The impact of radiographic retropharyngeal adenopathy in oropharyngeal cancer

Abstract

Background We performed this study to define the incidence of radiographic retropharyngeal lymph node (RPLN) involvement in oropharyngeal cancer (OPC) and its impact on clinical outcomes, neither of which has been well established to date. Methods Our departmental database was queried for patients irradiated for OPC between 2001 and 2007. Analyzable patients were those with imaging data available for review to determine radiographic RPLN status. Demographic, clinical, and outcome data were retrieved and analyzed. Results The cohort consisted of 981 patients. The median follow-up was 69 months. The base of the tongue (47%) and the tonsil (46%) were the most common primary sites. The majority of patients had stage T1 to T2 primary tumors (64%), and 94% had stage 3 to 4B disease. Intensity-modulated radiation therapy was used in 77% of patients, and systemic therapy was administered in 58% of patients. The incidence of radiographic RPLN involvement was 10% and was highest for the pharyngeal wall (23%) and lowest for the base of the tongue (6%). RPLN adenopathy correlated with several patient and tumor factors. RPLN involvement was associated with poorer 5-year outcomes on univariate analysis (P