What are the causes and risk factors?

Almost all cases of cervical cancer are caused by an infection called human papillomavirus (HPV). 

Infection with HPV – HPV is the name for a group of viruses. It is a common infection that affects the surface of different  areas of the body, such as the cervix, vagina and skin.

There are more than 100 different types of HPV, including over 40 types that affect the genitals. Genital HPV is usually spread during close contact with genital skin during sexual activity. This includes penetrative sex as well as oral sex. Using condoms or dental dams offers some protection against HPV.

About four out of five people will become infected with at least one type of genital HPV at some time in their lives. Some other types of HPV cause common warts on the hands and feet.

Most people will not know they have HPV as it doesn’t cause symptoms. In most people, the virus is cleared quickly by the immune system and no treatment is needed. If the infection doesn’t go away, there’s an increased risk of developing changes in the cervix. These changes usually develop slowly over many years.

Thirteen types of genital HPV are known to cause cervical cancer. Screening tests are used to detect most of these types of HPV or the precancerous cell changes caused by the virus. There is also a vaccine that protects people from some types of HPV.

National HPV vaccination program

HPV can be prevented through vaccination. The first vaccines protected against two high-risk types of HPV that cause about 70% of cervical cancers.

The most common HPV vaccine now used in Australia protects against seven high-risk types of HPV known to cause 90% of cervical cancers.

The vaccine also offers some protection against other less common cancers associated with HPV, including vaginal, vulvar, penile, anal, and mouth and throat cancers.

As part of the national HPV vaccination program, the vaccine is free for girls and boys aged 12–13. If you weren’t vaccinated at school, talk to your doctor about whether you would still benefit from having the vaccine. For women aged 25 and older, the best protection against cervical cancer is cervical screening.

The HPV vaccine does not treat precancerous cell changes or cervical cancer.

If you’ve been vaccinated, you will still need regular screening tests as the HPV vaccine does not provide protection against all types of HPV.

For more information, visit www.hpvvaccine.org.au.

What are the risk factors?

Smoking and passive smoking – Chemicals in tobacco can damage the cells of the cervix, making cancer more likely to develop in people with HPV.

Using oral contraceptives (the pill) for a long time – Research has shown that taking the pill for five years or more increases the risk of developing cervical cancer in people with HPV. The reason for this is not clear. However, the risk is small and the pill can also help protect against other types of cancer, such as uterine and ovarian cancers. Talk to your doctor if you are concerned.

Having a weakened immune system – The immune system helps rid the body of HPV. Women with a weakened immune system have an increased risk of  developing cervical cancer and need to have more frequent cervical screening tests. This includes women with the human immunodeficiency virus (HIV) and women who take medicines that lower their immunity.

Exposure to diethylstilbestrol (DES) – This is a manufactured form of the hormone oestrogen. DES was prescribed to pregnant women from the 1940s to the early 1970s to prevent miscarriage. Studies have shown that women exposed to DES because their mother took DES when pregnant have a small but increased risk of developing clear cell adenocarcinoma, a rare type of cervical cancer.