In recent years, scientists have made much progress toward understanding what happens in cells of the cervix when cancer develops. In addition, they have identified several risk factors that increase the odds that a woman might develop cervical cancer (see the previous section).

The development of normal human cells mostly depends on the information contained in the cells' chromosomes. Chromosomes are large molecules of DNA. DNA is the chemical that carries the instructions for nearly everything our cells do. We usually look like our parents because they are the source of our DNA. However, DNA affects more than the way we look.

Some genes (packets of our DNA) have instructions for controlling when our cells grow and divide. Certain genes that promote cell division are called oncogenes. Others that slow down cell division or cause cells to die at the right time are called tumor suppressor genes. Cancers can be caused by DNA mutations (gene defects) that turn on oncogenes or turn off tumor suppressor genes. HPV causes the production of 2 proteins known as E6 and E7. When these proteins are produced, they turn off some tumor suppressor genes. This may allow the cervical lining cells to grow uncontrollably, which in some cases will lead to cancer.

But HPV does not completely explain what causes cervical cancer. Most women with HPV don't get cervical cancer, and certain other risk factors, like smoking and HIV infection, influence which women exposed to HPV are more likely to develop cervical cancer.

Last Medical Review: 09/14/2009
Last Revised: 10/28/2009