Overview of CIN

The cervix is the lower part of the womb (uterus), sometimes called the neck of the womb. It is possible for your specialist to see and feel the cervix during an internal vaginal examination.

The surface layer of the cervix is made up of two different types of cells where the cells in the vagina meet the cells which line the womb. The vaginal cells are flat skin-like cells called squamous cells. The cells lining the womb are taller glandular cells called columnar cells, which produce mucus. The place where these cells meet is known as the transformation zone. Cells in this area can become abnormal and are therefore examined in the cervical screening test.

Sometimes an abnormality will be due to pre-cancerous changes in the cells of the cervix. When cells undergo this type of abnormal change, the process is call dysplasia. Changes in the squamous cells of the cervix cause CIN, which stands for cervical intra-epithelial neoplasia. CIN is not cancerous.

Cervical screening is a way of preventing cancer. Around 3200 women are diagnosed with cervical cancer in the UK each year, with 95% of cases being in women over 35. However, deaths from cervical cancer have fallen by more than 40% over the last 20 years, mainly because of improvements in early detection and treatment.

Abnormal cells can be detected by performing a laboratory test on a small sample of cells from the surface of the cervix. This test is often called a smear or pap test. Almost half of women newly diagnosed with cervical cancer have never had a smear and 15% of them haven't had one for five years. The greatest risk factor for cervical cancer now is failing to go for regular smear tests.