Abstract

WEPE087 - Poster Exhibition

Relative accuracy of cervical and anal cytology for detection of histopathologic high grade lesions by magnification guided biopsy: a cutpoint specific meta-analytic comparison

E. Cachay, W. Agmas, W. Mathews

University of California at San Diego, Medicine, San Diego, United States

Background: We recently reported, using a receiver operating characteristic (ROC) area metric, the first meta-analytic comparison of the relative accuracy of cervical and anal cytology in detecting moderate or severe (HSIL) histopathologic lesions by magnification directed punch biopsy (Mathews et al., PLoS One 2011, 6: e24946). The aim of the present research was to meta-analytically examine cutpoint specific operating characteristics (sensitivity [SE], specificity [SP]) of cervical and anal cytology in detecting HSIL histopathology by colposcopic and high resolution anoscopic (HRA) directed punch biopsy.
Methods: Eligible studies were identified by MEDLINE citation of relevant publications between 1990 and 2010. The primary eligibility requirement was availability of tabulated cytology (normal, ASCUS, LSIL, HSIL or ASC-H) and biopsy (< HSIL, ≥ HSIL) counts. Meta-analysis and meta-regression of diagnostic accuracy was performed using metandi and midas, respectively, implemented in Stata 11.2. QUADAS study quality criteria were rated and heterogeneity examined using I²statistic.
Results: 33 cervical and 11 anal publications were eligible. The Table presents the principal meta-analytic comparisons.

	Sensitivity (SE)				Specificity (SP)
Cytology Cut Point	Anal		Cervical		Anal		Cervical
	SE	95% C.I.	SE	95% C.I.	SP	95% C.I.	SP	95% C.I.
(HSIL or ASC-H)vs.(LSIL,ASCUS,Normal)1	0.30	(0.19-0.44)	0.63	(0.56-0.69)	0.93	(0.90-0.95)	0.96	(0.95-0.98)
(HSIL or ASC-H,LSIL)vs.(ASCUS,Normal)2	0.73	(0.62-0.82)	0.80	(0.75-0.85)	0.55	(0.45-0.65)	0.76	(0.66-0.83)
(HSIL or ASC-H,LSIL,ASCUS)vs.(Normal)3	0.90	(0.76-0.96)	0.91	(0.88-0.94)	0.33	(0.20-0.49)	0.53	(0.40-0.66)

[Meta-analytic comparisons]


1. Joint model comparison (cervical vs. anal): p< 0.001; I²=92; 2. Joint model comparison (cervical vs. anal): p< 0.001; I²=82; 3. Joint model comparison (cervical vs. anal): p=0.04; I²=68
The graphic shows ROC curve areas to compare the performance of anal and cervical cytology at different cut-points for identification of HSIL histological lesions.


[ROC combined]


Conclusions: Using a cytology cutpoint of HSIL or ASC-H, anal cytology is less sensitive but comparably specific compared to cervical cytology. However, using a cutpoint of ASCUS, differences in accuracy were of borderline significance. Study heterogeneity was large in both screening settings.
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