Predictors for negative large loop excision of the transformation zone (LLETZ) in a primary HPV screened population
To assess rates of histologically negative large loop excisions of the transformation zone (LLETZ) and potential predictive factors within a single UK Colposcopy Unit. Retrospective cohort study. Jessop Wing Colposcopy Unit, Sheffield, U.K. Patients coded upon the Colposcopy database as having undergone a LLETZ procedure. Univariate (Chi squared, t-test) and multivariate logistic regression analysis. Histological negative LLETZ sample. 2,969 patients underwent a LLETZ procedure; 291 (10 %) procedures resulted in a negative LLETZ. Older age group (p < 0.0001), referral with negative cytology high risk human papillomavirus (hrHPV) detected (p < 0.0001), unsatisfactory colposcopy (p < 0.0001), repeat LLETZ (p < 0.0001), and biopsy and treat procedures (p = 0.0005) were found significant predictors of negative LLETZ. Patients with negative LLETZ were significantly less likely to have had a 'select & treat' procedure (p < 0.0001). Due to the increased sensitivity of HPV testing in combination with cytology for the detection of high-grade disease, it is more likely a negative LLETZ will occur following positive biopsy. This may be due to the detection of small volume high-grade disease removed by the punch biopsy alone, spontaneous regression of disease, or resolution due to localised immune responses and healing. As increasing age and unsatisfactory colposcopy are significant risk factors for obtaining a negative LLETZ, the authors recommend further studies are conducted in this more challenging referral population.