancer, if present, is at:
Stage 0 – no cancerous cells, but presence of abnormal cells that could be pre-cancerous
Stage 1 – cancer cells present in the cervix only
Stage 2 – cancer cells present outside of cervix, too, but not reached pelvis or lower vagina yet
Stage 3 – cancer has spread to pelvis or lower part of vagina
Stage 4 – cancer has spread to bowels, bladder or other organs (such as lungs)
The most significant mode of preventing cervical cancer is by vaccination. The HPV vaccine, an intramuscular injection, was first introduced in 2008, and has since been administered to girls and boys around the age of 11-12 years. However, women up to the age of 26 years who have not been vaccinated are also recommended to receive the vaccination. The initial injection is followed up with a booster dose after a minimum interval of five months. A third dose may be required for women over 26 years who choose to receive the vaccine (usually less effective as they may already have been exposed to HPV).
It is equally important for women within the age range of 21-65 years to get a Pap smear test done every 3-5 years (as recommended by their doctor).
Additionally, practising safe sex, refraining from having multiple partners, and refraining from smoking could also help to reduce the risk of cervical cancer.
Treatment and prognosis for cervical cancer principally depend on what stage it is detected at.
If diagnosed early, cervical cancer is often curable and is often first approached with surgery. This could be:
- cone biopsy or large loop excision of the transformation zone (LLETZ), if it is still very small
- trachelectomy, where only the cervix, surrounding tissue and part of the vagina are removed
- hysterectomy, where the cervix and uterus are removed; ovaries and fallopian tubes may be removed, depending on spread
- pelvic exenteration, where the cervix, vagina, uterus, fallopian tubes, bladder and rectum may all be removed
- radiotherapy may be used by itself or in combination with surgery upon early detection
- chemotherapy may be used in combination with radiotherapy, or by itself to slow down progress of the cancer if it detected a little later on
In cases of late diagnosis where a cure is unlikely, palliative care may be administered instead of actual treatment, in order to control pain and symptoms and make the patient feel as comfortable as possible.
Cover illustration adapted from VectorStock.