In this Article
What Is The Pap Smear?
The Pap smear, also called a Pap test, is a painless, noninvasive procedure that doctors and other specially trained healthcare providers use to screen for cancer of the cervix (the lower part of the uterus, or womb, where a baby grows).
This procedure involves
- collecting cells from the cervix and the vagina
- preparing the cell sample for evaluation under a microscope
- examining the cell sample for infections, abnormal cells that may grow into a cancerous tumor, and cancer
The Pap smear is a screening technique. It is used to detect cervical cancer or cervical abnormalities that might become cancer in women who don’t have any symptoms of these conditions.
The Pap smear cannot prove that a woman doesn’t have cervical cancer, but it can detect 95 percent of all cervical cancers and precancerous abnormalities. It is not a diagnostic test used to identify the illness or condition responsible for symptoms.
Nice To Know:
Doctors, scientists, and engineers are working together to improve Pap smear accuracy. Laboratories that analyze Pap smears are rapidly adopting automated techniques, and many experts believe the new technologies will make important contributions to the screening process.
Facts About The Pap Smear
Nice To Know:
Free Pap Smear Day
National Pap Smear Day was observed on January 14, 2000. Sponsored by the National Cervical Cancer Coalition and endorsed by the Centers for Disease Control and Prevention, this unprecedented program provided free Pap smears to women who hadn’t been screened for at least three years.
Who Should Have A Pap Smear?
Experts estimate that 35,000,000 women in the United States should have regular Pap smears. About one-third of all women who should have regular Pap smears do not.
A girl or woman should have a Pap smear if she:
- has reached the age of 18
- is sexually active
- has been sexually active
A girl or woman should have regular Pap smears even if she has no cancer symptoms. (If she has cancer symptoms, the doctor will perform diagnostic tests to confirm or rule out the diagnosis of cancer.)
The American Cancer Society recommends that a girl or woman have her first Pap smear when she reaches the age of 18 or becomes sexually active. Because cervical cancer progresses slowly, some doctors think that a girl or woman doesn’t need to have a Pap smear every year if
- she’s reached the age of 65
- she’s had normal test results for 3 years in a row
Does A Woman Need A Pap Smear After She’s Had A Hysterectomy?
- A woman who has had a hysterectomy should ask her gynecologist or family doctor whether she should continue having regular Pap smears.
- If a woman had a hysterectomy because she had cancer or a precancerous condition of the
cervix, her doctor may advise her to have a Pap smear at least once a year.
- If a woman who has had a hysterectomy did not have cancer or a precancerous condition of the cervix, her doctor may want to perform regular Pap smears to detect possible precancerous changes in the vaginal wall.
- Some physicians doubt whether a woman who has had a hysterectomy benefits from having a Pap smear.
Should Older Women Have Pap Smears?
Instances of cervical abnormalities are increasing most rapidly among older women, and 25 percent of all cervical cancers occur in women over the age of 65.
Some doctors doubt that having a Pap smear benefits an older woman who has a history of normal test results. Others argue that older women experience body changes that make it difficult to obtain adequate cervical cell samples and therefore regular Pap smears should be mandatory for post-menopausal women.
A woman who is not sure whether she should continue having regular Pap smears should discuss her concerns with her gynecologist or family physician.
Why Are Regular Pap Smears So Important?
Having Pap smears at recommended intervals is the most important thing a woman can do to protect herself from developing cervical cancer.
Regular Pap testing is important because
- no test is 100 percent accurate
- no one can predict who will develop cervical cancer
- this procedure enables healthcare providers to detect early precancerous changes in the tissue of the cervix and treat them before they become cancerous
- women who have regular Pap smears are much less likely to develop cervical cancer than are women who don’t have the test regularly, because they get early treatment for precancerous conditions.
Between 60 and 80 percent of women with newly diagnosed cervical cancer haven’t had a Pap smear in at least 5 years. A woman who’s had regular Pap smears can still develop cervical cancer, but her condition will almost certainly be diagnosed in its earliest, most curable stage.
Nice To Know:
When a woman has had three normal Pap smears in a row
A woman may need more-frequent Pap smears if she
How Should A Woman Prepare For A Pap Smear?
- A woman who is still menstruating should schedule a Pap smear about two weeks after the start of the menstrual period. That’s the stage of the cycle when the doctor can obtain the clearest, cleanest sample of cervical cells.
- A woman who has reached menopause can schedule a Pap smear at any time of the month.
- A woman who is having abnormal bleeding or any other gynecological problem should see her doctor right away.
What Activities Should A Woman Avoid Before Having A Pap Smear?
