Liquid-based cytology detects more cervical cancer

Liquid-based cytology detects more cervical cancers than conventional cytology in Pap smears and also reduces the percentage of unsatisfactory smears, according to the results of two studies published online June 29 in BMJ.

In the first study, Elizabeth Davey, MBBS, MPH, from the University of Sydney in Australia, and colleagues compared the accuracy of conventional cytology and liquid-based cytology using a computerized reading system, the ThinPrep Imager, on Pap smear samples from 55,164 Australian women.

The researchers found that the computerized system detected 1.29 times more high-grade squamous disease per 1,000 women screened compared with conventional cytology. Only 1.8% of slides were unsatisfactory for imaging compared with 3.1% for conventional cytology. More of the image-read slides contained low-grade cytological abnormalities, the report indicates.

Ronco's team found that liquid-based cytology detected more lesions but was not significantly better than conventional cytology in detecting lesions of grade 2 or higher. There was a large reduction in unsatisfactory smears, the authors note.

Davey E, d'Assuncao J, Irwig L, et al. Accuracy of reading liquid based cytology slides using the ThinPrep Imager compared with conventional cytology: prospective study. BMJ. 2007;335:31.