Randomized controlled trial evaluating rapid pre-screen of cervical cytology specimens.

A randomized controlled trial of 75,355 cervical cytology specimens was performed comparing rapid pre-screen with no pre-screen. While the percentage of cases receiving a final report of definite high-grade abnormality was higher in the no pre-screen arm (no pre-screen = 0.70%, pre-screen = 0.65%), the percentage of cases receiving a final report of possible or definite high-grade abnormality was essentially identical in the two arms of the trial (no pre-screen = 1.22%, pre-screen = 1.21%). In the randomized trial, one extra cytology report of definite high-grade abnormality was made for every 12,568 slides pre-screened. This level of benefit was reduced by about half when rapid pre-screen was adopted as a routine laboratory practice.     

Liquid-based cytology improves productivity in cervical cytology screening.

Objectives: The ThinPrep test was introduced into our institution on a phased basis over 3 years between January 2002 and December 2004. This study set out to assess its effect on productivity (as measured by output of cases per medical scientist per day) during the changeover period. Numbers of high and low-grade lesions and of unsatisfactory slides were also monitored. Methods: The percentage conversion from conventional preparation to liquid-based cytology (LBC) and output of cases per medical scientist per day were calculated from our database at 6-month intervals. The average backlog, average number of cases received per month and percentage of unsatisfactory and abnormal cases were calculated similarly. Results: Over the study period 92 084 cases were received. The percentage of cases using ThinPrep increased: from 9% in January 2002 to 73% in December 2004. During the study there was an increase in output from 17.0 to 22.3 cases per medical scientist per day, representing a 31% improvement at 73% conversion. Numbers of unsatisfactory cases decreased substantially and the numbers of low and high-grade diagnoses were relatively constant. Conclusions: The change to ThinPrep has improved productivity and decreased the number of unsatisfactory cases. There was no adverse effect on quality during the changeover.     

Computerized interactive morphometry of brushing cytology specimens

Forty-two bronchial brushing cytology specimens were evaluated by a video-based computerized interactive morphometry (CIM) system with an interactive peripheral consisting of a touch-sensitive screen mounted over a high-resolution video monitor. The system was programmed to allow a trained observer to rapidly measure nuclear and cytoplasmic profile diameters of randomly selected cells and to calculate their nuclear-cytoplasmic ratios. The specimens included 13 cytologic slides with no malignant cells present, 14 with non-small cell carcinoma cells and 15 with small cell carcinoma cells. The cases were divided into two groups: a training set composed of slides with "known diagnosis" and a test set of slides with "unknown diagnosis". A data set was constructed with the measurements from the cases with "known diagnosis," and an algorithm that allowed the classification of cases by hierarchical analysis was developed. The data was also analyzed with statistical methods of classificatory discriminant analysis. Utilizing the information in the data base, the slides with "unknown diagnosis" were classified individually; all cases were correctly classified by the procedures. Potential applications of CIM in cytology are discussed.     

Liquid-based cytology for cervical screening

England and Wales' new National Institute for Clinical Excellence (NICE) has completed the first of its appraisals and issued guidance on a diagnostic technique rather than a therapeutic intervention. ¹ It was directed to examine the use of liquid-based cytology (LBC) for cervical screening and took evidence from a wide variety of sources. LBC is a new method of preparing cervical samples for cytological examination. Unlike the conventional 'smear' preparation it involves making a suspension of cells from the sample and this is used to produce a thin layer of cells on a slide.     

Statistical measurements of accuracy in cervical cytology

Statistical measures that can be used to monitor the level of accuracy of cervical cytologic screening are examined: sensitivity, the false-negative rate, the interval cancer rate among women with negative reports and the predictive value of a positive test. Sensitivity and the false-negative rate are subject to biases and problems of determination that may make them less useful as measures of accuracy. The interval cancer rate and the positive predictive value may be better methods of assessing the frequency of serious abnormalities following negative cytologic reports and the accuracy of cytologic reports of serious abnormalities, respectively. It is important to recognize that no single measure of accuracy can adequately define a laboratory's performance. The use of statistical analyses can be invaluable in placing in context the criticisms of cervical cytology as an appropriate screening test for the prevention of cervical cancer; statistical analysis should be used as one component of quality control.     

