Objective: To analyze the relationship between large loop excision of the transformation zone (LLETZ) depth and the persistence of disease and human papillomavirus (HPV) infection in patients with cervical intraepithelial neoplasia grades 2 and 3. Methods:A cross-sectional observational retrospective study included women with cervical intraepithelial neoplasia grades 2 and 3 who underwent LLETZ at Hospital Universitario Santa Lucía, Cartagena, Spain, from November 1, 2011, to December 31, 2016. Follow-up of cytology and HPV detection were performed at 6 and 12-18 months after surgery. Results:In this study of 256 women, multivariate analysis revealed that conization depth of 10 mm or less did not indicate an increase of persistence/recurrence of pathological cytology at 6 months (P=0.094) and after 12-18 months (P=0.234), or infection by HPV at 6 months (P=0.675) and 12-18 months (P=0.938) after LLETZ. The affected endocervical margin at 6 months is the sole independent risk factor for persistence, both in the lesion (P=0.003) and HPV (P=0.004).Conclusion: Conization depth lower than 10 mm at LLETZ did not increase disease persistence or infection by HPV in an 18 month monitoring period. Therefore, higher depth conizations would not be justified to ensure favorable oncological results. K E Y W O R D S Cervical intraepithelial neoplasia (CIN); Conization depth; Disease persistence; HPV persistence; Large loop excision of the transformation zone (LLETZ) 1 | INTRODUCTION Cervical intraepithelial neoplasia (CIN) is a group of precancerous lesions that can potentially lead to cervical cancer. If untreated, women with high-grade CIN are at very high risk of developing cervical cancer. 1 The most widely accepted method for treating CIN grade 3 is conization. 2 Large loop excision of the transformation zone (LLETZ) has demonstrated high efficacy both for the treatment of CIN and the prevention of cervical cancer. Recurrence/residual rates, however, range from 5% to 30%. 1 Persistent infection by human papillomavirus (HPV) has been shown to be a predictive indicator of disease recurrence following conization. 3 Previous studies have supported the findings of an increase in obstetric morbidity in women who have had conization.Consequently, CIN treatment has been related to an increased risk of gestational loss, preterm birth, low weight birth, premature rupture of membranes, and an increase in the rate of cesarean delivery in future pregnancies, 4-6 which could be due to the increase of cone depth. 7 European colposcopy guidelines 8 recommend an 8-10 mm conization depth in women of reproductive age as optimum LLETZ | 317Lara-Peñaranda eT aL.

Objective: The aim of the study was to determine if the depth of large loop excision of the transformation zone (LLETZ) is a risk factor for presenting affected endocervical margins. Methods: A cross-sectional retrospective study was performed on 353 patients that underwent LLETZ after presenting cervical biopsies with CIN grade 2 and grade 3 or persistent CIN grade 1 at Hospital Universitario Santa Lucía, Cartagena, Spain, from November 2011 to December 2016. Automatized measurement of the LLETZ depth was performed in microns and added to cervical canal extensions when these were performed. Other variables studied in positive endocervical margins were age (under or over 35 years), premenopause/postmenopause, number of affected quadrants, CIN grading, the presence of HPV 16 before LLETZ, parity (nulliparous vs multiparous) and the location where the LLETZ was performed (operating room vs consultation room). Results: Our multivariant analysis showed that LLETZ depth ≤ 10 mm did not increase the risk in affected endocervical margins (P = 0.366) and no statistically significant difference between the two groups (affected and nonaffected margins) was found. CIN grading and parity did prove a statistically significant association (P = 0.039 and P = 0.011, respectively). Age, menopause, number of affected quadrants, HPV 16 and the location did not show statistical association with positive endocervix margins. Conclusions: LLETZ depth equal to or lower than 10 mm was not proven to be a risk factor to have affected endocervical margins after the treatment. Therefore, higher LLETZ depth would not be justified to ensure oncological results.