Comparative Diagostic Yields in Two Oral Cancer Studies

Oral Squamous Cell Carcinoma (SCCA) in at-risk populations continues to be resistant to reduction in morbidity and mortality. Objectives: Conventional wisdom dictates that early lesion identification may enhance biopsy and change this pattern. We studied biopsy yields in two population-based studies to determine expression of mucosal lesions. Methods: In a study of 13,027 lesions submitted to Temple University Oral Pathology, 56 patients provided suspicious biopsies, and in a study of Tolonium chloride stain in previous surgical and radiation fields, 95 patients provided 83 biopsies with protocol of sequential visual exam followed by Tolonium chloride stain exam, each by a blinded examiner. Pathologists, blind to exam results, provided definitive diagnoses. Results: Temple Pathology biopsies found mild dysplasia (32.8% pts) , moderate-severe dysplasia (32.8%), carcinoma-in situ (8.2%) and SCCA (26.2%). Tolonium chloride study biopsies produced mild dysplasia (13.3%), severe dysplasia (6%), carcinoma-in-situ (10%), SCCA (26.5%) and 44.2% other. Of these biopsies, 40.0% were clinically suspicious for SCCA. 96.2% true SCCA and a majority of erythroplakia (63.9%) were suspicious for cancer. Of histological SCCA, all true positive SCCA were found by positive Tolonium chloride stain, while 40% were visual exam negative. False positive SCCA were found in 5% visual exams, and non-cancers were found in 50% Tolonium chloride stains, also positive in 22% visual exams. Diagnostic yields were similar in both clinical studies, establishing SCCA/carcinoma-in-situ yields of 34.4% to 36.5%. Visual exam sensitivity = 0.40, Positive Predictive Value = 36% while Tolonium chloride sensitivity = 0.98 (p = 0.0002), PPV = 33%, with no Kappa difference. Conclusions: Comparison of contemporary practice standards with Tolonium chloride to aid diagnosis shows stain to be reliable, repeatable and reproducible within at-risk groups. False negative findings were minimal, clinical complications within practice patterns and diagnostic yield enhanced by Tolonium chloride stain. Supported by Zila, Inc.