Impact of waiting time on nodal staging in head and neck squamous-cell carcinoma treated with radical intensity modulated radiotherapy

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 databases 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.

Impact of delays in radiotherapy of head and neck cancer on outcome

BACKGROUND

In head and neck cancer (HNC), the relationship between a delay in starting radiotherapy (RT) and the outcome is unclear. The aim of the present study was to determine the impact of the amount of time before treatment intervention (TTI) and the growth kinetics of individual tumors on treatment outcomes and survival.

METHODS

Two hundred sixty-two HNC patients with 273 primary tumors, treated with definitive (chemo) RT, were retrospectively analyzed. The TTI was defined as the time interval between the date of histopathologic diagnosis and the first day of the RT course. Volumetric data on 57 tumors were obtained from diagnostic and RT planning computer tomography (CT) scans in order to calculate the tumor growth kinetic parameters.

RESULTS

No significant association between locoregional control or cause-specific hazards and TTI was found. The log hazard for locoregional recurrence linearly increased during the first 40 days of waiting for RT, although this was not significant. The median tumor volume relative increase rate and tumor volume doubling time was 3.2%/day and 19 days, respectively, and neither had any impact on locoregional control or cause-specific hazards.

CONCLUSION

The association between a delay in starting RT and the outcome is complex and does not harm all patients waiting for RT. Further research into imaging-derived kinetic data on individual tumors is warranted in order to identify patients at an increased risk of adverse outcomes due to a delay in starting RT.