Predictive Factors of Lymph Node Involvement in Differentiated Thyroid Cancers

Abstract

Introduction: Thyroid cancer is the most common type of endocrine malignancy. The objective of our study was to determine the pre and intraoperative predictive factors of lymph node involvement in differentiated thyroid cancers.

Material and methods: This is a prospective observational and single-center study over a period of 48 months involving a total of 101 patients diagnosed with papillary thyroid carcinoma without evidence of pre- and intraoperative lymph node metastases (cN0). All patients underwent total thyroidectomy with bilateral prophylactic central dissection performed immediately.

Results: The average age of the male patients was 44.11 years (standard deviation of 14.56), with no significant difference with that of the female sex 46.29 (standard deviation = 15.41). Nodal invasion (pN1a) is found in 22.77% of whom 17/23 are under 55 years old (73.91%) against 6/23 (26.08%) of patients whose age is ≥ 55 years. lymph node invasion ipsilateral to the CPT is found in 9.90% on the left and 10.89% on the right. Bilateral central invasion is found in 2/23 patients, i.e. (1.98%), the number of metastatic nodes varied from 1 to 11 nodes. Extracapsular extension and angioinvasion were significant risk factors for lymph node involvement with p values respectively (p=0.04 and p=0.050).

Conclusion: Adequate understanding and application of prognostic factors is currently our best approach to optimize individual decision-making in patients. In our study a primary tumor size >2.0 cm, extracapsular spread and angioinvasion were significantly correlated risk factors for lymph node metastasis with a number of metastatic nodes qualifying these patients as an intermediate risk group for recurrence according to ATA guidelines. These patients will benefit from prophylactic central dissection even in the absence of clinically evident central compartment lymphoganglion metastasis.