What Causes Cervical Cancer?

We don't know exactly what causes cervical cancer, but certain risk factors are believed to have an effect. Medical history and lifestyle - especially sexual habits - play a role in a woman's chances of developing cervical cancer.

The most significant risk factors are:

• Human papillomavirus (HPV)

• Sexual history

Various other risk factors have also been identified.

Human Papilloma Virus (HPV)

Human papillomavirus (HPV) is a virus that can infect:

• The genital tract

• The external genitals

• The area around the anus

HPV has nothing to do with HIV, the virus that causes AIDS. There are 46 genetic types of HPV, but not all are dangerous. Only certain types of HPV, which can be transmitted from one person to another during sexual contact, increase the risk of cell dysplasia (abnormal cell growth) and/or progression to cervical cancer.

The HPV types that produce genital warts (lesions that are raised and bumpy, or flat and almost impossible to see) are different from those that cause cervical cancer. However, women who have a history of genital warts have almost twice the risk of an abnormal Pap smear as other women.

Sexual History

A woman has a higher-than-average risk of developing cervical if she:

• Has had multiple sexual partners

• Began having sexual relations before the age of 18

• Has a partner who has had sexual contact with a woman with cervical cancer

Other Risk Factors

It is probable that other factors contribute to cervical cancer, such as:

• Poverty. Women who are poor may not have access to medical services that detect and treat precancerous cervical conditions. When such women develop cervical cancer, the disease usually remains undiagnosed and untreated until it has spread to other parts of the body. Women who are poor are often undernourished, and poor nutrition can also increase cervical cancer risk.

• Pap test history. Not having regular Pap tests increases the chance of unrecognized cervical cancer. Between 60% and 80% of women with newly diagnosed cervical cancer have not had a Pap test in at least five years.

• Tobacco use. Women who smoke are about twice as likely to develop cervical cancer as women who do not. The more a woman smokes - and the longer she has been smoking - the greater the risk.

• Eating habits. A diet that doesn't include ample amounts of fruits and vegetables can increase a woman's risk of developing cervical cancer.

• Weakened immune system. A woman whose immune system is weakened has a higher-than-average risk of developing cervical lesions that can become cancerous. This includes women who are HIV-positive (infected with the virus that causes AIDS). It also includes women who have received organ transplants and must take drugs to suppress the immune system so that the body won't reject the new organ.

  For more detailed information about AIDS, go to AIDS And Women.

• Hormonal medications. Some experts suggest that hormones in oral contraceptives (birth control pills) can make women more susceptible to Human papillomavirus (HPV). At least one study has indicated that taking birth control pills significantly increases a woman's risk of developing HPV-related genital warts. Other research suggests that using oral contraceptives for five years or longer slightly elevates a woman's risk of developing cervical cancer, especially if she began taking the Pill before the age of 25.

• Diethylstilberstrol (DES). A rare type of cervical cancer has been diagnosed in a small number of women whose mothers took diethylstilbestrol (DES), a medicine that was once used to prevent miscarriage.

• Douching. Because douching may destroy natural antiviral agents normally present in the vagina, women who douche every week are more apt to develop cervical cancer than women who do not.

• Chemical exposure. Women who work on farms or in the manufacturing industry may be exposed to chemicals that can increase their risk of cervical cancer.

Women with a weakened immune system due to the virus that causes AIDS are more likely to develop cervical cancer:

• Cervical cancer is very common in women who are positive for human immunodeficiency virus (HIV).

• Cervical cancer is sometimes the disease that first suggests a diagnosis of acquired immunodeficiency syndrome (AIDS)

• HIV can compound the effects of Human papillomavirus (HPV), causing cervical changes to progress more rapidly into cervical cancer than they otherwise might.