For over 30 years, screening for cervical cancer has used the conventional Pap smear. Despite the limited accuracy of the test, the incidence of cervical cancer has fallen substantially. Liquid-based cytology has been developed as an alternative and has been reported to increase the sensitivity of smear tests and decrease the proportion of slides that are unsatisfactory for assessment. However, in a review of 56 studies (1.25 million slides) Elizabeth Davey (University of Sydney, New South Wales, Australia) and colleagues conclude that there is no evidence that liquid-based-cytology reduced the proportion of unsatisfactory slides or detected more high-grade lesions than the conventional technique.
Dr Davey comments: "Although we did not find liquid-based cytology to be more accurate than conventional cytology, equivalent performance might be sufficient if liquid-based cytology has other advantages, such as the opportunity for concurrent HPV DNA testing, reduces reading times, or is more economical than conventional cytology."
See also accompanying Comment.
Contact: Dr Elizabeth Davey, Screening and Test Evaluation Program, School of Public Health, Edward Ford Building, A27, University of Sydney, NSW 2006, Australia. T) 61-29-351-6591, daveye@health.usyd.edu.au
The Lancet