Analysis of clinical factors correlated with the accuracy of colposcopically directed biopsy

Many factors affect the accuracy of colposcopically directed biopsy (CDB). This study aimed to compare the histological results of CDB with those of cone specimens and to determine clinical factors associated with the accuracy of CDB in defining the extent and severity of cervical intraepithelial neoplasia. We studied 513 patients diagnosed with cervical intraepithelial neoplasia by CDB who underwent conization between September 2012 and December 2016. We retrospectively evaluated the agreement between histological results on biopsies and cone specimens and analyzed factors influencing the accuracy of the results. The overall agreement between the histological results on biopsy and the corresponding cone specimens was 74.1%; underestimation occurred in 6.4% of cases. The agreement between histological results on biopsy and cone specimen was 54.5% for low-grade lesions, 78.2% for high-grade lesions, and 28.9% for microinvasive cervical cancer. The overall agreement between high-grade cytology and the final histological diagnosis was 86.7%. By univariate analysis, patient age (p = 0.026), menopausal status (p = 0.018), type of transformation zone (p = 0.003), number of biopsies (p = 0.002), and cone width (p = 0.015) were found to be associated with the accuracy of CDB. However, multivariate logistic regression revealed that cone width (p = 0.044) was the only independent factor correlated with CDB accuracy. Our data suggest that old age (≥50), postmenopausal status, and transformation zone type 3 might be positively associated with the under-diagnosis of CDB. Three or more biopsies and cone width ≥21 mm might improve CDB accuracy. However, cone width was the only independent factor correlated with CDB accuracy.