Followup of patients with papillary thyroid cancer: in search of the optimal algorithm

Cervical recurrence occurs in up to 30% of patients after surgical treatment for papillary thyroid cancer. This study sought to determine an appropriate algorithm for followup evaluation.

Patients undergoing total thyroidectomy for papillary thyroid cancer were identified. Clinicopathologic data were recorded, as were the results of all followup evaluations including radioiodine scan, cervical ultrasonography, and serum thyroglobulin levels. The disease recurrence-free survival probability was estimated, and risk factors for recurrence were determined.

Thyroidectomy with or without neck dissection was performed in 162 patients. We excluded 36 patients (followup less than 6 months in 26, extracervical disease at diagnosis in 4, unknown tumor size in 6) from the analysis. Of the remaining 126 patients, 109 (86.5%) had no evidence of disease, with serum thyroglobulin < 1 ng/mL at last followup; 4 (3.2%) had no evidence of disease (negative imaging), with serum thyroglobulin > 1 ng/mL, and 13 (10.3%) had recurrent disease. Cervical recurrence occurred in nine patients, all detected by routine ultrasonography. Pulmonary metastases occurred in four patients; three were diagnosed by chest CT and one by radioiodine scan. Thyroid stimulating hormone-suppressed thyroglobulin levels were available in 11 of the 13 patients and were elevated in 9. Patients with high T stage (extrathyroidal extension), or high N stage had an increased risk of recurrence.

A followup strategy emphasizing routine cervical ultrasonography and unstimulated thyroglobulin is effective in identifying patients with recurrent papillary thyroid cancer, and may minimize the indiscriminate use of therapeutic radioiodine for radiographically occult disease. Surgery remains the optimal treatment of cervical recurrence, which is the dominant pattern of treatment failure.