Pap smear

The Pap test is an examination of the cells of the cervix that are applied to a slide for microscopic examination after cell smear.

The goal of the Pap test is to find cellular changes that can lead to cervical cancer.
The cells are examined under the microscope to see if they are precancerous or malignant (carcinogenic) cells.

A Pap test is a simple, quick, and relatively painless screening.
This examination has prevented countless deaths from cervical cancer and is used to detect uterine tumors.


What is dysplasia?

Cells that cover the cervix can undergo mild or severe changes before they degenerate into cancer. These changes are called dysplasia. Dysplasia does not always lead to cancer.

Cervical cancer and human papillomavirus (HPV)

Cervical cancer is almost always associated with human papillomavirus (HPV), which is transmitted through contact between genitals and skin during sexual intercourse.

There are several types of human papillomavirus. Some strains cause warts on the hands, others papillomas on the feet. About 50 species infect the skin of the genitals. Some of them (types 6 and 11) can cause genital warts, which, although harmless, are uncomfortable.
Other types cause insidious or invisible infections.
Some high-risk HPV (most commonly types 16 and 18) can cause cervical cancer.

The majority of people infected with any of these types develop immunity and easily eliminate the virus from their body.
This may take a year or two, but therapy is not required.
In rare cases, the virus can persist in a woman’s cervical cells and cause changes in the cells. If these changes are not detected and treated, the woman’s risk of developing cervical cancer increases.
The first stages of the change in cervical cells do not cause symptoms. The only way to find out if abnormal cells are present on the cervix is the Pap test.

Risk factors for the development of cervical cancer

  • Presence of some human papillomavirus (HPV) on the cervix
  • Smoke
  • Existing sexually transmitted infections, such as chlamydia
  • Early age at first sexual intercourse
  • Early age at first birth
  • Number of sexual partners.

A Pap test is not used to detect ovarian cancer, any other type of cancer, or disease of the reproductive system. He also does not detect any sexually transmitted diseases.

What is cervical cancer?

Cervical cancer is an abnormal growth of the cells that cover the surface of the cervix uteri. The cervix is the lower and narrow part of the uterus. It connects the uterus to the vagina.

Who is at risk?

Women who have had sexual intercourse, many sexual partners, or more than three births at a young age carry a higher risk of cervical cancer.
Cervical cancer can occur at any age. The highest risk of cancer in the early stages is at the age of 30 to 40 years. The highest risk of invasive carcinoma is at the age of 40-50 years.

Who should have a Pap test?

For a woman, pregnancy is not an obstacle to a Pap test. Swabs for the Pap test can be done safely at any time during pregnancy.
The smear test is not indicated in women who have undergone a hysterectomy (removal of the uterus) due to a benign disease.
Women who have had a hysterectomy in which the cervix has not been removed, also called a subtotal hysterectomy, should continue screening in the same way as women who have not undergone a hysterectomy.
All women between the ages of 18 and 70 should have a Pap test every two years.
This also applies to women who have received a vaccination against HPV, because the vaccination does not protect:

  • against all types of HPV that can cause cancer,
  • against the papillomavirus, to which women were already exposed before vaccination.

When does the Pap test have to be done? How often should it be repeated?

In the UK, the first screening at the age of 25 is recommended.

Routine screening: England:
A normal check-up should be done every three years between the ages of 25 and 49, and every five years from the age of 65.

Discontinuation of the Pap test from the age
of 70 
Women who have had at least two normal results from a Pap test in the five years before age 70 may stop taking it. Women over the age of 70 who have not taken the two-year Pap test regularly or who have had an abnormal result in recent tests should continue the Pap test for a few years.

Why is the Pap test so important?

If a Pap test is performed regularly, cervical cancers can be detected early and precancerous changes can be treated.
Cervical cancer deaths have decreased by more than 30% over the past 60 years, mainly due to regular screening using Pap testing.
Many women who developed cervical cancer never had a Pap test.
If a regular Pap test and, if necessary, early treatment is performed, most tumors on the cervix can be prevented.
Research has shown that with regular Pap testing, the individual is more likely to survive cervical cancer.
With early detection, the possibility of curing cervical cancer is very high.

The screening

To prepare for the examination, sexual intercourse and vaginal washes must be avoided 2 days before the Pap test.
The examination must not be carried out 4-5 days before and 4-5 days after the menstrual period.
A disposable speculum made of plastic (or heated metal) is inserted through the vagina to detect the scale epithelium in the cervix.

Liquid cytology (LBC) is the method of choice today.
A brush (instead of a spatula) is used, which is rotated on the scale epithelium (usually in the cervical canal).
There are two different systems of LBC.
Both systems use similar brushes.
In one, the brush head containing the cells is immersed in a small ampoule containing a special preservative liquid.

The head is then sent to the laboratory in this ampoule (this is the method according to SurePath®).
The brush is then rinsed in the preservative so that the cells remain in the vial.
After that, the brush is discarded (this is the method according to ThinPrep ®).
The time to receive the data is short, the results are sent to the patient and are available to him after about two weeks.
In the old smear methods, a brush or wooden spatula is used to remove tissue from the cervix.
The instruments are rotated twice 360° on the cervix to obtain cells.
In both methods, material is obtained that is smeared on a slide and sprayed or wetted with a fixing solution before being transported to a laboratory.

How to interpret the Pap test, guidelines

The cervical cells undergo a series of changes before they degenerate cancerously.
The time interval between two Pap tests depends on the type of problem you’re suffering from.

Interpretation of smear results
The cells are analyzed in the laboratory, looking for nuclear abnormalities and other cellular characteristics.
There is no uniform procedure for laboratories, but a report must show the following results:


The endocervical cells have normal nuclei.

