After surgical treatment of locoregionally advanced head and neck squamous cell carcinoma (HNSCC), (i) two or more regional lymph nodes involved (LN > 2), (ii) extracapsular spread (ECS) of disease, or (iii) microscopically involved mucosal margins of resection (margin) upgrade the disease to high-risk status, which is often targeted with adjuvant chemoradiotherapy (CRT) to improve locoregional control and survival. However, the administration of CRT is associated with increase in the incidence of severe acute toxicity. Oropharyngeal squamous cell carcinoma (OPSCC) is recognized as distinct group of tumors with favorable clinical outcomes.Objective
The objective was to evaluate the adjuvant therapy in patients with high-risk OPSCC characterized by LN > 2, positive ECS, and positive margins.Methods
We retrospectively analyzed 45 patients with high-risk OPSCC who underwent resection of the primary tumor and/or neck-dissection followed by no adjuvant therapy (n = 19), radiotherapy alone (RT) (n = 17), or CRT (n = 9), at the Shizuoka Cancer Center between 2003 and 2011.Results
The median follow-up period was 37.2 months. Patients' characteristics including gender, age, smoking status, and pathological findings (T/N-pathological stage, LN > 2, ECS, margin, keratinizing status) did not significantly differed among the three group. There were no significant differences in disease-free survival (DFS) for the RT group or the CRT group compared with the no adjuvant group (RT; HR = 0.23, P = 0.067, CRT; HR = 0.71, P = 0.617). After adjustment for significant features by multivariate Cox regression analysis, positive margin, positive ECS, LN > 2, and no administration of adjuvant CRT were not significantly associated with worse DFS.Conclusions
Adjuvant CRT may not be necessarily recommended for patients with OPSCC characterized by LN > 2, positive ECS, and positive margins. Specific category for high-risk OPSCC is warranted. The status of p16 expression is currently under investigation.