Cervical cancer - Risk factors

HPV infection

It is now known that at least 95 per cent of cervical cancers are caused by the HPVAn abbreviation for human papilloma virus, a sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers. virusA microbe that is only able to multiply within living cells.. HPVAn abbreviation for human papilloma virus, a sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers. is a very common sexually transmitted virusA microbe that is only able to multiply within living cells., but only some strains impart a high risk of developing cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body..

Your risk of contracting HPVAn abbreviation for human papilloma virus, a sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers. is highest if you have unprotected sex, and the more sexual partners you have, the higher your risk of coming into contact with the virusA microbe that is only able to multiply within living cells..

Using barrier methods of contraceptionA means of preventing pregnancy. cannot completely eliminate your risk of contracting HPVAn abbreviation for human papilloma virus, a sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers., but greatly reduces your risk.

More information about the HPVAn abbreviation for human papilloma virus, a sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers. virusA microbe that is only able to multiply within living cells. is on the Explained page. Learn about reducing HPV risks.

Women who smoke are twice as likely to develop cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. as those who do not.

Other risk factors

Unlike HPVAn abbreviation for human papilloma virus, a sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers. infectionInvasion by organisms that may be harmful, for example bacteria or parasites., other risk factors have not been proven to cause cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body.. Many women who have these risk factors do not develop cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body., however they can make it more likely that you will develop the disease. Other risk factors include;

Smoking

Women who smoke are twice as likely to develop cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. as those who do not.

Researchers think that smoking affects the way that immune cells in the cervixAny neck-like structure; most commonly refers to the neck of the uterus. respond to the HPVAn abbreviation for human papilloma virus, a sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers. virusA microbe that is only able to multiply within living cells.. These cells can help to fight HPVAn abbreviation for human papilloma virus, a sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers. infectionInvasion by organisms that may be harmful, for example bacteria or parasites. and protect other cells in the cervixAny neck-like structure; most commonly refers to the neck of the uterus. from changes that can lead to cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body.. The chemicals in tobacco smoke stop these immune cells from working properly.

Chlamydia infection

A common sexually-transmitted infectionInvasion by organisms that may be harmful, for example bacteria or parasites. caused by Chlamydia bacteriaA group of organisms too small to be seen with the naked eye, which are usually made up of just a single cell. has also been linked with an increased risk of developing cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body.. Women with this infectionInvasion by organisms that may be harmful, for example bacteria or parasites. are often unaware that they have it.

Genital herpes infection

Women who have genital herpesA sexually transmitted infection caused by the herpes simplex virus. are twice as likely to develop cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. as those who do not.

The oral contraceptive pill

Women who use oral contraceptionA means of preventing pregnancy. for five years or more have a higher risk of cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body.. Doctors don't yet know whether this is due to the oral contraceptives themselves or because women who take them are more likely to contract HPVAn abbreviation for human papilloma virus, a sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers. infections.

Whatever the cause, the risk is quite small, and doctors would not generally suggest that women should stop taking oral contraceptives because of it. Once a woman stops taking oral contraceptives, her risk of cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. starts to fall, so that by ten years after stopping, her risk is the same as a woman who has never taken them.

A suppressed immune system

Women who have a suppressed immune systemThe organs specialised to fight infection., usually because they are taking immune-suppressing drugs, which prevent the body's immune systemThe organs specialised to fight infection. from working properly, have an increased cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. risk.

Researchers think this is because these women's immune systems have difficulty dealing with HPVAn abbreviation for human papilloma virus, a sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers. infections.

HIV infection

Women who are HIV-positive have an increased risk of developing cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body.. It is thought that this is because the HIV virusA microbe that is only able to multiply within living cells. reduces the ability of a  women's immune systemThe organs specialised to fight infection. to combat HPVAn abbreviation for human papilloma virus, a sexually transmitted virus that can cause genital warts and may also have a role in the development of various cancers. infections.

Multiple childbirths

Women who have had numerous children are more likely to develop cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body.. A woman with seven or more children is twice as likely to develop cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. as a woman with two children. You are also more likely to develop cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. if you have your first baby at a young age. For example a woman who has her first baby at 17 has twice the risk of one who is a first time mother at 25.

Doctors do not know why this is. They think it may be to do with:

  • The effect pregnancy has on the immune systemThe organs specialised to fight infection.
  • The effects of hormonal changes in pregnancy.

Diethylstilbestrol

Between the 1940s and the 1970s, some women at risk of having a miscarriageThe spontaneous loss of pregnancy. were prescribed a hormonal drug called diethylstilbestrolSynthetic female sex hormone sometimes abbreviated to DES. (DESAn abbreviation for diethylstilbestrol, a synthetic female sex hormone.).

Much later it was found that the daughters of these women have an increased risk of cervical and vaginal cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body.. About one in 1,000 of the daughters of women prescribed these drugs will develop cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. of the cervixAny neck-like structure; most commonly refers to the neck of the uterus. or vagina.

Almost all of this group have detectable changes in the cells of the cervixAny neck-like structure; most commonly refers to the neck of the uterus. like the pre-cancerousMalignant, a tumour that may invade surrounding tissues or spread to distant parts of the body. changes that can be detected on cervical screening tests. Therefore it is often recommended that these women have colposcopyClose examination of the cervix of the uterus using a magnifying instrument with attached light source, known as a colposcope. to see whether these changes are present.

If this examination shows that you have changes in your cervixAny neck-like structure; most commonly refers to the neck of the uterus. caused by DESAn abbreviation for diethylstilbestrol, a synthetic female sex hormone., you will be advised to have regular colposcopyClose examination of the cervix of the uterus using a magnifying instrument with attached light source, known as a colposcope. examinations. Women with DESAn abbreviation for diethylstilbestrol, a synthetic female sex hormone. cellThe basic unit of all living organisms. changes are monitored more closely than others because they have a 12 times higher risk of cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body..

If you believe you may be at risk of cervical cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body., speak to your doctor.  You may also want to look at our practical help section for more information on the HPV vaccine