Prognostic value of paranasopharyngeal extension of nasopharyngeal carcinoma on local control and short-term survival

The local tumor control of 262 patients with nasopharyngeal carcinoma (NPC) at median follow-up of 27 months was studied with reference to the paranasopharyngeal and other aspects of extranasopharyngeal extension of tumor, as well as to other possible prognostic factors. Only cranial nerve palsy, oropharyngeal involvement, and paranasopharyngeal extension of tumor were found to be significant in a multivariate analysis using Cox model for factors influencing local tumor control. Other factors and other parameters of extranasopharyngeal extension of tumor, namely, erosion of the base of skull, intracranial extension, and involvement of nasal fossa, were found not to be significant. The degree of paranasopharyngeal extension in each side was correlated with scales measuring extranasopharyngeal extension of tumor in other directions (p = 0.001). Although the T stage and the paranasopharyngeal extension were individually found to be well correlated with local tumor control, the prognostic value of paranasopharyngeal extension remained significant among subgroups of patients with T3 and T4 disease (p = 0.1044 and 0.0010, respectively).