Newer techniques that employ liquid-based cytology (e.g., ThinPrep) have been developed to improve the sensitivity of screening. As with the Papanicolaou (Pap) test, the optimal studies to determine the sensitivity and specificity of these technologies have not been done. Some less than optimal studies show that sensitivity is modestly higher for detecting any degree of cervical intraepithelial neoplasia, with modestly lower specificity.[1,2] One careful study, however, showed that conventional Pap testing was slightly more sensitive and specific than liquid-based cytology.[3]

The evidence is also mixed about whether liquid-based techniques improve rates of test adequacy.[1,2] One advantage of liquid-based cytology is that human papillomavirus testing (see below) can be done on the same preparation; one disadvantage is that liquid-based approaches are more expensive than conventional Pap testing. No study has examined whether liquid-based cytology actually reduces the number of women dying of cervical cancer compared with conventional Pap testing.

References

1. Hartmann KE, Hall SA, Nanda K, et al.: Screening for Cervical Cancer. Rockville, Md: Agency for Health Research and Quality, 2002. Available online ¹. Last accessed February 20, 2007. 
   
   
2. McCrory DC, Matchar DB, Bastian L, et al.: Evaluation of Cervical Cytology. Rockville, Md: Agency for Health Research and Quality, 1999. Evidence Report/Technology Assessment No. 5. AHCPR Publication No. 99-E010. Also available online ². Last accessed February 20, 2007. 
   
   
3. Coste J, Cochand-Priollet B, de Cremoux P, et al.: Cross sectional study of conventional cervical smear, monolayer cytology, and human papillomavirus DNA testing for cervical cancer screening. BMJ 326 (7392): 733, 2003.  [PUBMED Abstract]