Cervical cancer

 

What is cervical cancer?

The cervix is the lower part of the womb that protrudes into the vagina. It is sometimes called the neck of the womb and it has a channel running through the middle, which at one end opens into the vagina and at the other opens into the cavity of the womb. Cervical cancer occurs when a malignant (cancerous) growth develops in the cervix. There are actually two forms of cervical cancer, one called squamous cell carcinoma which accounts for 95% of cases and which this factsheet will concentrate on, and a much rarer form called adenocarcinoma.

Cervical cancer affects approximately 2,800 women each year in the UK although as a result of the cervical smear programme this has fallen significantly over the years.

How does it occur?

Cervical cancer is different to many cancers because before it happens there is often what is called a 'pre-cancerous' phase where the cells of the cervix are abnormal in appearance when looked at under the microscope but are not yet cancerous. These 'pre-cancerous' cells can exist in various forms for many years before they become malignant (cancerous) and the milder forms of abnormal cells may even revert to normal without any treatment.

Therefore, if these pre-cancerous cells remain undetected and untreated they can, in some cases, become cancerous. As a result, detection of these 'warning cells' forms the basis for the cervical smear test which is described below and which is well known to most women. It also gives doctors a chance to treat these abnormalities at a stage when they are easy to treat and before cancer has a chance to develop.

 

Why does it occur?

No one knows why cervical cancer occurs but it seems to be more common in certain categories of women: those who smoke, those who have had more than one sexual partner, those whose partner has had several sexual partners and women who have had sexual intercourse or a first pregnancy at an early age. Women whose first sexual intercourse takes place under the age of 20 are at twice the risk of those who start after that age. Cervical cancer is extremely rare in those who have not had sexual intercourse.

The reason for the link between cervical cancer and sexual intercourse seems to be due to a very strong connection between it and certain strains of a virus called the human papilloma virus (HPV), other strains of which cause genital warts. This virus can be passed on during sexual intercourse, and seems to play an important part in causing abnormalities in the cells of the cervix which can, in some cases, go on to develop into cervical cancer. In fact the high-risk strains of HPV have now been found in more than 99% of cervical cancer with 70% of cervical cancer being triggered by just two of these strains.

However, many of the women infected with these viruses do not develop cervical cancer or pre-cancerous changes so there must be other factors involved.

What are the symptoms?

The pre-cancerous phase gives no symptoms; these warning cell changes can only be detected at this stage with a cervical smear or a colposcopy, as described below. Even cervical cancer itself may not cause any symptoms, which is why it is so important for women to have regular cervical smears. Cervical cancer may, however, cause an offensive discharge or vaginal bleeding between periods or after intercourse or it may be the cause of vaginal bleeding after the menopause. There are many other causes for these symptoms, but if these do occur, then medical advice should be sought.

 

What tests are done to detect cervical cancer?

Cervical smear

Cervical cancer is one of the few cancers that is preventable because pre-cancerous cell changes can be picked up by a screening test at a stage when fairly simple treatment can prevent progression of the condition to a more serious phase. This screening test (a cervical smear) has been available in the UK since 1967 and formalised into an NHS screening programme in 1988 and aims to test all women between the ages of 25 and 64. The programme now tests over 4 million women every year and has been found to be extremely effective in reducing the rates of cervical cancer in the UK (see below).

The reason for not including women under the age of 25 in the screening programme is that at this age invasive cervical cancer is very rare and also very young women may get more abnormal results when in fact there is nothing wrong (something called a 'false positive result') causing them to have unnecessary investigations and worry. However, women under the age of 25 who have worrying symptoms or who are concerned should contact their GP for further advice.

Since October 2003 the programme has consisted of inviting all eligible women from the age of 25 to 49 every three years for a cervical smear and every five years for women aged 50-64. If the result of the smear is abnormal, the woman may be recommended to have more frequent smear tests, say every six or twelve months, until the abnormalities improve or reach a stage where further investigation is required.

The smear test is very simple and is routinely carried out by the practice nurse, GP or nurse in a family planning clinic. It involves a small instrument called a speculum being inserted into the vagina to allow the person taking the smear to see the cervix and then a few cells are removed from the surface of the cervix by lightly scraping it with a specially designed spatula. Sometimes a small brush will also be used to obtain cells from particular parts of the cervix. These samples are then put on a microbiological slide for analysis under a microscope at the local laboratory.

