General Information
Cervical Cancer Detection at Yale Pathology Cytoprep Laboratory
Since the introduction of the Pap smear test for the early detection of cervical cancer in 1941 there has been a 70% reduction in the cervical cancer mortality rate, the most significant reduction of mortality attributable to any modern medical test. The latest developments in cervical cancer detection technology promise to reduce this rate even further.
While instrumental in reducing mortality rates, the conventional Pap smear test does have limitations, including the occasional obscuration of cells on the slide by blood and/or inflammation and the deterioration of the cells through air-drying after the sample is smeared on a slide. Another problem is the routine discarding of a high percentage of cells that are thrown away in the doctor’s office on the sampling device. Liquid-based Pap test technologies are designed to overcome these limitations by placing the cervical sample immediately in a fixative vial, eliminating air-drying, and allowing for the transfer of a higher percentage of cells to the specimen container.
In the ThinPrep® Pap test, the first liquid based technology available, the cells are presented as a monolayer in a 20mm diameter circle that can be viewed by the cytopathologist with little in the way of obscuring blood and inflammation, offering a greater sensitivity in the detection of abnormality. In the alternative liquid-based Pap test, the AutoCyte PREP® System, gynecologic samples are collected with a brush that remains in the specimen vial; this virtually assures 100% transfer of the patient’s sample to the cytology laboratory. The increased sensitivity of either liquid-based test ensures that more slides are satisfactory for evaluation and reduces the number of unnecessary patient callbacks for repeat testing.
Another new technology, the FDA-approved AutoPap® Primary Screening System, has also been adopted at Yale as a means of improving accuracy in the laboratory. This is a computerized instrument that screens Pap smear slides through high-speed, high-resolution video microscopy. The system ranks slides according to the likelihood of abnormality, allowing up to 25% of Pap smears deemed normal to be “archived” without human review. The collective wisdom of leading pathologists has been programmed into screening algorithms to accurately identify abnormal cells. Clinical trials show that the AutoPap® system improves a laboratory’s ability to detect abnormal cervical cells, while also effectively assessing specimen adequacy.
Frequently Asked Questions
How do I prepare for the test?
Tell your health care provider (1) if you’ve had a prior abnormal Pap smear; (2) if you might be pregnant; and (3) if you are taking any medications, including birth control pills. Avoid douching, using tampons, having intercourse, and tub bathing 24 hours before the test. Empty your bladder just before the test.
What do the results mean?
Results are reported using the Bethesda Classification System
- Negative for Dysplastic or Malignant Cells (no abnormalities found)
- Atypical Squamous Cells of Undetermined Significance or ASCUS (abnormal findings, which may be related to a benign or a precancerous condition; follow-up recommended)
- Low Grade Squamous Intraepithelial Lesion (precancerous condition)
- High Grade Squamous Intraepithelial Lesion (precancerous condition)
- Carcinoma (malignant lesion)
When should Pap testing begin and how long should it continue?
Screening should begin when a woman becomes sexually active, requests contraception, or reaches the age of 18. Routine Pap tests should then be performed annually, as long as the previous Pap test was normal. Pap test screening should continue through the age of 65, and then may be reduced to once every 3 years as long as there are 2 consecutive Pap tests that were normal, and no other pre-existing risk factors or medical conditions are present.