Utility and Reproducibility of the International Federation for Cervical Pathology and Colposcopy Classification of Transformation Zones in Daily Practice

Objective To compare the distribution of International Federation for Cervical Pathology and Colposcopy (IFCPC) transformation zone (TZ) types among women in different age groups referred to 8 colposcopy clinics. Materials and methods Between February 2012 and February 2013, we prospectively collected individual patient data from 8 clinics within the German Colposcopy Network (G-CONE). Data were analyzed using ODSdysplasie, software designed to allow continuous quality assessment in colposcopy clinics. The distribution of IFCPC-classified TZ was compared between different centers for the following age groups: younger than 30 years, between 30 and 50 years, and older than 50 years. Results Of 3,761 patients included in the analysis, 2,153 (57%) were classified as having type 2 TZ, 906 (24%) as type 1 TZ, and 702 (19%) as type 3 TZ. Type 3 TZ was the most commonly reported type in women older than 50 years (70%). We found that the relative distribution of type 3 TZ between age groups was similar in the participating colposcopy clinics. However, there was evidence of heterogeneous distribution of types 1 and 2 TZ between age groups in different clinics, ranging from 7.8% to 66.4% for type 1 TZ in women younger than 30 years and 28.9% to 78.1% for type 2 TZ in women 30 to 50 years old. Conclusions Although IFCPC type 3 TZ seems to be a reproducible finding, the distribution of types 1 and 2 TZ showed significant heterogeneity. A more precise anatomic distinction between types 1 and 2 TZ in the IFCPC terminology could improve reporting of colposcopy findings.