Pinky Ronen, M.D.
The Papanicolaou smear (Pap test) is a test used to screen women for cervical precancer or cancer. Testing for human papillomavirus (HPV) is another type of test for cervical cancer that can be used in women over age 30 in conjunction with the Pap test. Pap tests can find cervical cancer and precancer in the early stages when it can be treated, and thus may reduce the number of deaths from cervical cancer. This article reviews tests used to screen for cervical cancer and a description of both normal and abnormal Pap test results.
The most important risk factor for cervical cancer is infection with the human papillomavirus (HPV). There are over 100 different types of HPV; however, most types of HPV do not cause cancer. At least 80 percent of women are exposed to the HPV virus during their lifetime. Most of the time, the body's immune system gets rid of the virus before it does harm.
Researchers have labeled the HPV types as being high or low risk for causing cervical cancer.
HPV is spread by direct skin-to-skin contact, including sexual intercourse, oral sex, anal sex, or any other contact involving the genital area (eg, hand to genital contact). It is not possible to become infected with HPV by touching an object, such as a toilet seat. Most people who are infected with HPV have no signs or symptoms. Most HPV infections are temporary and resolve within two years. When the virus persists (in 10 to 20 percent of cases), there is a chance of developing cervical precancer or cancer. However, it usually takes many years for HPV infection to cause cervical cancer.
Since HPV is transmitted by sexual contact, having multiple sexual partners is associated with an increased risk for cervical cancer. Condoms provide only partial protection. Smoking can increase the risk of cervical cancer up to fourfold, as does having a condition or taking a medicine that weakens the immune system.
A vaccine is available to help prevent infection with some types of HPV (types 6, 11, 16, and 18) and is recommended for girls or women between the ages of 9 and 26 years and for boys or men between the ages of 9 and 21 years, but can be given up to 26 years of age. Smoking cessation is recommended for those who smoke.
There are several ways to screen for cervical cancer. The traditional screening test is called a Pap test.
If you are 30 years or older, your doctor or nurse may recommend HPV testing in addition to a Pap test. If your HPV test and Pap test are negative, repeat testing is not usually needed for five years. HPV testing may also be done if the results of your Pap test results are unclear.
Younger women — In the United States, the first Pap test is recommended at age 21; some other countries suggest that screening begin at age 25. Cervical cancer is very rare in younger women. Pap smear screening before age 21 in girls and women who are sexually active is not recommended because of the very high risk of false-positive results because many HPV infections in this group are temporary. There is concern that procedures done to follow-up on these results will impair a young women’s future fertility. In the past, experts recommended that every woman have a Pap test every year. This has changed, and Pap testing is suggested every three years for most women over age 21. More frequent testing may be needed if test results are not normal, or for women with HIV disease or other specific immune system conditions. Even if you have had a vaccine for human papillomavirus, you will still need cervical cancer screening.
Most experts feel that women who are 65 years or older can stop having Pap tests if:
For two days before your Pap test, do not put anything in your vagina (eg, spermicide, creams). A Pap test can be done at any time during your menstrual cycle.
The results from your Pap test will be available a few weeks after your visit. Pap test results may be reported as: