• A retrospective review of records and microscopic slides was carried out on 151 patients, encompassing nine specific upper aerodigestive tract cancer sites, correlating depth of invasion with node metastases and outcome. In this preliminary descriptive study, thickness was found to be more closely related to node metastasis and to survival than was surface diameter in middle-stage tumors, particularly in tongue, floor of the mouth, buccal mucosa, gum, and soft palate sites. Thickness, depth of penetration, and bone involvement appear to represent the degree of general tumor aggressiveness better than does surface extent. A substitution of thickness measurement for surface diameter (T) in the present TNM staging system is suggested.
(Arch Surg 1986;121:1410-1414)