PROGNOSTIC-SIGNIFICANCE OF DEPTH OF INVASION IN CANCER OF THE LARYNX

To determine the prognostic significance of depth of invasion in laryn geal cancer, the depth of invasion of tumor was measured with an ocula r micrometer on the laryngectomy specimens of 94 surgically treated pa tients with T1, T2, and T3 laryngeal cancer and was expressed in milli meters. There was a significant negative correlation between the depth of invasion and disease-free survival. The tumors with no clinical in volvement of regional lymph nodes in neck (NO neck) had significantly less depth of invasion than those with involvement (N+ neck). The tumo rs with pathologically confirmed cervical lymph node metastasis had si gnificantly more depth of invasion than those without metastasis. For tumors with a depth of invasion equal to or greater than 3.25 aaarn, t he rate of cervical metastasis in this study has always been significa ntly higher than for those with a depth of invasion less than 3.25 mm (P < .05), The mean depths of invasion for cases with and without recu rrence were not significantly different, According to the multivariate analysis, depth of invasion (P = .047) and patient age (P = .113) sig nificantly affected the disease-free survival independently. The depth of invasion did not significantly affect the recurrence and the inter val between surgery and the development of recurrence (P > .15). The d epth of invasion should be measured in every laryngectomy specimen. Th e depth of invasion influences the cervical metastasis and disease-fre e survival significantly but does not affect the recurrence rate. The depth of invasion plays an independent role in determining the disease -free survival.