European Collaborative Multicenter Observational Study: Modular Treatment With PMMR and Targeted Compartmental Pelvic Lymphadenectomy Followed by Therapeutic Pelvic and Paraaortic Lymphadenectomy in Node Positive Disease for Locoregional Control in Endometrial Cancer FIGO Stages I-III

Intermediate/high risk endometrial cancer shows locoregional recurrence rates up to 20%. Also in so called low-risk disease 5-10% incidence of nodal metastasis is reported. Although adjuvant radiotherapy may reduce these recurrences there has been no survival benefit. To avoid toxicity of irradiation and preserve the full potential of radiotherapy for salvage treatment of recurrences surgery should avoid locoregional recurrence. According to the concept of ontogenetically based compartmental surgery it may be suggested that this may be achieved by PMMR and therapeutic LNE as it has been already shown for TMMR in cervical cancer and TME in rectal cancer. First, monocentric data have shown feasibility and safety of this approach and are promising with respect to reduce locoregional recurrence rate significantly. On parallel it has also been convincingly shown that sentinel node detection shows a high level of accuracy in precluding nodal involvement in endometrial cancer. Thus, unnecessary complete lymphadenectomy may be avoided in patients with proven node negative disease. However, this procedure is aimed on diagnostic and not therapeutic goals. Nevertheless, therapeutically it fits well in the surgical concept of compartmental surgery indicating the peripheral border of therapeutic surgical approach. This leads to the concept to resect the embryologically determined tissue of risk en bloc together with the "sentinel nodes" of the draining lymph compartment (module I). In case of positive node extended therapeutic pelvic and paraaortic lymphadenectomy (module II) may be indicated. This should now be evaluated in a European collaborative observational trial. The surgical arm (cohort A) will include Patients who have received surgical treatment (module I) and in case of positive nodes or enhanced risk for isolated positive paraaortic nodes (module II) and don't want to receive adjuvant radiation therapy; in intermediate/high risk situations, however, adjuvant chemotherapy should be offered to these patients. For patients with high-risk carcinomas who do not want to be treated with the modular concept, the option of receiving systematic lymphadenectomy during primary surgery will be given. Patients who prefer to be treated according current clinical practice will be asked to participate in cohort B to be observed as concomitant control and will be treated according to current clinical practice based on the European ESMO/ESGO/ESTRO-Guidelines. Primary endpoint will be loco-regional recurrence and recurrence free survival. Follow up is planned for 5 years following date of first surgery (module I).