The influence of histologic grade in intraoral squamous cell carcinoma

Abstract

Statement of the Problem: Advances in adjuvant therapies and refinements in ablative and reconstructive techniques during the last decade have improved functional and aesthetic outcomes of patients with oral squamous cell carcinoma (OSCC). However, there has been little change in the overall survival of these patients. Materials and Methods: The purpose of this retrospective study was to review the outcome of patients with OSCC treated at a single institution by primary surgical resection with or without adjuvant radiotherapy or chemoradiotherapy and to identify factors affecting survival and locoregional control. Method of Data Analysis: The records of 233 patients with OSCC treated at a single institution from 1993 to 2003 were identified from the Legacy Emanuel Hospital and Health Center’s cancer registry. All patients undergoing surgical resection as a primary treatment modality were included in the study. Patients with nonresectable disease, distant metastasis, and those with inadequate follow-up data were excluded from the study. Patients with positive surgical margins, high grade histology, aggressive biologic behavior, or advanced staged disease underwent adjuvant radiotherapy or chemoradiotherapy. The data collected included age, sex, race, tumor site, margin status, grade, TNM stage, cancer therapies, and cancer status. Data were statistically analyzed in an attempt to identify predictors of locoregional control and disease-free survival. Descriptive statistics were calculated for each variable and survival was calculated using the Kaplan-Meier method. Prognostic factors were analyzed using the Cox proportional hazard model. Results: Two hundred fifteen patients consisting of 119 males (48%) and 123 females (52%), with an average age at diagnosis of 66 years (SD ± 14), met the criteria for inclusion in the study. Average tumor size was 23.5mm (SD ± 14.1). Site distribution was as follows; 73 (33.5%) tongue, 40 (18.3%) floor of mouth, 13 (6.0%) palate, 19 (8.7%) cheek, 27 (12.4%) retromolar trigone, 31 (14.2%) upper gingiva and 12 (5.5%) lower gingiva, and 3 (1%) tumor of unspecified location. Seventy patients were identified with grade 1 histology (33%), 117 grade 2 (54%), and 28 grade 3 (13%). There were 106 patients with stage 1 disease (49%), 40 with stage 2 (18%), 17 with stage 3 (8%), and 52 with stage 4 (24%). Positive margins were found in 32 patients (15%). Overall 5-year survival was 56% and disease-free survival at 5 years was 58%. Stage and grade were identified as having a statistically significant effect on survival (P = .0014, likelihood ratio chi-square = 10.7, 3 degrees of freedom and P = .026, likelihood ratio chi-square = 5, 1 degree of freedom, respectively). Neither age, sex, race, tumor site, nor positive margins demonstrated a statistically significant effect on survival (P > .05). Conclusion: Tumor grade and stage are important predictors of survival in patients with oral cavity squamous cell carcinoma. References Funk GF, Karnell LH, Robinson RA, et al: Presentation, treatment, and outcome of oral cavity cancer: A National Cancer Database report. Head Neck 24:165, 2002 Shah JP, Cendron RA, Farr HW, et al: Carcinoma of the oral cavity. Factors affecting treatment failure at the primary site and neck. Am J Surg 132:504, 1976