Liquid-Based Cytology Is as Effective as Conventional Smears

The routine Papanicolau (Pap) test has been compared to liquid based cytology to evaluate the efficiency and effectiveness of systems based on cytocentrifugation. The sensitivity and specificity of the liquid-based gynecological system was assessed.

In a study carried out at Vilnius University, (Vilnius, Lithuania), 2,945 women referred to prophylactic check-up were enrolled. Split sample design was used in 1,500 women and residual cervical cytology specimen from all these cases was placed in fluid for cytocentrifugation preparation after performing conventional smears. The centrifugation was performed in a low speed centrifugal force device called the Shandon PapSpin. The direct-to-vial study was carried out in another cohort of 1,445 women in whom the entire cervical material was investigated using only the PapSpin technique.

In the split sample group, conventional smears showed a higher proportion of atypical cells undetermined significance (ASC-US): 2.1% compared to 0.7% in the PapSpin samples. A higher proportion of unsatisfactory samples were found in the conventional smear group1.7% compared to 0.4% of cases in the device group. In the split sample group, the sensitivity of the conventional and PapSpin tests was 68.7% versus 78.1%, and the specificity 93.8% versus 91.8%, respectively. In the direct to vial group, PapSpin sensitivity was 75.9% and specificity 96.5%. The Shandon PapSpin is manufactured by Thermo Shandon (Pittsburgh, PA, USA).

The PapSpin method offers several advantages such as the opportunity to prepare duplicate slides, option for Human Papilloma Virus (HPV) DNA testing and cell block preparations from residual material. Microscopic evaluation of thinner cell preparations is less time consuming than the conventional Pap smears. The study was published online in March 2010, in Cytology Journal.

Related Links:
Vilnius University
Thermo Shandon