Cervical cancer is the leading cause of cancer related deaths in women in Africa. In South Africa new cases occur about twice as common as the rest of the world. There are thousands of new cases reported every year in South Africa. One of the main reasons for this high incidence, is inadequate use of screening tools which can assist in detecting premalignant (prior to cancer) stages of cervical cancer. Unlike most other cancers, the symptoms of cervical cancer (such as abnormal bleeding) may only occur when the cancer is advanced. Screening is so important to detect cell changes early.
Most of the time, cervical cancer is a condition that first starts with a sexually transmitted infection called Human Papilloma Virus (HPV). There are over 100 HPV subtypes of which only 12 can cause cervical cancer. Two sub-types (16 and 18) cause about 70% of all cervical cancer. HPV infection can cause changes to the cells of the cervix which progressively become more and more abnormal over time. A collection of abnormal cells causes abnormal tissue changes which progressively get deeper and deeper into the cervix until it invades past the superficial layer of tissue and becomes a cancer. This process in a healthy person can take up to 20 years and in most healthy people the body will repair the abnormal cells and fight off the infection.
We have very good screening tools available, and if used correctly, should result in preventing almost all cervical cancer.
The pap smear is a screening tool that has been used for many years. This involves scrapping some cells off the cervix and placing them on a slide with a special stain and then looking at the cells under a microscope. However, this method is seldomly used as there are limitations to its accuracy.
Looking at the cells of the cervix is still done, but a gentle silicone brush is used on the cervix and the cells are placed in a liquid medium, these cells are then separated and viewed under a microscope in a similar way to the pap smear.
Instead of looking for abnormal cells through a microscope a technique is now used to detect HPV using the same liquid medium, this is more accurate than looking at the cells and allows you to be more reassured if it is negative.
It is recommended both internationally and in South Africa that screening should only start at the age of 25. Individuals who are younger than this often clear the infection on their own. In South Africa the interval of screening should be every 1-3 years and can be stopped at the age of 65.
Abnormal screening tests
If your test is abnormal there are three possible outcomes:
- You may have a low risk result and need to repeat a test in 6 months time.
- You may have a high risk result and need to do a small procedure where a microscope is used to look at your cervix (for abnormal tissue changes) and a biopsy is taken of any abnormal tissue.
The main aim of screening is to detect and treat any abnormal tissue before it becomes a cancer, which can be easily achieved if screening is done routinely. Don’t wait, screen! It could save your life!