Cervical cancer

Risk factors for cervical cancer

Although the cause of cervical cancer is not yet fully understood there are a number of factors which are linked to a greater risk:

• Age. Most cases of cervical cancer occur in women over the age of 35 although it may be increasing in frequency among women aged 20 to 35. Older women can be at risk because they may mistakenly believe that, after menopause, regular smear tests are not necessary.
• Sexual history. Having sex at an early age, multiple sexual partners or a history of unprotected sex or sexually transmitted disease are linked to a higher risk.
• Smoking cigarettes. This is possibly due to an effect upon the immune system.
• Low immunity, because of certain illnesses (including HIV), organ transplants, or medications that suppress the immune system.
• The greatest risk factor for cervical cancer is not having regular smear tests.

Cervical cancer and human papilloma virus (HPV)

The link between cervical cancer and sexual activity led to the discovery that that the human papilloma virus (HPV), which is transmitted sexually, is to blame in most cases. There are over 90 different strains of HPV. Some strains (mainly types 6 & 11) are associated with genital warts, but high-risk strains (especially types 16 and 18) can cause the cellular changes that can lead to cervical cancer.

HPV is passed on by skin-to-skin contact in the genital area, which means that full sexual intercourse is not always necessary and ? although condoms reduce the risk of exposure by around 70% ? they do not offer full protection. Having HPV does not mean that a woman has been promiscuous or careless. Only one sexual experience is needed to catch HPV, and it is so widespread that some experts believe it is almost inevitable that sexually active women will acquire it at some point in their lives, most often in adolescence or early adulthood when they become sexually active. However, many women with a healthy immune system clear the virus. If it is not cleared, it is usually many years before abnormal cells develop in the cervix and having regular cervical smears will detect these changes and allow treatment before cervical cancer develops.

So, while almost all women who develop cervical cancer have HPV, not all women with the virus will develop cervical cancer.