Objective: An increased interval between symptomatic disease and treatment may negatively influence oncologic and/or functional outcomes in head and neck cancer (HNC). This systematic review aims to provide insight into the effects of time to treatment intervals on oncologic and functional outcomes in oral cavity, pharyngeal, and laryngeal cancer.
Data sources: PubMed, EMBASE, and Cochrane library were searched.
Review methods: All studies on delay or time to diagnosis or treatment in oral, pharyngeal, and laryngeal cancer were included. Quality assessment was performed with an adjusted version of the Newcastle-Ottawa scale. Outcomes of interest were tumor volume, stage, recurrence, survival, patient-reported outcome measures (PROMs), toxicity, and functionality after treatment.
Results: A total of 51 studies were included. Current literature on the influence of delay in HNC is inconsistent but indicates higher stage and worse survival with longer delay. The effects on PROMs, toxicity, and functional outcome after treatment have not been investigated. The inconsistencies in outcomes were most likely caused by factors such as heterogeneity in study design, differences in the definitions of delay, bias of results, and incomplete adjustment for confounding factors in the included studies.
Conclusion: Irrespective of the level of evidence, the unfavorable effects of delay on oncologic, functional, and psychosocial outcomes are undisputed. Timely treatment while maintaining high-quality diagnostic procedures and decision making reflects good clinical practice in our opinion. This review will pose practical and logistic challenges that will have to be overcome.
Keywords: diagnostic delay; head and neck cancer; survival; therapeutic delay; time interval; tumor stage.