The national average rate for inappropriate smears is about 9%. Inappropriate smears may result from material that is inadequate or illegible, poorly fixed or underdistributed on the slide, or contains pus, blood or inflammatory exudate, or shows complete cell dissolution (may occur due to hormone treatment).

Positive Pap test

Borderline: About 5% of the swabs are borderline. The cells have a nuclear abnormality, but the pathologist cannot say with certainty that there is evidence of dyscariosis.
Many of these patients show normal smears in the future.
Infection with human papillomavirus (HPV) sometimes occurs in this group of patients. Very few of these patients develop cancer.

Mild dyscariosis: This is present in about 4% of smears. Cells with mild nuclear abnormalities usually regress on their own and show normal smears again in the future.
An HPV infection is common.
The system for classification for cervical neoplasms (CIN) must not be applied to smears, but to material from a cervical biopsy obtained during a colposcopy. Nevertheless, mild cell dysplasia usually corresponds to CIN 1.

Moderate dyscariosis – Usually the CIN corresponds to 2 and can be detected in about 1% of the samples. CIN 2 is considered a precancerous disease and speaks for a medium probability of developing cancer.

High-grade dyscariosis – Equivalent to CIN 3. This is present in about 0.5% of swabs and corresponds to an increased risk of cancer.
About 0.1% of smears show nuclear changes and other typical cancerous changes.

Glandular neoplasms – Rarely one sees abnormalities of glandular cells that may indicate to:

  • adenocarcinoma in situ,
  • adenocarcinoma of the cervix,
  • adenocarcinoma of the endometrium,
  • Adenocarcinoma of an extrauterine organ.

Pap Test Reliability

Unfortunately, the test is not always reliable, because in about 15% of cases the results are false negatives, while about 10% of examinations have a false positive.

Dealing with the results

Negative (normal)
One should:

  • Look for and treat possible diseases, such as infections.
  • Conduct another preventive examination at the scheduled time if there is a negative result.

Immediately after treatment of infection or atrophy, repeat the examination, preferably within three months.
The Pap test must be repeated as soon as possible if it has been assessed as technically unsuitable.
If the result persists (three test samples are inadequate), an examination by colposcopy is recommended.

Borderline changes in the nucleus of endocervical cells need to be studied more thoroughly by colposcopy.

Borderline changes in the nuclei of the squamous epithelium:
It is necessary to treat other associated conditions and repeat the examination within six months (especially important if there is an infection by papillomavirus).
Most of the smears return to normal at this stage.

Colposcopy is required if three consecutive smears showed borderline changes in the nuclei in the squamous epithelium.
Before a woman can start routine preventive care again, a period of 10 years must pass.

Three consecutive negative results six months apart are a necessary prerequisite for returning to normal preventive care.
Repeat the test every three to six months if the differential diagnosis fluctuates between benign/reactive changes, if dyscariosis is high or glandular neoplasms have already occurred.

Mild dyscariosis
Ideally, in case of mild dyscariosis, the doctor prescribes colposcopy. However, one can also repeat the test within six months, as many have returned to normality at this stage.
After two tests with indications of mild dyscariosis, one must always resort to colposcopy before returning to normal preventive routine.
Three consecutive negative results six months apart are required before returning to normal preventive care routines.

If, after treatment of a carcinoma in situ phase 2 or a worse cancer, the Pap test shows a mild nuclear change, a colposcopy must be performed.
In some regions, women with borderline or mild dyscariosis are referred to a DNA test for HPV.
Women who test positive for high-risk HPV types should have a colposcopy immediately.
Research has shown that the DNA test for papillomavirus allows early detection of a grade CIN 2 lesion.
When these lesions are treated appropriately, it provides discreet protection against grade CIN 3 cervical tumors.

Types with a high risk of HPV (16, 18, 31, 33) are almost 100% present in all cervical tumors.
In contrast, women with a mild or borderline outcome who are not infected by the high-risk papillomavirus have a very low chance of developing cervical cancer.
The HPV test is not currently recommended for primary screening.

Pap test in older women
Menopause does not protect women from cervical cancer. In fact, the majority of cases of cervical cancer arise in women over 50 years of age. The most common type of cervical cancer develops over the period of 10 years. Older women mistakenly believe that the risk of cervical cancer is low, perhaps because they have become widows or are sexually inactive.

Lesbians and Pap test
Lesbian women should have a Pap test every two years, as the papillomavirus spreads through genital skin contact.

Long-lasting monogamy and Pap test
Many older women who have been married or have lived monogamous for decades believe that screening is only necessary for women who have had different sexual partners.

Pap test and long-term abstinence
Since cervical cancer is linked to sexual activity, some women who have remained unmarried for many years – such as some divorced women or widows – mistakenly believe that they are not at risk. It does not matter how much time has passed, you should have the regular Pap test done until the age of 70.

Pap test after hysterectomy
A hysterectomy is the surgical removal of the uterus. Women who need to have a regular Pap test after the procedure of a hysterectomy are those:

  • who still have their cervix,
  • in which the hysterectomy was due to a gynecological tumor,
  • have never had a Pap test done in their lives or regularly.

Some women undergo a hysterectomy due to cervical cancer. Even if the cancer has been completely removed by surgery, it is necessary to continue with a regular vaginal Pap test (usually every year), depending on the gynecologist’s recommendations.
Some women do not need to have Pap tests after a hysterectomy, for example in the following cases:

  • The operation was performed to treat non-carcinogenic diseases such as endometriosis, uterine prolapse or menstrual problems.
  • The cervix was taken during the hysterectomy (total or radical removal of the uterus).
  • Before the hysterectomy, the woman had had a Pap test regularly every two years, which showed no significant abnormalities.

Read more: