Cervical cancer

Tuesday 1 October, 2013

On this page: The cervix | Cervical cell changes | What is cervical cancer? | What types are there? | What are the risk factors? | How common is it? | What are the symptoms? | What is a Pap smear? | The HPV vaccine

The cervix

The cervix is part of the female reproductive system. The female reproductive system also includes the uterus (womb), ovaries, Fallopian tubes, vagina and vulva.

The cervix is the lower, cylinder-shaped part of the uterus that connects to the vagina. It is also called the neck of the uterus. It has an outer surface that opens into the vagina and an inner surface that faces into the uterus. The inner part is called the cervical canal.

The functions of the cervix include:

  • producing moisture to lubricate the vagina
  • producing mucus that helps sperm travel up to the Fallopian tube to fertilise an egg from the ovary
  • holding a developing baby in the uterus during pregnancy.
  • widening so the baby can be born via the vagina (birth canal).

The cervix is covered by two kinds of cells, which line the surfaces of many organs and body systems. These are: 

  • Squamous cells
    flat, thin cells found in the outer layer of the cervix that opens into the vagina (ectocervix)
  • Glandular cells or columnar cells
    column-shaped cells that produce cervical mucus and are found in the cervical canal (endocervix).
Glandular cells from the cervical canal are constantly migrating outside the canal. When this happens, the cells undergo changes that convert them back to squamous cells. This change process is called squamous metaplasia, and the area where it takes place is known as the transformation zone.

The female reproductive system

Cervical cell changes

Sometimes the cells in the cervix start to change and no longer appear normal. This may mean you have a precancerous lesion, which is not cancer but may lead to cancer. Cervical cell changes may be found during a routine Pap smear.

There are different types of early cell changes, which are also called epithelial abnormalities.

  • Atypia
    The cervical cells have changed slightly. The cells may return to normal by themselves or the changes may worsen. If a cell shows signs of atypia, it does not necessarily mean you have cancer or will get cancer. Atypia can also be caused by infection or irritation.
  • Squamous abnormalities
    The squamous cells of the cervix are abnormal. This may be classified as a low-grade or a high-grade abnormality on a Pap smear. High-grade abnormalities are precancerous. Although they do not usually cause symptoms, abnormalities may progress to early cervical cancer if they're not detected and treated.
  • These squamous changes are also called cervical intraepithelial neoplasia (CIN) and are graded according to how severe they appear on a biopsy of the tissue. Early changes are categorised as CIN 1 and they will usually disappear without treatment. Further abnormal changes are categorised as CIN 2 or CIN 3. 
  • Glandular abnormalities
    The glandular cells of the cervix are abnormal. These abnormalities on a Pap smear always require further assessment as they may be either precancerous or cancerous.

If the results from a Pap smear show that your cervix has some abnormal changes, your doctor will recommend that you have either:

  • another Pap smear in 6-12 months to monitor the cells
  • a biopsy to look at the cervical cells in more detail, which is done using a microscope called a colposcope

The doctor’s recommendation will be based on the grade of the abnormal changes.

"My doctor said that because I had regular Pap smears, the cancer was picked up while it was small. The treatment was straightforward and my body is intact."

What is cervical cancer?

Cervical cancer is a malignant tumour found in the tissues of the cervix. It occurs when abnormal cells in the cervix turn into cancer cells. The cancer cells break through the surface cells (epithelium) and into the underlying tissue (stroma) of the cervix.

Cervical cancer most commonly begins in the cells of the transformation zone. At diagnosis, the cancer is often just within the cervix, but it may spread to tissues around the cervix (e.g. the vagina) or to other parts of the body.

What types are there?

The two main types of cervical cancer are named after the cells they start in:

  • Squamous cell carcinoma
    The most common type, accounting for about 8 out of 10 cases.
  • Adenocarcinoma
    A less common type, starting in the glandular cells. It is more difficult to diagnose, as it is high in the cervix and hard to reach with tools used for testing.

What are the risk-factors?

The main cause of cervical cancer is an infection called human papillomavirus (HPV). There are also other known risk factors.

  • HPV

    Most cases of cervical cancer occur many years after infection with a strain of human papillomavirus, which is the name for a group of wart viruses. HPV is a common infection affecting the surface of different body areas, such as the skin, vagina and cervix. About four out of five people will become infected with a type of HPV at some time in their lives.

