Comparison of Two Surgical Approaches in the Treatment of Cervical Dysplasia: Complete Removal of the Transformation Zone (LLETZ) Versus Isolated Resection of the Colposcopically Visible Lesion (LEEP)

Cervical cancer is one of the most common cancers in women and one of the leading causes of death in women worldwide. Pre-cancerous lesions (dysplasias) are detected by the preventive smear test at the gynecologist and can thus contribute to a 100% chance of cure if they are clarified by a colposcopic examination as part of the dysplasia consultation and dysplastic lesions are then surgically removed if necessary (conization).

In practice, there are four different methods by which conization can be performed: Knife Conization, Laser Conization, Large Loop Excision of the Transformation Zone (LLETZ) and Loop Electrical Excision Procedure (LEEP). The first three methods have in common that they aim to remove the entire transformation zone. The rationale for this is that both the precancerous lesions and the cervical carcinoma itself originate in the transformation zone of the cervix. This thesis would support the idea of resecting the lesion while taking the remaining healthy transformation zone along as a precaution. However, it is clear that with the removal of the entire transformation zone, healthy tissue is removed in addition to the lesion itself. Any increase in radicality may increase the complication rate of the procedure, especially with regard to the most feared long-term complication of preterm birth, because the more cervical tissue is removed, the higher the risk of subsequent preterm birth. This connection speaks in favor of the use of LEEP, in which only the visible dysplastic tissue in healthy tissue is removed in the sense of a radical resection, without at the same time also removing the entire transformation zone, especially in women who still wish to have children.

In summary, the aim of conization is on the one hand to achieve a high level of oncological safety (low recurrence rate, high R0 resection rate) by resecting sufficient dysplastic tissue, and on the other hand to avoid excessive tissue resection, because this would increase the risk of premature birth in a subsequent pregnancy.

There is no direct head-to-head comparison between LEEP and LLETZ in the literature regarding oncologic safety, for which complete resection of the dysplastic lesion (so-called 'in-sano resection') is the most appropriate postoperative surrogate parameter. In a Pubmed literature search (search date: February 10, 2021, search terms: conization, LEEP, LLETZ, resection margin, randomized), no prospective randomized study on this topic was found. Further clinical studies are therefore useful to optimize surgical therapy for cervical dysplasia

The primary objective of the present study is to compare LLETZ (resection of the dysplastic lesion including the transformation zone) with targeted resection of the colposcopically conspicuous lesion only (LEEP) and to compare it with regard to oncological safety (defined as non-in-sano rate).