THE PROGNOSTIC-SIGNIFICANCE OF PARAPHARYNGEAL TUMOR INVOLVEMENT IN NASOPHARYNGEAL CARCINOMA

From 1984 to 1989, 903 treatment-naive non-disseminated nasopharyngeal carcinomas (NPCs) were given primary radical radiotherapy. All patien ts had computed tomographic and endoscopic evaluation of the primary t umour. Potentially significant parameters were analysed by both univar iate and multivariate methods for independent significance. In the who le group of patients, the male sex, skull base and cranial nerves(s) i nvolvement, advanced Ho N-level, presence of fixed or partially fixed nodes and nodes contralateral to the side of the bulk of the nasophary ngeal primary, significantly determined survival and distant metastasi s rates, whereas skull base and cranial nerve involvement, advanced ag e and male sex significantly worsened local control. However in the Ho T2No subgroup, parapharyngeal tumour involvement was the most signifi cant prognosticator that determined distant metastasis and survival ra tes in the absence of the overriding prognosticators of skull base inf iltration, cranial nerve(s) palsy, and cervical nodal metastasis. The local tumour control of the Ho T2No was adversely affected by the pres ence of oropharyngeal tumour extension. The administration of booster radiotherapy (20 Gy) after conventional radiotherapy (60-62.5 Gy) in t umours with parapharyngeal involvement has led to an improvement in lo cal control, short of statistical significance.