Abnormal Pap Smear Test Results: What They Mean for You
Medical test results can be full of unfamiliar acronyms or confusing medical jargon, but “abnormal” is a word most of us understand as a concerning result. When it comes to pap smears—a common health screening conducted in your primary care provider (PCP) or OB/GYN’s office—abnormal results could mean several things. An abnormal pap result often does not mean you have cervical cancer.
Stephanie J Alimena, MD, a Mass General Brigham Cancer Institute gynecologic oncologist, explains what a pap smear is, what types of abnormal results you might see, and what happens if you get an abnormal result.
Why do I need a pap smear test?
If you have a cervix, you’re at risk of cervical cancer.
The cervix is the very bottom part of the uterus. Your health care provider can perform a pelvic exam in their office to see and check your cervix.
In virtually all cases, cervical cancer and precancer are caused by human papillomavirus (HPV), a sexually transmitted infection (STI). This is an extremely common virus: about 8 in 10 people contract the virus at some point in their lives. It doesn’t cause symptoms, but over time it can change the cells in the cervix to become precancerous or cancerous.
The good news is that it generally takes many years between the start of an HPV infection and diagnosing invasive cervical cancer. Getting regular pap smear tests can detect precancerous changes so your health care provider can treat those changes long before they have time to become cancer.
What is a pap smear test?
A pap smear is a routine health screening for patients with a cervix conducted in your primary care provider’s office or your OB/GYN provider’s office.
“During a pelvic exam we use a speculum, a device placed in the vagina that separates the vaginal walls so we can see the cervix,” explains Dr. Alimena. “We use a small brush to collect cells that have already fallen off your cervix. The test may feel uncomfortable due to pressure from the speculum but usually doesn’t cause pain. If you have concerns about past pain, trauma, or anxiety, let your provider know. We can discuss options to help.”
The cells are examined under a microscope later in the lab to detect the probability of finding precancerous cells. Precancerous cells are cell changes that can lead to cervical cancer in the future. A pap smear test can also detect the presence of cervical cancer cells, which is a much less common result.
The Centers for Disease Control (CDC) recommends getting pap tests starting at age 21. Depending on your results and health history, your provider may recommend:
- Pap screening only every 3 years
- HPV screening only every 5 years
- HPV and pap screening every 5 years
- More frequent pap and/or HPV screening, depending on your prior pap and HPV test history
Some people don’t need routine pap screening. For example, you may not need routine pap smears if your doctor removed your cervix as part of a total hysterectomy for non-cancerous conditions and you never had an abnormal pap or HPV test before that. Hysterectomy is a surgery to remove the uterus, to treat heavy bleeding, pain, fibroids, or other conditions.
You also don’t need routine pap smears if you’re over age 65 and you:
- Have 10 years of normal or negative pap or HPV tests
- Don’t have a history of cervical precancer or cervical cancer in the past 25 years
- Don’t have any health conditions that suppress your immune system
- Were never exposed to diethylstilbestrol in utero (a fairly uncommon scenario, which only a possibility if you were born between the late 1940s to 1971)
Follow your doctor’s recommendation for your screening schedule, as it varies based on your personal risk factors including age and medical history.
What happens if my pap test is normal?
If your pap smear test is normal or negative, it means the test didn’t find any cell changes.
You might still need additional testing if you have a positive HPV test, even if your pap test results are normal. Your doctor tells you if this is the case.
Otherwise, your doctor confirms when you need your next pap test. If you’ve never had an abnormal result before, you follow the screening schedule they recommend. Your next test is likely in 3 to 5 years under most circumstances.
What happens if you have an abnormal pap test result?
A pap test is a screening test, which means your doctor can’t diagnose whether you have precancerous or cancerous changes with just this test.
Not everyone who has an abnormal pap test is diagnosed with precancerous or cancerous changes. Most people with a cervix have an abnormal pap test at some point in their lives and most of them will not have a precancer or cancer diagnosed.
When a pap test is abnormal, it generally means that you need additional testing—something called a diagnostic test—to truly rule in or out precancerous or cancerous changes. Sometimes, depending on the pap and HPV test results, your doctor may recommend another pap and/or HPV test in a year instead of going to colposcopy.