In the 48 hours before having a Pap smear, a woman should not
- have intercourse
- take a tub bath
- use tampons, spermicides, vaginal lubricants, or feminine deodorant sprays or powders
These activities can irritate the cervix. Avoiding them helps ensure collection of an adequate cell sample.
Nice To Know:
It’s a good idea to avoid scheduling a Pap smear during a holiday season when lab technicians may be preoccupied.
Nice To Know:
Questions A Woman’s Healthcare Provider Will Ask
The healthcare provider who performs a Pap smear will want to know the date of the first day of a woman’s last menstrual period and whether she
How Is A Pap Smear Performed?
A Pap smear is performed in a doctor’s office, hospital, or clinic by a
- physician assistant
- nurse midwife
- nurse practitioner
or other specially trained healthcare provider. Each of these professionals is also qualified to perform a pelvic examination, which can help detect cancer in female reproductive organs other than the cervix.
During a pelvic examination, the woman takes off her clothes, puts on a short paper or cotton gown that opens in the front, and lies on her back on an examining table. She positions herself for the Pap smear by bending her knees, aligning the tops of her thighs with the edge of the table, and placing her feet in stirrups or supports.
The healthcare provider performing the examination
- looks for lumps, sores, inflammation, or other abnormalities of her external genitals
- inserts a metal or plastic instrument called a speculum into the
- uses a small disposable swab, wooden spatula, brush, or soft-bristled “broom” to remove cells from the entrance to the canal that connects the cervix with the
- may also remove cells from the back of the cervical canal.
- places the cell sample on a glass slide, which is sent to a laboratory for examination under a microscope.
After removing the speculum, the healthcare provider gently inserts two gloved fingers into the woman’s vagina and places his or her other hand on her abdomen. This enables the examiner to determine the size, shape, and consistency of the woman’s uterus, ovaries, vagina, and
A woman may feel some mild discomfort, cramping, or pressure during a Pap smear or pelvic exam. These procedures should not be painful.
Nice To Know:
Most cervical cancer originates at the entrance to the canal that connects the cervix with the uterus. About 10 percent of all cervical cancers begin in the back of the cervical canal, but cell samples are rarely taken from this area.
Nice To Know:
It’s a good idea to take a panty liner or thin sanitary pad when having a Pap smear. Light bleeding or spotting may occur afterward.
Nice To Know:
Test kits are available that allow a woman to give herself a Pap test. These tests can be done at home but they
Who Analyzes A Pap Smear?
At the laboratory, a Pap smear is examined by a cytotechnologist, a professional specially trained to recognize abnormal cells that could indicate the presence of cancer or a precancerous condition.
If the cytotechnologist spots something suspicious, a pathologist, a doctor who specializes in identifying diseases under a microscope, studies the slide and classifies the cell sample.
Is The Laboratory Reputable?
Make sure that the cell sample is evaluated and classified by a laboratory accredited by the American College of Pathologists or another professional or governmental accrediting group.
If the laboratory is accredited,
- the facility has been inspected by independent professionals
- laboratory personnel use recognized quality control and quality assurance techniques
- pathologists and cytotechnologists who analyze Pap smears have the training and experience to recognize cell abnormalities
Questioning Laboratory Credentials
Ask the doctor about the credentials of the laboratory evaluating the Pap smear. Ask for
- the name of the laboratory
- where the laboratory is located
- whether the laboratory is accredited
- when the laboratory was last inspected
- whether the doctor has a good relationship with the professionals who will examine and classify the cell sample
- a copy of the Pap examination report
- an explanation of Pap smear results.
Nice To Know:
To find out whether a specific laboratory is accredited to examine PAP smears, call the College of American Pathologists Public Information Service at 1-800-LAB-5678.
If your Pap smear is being sent to a lab that isn’t accredited, you may request that it be sent to an accredited lab.
Nice To Know:
All laboratories that process Pap smears must comply with the stringent requirements of the Clinical Laboratory Improvement Amendments of 1988.
How Are Pap Smear Results Classified?
Laboratories use one of two systems to classify Pap smear results.
Traditional Reporting System
The older system classifies each cell sample as
Mild, moderate, or severe abnormality
Suspicious for an invasive cancer, that is, cancer that is likely to infiltrate and destroy surrounding tissue
The Bethesda System
Developed during a conference of cancer specialists at the National Institutes of Health (NIH), this newer system is replacing the older classification method.
