Is large loop excision of the transformation zone depth a risk factor for affected endocervical margins?

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.

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).

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.

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.