A risk factor is any factor that is associated with increasing someone’s chances of developing a certain condition, such as cancer. Some risk factors are modifiable, such as lifestyle or environmental risk factors, and others cannot be modified, such as family history and inherited factors.
Having 1 or more risk factors does not mean that a person will develop cancer. Many people have at least 1 risk factor but will never develop cancer, while others with cancer may have had no known risk factors. Even if a person with cancer has a risk factor, it is usually hard to know how much that risk factor contributed to the development of their disease.
Cervical cancer is not infectious. It is not caused by an inherited faulty gene, so other members of your family are not likely to be at risk of developing it.
Risk factors for cervical cancer are:
- infection with human papillomavirus (HPV), a virus transmitted by sexual activity
- lack of regular Pap tests
- taking contraceptive pills for a long time
- previous abnormality or cancer of the cervix
- having many children
- diethylstilboestrol (DES).
HPV is a group of wart viruses that can affect the surface of any part of the body, including the skin, vagina and cervix. The virus is spread from person to person through genital skin contact.
HPV does not often cause any symptoms, so many people are unaware they are infected.
HPV infection is very common – about 4 out of 5 women will be infected with genital HPV at some point in their lives. About 98% of infections are quickly cleared by the immune system. But, if the virus lays dormant for several years and the immune system is unable to clear it, it may lead to cervical cancer.
More than 100 types of HPV have been identified, and about a dozen of these are considered high risk because they can lead to cancer. The HPV vaccine (also known as the ‘cervical cancer vaccine’) can protect against several types of HPV, including types that cause cancer.
Precancerous cells (also called cervical abnormalities) that are caused by HPV can be detected by a Pap test.
Chemicals in tobacco may damage the cells of the cervix and make cancer more likely to develop.
Cervical cancer is more common among women who don’t have regular Pap tests.
All women who have ever had sex should have a Pap test every 2 years between the ages of 18 and 70. The Pap test increases the likelihood of identifying precancerous cells. This means that precancerous cells can be removed or treated as early as possible, which reduces the risk of developing invasive cervical cancer.
Regular Pap tests are important, even if you have been vaccinated against HPV.
Cervical cancer mainly occurs in women over 35 years old and is less common in women under 25. Around 70% of cervical cancers are diagnosed in women under 60 years old.
Using contraceptive pills (also called birth control pills, or the ‘pill’) for 5 or more years may increase the risk of cervical cancer in women who also have HPV infection. This risk decreases quickly if you stop using the pill.
Women who have a high-grade cervical abnormality (i.e. they have precancerous cells in their cervix) or who have had one in the past, are at high risk of developing cervical cancer.
Usually, women who have an abnormal Pap test result are asked to have a Pap test every year (instead of every 2 years) so that the changes can be monitored. Often, the cervical cells will return to normal by themselves. You can return to 2-yearly Pap tests if you have 2 negative Pap tests in a row (i.e. the tests do not show any abnormalities). These 2 tests should also include HPV DNA testing (which determines whether you have an HPV infection), and should be taken at least 4 months after treatment and at least 1 year apart.
Women who have been diagnosed with cervical cancer in the past are also at higher risk of developing cervical cancer again. Your doctor will discuss how to manage this risk with you.
Studies suggest that giving birth to 5 or more children may slightly increase the risk of cervical cancer for women who have HPV infection.
DES is a synthetic form of the female hormone oestrogen. It was used to prevent miscarriage and other complications of pregnancy, and was given to some pregnant women during the late 1940s and 1950s, and used less in the 1960s and 1970s. DES is no longer given to pregnant women.
DES may increase the risk of a rare form of cervical cancer (and some other cancers of the reproductive system) in daughters who were exposed to this drug before they were born (i.e. if your mother took DES while she was pregnant with you).
If you were exposed to DES before you were born, you should have Pap tests and pelvic examinations every year, and discuss your risk of cervical cancer with your doctor.
For more information, see Cancer Australia’s webpage on DES.
Find out more about:
- Lifestyle and risk reduction
- Position Statement on Lifestyle risk factors and the primary prevention of cancer