05-06-2017 | Thyroid cancer | Article
Disease Progression in Papillary Thyroid Cancer with Biochemical Incomplete Response to Initial Therapy
Journal: Annals of Surgical Oncology
Authors: Nicole K. Zern, MD, Roderick Clifton-Bligh, PhD, Anthony J. Gill, MD, FRCPA, Ahmad Aniss, Stan Sidhu, PhD, FRACS, Leigh Delbridge, MD, FRACS, Diana Learoyd, PhD, Bruce Robinson, MD, Mark Sywak, FRACS, MMed Sci
Publisher: Springer International Publishing
Abstract
Background
Dynamic risk stratification is utilized in the follow-up of patients with papillary thyroid carcinoma (PTC). Analysis of outcomes after biochemical incomplete response (BIR) to initial therapy will allow better individualization of care.
Methods
A total of 494 patients with PTC were followed prospectively. Immunohistochemistry (IHC) for BRAFV600E mutation was completed on all surgical specimens. After exclusion of patients with inadequate data, 353 patients were stratified into four categories of response to initial therapy: excellent, biochemical incomplete, structural incomplete, or indeterminate. Patients with BIR, defined as elevated stimulated thyroglobulin >2 µg/L with negative imaging, were analysed for progression of disease. The primary outcome measure was development of structural recurrence.
Results
Forty-nine of 353 (13.9%) patients had BIR. BRAFV600E mutation was present in 32 of 49 (65.3%) with BIR. Progression to structural recurrence occurred in 8 of 49 (16.3%) with BIR, all of whom were positive for the BRAFV600E mutation (p = 0.02). Nine patients (18%) with BIR remitted during follow-up to no evidence of disease (6 had additional RAI therapy). After mean follow-up of 35 months, 12 patients with BIR (24%) remained biochemically abnormal with no structural evidence of disease.
Conclusions
Patients with BIR following initial treatment for PTC have generally favorable outcomes. Positive IHC for BRAFV600E identifies patients at risk of structural disease recurrence.