What is Pap Smear

[Extracted from eMedicine Health]

Cancer of the cervix (cervical cancer) is the second most common cause of cancer-related disease and death among women worldwide. The best way to detect cervical cancer is by having regular Papanicolaou tests, or Pap smears. (Pap is a shortened version of the name of the doctor who developed the screening test.) A Pap smear is a microscopic examination of cells taken from the cervix.

A Pap smear can detect certain viral infections (such as human papillomavirus [HPV]) and other cancer-causing conditions. Early treatment of these conditions can stop cervical cancer before it fully develops. A woman may have cervical cancer and not know it because she may not have any symptoms.

The incidence of cancer and deaths from cervical cancer has significantly declined over the years because of prevention, screening, and early detection by the Pap smear. In the United States, about 2-3 million abnormal Pap smear results are found each year. Most of them indicate the early stages of disease and need reasonable observation by a doctor.



a) Risks factors for cancer of the cervix include the following :

i) Multiple sexual partners (or sexual partners who have had multiple partners)

ii) Starting sexual intercourse at an early age

iii) Viral infection, such as HPV, human immunodeficiency virus (HIV), or herpes simplex virus (HSV)

iv) Weakened immune system

v) Previous cancer of the lower genital tract

vi) Smoking

Cervical cancer screening is recommended yearly starting when women are aged 18 years, or when they become sexually active if younger than 18 years. Physicians may screen a woman less frequently if she had negative Pap smear results 3 years in a row or is not sexually active.

No upper age limit for screening exists because the incidence of cancer of the cervix increases with age at a time when women may be less likely to get a Pap smear. Diagnosis of most of these cancers is in women older than 50 years. Even after menopause, a woman should continue to have regular Pap smears.

b) The National Cancer Institute encourages women aged 65 years and older to get a Pap smear at least every 2 years (Medicare covers the cost), and every year if they are at higher risk and advised by their doctor. Many older women believe they no longer need Pap smears (and think they are not at risk for cervical cancer) because of their age, because they may not be sexually active, or because they have had a hysterectomy. That is not correct. These women need Pap smears because their risk is higher.

If a woman has had her uterus removed, she should still have yearly screening if there is a history of abnormal Pap smear results or other lower genital tract cancer.



Pap Smear Preparation

The best time to have a Pap smear is when the woman is not menstruating. A woman could ask for a female doctor if that would make her feel more comfortable.

For 2 days before the test, avoid the following because these might hide any abnormal cells :

** Intercourse
** Douches
** Vaginal medications (except as directed by your doctor)
** Vaginal contraceptives such as birth control foams, creams, or jellies

A Pap smear is usually part of a pelvic exam and accompanied by a breast exam performed by the health care provider. It should only take about 1 minute to perform a Pap smear during this overall exam.

a) The woman will lie on the examination table on her back with her knees up and bent and her feet in stirrups (rests). While she is lying on an examination table, her health care provider will use a small metal or plastic instrument called a speculum to open the vagina so that the walls of the vagina and cervix can be seen clearly.

b) A sample of mucus and cells will be obtained from the cervix (the part of the uterus that extends into the vagina) and endocervix (the opening of the cervix) using a wooden scraper or a small cervical brush or broom.

c) The sample of cells is evenly applied to a glass slide and sprayed with a fixative. This sample is sent to the lab for close and careful examination under a microscope. If the doctor is using a new kind of Pap smear called a ThinPrep test, the sample is rinsed into a vial and sent to a lab for slide preparation and examination.

d) A cytologist (a specialist trained to look at the cells and interpret a Pap smear) reviews both types of tests.

e) Some discomfort during the test may occur. Most women feel nothing at all or feel pressure. Staying relaxed will help stop any discomfort. The woman should breathe slowly and concentrate on relaxing her stomach and legs.

f) A Pap smear should not be painful. If experiencing pain during the test, the woman should tell her doctor.



After the Procedure
The health care provider sends a letter with test results. If there is a problem, the woman's provider may contact her. For peace of mind, she can also call the clinic to get the results. Before leaving after the exam, she can ask how long it takes the office to receive the lab report.

A negative or normal test finding means that the cervix looks healthy. All the cells are of a healthy size and shape.



