Image Analyzer Identifies More Cervical Cancers

A new computerized test detects more high-grade cervical cancers than the conventional Papanicolaou (Pap) smear.

The test, dubbed the ThinPrep Imager (TIP), allows for longer time between screenings, which means that fewer women will be retested based on inconclusive Pap findings. The technology was based on developing imagers to read conventional smears. The imagers read an especially prepared liquid based sample (LBC). The process depends on placing the sample into a liquid preservative from which a monolayer of cells can be prepared. The sample is cleared of as much extraneous material (blood and inflammatory cells) as possible by filtration.

The Pap smear is one of the most commonly performed pathology tests. Unlike other high volume tests, it is still performed manually in much of the world. The technique persists even though the Pap test has a relatively low sensitivity for significant disease and an acknowledged false-negative rate. Used as a screening test, especially in an organized screening program, the Pap test has had a significant effect on the reduction in the incidence and mortality from cervical cancer.

In a study carried out by the cytology department at Douglass Hanly Moir Pathology (Sydney, Australia), medical director Dr. Annabelle Farnsworth and coworkers examined the computerized TIP reading system to evaluate liquid-based cytology slides. The imager highlights slides that need further examination were then examined by a cytologist.

In samples from 55,164 Australian women, the team found 1.3 more cases of high-grade cervical abnormalities per 1,000 women screened by the TIP than by the conventional Pap test. In addition, when using the TIP there were fewer unsatisfactory slides than with the conventional test--1.78% and 3.09 % respectively. The study findings were published in the June 30, 2007 issue of the British Medical Journal.

"Liquid-based cytology slides were always meant to be read by computerized technology,” said Dr. Farnsworth. "It [has] taken a long time for this to happen.”


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Douglass Hanly Moir Pathology