Does the ThinPrep® Pap Test detect more abnormals than the conventional Pap smear?
FDA approval of the ThinPrep Pap Test as a replacement for the conventional Pap smear and the claim that the ThinPrep Pap Test is "significantly more effective" was based on extensive data submitted from a multi-site clinical trial. This study of 6747 women was conducted using a multi-site, double-blinded protocol. Performance based on initial screening was validated by independent pathologist review. The results of this study indicate that the ThinPrep Pap Test significantly increases the detection of low-grade or more severe lesions by 65% in screening populations and 6% for high risk populations when compared with the conventional Pap smear.

Does the increased detection with the ThinPrep Pap Test come at a loss in specificity?
No, studies done as part of the recent clinical trial showed that the improved detection of positive cases by the ThinPrep method did not cause increased false-positive diagnoses.

The ThinPrep Pap Test only examines approximately 70,000 cells with many more left unexamined in the vial. How do you know you are not leaving important cells unexamined?
The gentle mixing of the sample before preparing the slides ensures a thorough sampling of the cells present. As part of the validation of the ThinPrep Pap Test, ten or more slides were made from single vials. These studies showed that the first slide prepared from the vial is representative of the remainder of the material.

Conventional Pap smears have approximately 300,000 cells, and the ThinPrep slides have approximately 70,000. How can the ThinPrep method claim to be higher quality?
With a conventional Pap smear there is tremendous variability in the number of cells transferred to the slide, from as few as 4,000 to up to 300,000. When higher numbers of cells are on the slide they are often overlapping, or obscured by inflammation, blood or mucus. The sampling of the cervix by the conventional Pap smear is quite variable.

With the ThinPrep Pap Test, approximately 70,000 diagnostic cells are collected that provide a more representative sampling of the specimen taken from cervix. These are consistently displayed to the cytologist in a high quality preparation. In the clinical trials that led to FDA approval, the ThinPrep Pap Test detected more positive cases than the conventional Pap smear, proving that the ThinPrep Pap Test is significantly more effective than the conventional Pap smear in a variety of patient populations.

Does the ThinPrep method assist in the identification of infections and benign cellular changes?
Yes, the identification of infection and benign cellular changes can be made with the ThinPrep Pap Test.

Does ThinPrep Pap Test lose tumor diathesis which would make the diagnosis of cancer difficult?
Actually, tumor diathesis is preserved by the ThinPrep Pap Test. Tumor diathesis is the tissue necrosis that accompanies invasive cancer. Not all cancers have diathesis, but it is a useful feature for detection when present.

Can special stains be performed on slides prepared using the ThinPrep System?
Yes, silver or other histochemical stains as well as immunocytochemistry are readily performed on cells in the ThinPrep vial.

Can the ThinPrep System be used with computer rescreening technology?
Just as ThinPrep slides are easier for humans to examine, most computer imaging systems should be able to examine ThinPrep slides more quickly and more accurately. Preliminary studies with one system have shown this to be the case, but before computer systems are broadly used to examine ThinPrep slides, the manufacturers of computer systems will need to perform clinical trials, and seek FDA approval.

A conventional Pap smear is an established and trusted method and computer rescreening has been approved for the conventional Pap smear. Why should we switch to the ThinPrep Pap Test?
The ThinPrep Pap Test is a better quality test that detects more positive cases. There are several limitations to the conventional Pap smear, including poor sample preparation and difficulty in seeing abnormal cells obscured by blood, mucus or inflammation. The ThinPrep Pap Test improves both the sample preparation and the quality of the slides that are reviewed microscopically. Computer rescreening cannot solve the sampling problem associated with discarding most of the sample remaining on the collection device from preparing a conventional Pap smear.

Does Elkhorn Mountain Cytology provide training for laboratories and physicians implementing the ThinPrep Pap Test?
Training the physician office staff in the collection of the sample is accomplished by watching a brief videotape and/or a demonstration from the laboratory staff.

Cytyc Corporation has developed a very efficient training program for cytotechnologists and pathologists and most achieve proficiency after a few days of training.