What does the pap smear test for, and how reliable is it anyway? A pap smear is a test to look for abnormal, potentially precancerous or cancerous cervical cells. This test involves using a brush to sweep cells away from the cervix to be looked at with a microscope or even a computer for abnormal characteristics. These cells can be low-grade (less abnormal), high-grade (more abnormal), or ASCUS (uncertain how abnormal). Depending on a patient’s age (generally 30 or older), HPV testing may also be done at the same time. This test uses the same cells to check for evidence of HPV (human papilloma virus) strains that may lead to cervical cancer if left untreated, and the result is either positive (the virus is present) or negative (it isn’t). Other strains of the virus can lead to warts, either genital or elsewhere, but these aren’t tested for with a pap smear because they typically don’t cause cervical cancer. With use of both tests together, we can detect nearly 99% of high-grade lesions (markedly abnormal precancerous cells).
I have an abnormal pap smear. Do I have cancer? Am I going to die? In a study of over 200,000 women, even those with either an abnormal pap or HPV test or both had only a 0.2% chance of having cervical cancer at the time of the test. Even for those 2 in 1,000 who have cervical cancer, it generally responds very well to treatment in early stages.
What about babies? Am I going to be infertile? Many women (in fact, roughly 2/3 of all women) have HPV infections at some point in their lifetimes, and most of these women go on to have children. Many HPV infections are cleared by a women’s immune system, and even for those who require treatment of precancerous cells, pregnancies tend to be uncomplicated.
My pap smear came back abnormal. What’s the next step? Depending on your age (younger patients tend to be more likely to clear abnormal cells on their own) and type of lesion (low grade lesions are easier for a woman to clear than high grade ones), you may require colposcopy with cervical biopsies. During this procedure, the doctor applies an iodine solution and/or a vinegar-based solution to see areas of abnormal cells with a microscope. This is done using a speculum to visualize the cervix and then an instrument to take biopsies (a few millimeters in size) to make sure that a pathologist is able to see a sample from each area of abnormal cells. If these biopsies come back either normal or only low-grade (CIN 1) in nature, then you may just have to repeat your pap and HPV test in a year. If they are medium or high-grade (CIN 2 or 3) in nature, treatment to remove these cells may be required.
I have CIN 3. Does that mean I am for sure getting cancer? Even for the most abnormal precancerous cells, CIN 3, we see only about a 12% chance of developing cervical cancer, and on average, the transition from CIN 3 to cancer takes between 8-12 years. This is why for most women with no history of abnormal pap smear, we can offer screening every 3-5 years depending on the type of testing done. Still, we do take abnormal paps seriously, and we are very proactive in trying to prevent the development of cervical cancer from precancerous cells. Whereas an outpatient procedure to remove a small portion of the cervix is generally adequate to treat precancerous cells, cervical cancer may not be treatable even with hysterectomy and could require chemotherapy and radiation.
How can I avoid developing abnormal cervical cells? The most effective prevention is administration of the HPV vaccine. This is usually given in 2 doses between ages 11-12, although it can be given from ages 9-26. HPV is transmitted sexually (not inherited), so condom use and limiting the number of sexual partners can also reduce the chances of HPV infection.
In closing, pap smears and HPV testing are done to check for signs of precancerous changes that may develop into cervical cancer if left untreated or even signs of cervical cancer itself. By staying up to date with your screening, you can significantly reduce the chance of your first abnormal finding (if you have one) indicating a more serious condition. If you aren’t sure that you’re up to date on your cervical cancer screening, be sure to make an appointment with your doctor today!