Objective: To identify the risk factors affecting the outcome of operations for differentiated and aggressive thyroid carcinoma which may indicate the need for a more aggressive surgical treatment.
Design: Retrospective study.
Setting: University hospital.
Patients and interventions: 143 patients underwent total thyroidectomy with or without central neck lymphadenectomy or modified neck dissection. There were 85 papillary, 34 follicular, 6 widely-invasive follicular, 6 insular, five oxyphilic, five tall cell, and two diffuse sclerosing papillary carcinomas.
Main outcome measure: Disease-related survival.
Results: At 12-years, the survival was 96%, being 98% among patients with differentiated and 83% among those with aggressive carcinoma (p = 0.0006). Insular and oxyphilic carcinomas had the worst prognosis (at 10 years, 67% and 60%, respectively, p < 0.0001). The high-risk age, metastases, and extent score (AMES) group had worse survival than the low-risk group (12 years, 84% compared with 98%, p = 0.001). Among patients with differentiated carcinoma, the low-risk AMES group had also better outcome than those in the high-risk AMES group (at 12 years, 100% compared with 86%, p < 0.0001), but there was no such difference among patients with aggressive disease. Multivariate analysis showed that women (RR 14.28, 95% confidence interval (CI) 1.13 to 180.28), patients with tumours > or = 5 cm in size (RR 9.60, 95%CI 1.01 to 91.43) and AMES high-risk patients (RR 30.17, 95% CI 1.57 to 577.48) had the worst outcome.
Conclusion: In patients with differentiated thyroid carcinoma, total thyroidectomy and, if the AMES score indicates a high risk, central neck lymphadenectomy with or without modified neck dissection, is associated with a favourable outcome. Poorer outcome is expected if the carcinoma is aggressive, and an aggressive surgical approach is advocated as a routine.