Cervical cancer screening is probably the most successful cancer-screening program ever developed. One hundred years ago, cancer of the cervix was the leading cause of cancer for women in this country. Now it is not even in the top 10. This is largely because of the Pap smear, which was introduced in the 1950s.
Cervical cancer lends itself to a screening test, as the cervix can be directly visualized with simple equipment and its cells can be directly sampled with a relatively painless and risk-free procedure. In addition, cervical cancer is caused by the human Papilloma virus (HPV), which causes changes in the cervical cells that can be detected almost a decade before the onset of cancer.
A New Test to Detect HPV
Scientists have long known HPV is the causative agent, and a commercial test for it became available about a decade ago. As a result, the way standard screening works has changed somewhat.
Before the advent of the HPV test, women would go for yearly Pap smears. A single Pap test actually wasn’t that sensitive for detecting the disease, and there was a chance that even cancer could be missed by a single Pap smear. Screening worked quite well, however, because of the slow progression of HPV infection to cervical cancer. There was a good chance that if a single Pap smear missed the abnormal cells, repeated yearly testing would most likely find them in subsequent years.
The HPV test was introduced to improve the detection rate of the Pap smear. What has confused patients over the years, however, is thinking that a positive HPV test means you have a high risk for developing cancer. This is not the case at all. Here are a few facts all women should know about the HPV virus:
• About 40% of women under age 30 are infected at any one time
• 80% of sexually active women will be infected with HPV at one point in their lives
• The vast majority—greater than 90%—of HPV infections are transitory and will never cause any harm to the woman with the infection. The usual scenario is that her immune system will fight the virus and it will disappear within about 2 years.
New Screening Guidelines
What HPV testing has allowed gynecologists and women to do is skip the yearly screening if their HPV test is negative. Because the test is more sensitive, it doesn’t need to be done so often. The new guidelines (and they are changing all the time, as we learn more about HPV infections) are as follows:
• Under age 21, no Pap smear screening, as the rates of cervical cancer in young women are so low that screening in women younger than 21 leads to overtreatment.
• Age 21 to 30, Pap-smear screening every three years. (Again, the rates of cancer are so low in this age group that more frequent screening leads to overtreatment.)
• Older than age 30: Screening with Pap smear and high-risk HPV test. If you are negative for both, you can continue with screening every 3 years. If your Pap smear is negative and the HPV test is positive, you will need to have another Pap smear and HPV test in one year.
Consult Your Gynecologist
Of course, these guidelines are only for low-risk women. They become more complicated in women with a history of pre-cancer or cancer of the cervix. You would need to consult your gynecologist about your specific history.
The most important thing to take away is that if you have a single positive HPV test, don’t despair. The infection will likely resolve on its own without treatment. You should consult your gynecologist about further testing and treatment based on your individual situation.
To find an excellent gynecologist who is right for you, please call our Physician Referral Service at 866.804.1007.