Abnormal Pap smear results can be worrisome, at least until a second Pap smear reveals more information. Find out what Pap smears say about your cervical health.
A Pap smear is a useful screening tool that helps identify early cell changes so that if cervical cancer is present, it can be treated early. Since the Pap smear came into use as a cancer-screening tool more than 50 years ago, deaths from cervical cancer in the United States have decreased significantly.
“Pap smear tests for abnormality in the uterine cervix that may represent a pre-cancerous or cancerous disease on the cervix,” explains Concepcion Diaz-Arrastia, MD, director of gynecological oncology and associate professor at Baylor College of Medicine in Houston.
There are two basic types of Pap tests. Samples are collected the same way for each — your gynecologist will take a small amount of cells from the surface of your cervix to be analyzed in a lab. The older, traditional test examines the sample on a slide, while the more recent liquid cytology method places the sample cells in liquid in a vial. Studies show that both tests are equally reliable as tools for finding cervical cancer.
Decoding an Abnormal Pap Smear
In the lab, a technician will review the microscopic appearance of the cells on the slide or in the vials, looking for various types of abnormalities. Some labs use computerized programs to read Pap smear slides.
An abnormal Pap smear does not definitively mean that you have cancer. “Abnormal” simply means that the cells visible with analysis do not look like normal cells. There are various reasons that your Pap smear results could be other than normal, including:
- Inflammation or irritation of the cells of the cervix
- A cervical infection
- Hormonal changes
- The scrapings obtained did not contain enough cervical cells to get a proper interpretation
You will be asked to come in for additional testing to find out the cause of the abnormal results. You may need to have another Pap smear or a more detailed screening test, called a colposcopy. Or you may simply have to repeat the Pap smear if your doctor did not collect enough cells the first time.
Occasionally Pap smear results may be misread and interpreted as normal even though some cells are precancerous. But cervical cancer generally grows slowly, so it is likely that your next Pap smear will find these cells in time for effective treatment. For this reason, having Pap smears at the recommended intervals is a smart thing to do.
The Bethesda System of Pap Smear Results
When the results of your Pap smear go to your doctor, they are usually categorized according to a standard called the Bethesda System. That means your results will be placed in one of the following categories:
- Normal or no change.
- Atypical squamous cells of undetermined significance (ASCUS).
- Squamous intraepithelial lesion (SIL).
- Atypical squamous cells, cannot exclude HSIL.
- Atypical glandular cells.
- Cancer.
Your doctor may use different terms to discuss abnormal Pap smear results with you. “Dysplasia” refers to these possibly precancerous changes. Cervical intraepithelial neoplasia (CIN) with a number from 1 to 3 is a way of designating the degree of cellular change, with 1 being low-grade and 2 and 3 being high-grade changes.
The HPV Pap Smear
The human papillomavirus (HPV) can cause cervical cells to look abnormal. Usually your body will fight off HPV and a later Pap smear will show normal cells. However, some forms of HPV cause cervical cancer. If your abnormal results are due to the presence of HPV, you may have to have Pap smears more often until your doctor has decided that these changes are not precancerous.
Testing for HPV can be done at the same time as a Pap smear, either with one sample that tests for both or with two separate samples. HPV testing is recommended for women over age 30. The test may also be able to tell your doctor whether you have one of the types of HPV most likely to cause cervical cancer.
What Pap Smears Do Not Reveal
As effective as the Pap smear is, it doesn’t test for every possible abnormality in your reproductive system. It doesn’t show:
- Other reproductive cancers.
- Sexually transmitted diseases (STDs).
Current recommendations are for most women to have a Pap test every two years starting at age 21, unless their doctor recommends more frequent testing. After age 30, if a woman has had three consecutive normal PAP smears, the testing interval can be increased to three years.
Learn more in the Everyday Health Sexual Health Center.