The effect of treatment package time in head and neck cancer patients treated with adjuvant radiotherapy and concurrent systemic therapy

Abstract

Objectives: In patients with head and neck carcinoma, “treatment package time” (TPT) was proven to impact outcomes in cases receiving adjuvant radiotherapy alone. Its impact in patients receiving radiotherapy with concurrent systemic therapy has not been studied previously. The TPT influence on survival endpoints for patients treated with surgery followed by radiation and concurrent systemic therapy was analyzed. Methods: Institutional database to identify head and neck carcinoma cases treated with definitive surgery followed by concomitant chemo(bio) radiotherapy (CRT) was used. TPT was the number of days elapsed between surgery and the last day of radiation. %FINDCUT SAS macro tool was used to search for the cutoff TPT that was associated with significant survival benefit. Kaplan–Meier curves, log-rank tests as well as univariate and multivariate analyses were used to assess overall survival (OS) and recurrence free survival (RFS). Results: One hundred and three cases with a median follow up of 37 months were included in the study. Oropharyngeal tumors were 43%, oral cavity 40% and laryngeal 17% of cases. Concurrent systemic therapy included platinum and cetuximab in 72% and 28%, respectively. Optimal TPT was found to be < 100 days with significantly better OS (P = 0.002) and RFS (P = 0.043) compared to TPT ≥100 days. On multivariate analysis; TPT<100 days, extracapsular nodal extension, high-risk score, lymphovascular space and perineural invasion were independent predictors for worse OS (P < 0.05). T4, extracapsular nodal extension and high-risk score were all significantly detrimental to RFS (P < 0.05). Conclusions: Addition of concomitant systemic therapy to adjuvant radiotherapy did not compensate for longer TPT in head and neck squamous cell carcinoma. Multidisciplinary coordinated care must be provided to ensure the early start of CRT with minimal treatment breaks. Keywords: Head and neck cancer, Treatment package time, Adjuvant radiation therapy, Concomitant systemic therapy, Survival