Prognostic influence of parapharyngeal space involvement in nasopharyngeal carcinoma

Abstract

Purpose: To assess the prognostic influence of parapharyngeal space involvement in nasopharyngeal carcinoma (NPC).Methods and Materials: From January 1987 to December 1994, 197 untreated NPC patients were examined by CT scan before treatment. The parapharyngeal space was separated into pre-styloid and post-styloid compartments on axial images by the styloid process. Potentially significant parameters were analyzed by both univariate and multivariate methods using SPSS 8.0 software.Results: The actual survival, disease-free survival, and local failure-free rates were affected by the presence of parapharyngeal space involvement (p = 0.0115, p = 0.0035, p = 0.0367, respectively). The 5-year actual survival, disease-free survival, and the local failure–free rates in the patients without parapharyngeal space disease, or with pre-styloid and post-styloid compartment involvement were 87.9%, 88.0%, 96.9% and 75.0%, 71.2%, 93.7% and 60.5%, 57.7%, 86.8%, respectively. Parapharyngeal space involvement correlated well with lymphadenopathy and advanced N disease. Distant metastasis is more likely in the presence of obvious post-styloid compartment involvement (p = 0.0153). Age is a strong prognostic factor for survival.Conclusion: Parapharyngeal tumor involvement has significant predictive value. The parapharyngeal space involvement affects local tumor failure, regional tumor failure, and distant metastasis. Its survival rate is low