Almost all cases of cervical cancer are the result of persistent (ongoing) infection with HPV, which is short for human papillomavirus.1,3-5
What is HPV?
HPV is a commonly occurring wart virus that is spread through direct skin-to-skin contact.2,3,6
Over 100 different (geno)types of HPV have been identified and about 40 of these can infect the skin and membranes of the genital area in men and women.3,7 It has been estimated that 4 out of 5 people will have a genital HPV infection at some time in their lives.3,8,9 Among women, HPV infection rates tend to be highest in young adulthood (typically between the ages of 15 and 25 years).1,9
Although common, most genital HPV infections have no symptoms and are cleared from the body by the immune system within a year, so many people will be unaware they are infected.1-3
What is the link between HPV and cervical cancer?
When HPV remains in the body for long periods of time, infected cells can undergo change. Depending on the type of HPV infection, these changes might cause genital warts and other benign conditions. More rarely the changes can lead to cancer.2,3,6,10 There are about 15 HPV types that are described as high-risk – that is, they are cancer-causing.1,11 In Australia, the genotypes HPV–16 and HPV–18 have been detected in 70%–80% of cervical cancer cases.12
Most women infected with HPV (including types like 16 and 18) will not go on to develop cervical cancer, even women who already have changes that make their cervical cells more cancer-like (precancerous).11,13,14 This is because it takes decades for abnormal cervical cells to grow and become cancerous, and during this time the immune system may be able to clear the virus, allowing the altered cells to return to normal (regression).11,14
However, for a small number of women, having a long-term HPV infection, in addition to other factors such as smoking, other sexually transmitted infections or long-term use of the contraceptive pill, may influence the likelihood that infected cells become precancerous and then go on to become cancer.1,3,11,15,16