Use of the Thin Prep (R) Pap Test (TM) in clinical practice

The Thin Prep(R) Pap Test(TM) (Cytyc Corp., Boxborough, MA) received approv al by the Food and Drug Administration in May 1996 as an alternative to the traditional conventional smear. The present direct-to-vial study assessed the utility of thin-layer technology for cervicovaginal screening in clinic al practice. From May 1997-February 1998 (10 mo), 15,006 cervical smears we re processed and evaluated; of these, 5.423 (36.1%) were conventional smear s (CS) and 9.583 (63.9%) were Thin Prep slides (TP). Both methods were anal yzed to compare specimen adequacy and detection rates of cervical lesions. The TP method reduced the "satisfactory but limited by" rate by 97% and the unsatisfactory rate by 63%. For low-grade squamous intraepithelial lesions (LSILs), TP slides yielded 3.6% (348/9,583) as compared to 0.98% (53/5,423 ) for CS, an increase of 267%. The TP method detected a threefold increase in the number of high-grade squamous intraepithelial lesions (HSILs) of 1.0 % (100/9,583), as compared to 0.3% (17/5,425) for the CS group. The atypica l squamous cells of undetermined significance/squamous intraepithelial lesi on (ASCUS SIL) ratio was reduced by 54% in the TP group. In routine usage i n our laboratory, the Thin Prep(R) Pap Test(TM) yielded a significant incre ase in the detection of LSILs and HSILs as compared to conventional smears. Specimen adequacy was significantly improved Diagn. Cytopathol. 1999;20:70 -73. (C) 1999 Wiley-Liss. Inc.