Prognostic importance of vascular invasion in papillary thyroid carcinoma

Background: The prognostic importance of vascular invasion has not been ext ensively studied in patients with papillary thyroid cancer. Objective: To determine whether the presence of vascular invasion in papill ary thyroid carcinoma, even within the thyroid gland, is associated with mo re aggressive disease at diagnosis and a higher incidence of tumor recurren ce. Patients and Methods: We identified 410 patients who had been diagnosed wit h papillary thyroid cancer since 1986 who had a follow-up period of longer than 1 year (median follow-up, 5.5 years). Pathology reports were reviewed and patients were separated into 3 groups: no vascular invasion, intrathyro idal vascular invasion, and extrathyroidal vascular invasion. Main Outcome Measures: Statistical comparison was performed by univariate a nd multivariate analysis. Results: Patients with intrathyroidal vascular invasion were more likely to have distant metastasis at the lime of diagnosis (26.1% vs 2.2%, P =.001). Similarly, patients with extrathyroidal vascular invasion had a higher inc idence of distant metastases at diagnosis (40% vs 4.4%, P =. 02). Patients with tumors identified to have intrathyroidal vascular invasion were more l ikely to develop distant recurrence (20% vs 3%, P =.002). Conclusions: These associations were found to be independent by multiple re gression analysis. Patient age, sex, palpable or fixed lymph nodes, radiati on exposure, and race did not differ between the patient group with and tho se without vascular invasion. Preliminary analysis of our data suggests tha t the presence of vascular invasion in papillary thyroid carcinoma, even wi thin the thyroid gland, is associated with more aggressive disease at diagn osis and with a higher incidence of tumor recurrence.