Risks and causes of cervical cancer

In the UK, about 2 in 10 (20%) of cervical cancers are linked to smoking .

Smoking tobacco is linked to a higher risk of developing cell changes or cervical cancer. Research shows that smoking doubles your risk of developing cervical cancer. If we take lifetime risk as an example, it would increase from less than 1 in 100 (less than 1%) to about 2 in 100 (about 2%) in someone who currently smokes, compared with someone who has never smoked .

There is limited research about the risk of breathing in smoke from someone else’s cigarette. This is sometimes called passive smoking or second-hand smoking. However, the research we do have suggest that it may increase the risk of developing cervical cancer.  

Smoking affects your risk in different ways:

• Smoking weakens your immune system, so your body is less able to get rid of high-risk HPV.  
• Nicotine and the chemicals in cigarette smoke can damage your cells. This makes cancer more likely to develop. 

The exact risk depends on how long you have smoked for and the number of cigarettes you smoke per day.   

This might sound alarming, but remember that cervical cancer itself is rare. If you would like to stop smoking, the NHS has programmes to support you:

• England >
• Scotland >
• Wales >
• Northern Ireland >

Some conditions can affect your immune system. These can make your body less able to fight off HPV infections, and make cell changes and cervical cancer more likely to develop if you have high-risk HPV. 

We are not experts in auto-immune conditions, so it is important to speak with your GP or healthcare team for more information or support. 

Human immunodeficiency viruses (HIV)

HIV is the only condition where there is an official recommendation to have more regular cervical screening. If you have HIV you should go for cervical screening every year.  

This is done outside of the regular NHS Cervical Screening Programme. Check with your GP or the healthcare team managing the HIV about how to make appointments. 

In the UK, about 1 in 10 (10%) cervical cancers are linked to taking the contraceptive pill.

There is limited good quality research about the link between taking the pill and cervical cancer. The research that we have suggests that taking the pill for 5 years increases the risk of cervical cancer by about 2%. Evidence shows that risk can increase after taking the pill for more than 5 years. Experts don’t fully understand the reasons behind this yet . 

Once you stop taking the pill, this increased risk returns to normal within about 5 years .  

It is important to remember that the benefits of taking the pill often outweigh the risks. These benefits include:

• being an effective form of contraception (preventing pregnancy) 
• helping with heavy painful periods 
• reducing acne  
• reducing pre-menstrual syndrome (PMS)  
• lowering the risk of some cancers, including colorectal, endometrial and ovarian cancers.

If you take the pill and are worried, it is important to speak with your GP or practice nurse. They can help answer any questions, as well as talk through your options. You do not need more regular cervical screening if you take the pill.

Doctors used to prescribe medicine to some pregnant women who had miscarriages or gave birth early (premature delivery). This medicine was called diethylstilbestrol (DES). It was given to some pregnant women from 1938 until 1971.

DES and cervical cancer risk

If your mother was given DES while she was pregnant with you, you have a higher risk of developing a type of cervical cancer called clear cell cervical cancer. It is sometimes called cervical clear cell adenocarcinoma (CCA). 

In real numbers, this risk looks like about 1 in every 750 (0.13%) people exposed to DES developing CCA up to age 50. 

DES and cervical screening

It is not usually recommended that you have more regular cervical screening. Instead, you will get invitations every 1, 3 or 5 years from age 25, depending on your results and where you live.

Exposure to DES can cause changes to cells in the cervix and vagina. This is sometimes called vaginal adenosis. These cell changes may not cause any problems, but if you have them, your healthcare team may suggest you have cervical screening that looks for cell changes annually. This method of testing the cells is called cytology. 

This test would be done in a colposcopy department at a hospital, outside of the National Cervical Screening Programme. Check with your GP or healthcare team about how to make appointments.

Granddaughters (third generation)

If you are the granddaughter of someone who was given DES, evidence shows you are not at an increased risk of cervical cancer. 

Currently, HPV is most prevalent in teenagers, with a peak at about age 25. This is most likely why cervical cancer is most common in women and people with a cervix under the age of 45. 

