Cervical cancer causes
Cervical cancer occurs when the cells of the cervix change in a way that leads to abnormal growth and invasion of other tissues or organs of the body.
The risk of cervical cancer is increased with HPV infection, having children and smoking. Like all cancers, cancer of the cervix is much more likely to be cured if it is detected early and treated immediately.
- One of the key features of cervical cancer is its slow progression from normal cervical tissue, to precancerous (or dysplastic) changes in the tissue, to invasive cancer.
- The slow progression through numerous precancerous changes is very important because it offers opportunities for prevention, early detection and treatment.
- These opportunities have led to a decline in the number of cases of cervical cancer, and in deaths from cervical cancer.
Invasive cancer means that the cancer affects the deeper tissues of the cervix and may have spread to other parts of the body. This spread is called metastasis. Cervical cancers don't always spread, but those that do most often spread to the lungs, the liver, the bladder, the vagina, and/or the rectum.
Causes of cervical cancer
Cervical cancer begins with abnormal changes in the cervical tissue.
The risk of developing these abnormal changes has been associated with certain factors, mainly infection with human papillomavirus (HPV). In fact, HPV is the major cause of cervical cancer.
The NHS says around one in three women will develop a HPV infection within two years of starting to have sex regularly.
Some types of HPV cause genital warts, but the types that cause warts are not the types that cause cervical cancer. However, there are other types of HPV that are considered to be high risk for cancer of the cervix. HPV is passed on through sexual contact.
The two types of HPV which have the highest risk of causing cervical cancer are HPV16 and HPV18 - these are believed to have genetic material that can be passed into the cells of the cervix which can lead to a tumour.
Both these types of HPV are covered by HPV vaccination which is usually offered to girls during year eight at secondary school.
Because HPV can be transmitted by sexual contact, early sexual contact and having multiple sexual partners have been identified as risk factors for the development of changes that may progress to cancer because these sexual activities increase the risk of contracting HPV infection.
Cervical intraepithelial neoplasia
It can take around six years for cervical cancer to develop, before then a pre-cancerous condition called cervical intraepithelial neoplasia (CIN) may be detected.
This is not an immediate threat to a woman's health in the earlier stages, but it can lead to cancer for some woman later.
The NHS grades CIN from one to three to rank the seriousness of the condition
With CIN 1, the NHS says your chances of developing cervical cancer later are less than one in 30.
Around a third of women with CIN 1 will progress to CIN 2. Around half of women with CIN 2 will progress to CIN 3 and around a third of women classed as having CIN 3 will go on to develop cervical cancer.