What is a colposcopy?
After an abnormal pap test result, your doctor does a colposcopy, a diagnostic test.
“This is one of my areas of expertise,” says Dr. Alimena, who sees patients for colposcopies on a regular basis. If your PCP did your pap smear test, they may send you to someone like Dr. Alimena or another OB/GYN to do the colposcopy.
“In the office, we perform a pelvic exam using a speculum,” she explains. “We place a special dye on the cervix to help us see any potentially abnormal or precancerous cells using a small microscope called a colposcope.”
Dr. Alimena continues, “We look at the cervix through the microscope and if we see any abnormal areas on the cervix highlighted by the special dye, we may recommend a small biopsy.”
A biopsy is a quick procedure when your provider removes a tissue sample with a small tool. “It may feel slightly uncomfortable,” says Dr. Alimena, “but we use several techniques to help reduce pain and discomfort during the procedure to help. During the biopsy we remove only a few millimeters of tissue—about half the size of a pencil eraser or usually even less.”
A tissue biopsy is the only way to tell whether there are any precancerous or cancerous changes present. A pathology team examines the tissue biopsy in the lab with an even stronger microscope to see whether these changes are present.
Types of abnormal pap test results
“If your pap smear test results come back as abnormal, you might see different medical terminology that can be overwhelming,” says Dr. Alimena. “There is often additional testing needed to know what those changes mean, and to more fully rule out precancerous or cancerous changes. Remember that as a screening test, a pap smear can only tell us so much. It tells the probability that you have precancerous changes in the cervix, but it cannot diagnose them with the pap test alone. Tell your provider if you have any additional questions or concerns about your results or next steps. We want you to understand the results and connect you with any follow-up testing if needed.”
Here’s what each label means:
Atypical squamous cells of uncertain significance (ASC-US)
This is the most common abnormal pap test result. This means your cells look like they could be abnormal, but it’s the least worrisome abnormal pap result. It means the chances of finding precancer are slightly elevated. Sometimes, depending on your age, prior results, and the result of an HPV test if it was collected, you may be able to repeat testing in a year or you may need colposcopy. Ask your doctor what they recommend.
Squamous intraepithelial lesions (SIL)
There are two kinds of squamous intraepithelial lesions you might see in your pap test results: low-grade and high-grade.
- Low-grade squamous intraepithelial lesions (LSIL): This means the chances of finding precancerous changes are slightly higher than with an ASC-US result, but still not terribly high. Depending on your age, prior results, and the result of an HPV test if it was collected, you may be able to repeat testing in a year or you may need colposcopy. Ask your doctor what they recommend.
- High-grade squamous intraepithelial lesions (HSIL): This means the chances of finding precancerous changes are moderately high. This result almost always needs a colposcopy as a next step to determine for certain whether there are precancerous changes there. In some cases, depending on the HPV result and your prior pap history, your doctor may recommend you go directly to treating for precancerous changes instead of colposcopy. Ask your doctor what they recommend.
Atypical squamous cells where high-grade squamous intraepithelial lesion (HSIL) can’t be excluded (ASC-H)
This is similar to an HSIL result, but the chances of finding precancer are slightly less than with HSIL. With this result you almost always need a colposcopy as a next step to determine for certain whether there are precancerous changes present.
Squamous cell carcinoma or adenocarcinoma
Rarely, a pap smear test result reveals cancer cells. If your test shows squamous cell carcinoma or adenocarcinoma, your provider calls you to discuss the results and next steps. You need a biopsy to confirm this, since the pap test cannot say for certain whether there is cancer, and the chances of a false positive result are much higher with a pap test than a biopsy.
“After having a biopsy that confirms invasive cancer,” Dr. Alimena says, “your doctor connects you with a gynecologic oncologist like myself to discuss next steps. They will often recommend imaging studies to confirm whether the cancer is confined to the cervix or whether it has spread. The oncologist will often perform another pelvic exam to visualize whether there is a mass present. The imaging studies and exam by the oncologist will help determine a treatment plan.”
