A Novel 2-Metagene Signature to Identify High-Risk HNSCC Patients amongst Those Who Are Clinically at Intermediate Risk and Are Treated with PORT

Abstract: (1) Background: Patients with locally advanced head and neck squamous cell carcinoma (HNSCC) who are at biologically high risk for the development of loco-regional recurrences af-ter postoperative radiotherapy (PORT) but at intermediate risk according to clinical risk factors may benefit from additional concurrent chemotherapy. In this matched-pair study, we aimed to identify a corresponding predictive gene signature. (2) Methods: Gene expression analysis was performed on a multicentre retrospective cohort of 221 patients that were treated with postoper-ative radiochemotherapy (PORT-C) and 283 patients that were treated with PORT alone. Propen-sity score analysis was used to identify matched patient pairs from both cohorts. From differen-tial gene expression analysis and Cox regression, a predictive gene signature was identified. (3) Results: 108 patient matched patient pairs were selected. We identified a 2-metagene signature that stratified patients into risk groups in both cohorts. The comparison of the high-risk patients between the two types of treatment showed higher LRC after treatment with PORT-C (p<0.001), which was confirmed by a significant interaction term in Cox regression (p=0.027), i.e. the 2-metagene signature was indicative for the type of treatment. (4) Conclusion: We have identi-fied a novel gene signature that may be helpful to identify patients with high-risk HNSCC amongst those at intermediate clinical risk treated with PORT, who may benefit from additional concurrent chemotherapy.