A positive or abnormal test finding means that something unusual is in the sample. The test found cells of a different size and shape.

1) An abnormal Pap smear result does not always indicate cancer. Cells sometimes appear abnormal but are not cancerous. The woman will have to return to the clinic for follow-up care.

2) Remember that abnormal conditions do not always become cancerous, and some conditions are more of a threat than others.

3) An infection of the cervix may cause a positive test result. A yeast, trichomonas, chlamydial, or gonorrheal infection can cause the cervical cells to appear inflamed. After the infection is treated, the Pap smear result usually returns to normal.

4) Human papillomavirus (HPV) can also cause a test result to be positive. This virus may exist on the cervix or in the vagina and causes genital warts. Many types of HPV have been identified, and some are associated with cervical cancer. If the woman has HPV, she has a higher risk of developing cervical cancer.

5) The smear result may be positive because it shows changes that may become cervical cancer.

6) If a woman has an abnormal Pap smear result, a repeat test should be done every 4-6 months for 2 years until 3 consecutive negative tests have been obtained.

7) If the Pap smear result is positive because of an infection, the underlying cause should be treated. The test should then be repeated in 2-3 months, because cancer of the cervix can be hidden by an infection. A check-up with a doctor is necessary.

8) Although the Pap smear is the best method of detecting cervical cancer early, it is not perfect. Because even the best labs can miss some cell changes, a woman should have the test performed yearly, as the American Cancer Society recommends.

9) Recently, 2 computerized systems (PAPNET and AutoPap) have been approved by the US Food and Drug Administration to detect abnormal cells from a Pap smear. To ensure accuracy of the test, they use computer technology to recheck Pap smears for abnormal cells the technician may have missed. These tests cost more than a normal Pap smear, but they can be helpful if the woman is at high risk for cervical cancer. Consult a doctor about these methods.

Most laboratories in the United States use a standard set of terms called the Bethesda System to report, or interpret, test results. Under the Bethesda System, Pap smear samples that have no cell abnormalities are reported as "negative for intraepithelial lesion or malignancy" (meaning the woman does not have cancer).

Samples with cell abnormalities fall into the following categories (as outlined by the National Cancer Institute) :

a) ASC (atypical squamous cells): Squamous cells are the thin, flat cells that form the surface of the cervix. The Bethesda System divides this category into the following 2 groups :

i) ASC-US (atypical squamous cells of undetermined significance): The squamous cells do not appear completely normal, but doctors are uncertain what the cell changes mean. Sometimes the changes are related to HPV infection. ACS-US are considered mild abnormalities.

ii) ASC-H (atypical squamous cells cannot exclude a high-grade squamous intraepithelial lesion): The cells do not appear normal, but doctors are uncertain what the cell changes mean. ASC-H may be at higher risk of being precancerous.

b) AGC (atypical glandular cells): Glandular cells are mucus-producing cells found in the endocervical canal (opening in the center of the cervix) or in the lining of the uterus. The glandular cells do not appear normal, but doctors are uncertain what the cell changes mean.

c) AIS (endocervical adenocarcinoma in situ): Precancerous cells found in the glandular tissue.

d) LSIL (low-grade squamous intraepithelial lesion): Low-grade means there are early changes in the size and shape of cells. The word lesion refers to an area of abnormal tissue. Intraepithelial refers to the layer of cells that forms the surface of the cervix. LSILs are considered mild abnormalities caused by HPV infection.

e) HSIL (high-grade squamous intraepithelial lesion): High-grade means that there are more marked changes in the size and shape of the abnormal (precancerous) cells, meaning the cells look very different from normal cells. HSILs are more severe abnormalities and have a higher likelihood of progressing to invasive cancer.

When to Seek Medical Care
Early cervical precancers and cancer often have no signs or symptoms. Therefore, it is important to have regular Pap smears. Symptoms usually appear when the cancer has progressed.

The following symptoms must be reported to a health care provider right away :

* Unusual vaginal discharge
* Blood spots or light bleeding other than a normal period
* Bleeding or pain during sex

These symptoms do not conclude that someone has cancer. Other conditions may cause these symptoms, but a check-up is necessary to determine the cause.