[Prognosis of Papillary Thyroid Carcinoma with Local Invasion]

The aim of this study was to detect prognostic factors in patients with locally advanced papillary thyroid carcinoma.

The study included 72 patients (T4a/T4b 72/0, N0/N1a/N1b 25/15/32, M0/M1 68/4, mean follow-up 8.1 4.4 years) who underwent initial surgical treatment at Osaka Red Cross Hospital between April 1993 and April 2011.

Eleven patients died of PTC, 3 patients with recurrence died of unrelated disease and 10 patients are alive with recurrence. The overall 5-year survival rate was 88.3%, and the 10-year survival rate was 73.4%. The disease-specific 5-year survival rate was 91.4%, and the 10-year survival rate was 88.6%. The 5-year local control rate was 94.1%, and the 10-year local control rate was 85.4%. Patients with distant metastasis (M1), tracheal invasion and/or multiple organs invasion showed a significantly worse disease-specific survival rate based on a univariate analysis, which also revealed that tracheal invasion, laryngeal invasion, esophageal invasion and multiple organs invasion were risk factors linked to the development of distant metastasis during follow-up (recurrence as distant metastasis). The following were found to be clinically significant risk factors, based on the multivariate analysis among tracheal invasion, laryngeal invasion, esophageal invasion and recurrent laryngeal nerve invasion : Tracheal invasion was a risk factor for disease-specific survival, and tracheal invasion and laryngeal invasion were risk factors for recurrence as distant metastasis.

In this study, distant metastasis, multiple organs invasion, tracheal invasion and/or laryngeal invasion were shown to be higher risk factors.