Prognostic determinants in supraglottic carcinoma: univariate and Cox regression analysis

A series of 281 consecutive patients affected by supraglottic cancer and treated with surgery alone or with surgery followed by radiotherapy between 1983 and 1989 was reviewed to identify significant prognostic determinants.

Fifty-one variables (related to host, tumor, and treatment) were tested by univariate and multivariate analysis performed on absolute and determinate survival.

The final model of the multivariate analysis for absolute survival included the following covariates listed in order of higher relative risk of death: extracapsular spread, involvement of the medial wall of the pyriform sinus, thyroid cartilage invasion, metachronous tumor, anesthesiologic risk according to the American Society of Anesthesiologists classification (chi 2 = 71.28 with 6 d.f., p < .00001). The definitive model for determinate survival included: extracapsular spread, involvement of the medial wall of the pyriform sinus, extralaryngeal soft tissue invasion, and thyroid cartilage invasion (chi 2 = 82.74 with 5 d.f., p < .0001).

Extracapsular spread was the most important factor affecting the prognosis of patients with supraglottic carcinoma. A second important finding was that T and N category did not emerge as a significant independent prognostic predictor at multivariate analysis. The negative impact on absolute survival of physical status and metachronous tumor could be the expression of the influence of concomitant diseases on survival. These observations concur to reinforce the concept that the current TNM classification is rather inadequate in predicting the prognosis of patients with supraglottic carcinoma when the aforementioned variables are considered.