Tumor biologic prognostic parameters in T1N0M0 squamous cell carcinomas ofthe oral cavity

Background: Conventional prognostic factors in squamous cell carcinomas are tumor stage, tumor size, evidence of lymphnode metastases, extracapsular s pread of lymphnode metastases, and Broder's grading. Unfortunately these pa rameters are only of limited value in predicting the biological behavior an d ultimately the prognosis of a particular tumor. The present study was con ducted for determining objective prognostic factors based on tumor biologic examinations in patients with squamous cell carcinomas of the oral cavity. These parameters were compared to the conventional prognostic factors. Pat ients and Methods: Operative specimens of fourty-two patients who underwent surgery for a squamous cell carcinoma of the oral cavity with clinical TNM stage T1N0M0 were examined. All tumors were radically excised with histolo gic clear margins, which were confirmed by serial sections. The examination s included morphologic multifactorial tumor front grading, quantitative DNA analysis, and immunohistochemical assessment of proliferation markers (i.e . proliferating cell nuclear antigen [PCNA] and MIB1) and of oncogene produ cts (i.e. p53; nm23). Prognostic significance of particular parameters was evaluated by univariate and multivariate Cox regression models. Results: In clinical followup of 70 months on average, 6 patients developed local recu rrences and 5 patients lymphnode metastases. Three patients died of disease . Tumors which recurred had increased values for 2c Deviation Index, 5c Exc eeding Rate along with high tumor front grading scores and proliferation sc ores. Using multivariate Cox regression analysis, parameters which were hig hly significant for prognosis were 5c Exceeding Rate, tumor front grading s core and PCNA score. None of the clinical parameters achieved statistical s ignificance in the multivariate model. Tumors which recurred had also incre ased expression rates for p53 and nm23. Nevertheless this was statistically not significant. Conclusions: Tumor biologic examinations provide importan t informations about the clinical aggressivenes and ultimately about the pr ognosis of a particular tumor, Tumors with aggressive behavior can already be identified during initial diagnosis, which has consequences for the ther apeutic management of the patients.