Atypical glandular cells (AGC) or adenocarcinoma in situ (AIS)
These results show abnormal cell changes in the glandular cells that live higher in the canal of the cervix (closer toward the uterus than to the vagina). Sometimes these changes on a pap smear reflect something going on with the uterus, as there are also glandular cells in the uterus.
These results always require a colposcopy and sometimes a biopsy or ultrasound of the uterus to exclude precancerous or cancerous changes from the uterus.
Unsatisfactory
An unsatisfactory result means there weren’t enough cells in the sample or that the cells were clumped together. Sometimes this happens if there is atrophy (low estrogen levels in the vagina and cervix, caused by menopause) or if you were having your period on the day of collection.
It doesn’t mean that something is wrong with your cells, but that the test is incomplete. Your provider asks you to come back for another pap test in a few months to ensure you get accurate results.
Treatment for precancerous cells
After a colposcopy and biopsy, some patients may be diagnosed with precancerous cells. This result may appear as cervical intraepithelial neoplasia (CIN) 2-3 or adenocarcinoma in situ (AIS).
If a biopsy shows CIN 1, this is not a precancerous change, but a temporary change in the cells related to the HPV infection and doesn’t require treatment.
When precancerous cells (CIN 2-3 or AIS) are diagnosed, your provider recommends a procedure to excise (remove) the precancerous area on the cervix.
There are two types of procedures to treat these changes: a loop electrosurgical excision procedure (LEEP) or cone biopsy (also called a cold knife cone biopsy).
During a LEEP, your doctor uses a small wire loop attached to an electrical current to cut away abnormal cells. During a cone biopsy, your doctor uses a scalpel or laser knife to remove a cone-shaped section of abnormal cells.
Your doctor recommends the procedure that’s right for you. These procedures are highly effective at removing the precancerous cells from the cervix and preventing them from becoming cancer.
“Remember,” Dr. Alimena says, “even if you are diagnosed with precancerous cells, it still generally takes a very long time for those cells to become cancer. So the good news is there is time to intervene with one of those two types of excisions.”
Treatment for cervical cancer
“If you are diagnosed with cervical cancer, your tests, medical history, and future fertility goals will help determine your treatment plan,” says Dr. Alimena. “We use the stage, spread, and size of the cancer to tailor treatment recommendations.”
Treatment for cervical cancer may include:
- Surgery, including hysterectomy or in select cases, fertility-preserving surgery—this is used when cancer is confined to the cervix and a very small tumor
- Radiation therapy along with chemotherapy and sometimes immunotherapy—this is used for larger tumors confined to the cervix or cancer that has spread locally to the vagina, tissue surrounding the cervix, lymph nodes, or other nearby structures (bladder and rectum)
- Chemotherapy and other systemic treatments like immunotherapy—this is used for tumors that have spread distantly to other areas (lungs, upper abdominal tissues)
- Surgery, chemotherapy and other systemic treatments or participation in clinical trials for recurrent cancer
Your care team may include your gynecological oncologist, a radiation oncologist, a medical oncologist, and your OB/GYN, as well as nurses, rehabilitation specialists, psychologists, and others.
Preventing cervical cancer with pap and HPV screening saves lives
Regular health screenings—including pap and HPV screening—can help detect precancerous changes long before cancer develops, so that it can be removed. Pap smears can also detect cancers at earlier stages.
At the early stages of cervical cancer, the 5-year survival rate is 91%. At later stages—when the cancer has spread to nearby or distant parts of the body—the 5-year survival rate is lower. However, major advances recently have been made in treating cancers that have spread beyond the cervix, including the addition of immunotherapy.
Getting the HPV vaccine is another way to protect yourself. Your doctor can help determine if you should get the HPV vaccine.
“An abnormal pap test result can be scary, but when discovered early, abnormal cells and even cervical cancer are treatable,” says Dr. Alimena. “Remember, if your pap smear is abnormal, it means you may need additional testing but does not mean you definitely have cancer or even precancer. Talk to your provider if you have questions or concerns about your health history and screening schedule.”