Prognostic influence of parapharyngeal space involvement in nasopharyngeal carcinoma

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 (C) 2002 Elsevier Science Inc.