Differentiated carcinoma of the thyroid with extrathyroidal extension

Background: We have analyzed our experience with differentiated thyroid cancer patients with extrathyroidal extension (ETE) to investigate patterns of recurrence and define factors that predict failure. Patients and methods: The records of 1,012 patients treated surgically from 1930 to 1985 were reviewed. A total of 79 patients (8%) had ETE. The median length of follow-up was 10 years. Results: Patients with ETE were more likely to fail treatment and to die of their disease than were patients without ETE (77% versus 34% and 71% versus 13%, respectively; P <0.0001). Local, regional, and distant failures were more prominent among patients with ETE than among those without ETE (48% versus 9%, 41% versus 16%, and 37% versus 11% respectively; P <0.0001). Survival of patients with ETE was adversely affected by nonpapillary histology, distant metastasis, age >45, tumor size >4 cm, and incomplete excision (P ≦0.05). After stratification for age, survival in older patients was not affected by tumor size or incomplete excision, while in younger patients tumor size or the presence of distant metastasis did not adversely affect survival. Patients younger than 45 with negative margins had similar survival to patients without ETE (P = 0.46). Conclusions: Patients with ETE are more likely to die of their disease and to fail at all sites. Survival in older patients was not affected by incomplete excision while it was in younger patients. The presence of distant metastasis did not affect survival in younger patients. Our results suggest that among patients under 45, the presence of ETE does not adversely impact upon survival when the primary tumor is completely resected.