The Bethesda System classifies the adequacy of cell samples as
It describes epithelial cells as
- benign or noncancerous
The Bethesda System further classifies abnormal epithelial cells – the cells that make up the mucous membrane that lines the
squamous cellsof unknown significance (ASCUS)
- low-grade squamous intraepithelial
- high-grade squamous intraepithelial lesion (HSIL)
Abnormalities in cells that line the glands of the cervix may be
- atypical glandular cells of undetermined significance (AGUS)
- adenocarcinoma, that is, cancer of the glandular cells of the cervix
How Are Pap Smear Results Reported?
Laboratories generally report Pap smear results to the doctor a few weeks after the test is performed. The doctor then
- calls the patient to notify her of her test results
- mails test results to the patient
- makes the results available to the patient upon request
Do not assume the test was normal if the doctor doesn’t call or mail results.
Need To Know:
A woman who has had a Pap smear should always know and understand her test results. Finding out what those results are can
Nice To Know:
Laboratories hold onto Pap smear results for only three years. The patient may ask the doctor for copies of the test results. It may be useful to keep a file of test results so that they can be compared to later results.
How Accurate Are Pap Smear Results?
The Pap smear is the most effective cancer screening method in medical history. But even the most conscientious laboratories sometimes classify normal cell samples as suspicious or overlook abnormalities among the half million cells on each slide.
This may be due to the fact that using the conventional Pap testing technique:
- as much as 80 percent of every cell sample is discarded when the health care provider throws away the swab or spatula used in collecting it
- the small fraction of a cell sample that’s smeared onto a glass slide and sent to a laboratory for microscopic analysis may not include abnormalities that are present in the discarded cells
- blood, mucus, and inflammation make it difficult or impossible for technicians to accurately analyze as many as two of every five slides
- cells or slides can dry out and become distorted.
Suspicious Test Results
The Pap smear cannot prove that a woman doesn’t have cervical cancer. It can detect 95 percent of all cervical cancers and abnormalities like
squamous cellsof undetermined significance (ASCUS). Vaginal infection or human papillomavirus (HPV) causes these slight abnormalities in the flat (squamous) cells on the surface of the cervix.
- atypical glandular cells of undetermined significance (AGUS).These slight changes can occur when cells on the surface of the cervix or in the cervical canal become infected or abnormal.
- low-grade squamous intraepithelial
lesion(LSIL). A woman who has this common cervical abnormality is likely to also have anHPV infection, even if she and her sexual partner are monogamous and she has never had any visible warts. Most cases of LSIL can be successfully treated. The condition may get better without treatment, but 30 to 50 percent of women with untreated LSIL develop cervical cancer within five years.
- high–grade squamous intraepithelial lesions (HSIL). This highly curable condition may consist of benign (noncancerous) abnormalities or cancer cells that have not spread beyond the point where they originated. A doctor who detects HSIL performs
colposcopyor a biopsyto more accurately identify the abnormality. HSIL is also known as carcinomain situ.
- hyperkeratosis. Dried skin cells sometimes appear on the surface of the cervix of a woman who has had a cervical infection or has used a cervical cap or diaphragm. A doctor who detects hyperkeratosis recommends that the woman have another Pap smear in six months. If hyperkeratosis is still present at that time, the doctor may recommend a third Pap smear in six months or perform colposcopy.
Nice To Know:
Understanding Why Errors Occur
Experts agree that the conventional Pap test has a certain irreducible error rate. That means that even the most conscientious laboratories will sometimes
Why do errors occur?
Factors that affect the accuracy of any Pap test include whether the healthcare provider performing the screening
and whether the laboratory technologist analyzes the cell sample accurately.
False negatives. False negatives incorrectly indicate that the Pap smear is normal even though cancer or precancer is present. Inadequate sampling and improper slide preparation may be responsible for 90 to95 percent of all false negatives. They can also result from failure to recognize or correctly classify abnormal cells
False positives. False positives incorrectly indicate that cancer or precancer is present in a normal cell sample.
Between 10 and 60 percent of all Pap smears are incorrectly analyzed. False negatives, which are far more common than false positives, may be reported 20 and 45 percent of the time. A gynecologist or family doctor who doubts the accuracy of any Pap smear report will repeat the screening and perform any appropriate diagnostic procedures.
The United States Food and Drug Administration (FDA) has approved three new technologiesdesigned to
- improve screening accuracy by changing the way microscope slides are prepared and analyzed
- eliminate the inconvenience, anxiety, and expense of having to repeat tests when cell samples are compromised
These new technologies are
The only method approved to replace the conventional Pap smear is the ThinPrep Pap Smear. Unlike rescreening technologies that reevaluate cell samples a technician has classified as abnormal, the ThinPrep Pap changes the way cell samples are placed on a slide and prepared for analysis.
