The MonoPrep Pap test for the detection of cervical cancer and its precursors. Part I: results of a multicenter clinical trial.

The MonoPrep Pap Test (MPPT; MonoGen, Lincolnshire, IL) is a novel, liquid-based specimen collection and processing technology for cytologic and molecular testing. Its usefulness in the detection of cervical cancer and its precursors was evaluated in a multicenter, masked, adjudicated, split-sample study of 10,739 samples. After preparation of a conventional smear, the residuum on the collection device was rinsed into a collection vial from which an MPPT slide was prepared. Accuracy was assessed by masked reference interpretation by an independent pathologist. Slides prepared by MPPT, compared with smears, yielded statistically significant increases in relative sensitivity for atypical squamous cells of undetermined significance and worse, atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion/atypical glandular cells and worse, and low-grade squamous intraepithelial lesion and worse. There was no significant difference in relative specificity. MPPT provided a 58% reduction in unsatisfactory slides. There was no significant difference in the presentation of endocervical/transformation zone component or the detection of benign conditions. The MPPT is a promising new liquid-based technology for cervical cancer screening.

Testing automated liquid-based cytology samples with a manual liquid-based cytology method using residual cell suspensions from 500 ThinPrep cases.

We report a technical improvement upon a previously disclosed manual liquid-based cytology (MLBC) method; and, we use the improved method to prepare slides from residual ThinPrep specimens in order to see how often ThinPrep diagnoses correspond to diagnoses derived from exhaustive examination of their parent sample suspensions. Residual cell suspensions from 500 ThinPrep cases comprising (1) 20 low-grade squamous intraepithelial lesions (LSILs); (2) 200 high risk (HR) negatives and 20 ASC-US; and (3) 260 screening cytology specimens were studied. Institutional review committee guidelines allowed us to know diagnoses by groups of specimens, but did not allow us to know individual patient diagnoses, so we could not perform case-by-case matched outcome-comparisons. Cells were concentrated by conventional centrifugation and sedimented into a polymer gel that was then vortex-mixed and converted into a viscous cell-rich suspension. The cell suspension was smeared between two clean glass slides, which were air-dried and stained with the Papanicolaou stain. Two study-sets were created, comprising one slide from each case. Each of the two study sets was examined by two cytopathologists, and discordant diagnoses were adjudicated. Because of the ambiguity involved in the "atypical" (ASC-US, ASC-H, AGC) diagnosis categories, only outcomes at the level of LSIL or greater were recorded. All MLBC SILs were digitally imaged and abnormal slides plus digital images were sent to the laboratory that provided the residual automated liquid-based cytology (ALBC) suspensions. The final diagnoses were confirmed by the laboratory that provided the residual ALBC specimens. MLBC slides of the 20 LSIL cases afforded 2 high-grade squamous intraepithelial lesions (HSILs) and 18 LSILs. Those of the 200 HR-Negatives showed 3 HSILs and 30 LSILs; and those of the 20 HR-ASC-US showed 3 HSILs and 9 LSILs. MLBC slides of the 260 screening cytology specimens showed 1 Carcinoma, 3 HSILs and 20 LSILs; affording 3 HSILs and 14 LSILs more than originally diagnosed. The MLBC method of this report is useful for preparing cell suspensions for cytological examination. Our analytical method was exhaustive and used nearly all of the cell material that was provided to us for analysis; therefore, we conclude that this approach is useful for determining how well ALBC instruments represent their parent sample suspensions. It appears that "rare events" may be overlooked when limited sample aliquots are analyzed by ALBC instruments, and this probably accounts for our increased discovery of SILs by the MLBC method. Also, SILs often present as aggregates of cohesive cells which, if overlooked or ineffectively transferred to ALBC slides, would not be diagnosed.

Laboratory implementation of human papillomavirus testing.

Human papillomavirus testing is becoming an integral component of cervical cancer screening. Market forces will require most laboratories that perform Papanicolaou tests to develop a system for handling human papillomavirus testing also. Data and information are presented that may facilitate laboratories when addressing the following issues in the process of developing a human papillomavirus testing service: Which methodology is the best fit for the laboratory? Is it better to develop an in-house testing service or to send it out? How do I get started? What are the financial and economic issues, and how should they be managed?