Cervical Cancer Risk Factors

Nearly all cervical cancers — 99% of them — are caused by persistent infection with certain types of human papillomavirus (HPV). HPVs are a group of more than 150 related viruses. Some HPVs can lead to warts (papillomas) or cancer. Many HPVs are spread through skin-to-skin contact, oftentimes through sexual contact, including vaginal, oral and anal sex.

HPVs are so common that experts believe most adults have been infected at some point in their lives. The tricky thing about HPV infection is that most people don’t have any symptoms. You’d never know you had it, or that you could spread it to others. In most cases, the HPV infection resolves without treatment. However, sometimes the infection persists and chronic infection with HPV is what causes the cells to change, leading to dysplasia. A vaccine to prevent HPV is now available and experts recommend that children receive the HPV vaccine around age 11 or 12 as part of routine healthcare.

Other factors, in addition to HPV infection, also increase risk for cervical cancer. These factors include:

  • Skipping Pap tests. Cervical cancer is more common among women who don't have routine cervical cancer screening. The Pap test collects a sampling of cells from the cervix to examine for abnormal or pre-cancerous changes that occur in the cervix before progressing to invasive cervical cancer. As many as 60 to 80% of women diagnosed with invasive cervical cancer had skipped the Pap test for five years or more.
  • Smoking. Among women who are infected with HPV, smoking cigarettes increases the risk of cervical cancer.
  • Weakened immune system. Infection with HIV (the virus that causes AIDS) or taking drugs that suppress the immune system increases the risk of cervical cancer.
  • Sexual history. Women who have had many sexual partners have a higher risk of developing cervical cancer. Also, a woman who has had sex with a man who has had many sexual partners may be at higher risk of developing cervical cancer. In both cases, the risk of developing cervical cancer is higher because these women have a higher risk of HPV infection.
  • Long-term use of birth control pills. Using birth control pills for five years or more may slightly increase the risk of cervical cancer among women with HPV infection. However, the risk decreases quickly when women stop using birth control pills.
  • Having many children. Studies suggest that giving birth to many children (five or more) may slightly increase the risk of cervical cancer among women with HPV infection.
  • DES (diethylstilbestrol) exposure before birth. DES may increase the risk of a rare form of cervical cancer in women exposed to this drug before birth. DES was given to some pregnant women in the United States between about 1940 and 1971. (It is no longer given to pregnant women.)

Having an HPV infection or other risk factors does not mean that a woman will develop cervical cancer. Most women who have risk factors for cervical cancer never develop it.

Cervical cancer in Black and Hispanic women

While cervical cancer cases and deaths have decreased dramatically, by as much as 50% in the last three decades, the disease remains a serious health threat, especially among Black and Hispanic women.

We call these differences cancer health disparities. The reasons for such disparities are complex and are the focus of research across the country, including here at Roswell Park. Learn more about Roswell Park’s efforts to understand and combat cancer health disparities.

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