Herzog, Thomas J.

TPS5632 Background: Concurrent chemoradiation therapy (CCRT) is the standard of care for locally advanced cervical cancer (LACC); however, outcomes remain suboptimal in patients with high-risk disease. Recent studies suggest that integration of immunotherapy (IO) with definitive chemoradiation, or induction chemotherapy prior to CCRT improves outcomes. Whether treatment intensification with induction systemic therapy and IO prior to CCRT and IO further improves disease control remains unknown. Induction chemotherapy may reduce tumor burden, eradicate micrometastatic disease, and improve tumor immunogenicity prior to definitive CCRT. Preclinical and clinical data support synergy between systemic therapy or radiotherapy and immune checkpoint blockade, providing the rationale for evaluating an induction strategy incorporating chemotherapy and immunotherapy before standard CCRT with immunotherapy, followed by maintenance immunotherapy. Optional tumor tissue and blood samples will be collected for exploratory correlative analyses, including immune and molecular biomarkers associated with response, resistance, and patterns of failure. Methods: NRG-GY037 is a prospective, multi-institutional phase III randomized trial conducted through NRG Oncology. A total of 336 patients will be enrolled (168 per arm). Patients will be stratified by FIGO stage (III vs. IVA) and presence or absence of para-aortic lymph nodes (N2). The primary endpoint is progression free survival (PFS). The study has 90% power to detect PFS hazard ratio of 0.65 in the experimental arm. Treatment: Patients with previously untreated, high-risk LACC are randomized to receive either induction chemotherapy with pembrolizumab for 6 weeks followed by CCRT with pembrolizumab and pembrolizumab maintenance, or standard CCRT with pembrolizumab followed by pembrolizumab maintenance. Major Eligibility Criteria: Eligible patients have histologically confirmed cervical carcinoma (squamous, adenocarcinoma, or adenosquamous), TNM T3 and T4 disease, N0-2, ECOG performance status 0–1, and no prior definitive therapy for cervical cancer. Current Enrollment Status: The trial is actively accruing patients. No efficacy or safety data are available at the time of submission. Clinical Trial Registration: ClinicalTrials.gov identifier: NCT07061977. Clinical trial information: NCT07061977 .

5593 Background: We conducted an international survey to evaluate the differences in the systemic, radiotherapeutic and operative management of endometrial cancer (EC) in different regions of the world. Methods: In 2009 avalidated 15-item-questionnaire regarding surgical and adjuvant procedures of EC was sent to all German gynaecological clinics and in 2010 the English adapted questionnaire was set online as well as sent per post in most major gynaecological cancer societies. Results: 316 German institutions and 302 Institutions from 24 countries participated. We combined the different countries into regional groups: Central Europe (CE), southern Europe (SE), Asia and USA/UK. In Asian countries and in CE a lymph node dissection (LND) was performed routinely in 72.8% and in 55.6% of the cases, whereas in the USA/UK and in SE a LND was done mainly in selected cases when specific risk factors such as high-grade or non-endometrioid-histology applied (62.8% and 72.5%) than routinely (p < 0.001). A systematic pelvic and paraaortic LND was performed most frequently in CE 91.0%, in SE 76.9%, in Asia 70.9% and in USA/UK 68.6% (p < 0.001). A systematic LND with the intention of both adequate staging and for therapeutic value was performed in countries of central Europe to 74.6% and in Asia to 67.2%. In USA/UK the LND was seen merely as a staging instrument by 53.5% (p < 0.001). The LND was performed up to renal veins in CE in 86.8%, in Asia in 80.8%, in USA/UK in 51.2% and in SE in 45.1 %. A significant difference war found in the treatment for FIGO stage I (high risk factors (high grade, L1,V1)) and stage II disease between the countries: chemotherapy was applied in 84.8% of the participated centers in Asia,42.3% in SE, 21.2% in CE and only 13.6% in USK/UK (p<0.001).Vaginal brachytherapy was indicated as follows: USA/UK 84.1%, CE 78.8%, SE 78.8%, Asia 5.6% (p < 0.001). Conclusions: There is a large variety in the operative therapy and the clinical management of EC in different regions of the world. Future international prospective trials, will be necessary to improve and harmonize the evidence based treatment guidelines for EC- disease.

5087 Background: Indication, technique and extent of lymph-node-dissection (LND) in endometrial cancer (EC) remains controversial and is strongly debated in cancer community. We conducted a national- and at a second step an international-survey evaluating the current status-quo of the surgical and medical management of EC. Methods: A validated 15-item-questionnaire regarding surgical and adjuvant procedures of EC was sent to all major gynaecological cancer societies and study groups worldwide. The questionnaire could also be answered online. Results: In a phase-I-national trial, the questionnaire was validated on basis of 316 German institutions. On the phase-II-international survey a total of 302 questionnaires were answered from 24 countries, mainly from Japan (38.7%), Spain (8.3%), Austria (7%), United-Kingdom (6.3%), Italy (6%), USA (4.3%) and Canada (4%). The vast majority of the participating clinics were academic (62.8%), while 75.2% of them belonged to gynaecology. Only 0.7% of the clinics internationally reported never performing LND in EC. 62.3% of the clinics perform both a pelvic and paraaortic lymph node dissection. 59.1% of the participants performed a systematic lymph node dissection with the intention of both adequate staging and for therapeutic value. 15.05% of the clinics perform LND up to the common-iliac-arteries, 9.03% up to the inferior-mesenteric-artery and 70.6% up to the renal-veins. The most common risk-factors to indicate LND were: high-grading (93%), non-endometrioid-histology (90.1%), lymphovascular-invasion (55.3%), blood-vessel invasion (45.4%) and tumor-diameter >2cm (38.4%). For advanced stage III&IV disease the vast majority (60% and 80%, respectively) of the physicians indicated systemic chemotherapy alone. Conclusions: This study presents the large variety in clinical management of EC worldwide, underlining so the high need of future prospective randomised trials which will establish standard and evidence based treatment guidelines for EC- disease.