COMBINED-MODALITY THERAPY FOR SQUAMOUS CARCINOMA OF THE BUCCAL MUCOSA- TREATMENT RESULTS AND PROGNOSTIC FACTORS

Background. Reports on locoregional control and survival of squamous c ell carcinoma of buccal mucosa are scarce in literature. In this study , a single institution's experience of combined surgery and postoperat ive radiotherapy (RT) for buccal mucosal malignancy with favorable res ults was analyzed and presented. The prognostic factors on locoregiona l control were also discussed. Methods. From January 1988 to July 1994 , 57 patients with squamous cell carcinoma of buccal mucosa treated by surgery and RT were reviewed. The distributions according to American Joint Committee on Cancer (AJCC) staging were: stage II, 6; stage III , 21; and stage IV, 30 patients. Total dose of RT at the buccal area r anged from 45 Gy to 68.4 Gy, median 61.2 Gy. Tumor-related factors (AJ CC stage, T stage, histologic grading, pathologic tumor invasion to sk in of cheek, adjacent bony structures, and regional lymph nodes) and t reatment-related factors (surgical margin, radiation dose, and the tim e interval between operation and RT) were analyzed to determine their influence on locoregional control. Results. Three-year actuarial locor egional control rate, overall survival rate, and disease-specific surv ival rates were 64%, 55%, and 62%, respectively. Ten of these 22 patie nts (45%) with recurrent tumors were reoperated, but only 2 patients w ere successfully salvaged. Positive surgical margin and tumor invasion to skin of cheek were significantly poor prognostic factors on locore gional control by univariate analysis. In multivariate analysis, tumor invasion to skin of cheek was the only prognostic factor (p = .0014). Conclusions. Locoregional failure was the major cause of death for sq uamous buccal mucosa cancers managed with surgery and RT. Few recurren ces could be detected early and successfully salvaged. Skin of cheek i nvolvement is an important prognostic factor for buccal mucosa cancers , (C) 1997 John Wiley & Sons, Inc.