After collecting cells in the usual way, the healthcare provider using the ThinPrep Pap Test
- rinses the entire collection device into a vial of preserving solution
- sends the vial to a laboratory for microscopic analysis
At the laboratory
- the ThinPrep 2000 processor purifies the cell sample by reducing the amount of blood, pus, yeast, bacteria, mucus, inflammation, and other material it contains
- deposits a thin, even layer of processed cells onto a slide that a cytotechnologist will analyze
Studies indicate that the ThinPrep Pap Test can
- detect 65 percent more low-grade and more severe abnormalities in the general population
- detect six percent more abnormalities in women with cervical cancer risk factors
- reduce the number of inadequate cell samples by more than 50 percent
Cervical cancer experts are debating whether the ThinPrep Pap Test
- is likely to have a significant impact on cervical cancer prevention
- is the best way to improve cervical cancer screening technology
This system was initially used as a secondary or rescreening device to evaluate slides technologists had already examined. In 1998, the FDA approved AutoPap for use in screening smears before a doctor or technologist analyzes them.
In one study of more than 25,000 cell samples, this system identified 33 percent more suspicious cells than conventional screening.
AutoPap is the only technology approved for primary Pap screening. Technologists now provide secondary support, examining every smear AutoPap has analyzed.
Approved by the FDA for secondary Pap smear screening, PapNet reevaluates cell samples a technologist has classified as abnormal.
This computerized system
- focuses on areas of the slide where abnormal cells are most likely to be found
- takes 128 pictures of the cells
- projects magnified images onto a high-resolution video screen for review by a technician
Nice To Know:
Words of caution
The American College of Obstetricians and Gynecologists has
Nice To Know:
The HPV test
Approved by the FDA in 1999, the Hybrid Capture II test may
What Do Abnormal Pap Test Results Mean?
At least half of all women (50 to 80 percent) whose Pap smears are classified as abnormal
- don’t have cervical cancer
- don’t have a condition that will become cervical cancer
For a woman who has regular Pap smears, abnormalities detected by the test are most apt to be very early precancers. It can take as long as 10 years for these conditions to become cancerous.
The Pap smear is a screening procedure. It is used to detect cervical abnormalities in women who do not have any symptoms. It is not a diagnostic test. Diagnostic tests are performed to identify the cause of symptoms a woman is experiencing. The Pap smear can indicate the presence of abnormal cells but cannot indicate what conditions those abnormalities represent.
Abnormal Pap smear results do not
- identify the abnormality
- indicate whether treatment is necessary
- indicate what treatment is most appropriate
Abnormal Pap smear results do indicate the need for
- repeat screening
- diagnostic testing
Need To Know:
If your Pap smear reveals cancerous or precancerous abnormalities, you should have another Pap smear to
What Happens If A Second Pap Smear Shows Abnormal Results?
If the second screening indicates that abnormalities are still present, the woman’s doctor may perform one of the following diagnostic procedures.
Colposcopic biopsy. The doctor uses forceps to remove about 1/8 inch of tissue from an area of the cervix where abnormal cells have been detected. The doctor may use local anesthetic to numb the cervix, and a woman who undergoes this office procedure may briefly experience pain, mild cramping, or light bleeding.
Cone biopsy. This procedure consists of removing a cone-shaped piece of cervical tissue from the border between the
Endocervical curettage. Also called endocervical scraping, this procedure is used to remove cells from the endocervix. After using local anesthetic to numb the cervix, the doctor inserts a narrow instrument called a curette into the passage between the outer part of the cervix and the inner part of the
Generally performed at the same time as colposcopic biopsy, this procedure removes cells from the part of the uterus the colposcope cannot see. A woman who has endocervical curettage may experience menstrual-type cramping or light bleeding for a short time afterward.
What Happens If A Biopsy Shows Abnormal Results?
If biopsy indicates that a woman has cervical cancer, her family doctor or gynecologist will refer her to a cancer specialist called an oncologist. This cancer specialist will initiate appropriate treatment.
Need To Know:
A woman who has been treated for an abnormal condition detected by a Pap smear must be retested every three months for a year. If none of those screenings detect any abnormality, her doctor may say she needs to be tested only once a year.
A pregnant woman whose Pap smear is abnormal but whose diagnostic testing doesn’t suggest cancer can safely postpone definitive examination and biopsy until six weeks after her baby is born.
PAP Smear: Frequently Asked Questions
Here are some frequently asked questions related to Pap smear.
Q: Who should have a Pap smear?
A: Every girl or woman who is at least 18 years old and who is or has been sexually active should have regular Pap smears.
Q: How often should a girl or woman have a Pap smear?
