Pathological Features Frequently Found in Recurrent Papillary Thyroid Cancer

Abstract

Objectives: Despite the rising prevalence of malignant papillary thyroid carcinoma, locoregional recurrence remains low. Clinico-pathological features associated with recurrence are not well defined. The objective of this study is to describe and evaluate the various pathological features found in patients with recurrent papillary thyroid carcinoma. Methods: A retrospective review was conducted identifying patients who were found to have recurrent papillary thyroid carcinoma between July 2006 and May 2013 at the McGill University Thyroid Cancer Centre. Results: There was a total of 552 patients with malignant papillary thyroid carcinoma. Over the study period, recurrent disease occurred in 2.0% of patients (n = 11), of whom 10 were pT3N1b and 1 was a pT4aN1. When these patients were compared with the 541 patients who did not have recurrence of their disease, there were significant differences for sex ( P = .0271), size of primary tumor ( P = .0355), positive margins ( =0 0002), lymphovascular invasion ( P < .0001), extrathyroidal extension ( P = .0001), lymph node metastasis ( P < .0001), and extra-nodal extension ( P < .0001). There was no significant difference for age, presence of multifocal disease, and perineural invasion. On regression analysis, positive margins, lymphovascular invasion, regional lymph node metastasis, and extra-nodal extension were found to be independent predictors of recurrence ( P = .0011, P = .0248, P = .0146, and P = .0007, respectively). Conclusions: In patients with papillary thyroid cancer, sex, tumor size, and extra-thyroidal extension are features frequently found in patients with recurrence. However, positive surgical margins, lymphovascular invasion, lymph node metastasis, and extra-nodal extension were found to be independent predictors of recurrence in this study.