Radiotherapy dose escalation for the non-operative management of patients with unresectable locally recurrent rectal cancer (STEP-UP): Study protocol for a multicentre, prospective, open-label feasibility study

Background

Curative-intent management of locally recurrent rectal cancer (LRRC) generally comprises neoadjuvant therapy and surgery. In patients with unresectable LRRC, where surgical intervention is not feasible, management is limited to non-operative bimodality therapy with systemic therapy and radiotherapy. Evidence guiding the optimisation of non-operative management remains limited. In this context, the therapeutic goal is to achieve prolonged local control while minimising treatment-related adverse events and preserving quality of life. Radiotherapy dose escalation has been proposed as a potential strategy to achieve this balance. However, its feasibility and safety in the non-operative management of unresectable LRRC have not yet been established. As such, this study aims to evaluate the feasibility and safety of this radiotherapeutic approach, and to determine its impact on both symptom control and oncological outcomes.