To understand cervical cancer, it helps to be familiar with the anatomy of the cervix and surrounding areas. The uterine cervix is the neck of the uterus (or womb). If you were to think of an upside-down pear as a rough model of the uterus, the cervix would correspond to the narrow part of the fruit as it tapers toward the stem. The uterus is hollow in order to accommodate a fetus after conception occurs. This cavity opens to the vagina through the cervical canal, through which the fetus leaves the womb to enter the birth canal (the vagina) during childbirth.
The cause of cervical cancer remained a mystery for decades. Scientists had noticed since the mid-nineteenth century that cervical cancer was rare among nuns but common among prostitutes. They were puzzled by this observation but failed to draw a connection between cervical cancer and sexual activity. Later generations of researchers noticed that women with cervical cancer often had genital herpes as well, leading them to the erroneous conclusion that the latter caused the former. A possible link between cervical cancer and sex with uncircumcised men was investigated, but no such association could be supported by clinical research. Finally scientists at the National Cancer Institute proved that most types of cervical cancer are caused by a virus called human papillomavirus (HPV). Learn more about how HPV causes cervical cancer.
HPV is common; it is estimated that half of sexually active Americans have been exposed to one or another form of the virus. According the U.S. Centers for Disease Control and Prevention (CDC), six million people in the United States acquire HPV each year. For most people, however, HPV does not have any serious effects. Most women’s immune systems, when exposed to HPV, clear the virus, preventing it from causing any serious harm to the body.
In some women, however, the virus can integrate into cells of the cervix and cause damage to the cells, eventually leading to cancer. More than 90 percent of cervical cancer is caused by HPV infections—particularly, by strains 16 and 18—that infect cells of the cervix and are not cleared by the immune system.
Written by: the Healthline Editorial Team
Published on Jan 10, 2011
Updated on Oct 11, 2012
Medically reviewed by Jennifer Monti, MD, MPH