The primary risk factor for cervical cancer is infection with HPV, a sexually transmitted virus, which is present in more than 95% of cases and implicated in the cause of the disease. It is often known as the "wart" virus, as some types of HPV cause common warts that grow on feet, hands and the genital area.
There are over 100 different HPV subtypes - cancer of the cervix is thought to be predominantly the result of infection with 13 key high risk subtypes. The majority of women infected by high risk subtypes will clear the virus spontaneously, but in a small percentage of women it persists - it is these women who need regular supervision and care.
HPV types 1, 3 and 5 cause warts on the hands and feet (verrucas) of children. Types 6 and 11 can cause warts in the genital area. Most infections with HPV go away without causing any type of abnormality. The vast majority of women with HPV will not develop warts.
Types 16, 18 and 31 do not cause warts, but are associated with the development of cervical precancer and cancer. The virus may lay dormant in the cervix for many years, then enter the cell nucleus and trigger a precancerous and later cancerous change.
Warts and cervical precancer are encouraged by a decrease in the woman's immune system. Many researchers believe that cigarette smoking encourages cervical precancer. Concentrations of nicotine and cotinine in the cervix harms the cells.
Women with HPV changes on their cervix do not require treatment unless precancerous changes (dyskaryosis/dysplasia) develop.
Gardasil is a new vaccine manufactured by Merck & Co. It is designed to protect women against HPV types 16, 18, 6 and 11. Large scale studies have found no serious side effects following testing in up to 11,000 women. There have been no deaths yet recorded directly due to the vaccine and it is not designed to encourage promiscuity or under-age sex. Gardasil is a prophylactic vaccine and is designed to prevent establishment of HPV infection. It is therefore recommended that girls receive the vaccine before becoming sexually active. Gardasil does not prevent against all HPV types, and cervical screening is still recommended for eligible women. The vaccine does not protect against other sexually transmitted infections, and safe sex practices are still recommended.
Gardasil is given as a series of 3 injections over 6 months. In the UK, Cervarix is being used as a cervical cancer vaccine. This provides protection against HPV types 16 and 18 only, which cause around 70% of all cervical cancers. Cervarix is manufactured by GlaxoSmithKline. Vaccination programmes are currently being rolled out in the UK for girls aged 9 to 15, although women aged from 16 to 26 can also have the vaccine. If you have any questions you should visit your GP or family physician.