Comparative effectiveness trial of transoral head and neck surgery followed by adjuvant radio(chemo)therapy versus primary radiochemotherapy for oropharyngeal cancer (TopROC).

[BACKGROUND] For loco-regionally advanced, but transorally resectable oropharyngeal cancer (OPSCC), the current standard of care includes surgical resection and risk-adapted adjuvant (chemo) radiotherapy, or definite chemoradiation with or without salvage surgery. While transoral surgery for OPSCC has increased over the last decade for example in the United States due to transoral robotic surgery, this treatment approach has a long history in Germany. In contrast to Anglo-Saxon countries, transoral surgical approaches have been used frequently in Germany to treat patients with oro-, hypopharyngeal and laryngeal cancer. Transoral laser microsurgery (TLM) has had a long tradition since its introduction in the early 70s. To date, the different therapeutic approaches to transorally resectable OPSCC have not been directly compared to each other in a randomized trial concerning disease control and survival. The goal of this study is to compare initial transoral surgery to definitive chemoradiation for resectable OPSCC, especially with regards to local and regional control.

[METHODS] TopROC is a prospective, two-arm, open label, multicenter, randomized, and controlled comparative effectiveness study. Eligible patients are ≥18 years old with treatment-naïve, histologically proven OPSCC (T1, N2a-c, M0; T2, N1-2c, M0; T3, N0-2c, M0 UICC vers. 7) which are amenable to transoral resection. Two hundred eighty patients will be randomly assigned (1:1) to surgical treatment (arm A) or chemoradiation (arm B). Standard of care treatment will be performed according to daily routine practice. Arm A consists of transoral surgical resection with neck dissection followed by risk-adapted adjuvant therapy. Patients treated in arm B receive standard chemoradiation, residual tumor may be subject to salvage surgery. Follow-up visits for 3 years are planned. Primary endpoint is time to local or locoregional failure (LRF). Secondary endpoints include overall and disease free survival, toxicity, and patient reported outcomes. Approximately 20 centers will be involved in Germany. This trial is supported by the German Cancer Aid and accompanied by a scientific support program.

[DISCUSSION] This study will shed light on an urgently-needed randomized comparison of the strategy of primary chemoradiation vs. primary surgical approach. As a comparative effectiveness trial, it is designed to provide data based on two established regimens in daily clinical routine.

[TRIAL REGISTRATION] NCT03691441 Registered 1 October 2018 - Retrospectively registered.