The surgical management of laryngotracheal invasion by well-differentiated papillary thyroid carcinoma

Objectives: To determine prognostic factors for survival in patients with invasive well-differentiated thyroid carcinoma, specifically examining laryngotracheal invasion as an independent prognostic factor, and to compare types of surgical resection to determine treatment efficacy. Design: Retrospective review of patients with papillary invasive well-differentiated thyroid carcinoma surgically treated over 45 years. Setting: Academic tertiary care medical center. Patients: A total of 292 patients with invasive well-differentiated thyroid carcinoma were surgically treated between 1940 and 1995. Informed consent was obtained from all patients. Extent and location of tumor invasion were determined. Invasion of larynx and/or trachea occurred in 124 patients (41%). Patterns of invasion and techniques of surgical resection were evaluated. Intervention: Types of surgical resection performed: complete tumor removal (n=34), ''shave'' excision (n=75), and incomplete tumor excision (n=15). Main Outcome Measures: Cox regression analysis was used to determine significance of prognostic factors for survival; Kaplan-Meier curves were used to evaluate survival. A P value of less than .05 was statistically significant. Results: Patterns of invasion by thyroid carcinoma included direct spread through laryngeal framework into paraglottic space or spread from involved lymph nodes. Laryngotracheal invasion was a significant, independent, prognostic factor for survival (P<.05). Significance was reached when types of resection were compared for all patients (P<.05) as well as for those with laryngotracheal invasion alone (P<.001). Conclusions: Laryngotracheal invasion was a significant independent prognostic factor for survival (P<.05). When types of surgical resection were compared, the survival rates of patients who underwent shave excision were not different from those of patients who underwent radical tumor resection if gross tumor did nor remain (P>.05). Tumors with minimal invasion may be treated by shaving tumor from the aerodigestive tract. Gross intraluminal involvement should be resected completely to prevent complications.