Prognostic Factors for Persistent or Recurrent Disease of Papillary Thyroid Carcinoma with Neck Lymph Node Metastases and/or Tumor Extension beyond the Thyroid Capsule at Initial Diagnosis

Abstract

Reliable prognostic factors are needed in papillary thyroid cancer patients to adapt initial therapy and follow-up schemes to the risks of persistent and recurrent disease. OBJECTIVE AND SETTINGS: To evaluate the respective prognostic impact of the extent of lymph node (LN) involvement and tumor extension beyond the thyroid capsule, we studied a group of 148 consecutive papillary thyroid cancer patients with LN metastases and/or extrathyroidal tumor extension. Initial treatment, performed at the Institut Gustave Roussy between 1987 and 1997, included in all patients a total thyroidectomy with central and ipsilateral en bloc neck dissection followed by radioactive iodine ablation. Uptake outside the thyroid bed, demonstrating persistent disease, was found on the postablation total body scan (TBS) in 22% of the patients. With a mean follow-up of 8 yr, eight patients (7%) with a normal postablation TBS experienced a recurrence. Ten-year disease-specific survival rate was 99% (confidence interval, 97-100%). Significant risk factors for persistent disease included the numbers of LN metastases (>10) and LN metastases with extracapsular extension (ECE-LN >3), tumor size (>4 cm), and LN metastases location (central). Significant risk factors for recurrent disease included the numbers of LN metastases (>10), ECE-LN (>3), and thyroglobulin level measured 6-12 months after initial treatment after T4 withdrawal. We highlight an excellent survival rate and suggest risk classifications of persistent and recurrent disease based on the numbers of LN metastases and ECE-LN, LN metastases location, tumor size, and thyroglobulin level.