Accuracy of cervical specimens obtained for biomarker studies in women with CIN3

Objective: We developed a protocol to collect representative cervical specimens based on colposcopic evaluation from women treated with loop electrosurgical excision procedure (LEEP). Methods: We analyzed the histology of biopsies targeting the worst and a normal area on the cervical surface in 74 women referred for LEEP because of cervical intraepithelial neoplasia grade 3 (CIN3) detected in a previous biopsy. Lesions and normal tissue were identified in colposcopy, marked, and removed after LEEP. Cervical cytology specimens collected at the same time were analyzed using Pap cytology and human papillomavirus (HPV) genotyping. Results: All but two women had an abnormal colposcopic impression with 59 of 68 (87%) showing an impression of CIN2 or greater. In 19 of 58 (33%) women, the histology result of the frozen specimen targeting the worst lesion was ≤ CIN1. In 18 of 46 (40%) women, the histology of the frozen specimen targeting normal tissue was CIN2+. A concordant histology result in specimens targeting the worst lesion was associated with a greater extension of the CIN3 in the LEEP (p trend = 0.002) and a HSIL cytology result (p trend = 0.02). Conclusion: It is challenging to sample representative cervical tissue. Even in women with confirmed CIN3, colposcopy performance to identify the worst lesion on the cervix was limited. Correctly identified CIN3s were more likely to be larger lesions that may have a higher risk of progression to cancer.