Lymphovascular invasion and risk of recurrence in papillary thyroid carcinoma

Background Lymphovascular invasion (LVI) is an established adverse prognostic factor in many cancers, however, there are few studies assessing its significance in papillary thyroid carcinoma (PTC). We aimed to determine if LVI is an independent prognostic factor in PTC. Methods We conducted a single institution retrospective analysis of 610 patients with PTC treated between 1987 and 2016. LVI was defined as the presence or absence of cancer cells in blood vessels and/or lymphatics on histopathology. Multivariate Cox regression analysis was used to evaluate the association between LVI and recurrence‐free survival (RFS). Results The study cohort included 481 (78.9%) females and 129 (21.1%) males, with a median age of 47.6 years and median follow‐up of 3.4 years. LVI was present in 56 (9.2%) patients and was associated with nodal metastases (P