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HPV and oral contraception: your questions answered

The NHS Cervical Screening Programme aims to reduce the number of women who develop invasive cervical cancer and the number of women who die from it. It does this by regularly screening all women at risk so that conditions that might otherwise develop into invasive cancer can be identified and treated. All women between the ages of 20 and 64 are eligible for a free cervical smear test every 3-5 years. Around 70% of health authorities invite women every three years.
Earlier this year, results from an IARC (International Association for Research on Cancer) study, which looked at the effects of long-term use of oral contraceptives on the occurrence of cervical cancer in women with human papillomavirus (HPV), were published in The Lancet.(1) The research suggested that long-term use of the contraceptive pill could increase the risk of developing cervical cancer in women with HPV.
As well as carrying out cervical smears, one of the roles of the practice nurse is to provide family planning and contraception advice. This often involves reassuring concerned women and answering their questions. The following is taken from the NHS Cancer Screening Programme website, and consists of questions commonly asked by patients - in light of the recent evidence about HPV, we hope you find them useful.

What is HPV?
HPV is a sexually transmitted infection. There are more than 80 human papillomaviruses, a few of which are associated with an increased risk of developing cervical cancer. Exactly how these few high-risk strains of HPV cause cervical cancer is unknown.
Many women are infected with HPV at some point in their lives, but it is not yet possible to tell who will go on to develop abnormalities of the cervix. Many women will get rid of the virus naturally by the normal functioning of their immune system.
Most HPV infections disappear without causing any problems, and even those women who contract high-risk HPV rarely go on to develop cervical cancer.
What does the IARC study show?
It shows that women with HPV infection who have been using the pill for over five years are more likely to develop cervical cancer than those who have not. It was, however, carried out in women who live in countries that have no national cervical screening programme in place. In the UK the effectiveness of the NHS Cervical Screening Programme means that cervical abnormalities are usually detected at a precancerous stage, so that cervical cancer is now a relatively rare condition. What the study does demonstrate is the importance of regular cervical screening for all women, whether or not they use the pill.

Is the association between the pill and an increased risk of cervical cancer new?
No, this association is not new. For many years the long-term use of the pill has been linked with an increase in cervical cancer. This has been included in prescribing information and the leaflets in pill packets for a long time. What has been unclear in the past is how much of the association is due to the pill and how much to other factors, such as sexual behaviour and smoking. While the IARC study increases the evidence that the pill plays a role in the development of cervical cancer, it does not completely prove it. The pill is highly effective at preventing pregnancy and is generally very safe - its benefits far outweigh its risks for the vast majority of women who take it.

Should I be worried by these results?
Women who have regular smear tests significantly reduce their chances of developing cervical cancer. Cervical screening is not 100% perfect, but regular attendance for screening reduces a woman's chance of developing cervical cancer by between 80 and 90%.
If you are between 20 and 64, and you are, or have been, sexually active, and have not had a smear in the last five years, then you should have one as soon as possible. This is particularly important if you also use the pill.

What does the new research show about my risk of getting cancer?
Because the NHS Cervical Screening Programme is so effective, your overall risk of getting cervical cancer is very low. In 1990, there were about 15 cancers per 100,000 women per year, and this fell to about nine per 100,000 by 1996. There are now about four deaths per 100,000 women per year. In the IARC study, women who used the pill for less than five years had the same risk as those who had never taken it. In those who took the pill for 5-9 years, the risk was nearly three times higher than for women who had never used it, whereas in those who had used it for more than 10 years, the risk was four times higher. However, whether or not you take the pill, your overall risk is still extremely small. The benefits of oral contraception far outweigh the potential risks for the vast majority of women.

What should I do if I've been using the pill for more than five years?
While your risk of developing cervical cancer may be slightly higher if you have been using the pill for more than five years, there is absolutely no benefit in stopping taking the pill immediately. Cervical cancer takes many years to develop and in any event is very rare. The NHS Cervical Screening Programme prevents between 80% and 90% of cancer cases in women who attend for regular smears by detecting and treating early abnormalities.
However, if you feel that you do want to stop using the pill in the longer term, you should make a routine appointment to discuss alternative forms of contraception with your doctor or family planning adviser. In the meantime you should continue to take your pill, as you can become pregnant at any time after stopping.

I used to use the pill - what is my risk of cervical cancer?
The study reported in The Lancet found some evidence that risk remained high at least five years after stopping the pill, but there is a lot of uncertainty in this. We do not know whether women who have used the pill in the past are at greater risk of developing cervical cancer than women who have never used it. However, the risk of cervical cancer is very low in all UK women, whether or not they take, or used to take, the pill.

Will women who are long-term users of the pill be screened more frequently by the NHS Cervical Screening Programme?
No. While long-term use of the pill may slightly increase the risk of eventually developing cervical cancer, there is no clear evidence such use increases the speed at which the cancer could develop. Therefore the current interval of 3-5 years between smears will remain. Usually cervical cancer develops very slowly and the purpose of cervical screening is to detect and treat abnormalities that if left untreated might develop into cervical cancer.

I've already been treated for an abnormal smear. Does using the pill increase my risk of abnormalities reoccurring?
The study did not have any data on this, and we do not know the answer.

I get an invitation for screening only every five years. Is it my right to be screened every three years?
The recommended screening interval is between three and five years. Your GP does not have to provide you with a smear test every three years. However, if you have any unusual symptoms, such as bleeding after intercourse or between periods, please report them to your GP or practice nurse immediately.

I'm 19 and have been on the pill since I was 15. Should I be screened even though I'm not 20 years old?
We recommend waiting until you are 20 years old as incidence of cervical cancer in young women is rare, and extremely rare in teenagers.

Why don't you screen women under 20 when they could have been on the pill for several years?
We don't screen teenagers as their bodies, particularly the cervix, are still developing. Because of this a teenager may get an abnormal smear result when there is nothing wrong. This could lead to unnecessary treatment, and we therefore think that screening teenagers can do more harm than good. Cervical cancer is a very slow-growing disease, and is very rare in women under 20 - there were only two cases in England and Wales in 1998.

What about women over 64?
Women over 64 are invited if their previous two tests were not clear or if they have never been screened.
Women in this age group who have had three consecutive negative smears within the previous 10 years are known to have a very low risk of developing cervical cancer. Screening such women potentially induces more harm than benefit in terms of unnecessary anxiety. There is also an increased likelihood of inadequate smears, which occur more frequently in older women.

The NHS Cancer Screening Programme also produces useful factsheets on HPV testing for both women and smear takers. They can be found at http://www.cancerscreening.

NHS Cancer Screening Programmes
The Manor House
260 Ecclesall Road South
Sheffield S11 9PS
T:0114 271 1060
F:0114 271 1089


  1. Moreno V, Bosch FX, Muñoz N, et al. Effect of oral contraceptives on risk of cervical cancer in women with human ­papillomavirus infection: the IARC multicentric case control study. Lancet 2002;359:1085-92.

Many other ­organisations provide information about cervical cancer. For ­example:
3 Bath Place Rivington Street London EC2A 3JR
T:020 7696 9003 F:020 7696 9002
Cancer Relief
Cancer Helpline: 0808 808 2020
Research UK
PO Box 123
Lincoln's Inn Fields
T:020 7242 0200
Marie Curie
Cancer Care
89 Albert Embankment
London SE1 7TP
T:020 7599 7777
Cervical Screening Wales
Dr Cerilan Rogers
18 Cathedral Road
Cardiff CF11 9LH
T:029 2078 7802