Timing factors as prognostic variables in patients with head and neck squamous cell carcinoma treated with adjuvant radiotherapy: a literature review

SUMMARY INTRODUCTION Radiotherapy (RT) plays an important role in the treatment of patients with head and neck neoplasia, and is frequently used as postoperative adjuvant therapy. This study aimed to review the literature about timing factors that may influence the clinical outcomes of patients with advanced head and neck neoplasia treated with adjuvant RT. RESULTS Timing factors such as total treatment time, length of adjuvant RT, and the absence of interruptions during RT may influence the clinical outcome of these patients. CONCLUSIONS In the same way that certain tumor factors can affect the prognosis of patients with squamous cell carcinoma of the head and neck, some therapeutic timing factors are also prognostic factors and therefore, must be carefully orchestrated in order to avoid loss at therapeutic outcomes for these patients.

RESUMO INTRODUÇÃO A radioterapia (RT) tem importante papel no tratamento dos pacientes com neoplasia de cabeça e pescoço, sendo frequentemente utilizada como terapia adjuvante a fim de diminuir a probabilidade de recorrência local. O presente estudo tem o objetivo de realizar uma revisão da literatura para avaliar os fatores terapêuticos temporais que possam ter influência sobre os desfechos clínicos dos pacientes com neoplasia avançada de cabeça e pescoço tratados com RT adjuvante. RESULTADOS As variáveis terapêuticas, como o tempo total do tratamento, a duração da RT e a ausência de interrupções durante o tratamento radioterápico são capazes de impactar o resultado clínico dos pacientes. CONCLUSÕES Da mesma forma que determinados fatores tumorais podem afetar o prognóstico de pacientes com carcinoma de células escamosas de cabeça e pescoço, alguns fatores terapêuticos temporais também constituem fatores prognósticos e, portanto, devem ser rigorosamente orquestrados a fim de se evitarem prejuízos sobrepostos para esses pacientes.

Influence of time between surgery and postoperative radiation therapy and total treatment time in locoregional control of patients with head and neck cancer: a single center experience

OBJECTIVE: This study aimed to evaluate the effect of the delay to initiate postoperative radiation therapy (RT) on locoregional control to head and neck squamous cell carcinoma patients. METHODS: Retrospective cohort study that included patients submitted to surgery followed by adjuvant RT (with/without chemotherapy). The time interval between surgery and RT was dichotomized by the receiver operating characteristics curve method at 92 days. Other possible sources of heterogeneity with potential impact on locoregional control were explored by regressive analysis. RESULTS: A total of 168 patients were evaluated. The median time for locoregional recurrence (LRR) was 29.7 months. The relapse-free survival rates were 66.4% and 75.4% for patients who initiated RT more than and within 92 postoperative days (p=0.377), respectively. Doses lower than 60Gy were associated with worse rates of locoregional control (HR=6.523; 95%CI:2.266-18.777, p=0.001). Patients whose total treatment time (TTT) was longer than 150 days had LRR rate of 41.8%; no patient with TTT inferior to 150 days had relapses (p=0.001). CONCLUSIONS: The interval between surgery and RT did not show influence on locoregional control rates. However, doses <60Gy and the total treatment time >150 days were associated with lower locoregional control rates.