Effects of a larval antipredator response and larval diet on adult phenotype in an aposematic ladybird beetle

Many ladybird beetles respond to a potential predation event by `reflex bleeding' or secreting a noxious defensive chemical that is similar to hemolymph. Both adults and larvae show this response. Reflex bleeding is known to reduce predator attack rates and increase prey survival after an attack, especially when reflex bleeding is employed in combination with other cues such as odor and warning coloration. In this experiment, we examined how variability in the number of reflex bleeding events and food quality in the larval stage of the aposematic ladybird beetle Harmonia axyridis affected elytral color, development time, and terminal size in adults. Effects of reflex bleeding were subtle and may have been influenced by diet treatments. Adult color did not differ between bleed treatment groups but beetles that reflex bled tended to take longer to develop and grow to smaller sizes than control group beetles. There were clear and strong effects of larval diet on adult phenotype: an ad libitum pollen diet resulted in paler adult coloration, shorter development time, and larger adult size relative to a limited-availability aphid diet. Our results suggest that the best environment for producing bright-red coloration may not be the best environment for favorable expression of life history characters, especially under stressful conditions. Interactions between different life history stages of H. axyridis are also discussed. Received: 20 April 1997 / Accepted: 30 September 1997     

Diagnosing endometrial carcinoma with cervical involvement by cervical cytology

OBJECTIVE: To assess the relationship of a cervical cytologic diagnosis based on number, size and degeneration of malignant clusters and necrotic background to cervical involvement of endometrial carcinoma. STUDY DESIGN: Cervical smears of 53 women with endometrial carcinoma were evaluated for cervical involvement. The cytologic diagnosis was compared with actual involvement, and accuracy was calculated. Retrospectively, cytologic features, including number, size and degeneration of malignant clusters and necrotic background, were analyzed in involved and noninvolved cases. RESULTS: Cervical involvement was confirmed in 15 patients (28.3%). The number and size of malignant clusters in the involved cases were significantly larger than those in the noninvolved cases (P < .001 and < .01, respectively). The proportion of degenerated malignant cells and necrotic background in involved cases were significantly higher than those in noninvolved cases (P < .05). Cytologic diagnosis had a sensitivity and specificity of 62.5% and 86.8%, respectively. CONCLUSION: Cervical smears of involved cases revealed a large number and large size of malignant clusters. These findings support cytologic diagnosis based on number, size and degeneration of malignant cells and necrotic background. Cervical cytology is useful to exclude cervical involvement because of its high specificity and can help detect cervical involvement because of its moderately high sensitivity.     

Primary cervical lymphoma: the role of cervical cytology

Two cases of primary malignant lymphoma of the uterine cervix are reported. Both were confirmed by histology as high grade B cell lymphomas. In one case, the diagnosis was made on a second colposcopic biopsy after an initial cervical smear and colposcopic biopsy were negative. In the second case, dyskaryotic cells of uncertain type were identified in a cervical smear taken at colposcopy performed as part of follow up for previous cervical intraepithelial neoplasia (CIN)I. The cytologic features and differential diagnosis of this rare cervical neoplasm are discussed, with emphasis on the role of the Papanicolaou smear in the initial diagnosis of this tumour.     

The evaluation of human papillomavirus genotyping in cervical liquid-based cytology specimens; using the Roche Linear Array HPV genotyping assay

Objective:  To ascertain the usefulness of the Roche Linear Array human papillomavirus (HPV) genotyping assay for assessing HPV genotypes in liquid-based cytology (LBC) samples and to evaluate this methodology within a cytopathology laboratory. These tests are of importance as persistent infection with high-risk HPV genotypes is considered a causal factor in the development of cervical cancer.
Methods:  A total of 175 cervical LBC samples were tested using the Roche Linear Array HPV genotyping test. The suitability of the assay use in routine cytopathology laboratory was considered. HPV genotypes were matched to the cervical cytology results, which included negative, borderline nuclear abnormalities, mild, moderate and severe dyskaryosis.
Results:  The assay could be applied to screening samples with the combined result available at the reporting stage. There were no test failures. All samples used after cytological analysis had sufficient DNA for testing. The results were reproducible and easily read and there was concordance of results between biomedical scientists. The results of the assay showed co-infection with multiple HPV genotypes was common in both high-grade and low-grade cytology samples. The percentage of HPV+ samples in the normal cytology samples (although in this grouping the number of samples was low) was 37%. In the cytology samples reported as severe dyskaryosis the HPV genotypes most commonly found were HPV16 and HPV51.
Conclusion:  The assay was able to detect multiple HPV infection with a wide range of genotypes in LBC samples sent for routine cytological analysis. It would be suitable for use in a cytopathology laboratory. The results of the assay show that the genotype profile has some variation from other geographical regions, and more work is needed to determine population prevalence, to ascertain the impact of the HPV vaccine, to evaluate test for cure and HPV triage management.