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Risk factors

Although the exact cause of cervical cancer is unknown, it has been linked to certain risk factors.

A risk factor is anything that increases your chances of getting a disease. Having a risk factor does not mean that you will get cancer, and not having risk factors does not mean that you won’t get cancer. If you think you may be at risk of cervical cancer, you should discuss this with your doctor. You may want to ask about a schedule for checkups.

Cancer of the cervix is not infectious. An inherited faulty gene does not cause it and so other members of your family are not likely to be at risk of developing it.

The known risk factors for cervical cancer are:

  • human papillomavirus (HPV) infection (this virus is transmitted by sexual activity)
  • smoking
  • lack of regular Pap tests
  • age
  • using contraceptive pills for a long time
  • having many children
  • diethylstilboestrol (DES).

HPV infection

Human papillomavirus (HPV) is the name for a group of wart viruses. It can affect the surface of any part of the body, including the skin, vagina and cervix. This virus is spread from person to person through genital skin contact. It is so common that it could be considered a normal part of being sexually active.

More than 100 types of HPV have been identified, but about a dozen types are considered high risk because they can lead to cancer.

Around eight out of 10 women will become infected with genital HPV at some time in their lives and, for about 98 per cent of women, it is cleared rapidly by the immune system. However, HPV does not often cause any symptoms, so many people are unaware they have the virus. If the virus lays dormant for several years, it may lead to cervical cancer.

HPV can cause precancerous cells that can be detected by a simple test called the Pap test. All women who have ever had sex should have a Pap test every two years from the ages of 18–70 years.

Two vaccines against some types of HPV are available. For more information see Cervical cancer vaccine, below.

For more information about the Pap test, see Cervical cell changes and Pap test, below.

Smoking

Chemicals in tobacco may damage the cells of the cervix and make cancer more likely to develop.

Lack of regular Pap tests

Cervical cancer is more common among women who don’t have regular Pap tests. The Pap test increases the likelihood of identifying pre-cancerous cells, which enables the cells to be removed or treated as early as possible, reducing the risk of invasive cervical cancer.

Age

Cancer of the cervix occurs mainly in women over 35 years of age and is less common in women under 25.

Using contraceptive pills for a long time

Using contraceptive (birth control) pills for a long time (five or more years) may increase the risk of cervical cancer among women with HPV infection. However, the risk decreases quickly when women stop using contraceptive pills.

Previous history

If a woman has had a high-grade abnormality she is at high risk of developing cervical cancer. Such women should consult with their specialist or general practitioner for annual Pap smears and ongoing monitoring.

Women may return to two-yearly Pap smears upon receiving negative results from the ‘test of cure’. The test of cure is a series of two Pap smears, which includes HPV DNA testing, undertaken at least four months after treatment and at least one year apart, and must be completed by the health practitioner.

A previous diagnosis of cervical cancer also places women at greater risk of developing cervical cancer. Women with a past diagnosis of cervical cancer should discuss their management with their health practitioner.

Having many children

Studies suggest that giving birth to many children (five or more) may slightly increase the risk of cervical cancer among women with HPV infection.

Diethylstilbestrol (DES)

For more information about DES.