What Causes Cervical Cancer?
March 25, 2009We 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:
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.
Nice To Know:
Hybrid Capture Test
This new test, approved by the FDA in 1999, is able to detect 14 types of human papillomavirus (HPV) that can infect the
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.
Who Develops Cervical Cancer?
Cervical cancer is most often diagnosed in women who are between the ages of 50 and 55.
- Girls under age 15 rarely develop the disease, but the risk of cervical cancer does rise between the late teen years and the early 30’s.
- In both white and black women, cervical carcinoma in situ (a benign tumor) is most common between the ages of 25 and 30.
Some individuals are more likely to develop cervical cancer:
- City-dwellers and women who are members of racial or cultural minorities develop cervical cancer more often than other women do.
- Vietnamese women have the highest cervical cancer rate in the United States.
- Hispanics, Native Americans, and African Americans develop cervical cancer more often than white women do.
These statistics may reflect that:
- Many recent immigrants and other minority groups wrongly believe that a woman who isn’t sexually promiscuous doesn’t need to have a
Pap test . - African American women tend to have Pap tests less often than white women.
What Is Cervical Cancer?
Cervical cancer is a disease caused by the abnormal growth and division of cells that make up the cervix, which is the narrow, lower end of the uterus (womb).
“Cancer” is the name for a group of diseases in which certain cells in the body have changed in appearance and function. Instead of dividing and growing in a controlled and orderly way, these abnormal cells can grow out of control and form a mass or “tumor.”
A tumor is considered
The cervix is composed of three layers of tissue:
- An outer lining known as the serous membrane (slippery covering)
- A middle, muscular layer
- An inner lining known as the mucous membrane, which is composed of thin, flat, scaly cells called squamous cells. This inner lining has many tiny glands that secrete a clear, lubricating mucous.
Nearly all cervical cancers arise from the cells of the inner lining of the cervix.
Normally, cervical cells grow in an orderly fashion. However, when control of that growth is lost, cells divide too frequently and too fast.
Certain well-defined cellular changes may progress to cervical cancer:
- Mild cervical
dysplasia results when irregular cells are limited to the deepest one-third of the surface cell layer (known as theepithelium ) that lines the cervix. - Moderate cervical dysplasia occurs when uncontrolled cell growth continues, and up to two-thirds of the surface cell layer is abnormal.
- If abnormal cell growth progresses to include the full thickness of the surface cell layer, the condition is known as severe cervical dysplasia, or carcinoma in situ, or CIS. Carcinoma in situ does not penetrate surrounding tissues, stays within the confines of the epithelium, and is considered benign.
A tumor is considered malignant (cancerous) if abnormal cells:
- Penetrate the membrane that separates the surface cell layer and the underlying supportive tissue (called the stroma) of the cervix.
- Spread to the surrounding tissues or organs.
There are several types of cervical cancer:
- Squamous cell carcinoma (SCC) is the most common type of cervical cancer, accounting for 85% to 90% of all cases. It develops from the cells that line the inner part of the cervix, called the squamous cells. It usually begins where the part of the cervix that connects with the
vagina (called the ectocervix) meets the part of the cervix that opens into the uterus (called the endocervix). - Adenocarcinoma develops from the column-shaped cells that line the mucous-producing glands of the cervix. In rare instances, adenocarcinoma originates in the supportive tissue around the cervix. Adenocarcinoma accounts for about 10% of all cervical cancers.
- Mixed carcinomas (for example, adenosquamous carcinomas) combine features of both squamous cell carcinoma and adenocarcinoma.
Nice To Know:
Q. Is cervical cancer curable?
A. If caught in the early stages, cervical cancer is almost 100% curable. The chances of detecting cervical cancer at an early stage are greatly increased by having regular. Pap smears are probably the most successful of all screening procedures ever devised to detect early cancer.
For more detailed information about pap smear, go to PAP smears.
Facts About Cervical Cancer
- Cervical cancer is the second most common cancer of the female reproductive system. It accounts for 6% of all cancers in women.
- About 128,000 cases of cervical cancer will be diagnosed this year.
- Early-stage cervical cancer and
precancerous (tending to become cancerous) cervical conditions are almost 100% curable.
- The five-year relative survival rate for earliest-stage cervical cancer is 91%.
- Cervical cancer death rates fell by 74% between 1955 and 1992 and continue to drop by about 2% a year.
- The increased use of the
Pap test is mostly responsible for the decrease in the number of cervical cancer deaths. This simple, highly effective screening procedure can detect precancerous conditions of the cervix and more than 90% of all cervical cancers. The fact that thousands of women die each year of a disease that can be prevented or cured reflects widespread failure to have Pap tests as often as experts recommend.
- About one-third of women who should have regular Pap tests do not. Women who don’t have Pap tests at recommended intervals are far more likely to develop cervical cancer than women who regularly undergo the procedure.
- Between 60% and 80% of women newly diagnosed with cervical cancer have not had a Pap test within five years. Some of these women have never had a Pap test.
Researchers are investigating new methods of preventing, detecting, and treating cervical cancer and the precancerous conditions that can lead to it.
