Determinants of delay and association with outcome in head and neck cancer: A systematic review

Introduction: Head and neck cancers (HNC) are relatively fast-growing tumours, and delay in treatment initiation is associated with tumour progression and adverse outcome. An overview of factors contributing to delay can provide critical insights on necessary adjustments to optimize care pathways. This systematic review aims to identify factors associated with delay and summarize the effect of delay on oncological outcome measures. Methods: A search strategy was conducted according to PRISMA guidelines to search electronic data-bases for studies assessing the carepathway interval (days between first visit in head and neck oncology center and treatment initiation) and/or time-to-treatment-initiation interval (days between histological diagnosis and treatment initiation) and 1) determinants of delay and/or 2) effect of delay on outcome within these timeframes. Due to heterogeneity between included studies, a meta-analysis was not possible. Results: Fifty-two studies were eligible for quantitative analysis. Non-Caucasian race, academic setting, Medicaid/no insurance and radiotherapy as primary treatment were associated with delay. Advanced tumour stage was related to increased time-to-treatment initiation in the four common sites combined (oral cavity, oropharynx, hypopharynx, larynx). Separate determinants for delay in different tumour locations were identified. In laryngeal, oral cavity cancer and the four common HNC sites combined, delay in start of treatment is associated with decreased overall survival, although no cut-off time point could be determined. Conclusion: Race, facility type, type of insurance and radiotherapy as primary treatment were associated with delay and subsequent inferior survival in the four common sites combined. (C) 2021 The Authors. Published by Elsevier Ltd.