What Do Pap Smears Test for?

Overview

Once considered the leading killer among women, cervical cancer is no longer the menacing threat it used to be. And Pap smears are largely the reason why. In fact, the American Cancer Society credits Pap smears with slashing cervical cancer deaths by 74 percent from 1955 to 1992 and rates continue to decline. If done regularly, Pap smears offer one of the best ways to halt cervical cancer at an early stage. But, as effective as Pap smears are, not all women look forward to having them done and some women ignore them altogether. However, understanding what Pap smears test for is key to your survival.

What They Screen

Also called Pap tests, Pap smears are used to detect cervical cancer. Named after Dr. George Papanicolaou, who devised this method in the 40s, Pap smears screen for changes in your cervix. Abnormal, pre-cancerous cells, known as dysplasia, can eventually become malignant unless detected early by a Pap smear. In addition, Pap smears can prompt your doctor to take a closer look at your cervix and find out whether anything more is going on. Some cell changes can be caused by something as simple as a yeast infection. Others can be the result of human papillomavirus (HPV), which is commonly transmitted during sex and in high-risk forms, can lead to cervical cancer.
Some women assume that when they go in for Pap smears, they will be automatically tested for STDs. But, these tests are handled differently. For example, both chlamydia and gonorrhea are determined by urine and swab tests, not Pap smears.

Who Should Have Them

Because most women are at risk for cervical cancer and early intervention is vital, Pap smears should be done regularly. Women with weakened immune systems or who are HIV-positive are at greater risk and should be tested annually, according to the U.S. Department of Health and Human Services. For sexually active teens and women with multiple partners, it's important to get in every year. Aside from promiscuity, other risk factors include smoking and sexually transmitted diseases such as human papillomavirus (HPV), which can cause genital warts and in more serious forms is linked to cervical cancer. There are more than 100 strains in the HPV group and some stay hidden until Pap results point to abnormal changes in your cervical cells. Talk to your doctor about the best Pap schedule for you.

How It's Done

Expect to undress from the waist down and lie on an exam table with your knees bent and your feet in stirrups. Using a metal or plastic speculum to open the vagina, your doctor will collect cells from inside and around your cervix with a tiny brush or spatula. These cells are smeared on a glass slide for lab analysis. In some instances, the cells are placed in a solution that filters blood, excess mucus and bacteria, leaving only the cervical cells that need to be analyzed. Usually quick and painless, Pap smears may pose discomfort similar to menstrual cramps during speculum insertion and swabbing. But, most doctors are sensitive to this and proceed gently. If you feel extreme pain, let your doctor know.

Interpreting the Results

Most Pap smears are normal. But if results show an abnormality, your doctor will repeat the Pap and order a HPV test, which also collects cells from your cervix and checks for high-risk HPV genes. Keep in mind that an abnormal Pap smear doesn't mean you have cancer. A number of factors can produce irregularities including dysplasia, HPV and vaginal infections. But, high-grade changes to your cervical cells may warrant a colopscopy, which examines the cervix under strong magnification. If your doctor sees something atypical, tissue samples from your cervix are sent to the lab to determine whether the cells are cancerous, pre-cancerous or neither. Don't assume no news is good news. Follow-up with your doctor within two weeks.

Potential Errors

While Pap smears effectively detect cervical cancer, they're not always accurate. Some tests miss abnormalities (false negative) or note cancer is present when it isn't (false positive). Errors occur for a number of reasons including improper lab analysis, missed cell areas and obscurities caused by blood, bacteria and mucus on the slide. But, repeating the Pap test on a regular basis can help ensure consistent results. Also, you can help ensure accuracy by not scheduling an exam during your period and avoiding sex, tampons, foams, creams, jellies, suppositories and douching 48 hours before the test.

Pap Misconceptions

If you're an older woman or you've had a hysterectomy, you may think you don't need routine Pap smears. But, if you have a cervix, it's crucial to be screened. Even if your uterus or ovaries were removed, you still need to be checked. While Pap smears don't detect ovarian, vulvar, uterine or vaginal cancer, pelvic exams---which are usually done at the same time as your Pap smear---will uncover any suspicious growths, discharge or swelling. Both the Pap smear and pelvic exam underscore the importance of making them an essential part of your preventive health routine.