Why the cervical cancer screening age does not need to be lowered
Posted May 29 2012 9:43am
Following calls from patient groups and MPs to lower the age for cervicalRelating either to the cervix (the neck of the womb) or to the cervical vertebrae in the neck (cervical spine).cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. in England to 20, Dr Adeola Olaitan, Consultant Gynaecologist of University College Hospital London discusses why the age for cervical cancer screeningA way to identify people who may have a certain condition, among a group of people who may or may not seem to does not need to be lowered.
Cervical screening (smear test and cytologyThe study of cells, in medicine used to mean examination of cell samples under a microscope.) protects women against cervical cancer. This is because abnormal cells which cause no symptoms and are NOT cancer can be detected and if required, treated. If they are present, but not detected or treated, a woman is at significant risk of developing cervical cancer in the future. Women between the ages of 25 and 65 are invited for regular cervical screening on the NHS.
The NHS does not invite women below the age of 25 for cervical screening. The lower limit of the screening age was raised from 20 years in 2003, following a recommendation from the Independent Advisory Committee on Cervical Screening. In June 2009, the Committee reviewed the policy again and agreed unanimously that there should be no change. The UK National Screening Committee has, this month, recommended that the age of first invitation for cervical screening be raised to 25 years in Wales and Scotland, in line with the policy in England, on the basis if evidence of a large number of women screened and treated with relatively little benefit below this age.
Recently, a campaign led by MPs Mark Spencer and Andrew George, has called for the screening age to be lowered. This was prompted by the sad case of a young lady who died from cervical cancer under the age of 25. While the fear and concern that this has raised is understandable, I think it is important for young women to understand the facts behind the decision to start screening at 25 years.
I know that it can be difficult to appreciate what screening is, what it can achieve and what its limitations are but this is extremely important as it is the difference between what is likely to happen and what actually does happen. To use a crude example, the speed limit on the motorway is set at 70 miles per hour because there is good evidence that driving at higher speeds increases the risk of being involved in an accident and the possibility of dying or suffering serious harm or inflicting serious harm on others. This does not mean that everybody who drives faster than 70 miles an hour will be involved in a collision – in fact, a lot of people drive too fast and get away with it but if everyone drove faster than the speed limit, there would be far many more collisions on our roads.
In a similar way, screening for the prevention of cervical cancer looks at probabilities and estimates risks; based on this recommendations are made about who should be screened.
So let us look at the facts:
The cervical screening programme is designed to reduce deaths from cervical cancer but it does not do this in women under 25 years of age
Since the screening age was changed in England in 2003 there has been no increase in deaths from cervical cancer in women aged 20 to 25 years old or 25 to 30 years old. Women aged 20 to 25 are very unlikely to suffer from cervical cancer or die from it and the fact that there has not been an increase in the death rate supports the fact that screening is not effective in that age group.
Why screening in women under 25 years of age can do more harm than good
Cervical screening relies on experts in the laboratory looking at cells from the cervixAny neck-like structure; most commonly refers to the neck of the uterus. and deciding if they look normal or abnormal. What is sometimes overlooked it that a cervical screening test is not a diagnostic test. Therefore, a normal cervical screening report means that it is unlikely that there are pre-cancerous cellsCells that may become cancerous over time. on the cervix, while an abnormal test result means there is a high chance that there are pre-cancerous cells on the cervix.
If a woman has an abnormal screening result, she will be referred to a specialist Gynaecologist for an investigation called colposcopyClose examination of the cervix of the uterus using a magnifying instrument with attached light source, known as a colposcope. to decide if there is indeed an abnormality that requires treatment.
These abnormalities are common in women under the age of 25, but cervical cancer in this age group is very rare. It is really important to understand that one in three women screened under the age of 25 would have an abnormal result compared to one in 14 for all women screened (25-64 years old). This is because immature cells in the cervix can resemble abnormal cells. These changes will, in the majority of cases, resolve spontaneously.
There is a danger of screening in this age group as it may result in young women being referred for colposcopy. A large biopsyThe removal of a small sample of cells or tissue so that it may be examined under a microscope. The term may also refer to the tissue sample itself. may be taken from the cervix, which has the potential to damage the cervix, increasing the risk of miscarriageThe spontaneous loss of pregnancy. and premature deliveries in later life. Babies born prematurely have an increased risk of dying or having significant disabilities.
People have said to me “surely women under 25 years should have a choice about whether or not they wish to be screened.” The difficulty with this is that the points that I have made above are not generally known and if a woman under 25 has a screening test and minor abnormalities are detected, this is more likely to raise anxiety than reassure and is more likely to lead to additional tests that can harm the cervix.
Cervical screening is a test for women who are well and have no symptoms that may suggest cervical cancer.
It is important that women understand that cervical screening is not a test for cancer BUT a test to reduce the risk of developing cancer.
Screening is not the correct investigation for women who have symptoms that suggest cancer. Women with symptoms such as bleeding after sex, bleeding between periods or a smelly vaginal discharge should be referred to a Gynaecologist who may take a small sample (biopsy) from the cervix to exclude cancer. It is also important to realise that the vast majority of women under the age of 25 who have these symptoms will NOT have cancer.
So if women under 25 years are NOT eligible for screening, what can they do to protect themselves from cervical cancer?
If you want to protect yourself from developing cervical cancer, here are some important tips:
STOP SMOKING – Smoking is a risk factor for cervical cancer because it reduces the immune response of the cervix. There is good evidence that mild pre-cancerous changes on the cervix can improve if women stop smoking.
Use a condom – While there is no clear evidence that condoms prevent infectionInvasion by organisms that may be harmful, for example bacteria or parasites. of the high risk human papilloma virusA sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers., the virus that causes cervical cancer, condoms prevent other sexually transmitted infections such as Chlamydia. Infection with Chlamydia can cause bleeding after sex, a symptom that is also associated with cervical cancer.
In conclusion, I would suggest that any campaigns about cervical screening should be focused on educating women and providing them with accurate information to enable them to make informed decisions and should avoid scare-mongering and sensationalism.