    Genital HPV is usually spread via the skin during sexual contact. In most women, the virus is cleared quickly by the immune system and no treatment is needed.

    The precancerous cell changes caused by HPV can be found by a Pap smear. There is now also a vaccination against HPV.

    Women who have HPV are often unaware they have it. This is because HPV usually doesn’t cause noticeable symptoms.

  • Smoking
    Chemicals in tobacco can damage the cells of the cervix and make cancer more likely to develop.
  • Diethylstilbestrol (DES) exposure

    DES is a type of oestrogen-based medication, which was prescribed to women from the 1950s to the early 1970s to prevent miscarriage.

    Although rare, studies have shown that the daughters of mothers who took DES have an increased risk of developing a rare type of adenocarcinoma.

How common is cervical cancer?

In Australia, about 780 women are diagnosed with the disease every year. About 1.5% of all cancers in Australian women are cervical cancer.

Since the mid-1990s, the incidence of cervical cancer has decreased significantly. This is because more women are having regular Pap tests as part of the National Cervical Screening Program. It’s expected that the National Immunisation Program will cause a further reduction in cervical cancer cases in the coming years.

What are the symptoms of cervical cancer?

The early stages of cervical cancer usually have no symptoms. The only way to know if there are abnormal cells in the cervix, which may develop into cervical cancer, is to have a Pap smear (see opposite). If symptoms are present, they usually include:

  • vaginal bleeding between periods, after menopause or after intercourse
  • pain during intercourse
  • unusual vaginal discharge
  • excessive tiredness
  • leg pain or swelling
  • lower back pain.

These symptoms can also be caused by other conditions. However, see your general practitioner (GP) if you are worried or the symptoms are ongoing.

What is a Pap smear?

The main role of a Pap smear (also called a Pap test) is to help prevent cancer by detecting abnormal precancerous cells in the cervix. Women who are or who have ever been sexually active should have a Pap smear every two years, at least until age 70.

During the test, a doctor uses an instrument such as a brush or spatula to remove some cells from the surface of the cervix. This may feel slightly uncomfortable, but it usually only takes a minute or two. The sample is placed onto a glass slide or put into a fluid, and then sent to a lab where it is examined under a microscope for any changes.

A Pap smear is not used to diagnose cancer – if cancer is suspected, you will need other tests.

Occasionally, cancer cells are detected in a Pap smear, but this is uncommon. If you have an abnormal result, your GP may refer you to a specialist (gynaecologist) to discuss:

  • whether you need further tests or treatment
  • how you will be regularly monitored, including if you will have another Pap smear or more frequent Pap smears. (Women who have had abnormal cell changes should be tested more often, according to their doctor’s advice.)

To learn more, see An Abnormal Pap Smear Result: What this means for you.

The HPV vaccine

There is an HPV vaccine that provides protection against two strains of HPV that are known to cause about 70% of cervical cancers. The vaccine also offers some protection against other less common gynaecological cancers in women, including vaginal and vulval cancers.

As part of the National HPV Vaccination Program, the HPV vaccine is free for girls and boys aged 12–13 in Australia. Boys aged 14–15 will also receive the vaccine as part of a catch-up program.

Some older people who are already sexually active may still benefit from the vaccine – for information, including fees, talk to your GP.

The HPV vaccine cannot be given to treat cancer once a woman has already been diagnosed with precancerous cells or cancer. It also doesn’t provide protection against all types of HPV, so it is important to continue to have Pap smears even if you’ve been vaccinated.

For more details, talk to your GP or visit the websites www.immunise.health.gov.au or http://hpv.health.gov.au.

Reviewed by: A/Prof Selvan Pather, Gynaecological Oncologist, Sydney Cancer Centre, A/Prof in Obstetrics and Gynaecology, University of Sydney, NSW; Continence Foundation of Australia; Carmen Heathcote, Cancer Council Queensland Helpline Consultant; Yvonne Howlett, Cancer Council Queensland Helpline Consultant; A/Prof Michael Jackson, Director, Radiation Oncology, Prince of Wales Hospital, NSW; and Anne Steng, Patient.
Updated: 01 Oct, 2013