Postoperative (chemo) radiation in patients with squamous cell cancers of the head and neck - clinical results from the cohort of the clinical cooperation group "Personalized Radiotherapy in Head and Neck Cancer"

Abstract

Background: Postoperative (chemo) radiation improves tumor control and survival in high-risk patients with head and neck squamous cell carcinoma based on established risk factors. The clinical cooperation group "Personalized Radiotherapy in Head and Neck Cancer" focuses on the identification and validation of new biomarkers, which are aimed at eventually stratifying and personalizing the therapy concept. Hence, we reviewed all patients with head and neck squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx, treated with postoperative (chemo) radiation from 06/2008 until 06/2015 at the Department of Radiation Oncology in the University Hospital, LMU Munich. Here we report the clinical results of the cohort, laying the foundation for further research within the framework of a clinical cooperation group.

Methods: Patient data were retrospectively (until 2013) and prospectively (from 2013) collected and analyzed for outcome and treatment failures with regard to previously described and established risk factors.

Results: We identified 302 patients (median follow-up 45 months, average age 60.7 years), having received postoperative (chemo)radiation (median 64 Gy). Chemotherapy was added in 58% of cases, mostly Cisplatin/5- Fluorouracil in concordance with the ARO 96-3 study. The 3-year overall survival, local, locoregional and distant failure estimates were 70.5, 9.7, 12.2 and 13.5%, respectively. Human papillomavirus-associated oropharyngeal cancer was associated with a significant improved overall survival, locoregional, distant and overall tumor control rates in multivariate analysis. Additionally, in multivariate analysis, for local failure, resection status and perineural invasion, for locoregional and distant failure extracapsular extension and for overall survival the presence of nodal disease were significant adverse factors. Moreover, 138 patients have been treated in concordance with the ARO 96-3 protocol, corroborating the results of this study.

Conclusions: Our cohort represents a large unselected cohort of patients with head and neck squamous cell carcinoma treated with postoperative (chemo)radiation. Tumor control rates and survival rates are consistent with the results of previously reported data.

Keywords: Adjuvant; Chemoradiation; HNSCC; HPV; Head and neck cancer; Postoperative; Radiation therapy; Radiotherapy; Squamous cell carcinoma.

Fig. 1

Kaplan-Meier plots a Overall survival (OS), disease-free survival (DFS) and disease-specific survival (DSS) of all patients b local, locoregional, distant and any failure rates of all patients. c overall survival (OS), disease-free survival (DFS) and disease-specific survival (DSS) of the ARO-analogue subgroup d local, locoregional, distant and any failure rates of the ARO-analogue subgroup. Follow-up time was clipped at 60 months. Patients at risk are displayed under the respective plots. Censors are represented by crosses. P-Values (Log Rank) are shown

Fig. 2

Exemplary Kaplan-Meier plots for risk factors that are significant for recurrence in multivariate analysis. a Local recurrence and resection status (R1 vs R0) b Local recurrence and perineural invasion (Pn1 vs Pn0) c any recurrence and extracapsular extension (ECE vs no ECE/N0) d any recurrence and lymphovascular invasion (L1 vs L0). P-values (log rank) of the Kaplan-Meier estimates are shown. Follow-up time was clipped at 36 months. Patients at risk are displayed under the respective plots. Censors are represented by crosses

Fig. 3

Kaplan-Meier plots for patients with HPV-p16-positive oropharyngeal cancer (HPVOPC, blue line) vs all other Patients (non HPVOPC, green line) HPV-p16 negative oropharyngeal cancer (HPVneg OPC, red dotted line) are shown as reference for oropharyngeal cancer. a local recurrence b locoregional recurrence (loc.reg.) c distant recurrence d any recurrence e overall survival (OS) and f disease-specific survival (DSS); the plot for disease-free survival (DFS) is not shown (p < 0.001). Follow-up time was clipped at 36 months. Patients at risk are displayed under the respective plots. Censors are represented by crosses