A: She should have an annual Pap smear unless her doctor advises her to be tested more or less frequently.
Q: Can a Pap smear prove whether a woman has cancer?
A: No. A Pap smear can detect abnormal conditions of the
Q: Why are regular Pap smears so important?
A: Regular Pap smearing is the only way to detect early cervical cancers and conditions that could become cancerous.
Q: What happens if Pap smear results are abnormal?
A: The doctor will perform a second Pap screening. If the results of this procedure are also abnormal, the doctor will perform diagnostic procedures to identify the condition.
Q: Should a woman who is pregnant have a Pap smear?
A: A Pap smear is performed during a woman’s first prenatal visit with her obstetrician. If a woman who is pregnant has an abnormal Pap smear, her doctor will perform a
PAP Smear: Putting It All Together
Here is a summary of the important facts and information related to Pap smear.
- The Pap smear is the only procedure that can detect early cancerous or potentially cancerous conditions of the
- The Pap smear is a screening technique. It is used to detect abnormalities in women who do not have any disease symptoms. It is not a diagnostic procedure. Although the Pap test is a highly effective method of detecting cervical abnormalities, it cannot identify the abnormalities it detects.
- The Pap smear cannot prove that a woman doesn’t have cervical cancer.
- A girl or woman who is at least 18 years old or who is or has been sexually active should have a Pap smear every year unless her doctor says she should be tested more or less often.
- Having regular Pap smears is the most important thing a woman can do to protect herself from cervical cancer.
PAP Smear: Glossary
Here are definitions of medical terms related to Pap smear.
AGUS: Stands for Atypical Glandular Cells of Undetermined Significance. This diagnostic category indicates that light changes in cells in cervical glands have been seen under the microscope.
ASCUS: Stands for Atypical Squamous Cells of Undetermined Significance. This diagnostic category indicates that slight changes in flat cells on the surface of the cervix have been seen under the microscope.
Biopsy: Removal of a small sample of living tissue that will be examined under a microscope to determine whether disease is present
Carcinoma: Same as cancer; an uncontrolled growth of cells that tends to invade surrounding tissue and spread to other locations
Cervix: The lower third of the uterus or womb. The cervix projects into the vagina and contains the canal through which sperm enter, menstrual flow exits, and babies are born.
Chlamydia: A sexually transmitted disease
Colposcopy: An examination of the vagina with a colposcope, an instrument that has a light source and lenses that project the inner surface of the vagina and cervix onto a television monitor
Ectocervix: The part of the cervix closest to the vagina
Endocervix: The part of the cervix closest to the body
Epithelium: A lining membrane
Fallopian tubes: The two ducts between the uterus and the ovary through which eggs made in the ovary travel to the uterus
Human papillomavirus (HPV): A virus that causes warts on the skin and mucous membranes, causes genital warts, and is implicated as a cause of cervical cancer; it has nothing to do with HIV, the virus that causes AIDS
Lesion: A wound or injury
Ovary: The two ovaries produce the eggs for reproduction every month.
Pelvic examination: A noninvasive gynecologic examination to detect abnormalities in female reproductive organs
Squamous cells: Flat, scale-like cells of the inner lining of the cervix
Spermicide: Any of various contraceptive creams inserted into the vagina before sexual intercourse to kill sperm and prevent pregnancy
Uterus: The womb. If a fertilized egg is implanted in the uterus pregnancy begins. If the monthly egg is not fertilized, menstrual flow occurs from the uterus
Vagina: The canal that leads from the outer opening in a woman’s reproductive system to the mouth of the cervix
PAP Smear: Additional Sources Of Information
Here are some reliable sources that can provide more information on Pap smear.
American Cancer Society
National Cancer Institute Cancer Information Service
Helpful Web Articles
Pap Smears: What, Who, Why & When
Understanding your Pap Smear: Limiting Factors
from the American Society of Clinical Pathologists, Chicago, Illinois
These two articles from the ASCP give thorough, easy-to-understand coverage of Pap Smears and an explanation of why they are sometimes analyzed inaccurately.
Reproductive System Tests from Women’s Health Interactive
Good, user-friendly information about how the test is performed, and what a girl or woman can do to make it as comfortable and effective as possible.
Nice To Know:
National Cervical Cancer Public Education Campaign
Sponsored by the American Medical Women’s Association, the National Cervical Public Education Campaign is dedicated to providing women with the most current information concerning
The 2000 Campaign has partnered with online services and others to create the first Internet-based cervical cancer public education campaign. The effort aims to reach at least 5,000,000 women with life-saving information they can discuss with their healthcare providers.