In the future, research predicts that cervical cancer will be most common in women and people with a cervix aged 55 and older. This is mostly because of the HPV vaccine that is offered to teenagers. It will help prevent certain high-risk HPV types and mean that less younger women and people with a cervix get high-risk HPV and develop cervical cancer.

You have an increased risk of high-risk HPV and developing cervical cancer if:

• you have had sex with multiple people  
• you first had sex at a young age.

If you have had sex with more than 3 people, you have an increased risk of getting high-risk HPV types 16 and 18. These types cause about 7 in 10 (70%) cervical cancers. Many people have sex with more than 3 people during their life, so it is nothing to be embarrassed or ashamed about. It simply means there is more chance of coming into contact with high-risk HPV. 

Being pregnant and giving birth has been linked to an increased risk of cervical cancer, including being under age 17 when you had your first child or children.

There is not enough research about why risk is increased with pregnancy and childbirth. There is a theory that hormone changes during pregnancy could make the cells in your cervix more likely to hold onto high-risk HPV. 

There is no evidence that cervical cancer is hereditary. This means it is not passed down by a faulty gene, like some breast or ovarian cancers can be. You can develop cervical cancer even if no one else in your family has had it. Or you might not develop cervical cancer, even if someone else in your family has had it. 

There is limited research to show that if someone you have a close family relationship with had cervical cancer, your risk of developing it is slightly increased. This could be your mother, sister or grandmother. We don’t know the exact reason for this, but it may be because you share some risks with other people in your family, such as:

• smoking
• having a child or children at a young age
• having lots of children
• attending or not attending cervical screening.

You do not need more regular cervical screening if a close family member has had cervical cancer. 

Cervical screening can find high-risk HPV and cell changes which may develop into cervical cancer. It means you can have treatment or monitoring to prevent cervical cancer from developing. 

It’s your choice whether to go for cervical screening and we know that it isn’t always easy. If you want to go but are worried, we have more detailed information that may help. You might also want to give our free Helpline a call on 0808 802 8000, so our trained volunteers can talk through the appointment with you and offer some useful tips.

Read about cervical screening >

If you are under 25, you might be able to get the HPV vaccine for free. Some people over this age are also eligible for a free vaccine. You might also be able to pay privately for a vaccine. 

Read about the HPV vaccine >

Smoking weakens your immune system, so stopping smoking means your body is better able to get rid of HPV. If you would like to stop smoking, the NHS has programmes to support you:

• England >
• Scotland >
• Wales >
• Northern Ireland >

Using condoms or dental dams don’t completely protect against high-risk HPV. This is because it can live on the skin in and around the whole genital area – not just the part the condom or dental dams cover. But research has shown they offer some protection.

Thank you to all the experts who checked the accuracy of this information, and the volunteers who shared their personal experience to help us develop it. 

References

• Wild, CP., Weiderpass, E. and Stewart, BW. editors (2020). World Cancer Report: Cancer Research for Cancer Prevention. Lyon, France: International Agency for Research on Cancer. Available from: http://publications.iarc.fr/586. Licence: CC BY-NC-ND 3.0 IGO.
• Petry, K. et al (2018). Estimation of the individual residual risk of cervical cancer after vaccination with the nonavalent HPV vaccine. Human Vaccines & Immunotherapeutics. 14;7. pp.1800-1806.
• Malagon, T. et al (2018). Age at last screening and remaining lifetime risk of cervical cancer in older, unvaccinated women: a modelling study. The Lancet Oncology. 19;12. pp.1569-1578.
• Tjalma W. (2018). HPV negative cervical cancers and primary HPV screening. Facts Views Vis Obgyn. 10;2. pp.107-113.
• Brown, K. et al (2018). The fraction of cancer attributable to modifiable risk factors in England, Wales, Scotland, Northern Ireland, and the United Kingdom in 2015. British Journal of Cancer. 118;8. Epub.
• Roura, E. et al (2013). Smoking as a major risk factor for cervical cancer and pre‐cancer: Results from the EPIC cohort. International Journal of Cancer. 135;2. pp.453-466.

We write our information based on literature searches and expert review. For more information about the references we used, please contact info@jostrust.org.uk

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