Exploratory Study of Clonal Evolution in Cancer for Patients Undergoing Transoral Robotic Surgery for Radiation Exposed Residual/reCurrent Tumours of the Upper Aerodigestive Tract

Radical radiotherapy for head and neck squamous cell cancer (HNSCC) can be administered to primary disease with curative intent. Residual disease, recurrence or further tumours may subsequently occur in this irradiated field. It is unknown whether these cancers reflect primary resistance or represent the evolution of resistance on treatment. Understanding this could allow stratification of patients to more effective primary treatments, such as transoral robotic surgery, or help tailor systemic therapies for these cancers in previously irradiated fields. RECUT+ is an exploratory molecular analysis study to assess the selective impact of radiation therapy on HNSCC. Participants will be recruited from the Royal Marsden Hospital (RMH), Chelsea, a tertiary referral H\&N cancer unit in London, UK, specialising in transoral robotic surgery. Retrospective participants will be identified from previous Head and neck MDT lists at RMH. Prospective participants will be screened for by the RECUT+ team during the weekly H\&N MDT meetings at the Royal Marsden Hospital (RMH). Blood/saliva samples will be collected pre operatively (prospective participants) and post operatively (retrospective and prospective participants) for germline and circulating tumour DNA analysis. Biopsy samples from the original cancer and resected specimens from the post radiotherapy residual/recurrent/new primary disease will undergo molecular analysis to assess for any selective impact of radiotherapy on these further tumours.