Primary radiotherapy of squamous cell carcinoma of the oropharynx and pharyngolarynx: tentative multivariate modelling system to predict the radiocurability of neck nodes.

In a series of 1251 cases of squamous cell carcinomas of oropharynx and pharyngolarynx with clinically positive neck and treated primarily by radiation therapy a determinate group of 798 cases remained eligible for a multivariate analysis of the prognostic factors related to the regional outcome. Node size (p less than 0.0001), node fixity (p = 0.016) and T stage (p = 0.02) were the significant pretreatment factors independently predictive of neck node control. when regarding the treatment modalities in this determinate group of patients who received tumor doses of at least 55 Gy, only the treatment duration was found to be predictive (p = 0.002). Based on these factors, a multivariate model was constructed and tested by estimating the product-limit survival of the various groups of patients. The predictive accuracy of the equation was assessed by the log-rank test significance levels. The model may help to select, in many clinical situations, the appropriate approach of the management of metastatic neck disease, either by definitive radiation therapy or by combined modalities.