Vascular Invasion Predicts Advanced Tumor Characteristics in Papillary Thyroid Carcinoma
Papillary Thyroid Carcinoma (PTC) comprises more than 85% of the differentiated thyroid carcinomas. It has an incidence of 14.9 per 100,000, and has an overall 5-year survival rate of 97.5%. A variety of factors have been shown to increase recurrence of PTC, including age, soft tissue invasion, and distant metastases. There is evidence that vascular invasion in PTC is associated with a higher rate of tumor recurrence, but its association with other tumor features remains unclear.
In a single-institution retrospective review from January 2007 through December 2011, patients who had a diagnosis of thyroid malignancy through surgical pathology following thyroidectomy were identified. In those with PTC, we assessed correlation of vascular invasion with tumor recurrence, lymphatic invasion, capsular invasion, and tumor size.
Of the 536 patients identified with PTC, with a median length of thyroid cancer follow up of 8.6 years, 56 (10.4%) were found to have vascular invasion. Tumor recurrence was more likely in patients with vascular invasion (17.8%) than in those without (3.2%; P= < 0.0001, OR=6.68, 95% CI 2.79, 15.88). Lymphatic invasion was more common in the presence of vascular invasion (58.2%) than in its absence (14.5%; P= < 0.0010; OR=7.99, 95% CI 4.26, 15.37), as was capsular invasion (39.3% vs 11.3%, P < 0.0001, OR 12.2, 95% CI 4.5, 30.4). Logistic regression analysis showed that, in our model, tumor size is a moderate predictor of vascular invasion (AUC=0.7, 95% CI 0.66, 0.78, P < 0.0001; OR 1.3, 95%CI 1.1, 1.6).
In our dataset, the presence of vascular invasion in PTC was associated increased likelihood of lymphatic invasion within the specimen along with higher recurrence rate upon follow-up. Additionally, tumor size was found to be a predictor of vascular invasion. When confronted with larger tumor size one should consider total thyroidectomy at the index operation as vascular invasion, and therefore recurrence, is a higher concern.
Reilly J, Faridmoayer E, Lapkus M, Pastewski J, Sun F, Elassar H, et al. Vascular invasion predicts advanced tumor characteristics in papillary thyroid carcinoma. Paper presented at: The 78th Annual Meeting of the Central Surgical Association and the Midwest Surgical Association Combined Meeting; 2021 Jul 25-27; Virtual. Available at: https://centralsurg.org/meeting/program/2021/36.cgi