Baseline inaccuracy rates for the comparison of cervical biopsy to loop electrosurgical excision histopathologic diagnoses

OBJECTIVE: The purpose of this study was to quantify the baseline inaccuracies in histopathologic diagnosis between colposcopically directed cervical biopsies and loop electrosurgical excision procedure specimens. STUDY DESIGN: A retrospective review was made of cervical biopsies and loop electrosurgical excision procedure pairs (n = 448) that were performed at the University of Arizona between 1992 and 2000. Agreement was assessed by κ statistics and Spearman ρ coefficients. Subgroup analysis was performed (n = 139) to assess pairs with significant inaccuracy between biopsy and loop electrosurgical excision procedure, when these were performed within 28 days of each other. RESULTS: Eighty-one percent agreement was found between cervical biopsy and loop electrosurgical excision procedure histopathologic diagnoses, when compared to within 1 degree (κ, 0.73; P < .0001). A discrepancy that would be attributed to regression or progression was found: mild biopsy (regression, none by definition; progression, 4%), moderate biopsy (regression, 9%; progression, 0%), and severe biopsy (regression, 26%; progression, 0%). CONCLUSION: Even when colposcopically directed cervical biopsy correlates strongly with loop electrosurgical excision procedure histopathologic diagnosis, there is a definable percentage of patients for whom there is a discrepancy between these 2 diagnoses. This discrepancy represents an inherent inaccuracy of the diagnostic testing modality and should not be interpreted as progression or regression of disease.