If you are under 25 there is no need to have regular smear tests but you should begin having regular smears as soon as you are 25 if you are sexually active. There is no need to have smears if you have never had sexual intercourse with a man but you should start having smears at the recommended intervals once this is no longer the case.

The screening programme stops at 64, as long as the woman has not had 3 abnormal smears; because women who have had normal smears are very unlikely to go on to develop cervical cancer after this age. The Department of Health guidelines say that if your last three smears were normal when you are 64, there is no need to have any more but many older women have not had enough smears. (One of the reasons the cervical smear programme has not cut the number of cases of cervical cancer as quickly as it should is because there are so many older women who have never had smears).

A woman who is over the age of 64 and whose last three smears were normal will usually be removed from any further follow up smears. However, if she has had abnormal smears leading up to her 64th birthday she will remain in the regular smear programme in the normal way until she either has sufficient normal results or has received satisfactory treatment for her abnormal smears.

A woman aged over the age of 25 who has never had a smear should have one even if she is aged over 64, unless she has never had sexual intercourse. Remember, most women with cervical cancer have not had regular smears.

A new method of analysing the cervical cells is being introduced throughout the UK called Liquid Based Cytology (LBC).[4&5] The reason for the introduction is that using the current method, up to 80% of the cells collected are not transferred from the spatula to the microscopy slide. Also any blood or mucus leads to smears that are unsatisfactory necessitating the need for the smear to be repeated.

The difference with LBC is that the special 'broom' used to collect the cells is, instead of being smeared across a microscope slide, placed inside a vial of preserving fluid and in the laboratory the fluid is spun to concentrate the cells which are then filtered out and placed on a slide in a thin layer. The result is an even layer of cervical cells, which have been separated from any blood, or pus cells. This means that the smear is easier to read under the microscope and therefore is likely to be more accurate and fewer repeat smears will be needed. This is estimated to save 300,000 women a year from needing a repeat smear.

LBC also opens the way for computer-assisted analysis of smears to ease the burden on laboratory staff and possibly increase the accuracy of the test. In addition, the cells collected in with the LBC can be tested for HPV and such infections as Chlamydia and other sexually transmitted diseases.

Colposcopy and biopsies: If the result of the smear comes back with anything other than minor changes, if more than one smear in a row is sufficiently abnormal, or if the doctor suspects cervical cancer from the symptoms and examination, he or she would then refer the patient to a specialist. The specialist will do an examination of the cervix called a 'colposcopy', where an instrument like a microscope is used to take a closer look at the cells on the surface of the cervix. This is done as an outpatient and does not require a general anaesthetic, but allows the gynaecologist to make a more accurate diagnosis and possibly take small pieces of the cervix (biopsies) to be examined in the laboratory.

In most cases, colposcopy will result in the finding of non-cancerous cell changes, which are referred to as mild moderate or severe 'dyskaryosis' (this word means abnormal cell changes) or, more commonly, CIN 1,2 or 3. CIN stands for 'cervical intraepithelial neoplasia'. Both these systems are a way of grading how abnormal the cells of the cervix have become, but none of them mean that the person has cervical cancer. Slight abnormalities of the cells may become normal without necessarily needing to be treated, but more abnormal cells will almost certainly require further treatment.

Other tests: If the biopsies confirm cervical cancer, further tests are usually done to 'stage' the cancer, i.e. to see how far it has spread, since this will help to determine the treatment required. These tests may include a pelvic examination under anaesthetic, sometimes combined with an examination through a special telescope of the bladder (cystoscopy), lower bowel (procto-sigmoidoscopy) and/or pelvis (laparoscopy).

CT (computerised tomography) and MRI (magnetic resonance imaging) scans: The specialist may also order some specialised x-rays or even a CT or MRI scan, both of which provide very detailed images of the inside of the body, which assist this staging process.

 

What is the treatment?

Treatment of the pre-cancerous phase before it becomes cancer is usually fairly straightforward and involves either destroying or removing the abnormal cells in a variety of ways. This is often done at the same time as the colposcopy and may be done either without the need for anaesthetic or with the use of local anaesthetic. The cells can be destroyed with laser, by freezing with a special instrument or by cautery with a hot wire.

