Signs of Cervical Cancer May Be Present Years Before It Develops
June 23, 2000 -- A sexually transmitted virus that is responsible for many cases of cervical cancer can be found in a woman's body years before cancer develops. And researchers say that making tests for the human papillomavirus (HPV) part of routine cervical cancer screening can help detect these cancers early -- or at least identify women at risk so they can be followed closely.
"High-risk women could be identified by adding HPV ... testing to the cervical screening," says Nathalie Ylitalo, MD, the lead author of one of two new studies published in the medical journal The Lancet.
Up to 40 million Americans may be infected with HPV, according to the American Social Health Association. But, for most people who become infected, the immune system eliminates the virus on its own and no symptoms are ever apparent.
A common type of HPV, known as HPV 16, has been linked to many cases of cervical cancer. The current method for detecting cervical cancer is to look for changes in the cells on yearly Pap smears. The HPV test is available in the U.S., but is not approved for routine cervical cancer screening.
Ylitalo, of the Karolinska Institute in Stockholm, reports that women with the highest levels of HPV 16 in their bodies had a least a 30 times greater risk of cervical cancer than women who were not infected with the virus. Her research found that about one-fourth of women under age 25 with high levels of the virus developed cervical cancer within 15 years.
A second study, also by Swedish researchers, found that having high levels of the virus was linked to a 60 times increased risk of cervical cancer.
In both studies, the HPV infection was detectable in Pap smears taken an average of eight years before cancer developed, suggesting that an HPV test can identify women at high risk of cervical cancer years before any abnormal cells show up on their Pap smears.
Cervical cancer is the second leading cause of cancer-related deaths among women worldwide, after lung cancer. In the U.S., 15,000 women are diagnosed with the disease each year and 5,000 die. Worldwide, cervical cancer affects 500,000 women annually. According to the American Cancer Society and others, 50% to 60% of women who develop advanced cervical cancer have not had their recommended annual Pap smears in the previous three years, despite having had contact with a health care provider during that time.