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.