If the specialist finds that a large area of the cervix is involved or suspects that the pre-cancerous cells are coming from inside the cervical canal he may remove a cone-shaped section of the cervix. This is called a 'cone biopsy' and is usually done under general anaesthetic. The tissue removed is then analysed under a microscope.

If a woman is found to have cancer of the cervix then the treatment she receives will depend on a variety of factors including the stage of the cancer, her age and whether or not her family is complete. Usually treatment involves surgery and/or radiation therapy. If the cancer is only on the surface of the cervix, the gynaecologist may destroy the cancer cells in ways similar to those described above for pre-cancerous cells.

If the disease has invaded deeper layers of the cervix but has not spread beyond the cervix, the specialist may be able to remove just the affected tissue without having to remove the whole womb. However, it is more likely that he will advise a hysterectomy (removal of the womb including the cervix) and sometimes the ovaries and fallopian tubes are removed along with lymph nodes near the womb. This is called a Wertheim's hysterectomy.

In some cases radiation therapy (radiotherapy) is used instead of, or as well as surgery and on occasions cancer killing drugs are given (chemotherapy). Recent research suggests that survival rates for cervical cancer could improve by up to 50 per cent by adding chemotherapy to standard treatments so this type of treatment could become more common than in the past. The specialist will usually discuss with the patient why he has decided on a particular treatment and the pros and cons of each type.

 

Are there side effects of treatment?

The side effects of treatment depend on the type and extent of the treatment. The methods described for removing or destroying small areas of cancer on the surface of the cervix may cause no side effects, or at the most may result in crampy pain, a small amount of vaginal bleeding or a watery discharge. However, one effect of a cone biopsy is that the cervix may be weakened as a result and occasionally a woman may require the cervix to have a special stitch put into it to reduce the risk of a late miscarriage if she becomes pregnant at any time following this procedure.

A hysterectomy is major surgery and therefore the side effects will be those of any abdominal operation, but a gradual return to normal activity should be possible over the course of four to eight weeks.

If radiation therapy is given in cases where cancer has been diagnosed, the woman is likely to feel very tired especially as the treatment continues and she may also get other effects such as skin changes or even a narrowing of the vagina. It is a good idea for the woman to ask what to expect before the treatment starts. This also applies when chemotherapy is used since the side effects are variable but again it is usual for the patient to feel very tired and they are likely to feel nauseous, lose their appetite and also lose their hair.

 

Can cervical cancer be prevented?

The most important measure for preventing cervical cancer is for all women who are having or who have ever had sexual intercourse to have regular cervical smears as recommended by the cervical smear programme. It has been estimated that the cervical smear programme saves about 4,500 lives a year, the death rate dropping by about 40 % between 1987 to 1997. On the other hand, nearly 70 per cent of women who die from cancer of the cervix have not had routine cervical smears.

Other factors that can help to prevent someone from developing cervical cancer are delaying the start of sexual relations, or starting a family, until at least the end of their teenage years. Using barrier forms of contraception such as the cap and sheath are also thought to protect against cervical cancer, probably by preventing the transfer of HPV to the woman during intercourse. Finally, giving up smoking reduces the risk of developing cancer of the cervix.

Are there new developments in treating cervical cancer?

Since most cases of cervical cancer are related to HPV infection (see above), a vaccine against HPV has been produced and introduced into the national immunisation programme. From September 2008 girls aged 12-13 will be given the vaccine which will protect them from the effects of the virus. (From the end of 2009 there will also be a two year catch-up campaign to vaccinate all girls up to the age of 18 meaning that by the end of 2010 all girls between the age of 12 and 18 will have been vaccinated, hopefully before most of them will have started to have sexual intercourse and therefore been infected with the virus.)

Although in time the vaccine is likely to make a significant difference to the rates of cervical cancer, this will take some years to become apparent and until then women should continue to have regular cervical smears as advised by the cervical screening programme.

 

Where can I get further information?

Apart from contacting your own GP, the following organisation may offer further help:

Cancerbackup
3 Bath Place
Rivington Street
London
EC2A 3JR
Helpline: 0808 800 1234
Telephone: 020 7613 2121
Email: info@cancerbackup.org.uk
Website: www.cancerbackup.org.uk

Gynae C (UK)
Helen Jackson
1 Bolingbroke Road
Swindon
Wiltshire
SN2 2LB
Telephone: 01793 338885
Email: gynae_c@yahoo.com