Pap test: overview

• What is a Pap test?
• What is a pelvic examination?
• Who should have Pap tests?
• How do you prepare for a Pap test?
• How accurate are Pap tests?
• How are Pap tests graded?
• How often should Pap tests be done?

What is a Pap test?

A Pap test (named after Dr. George Papanicolau) is a test for cervical cancer.

During a Pap test, the health practitioner inserts a speculum into the vagina to visualize the cervix, and then scrapes some cells from the cervix, which are applied to a glass slide and submitted to the lab.

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What is a pelvic examination?

A pelvic examination is performed in order to detect palpable abnormalities (ones that can be felt) in the pelvic area. In a pelvic examination, the health practitioner inserts 2 fingers into the vagina, places their other hand onto the low abdomen and pelvis, and palpates (presses) the ovaries and other tissues between their hands.

It's very important to note that a Pap test is not the same thing as a pelvic examination, and that during a pelvic examination a doctor does not always do a Pap test.

If you're not sure whether you need a Pap test or a pelvic examination or both at the time of your visit to the health practitioner, make sure to ask.

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Who should have Pap tests?

Women should get regular Pap tests when they start having sexual relations; whether or not they are having sex yet, they should have regular Pap tests by the time they reach the age of 18 or 21 (recommendations depend on the province they live in).

After that, the schedule varies according to risk factors (see below).

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How do you prepare for a Pap test?

In a premenopausal woman, the best time to do a Pap test is during mid-cycle. You should try not to have a Pap test during your period because blood on the slide will make the reading unreliable.

As well, anything else that might interfere with the ability to obtain an accurate specimen from the cervix - intercourse, cervical manipulation, spermicidal foams and jellies, douching, using vaginal medications, and so on - should be avoided for 1 to 2 days before the test.

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How accurate are Pap tests?

Like all medical tests, Pap tests results are not 100% accurate.

Pap tests can fail to detect a precancerous or cancerous change when one is present, and can also report changes in the cervical cells when in fact there is nothing amiss.

Getting regular Pap tests is vital in reducing the consequences of these errors.

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How are Pap tests graded?

To understand Pap test results, it's important to know that the cells that line the cervix and the ones most often "scraped" in a Pap test are squamous cells, and that roughly 90% of cervical cancers occur in squamous cells as squamous carcinomas. When the glandular cells on the inside of the cervix become cancerous, these cancers are known as adenocarcinomas.

Results that do not require follow-up are reported as within normal limits or benign cellular changes.

Overall, about 1 in 10 Pap tests come back with abnormal results, but most of these are due to inflammation and not to a precancerous or cancerous change.

When the Pap test detects abnormally inflamed tissue, 2 different reporting systems are used to detail the changes, which will be reported as either atypical squamous cells of undetermined significance (ASCUS) or atypical dysplasia. These are followed with treatment for concurrent infection and either repeated Pap smears until the inflammation settles down or a colposcopy (a procedure in which the cervix is examined through a magnifying instrument, and during which biopsies are taken to determine that there is nothing more significant lurking in the cervix).

When the Pap test discovers inflamed glandular cells, the report will be atypical glandular cells of undetermined significance or atypical glandular cells. These are followed up with either more Pap smears or colposcopy and endocervical curettage (a procedure in which a biopsy is taken from higher up in the cervix).

More severe changes are reported as either low- or high-grade intraepithelial lesions (SIL), or as mild, moderate, or severe squamous dysplasia, or as CIN grades I, II, or III.

These are dealt with by treatment of any concurrent infection, watchful waiting, and more frequent repeats of the Pap smear (many milder changes return to normal eventually without requiring treatment), or colpsocopy.

For more advanced changes, therapy can consist of:

• cryosurgery (freezing the cells)
• lasers
• electric cautery
• a cone biopsy, during which the surgeon removes a cone-shaped slice of cervical tissue
• hysterectomy in selected cases, if required

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How often should Pap tests be done?

For many years, all women who are sexually active were advised to get Pap tests once a year, more often if the Pap test had detected an abnormality.

A yearly Pap test for every woman is no longer the universal standard. The general rule now is that a woman who has 2 normal Pap tests in a row, in consultation with her doctor, can reduce the rate at which she gets Pap tests to about once every 3 years, so long as she doesn't have extra risk factors for cervical cancer. This rule may vary depending on the province that you live in.

It's also very important to note that women over 65 suffer the highest rates of death to cervical cancer, but they get far fewer Pap tests than younger women do because not only are older women often reluctant to ask for this important screening test, but also physicians are not as rigorous about doing them on their older patients. Again, if you are not sure if you need a Pap test and pelvic examination, always ask your doctor.

Women who have had hysterectomies do not need routine Pap tests, unless they had cancer of the cervix, when they should continue to get regular Pap tests with scrapings taken from the vagina.

Also, always make sure to call your doctor's office to determine that your Pap test results have come back. Never depend on the adage that "No news is good news" because results can be lost or misplaced, so make it your responsibility to get your own Pap test results.

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