Cervical lymph node metastasis in differentiated thyroid carcinoma: does it have an impact on disease-related morbid events?

Abstract

The aim of the study was to evaluate the prognostic impact of cervical lymph node (CLN) metastasis in well-differentiated thyroid cancer (WDTC). A cohort of 164 patients who underwent thyroidectomy for WDTC in the last 12 years was studied. Patients were classified into those with CLN metastasis (group 1) and those without (group 2), with 82 patients in each group. Morbid events (recurrence and death) and prognostic risk factors were analyzed. The mean age of the whole group was 41.3±14.2 years, with 52.4% being at least 45 years old; 69.6% of the patients were female (P=0.02), with a female to male ratio of 2.3 : 1. Near-total thyroidectomy and radioactive iodine-131 therapy were performed in all 81.1% of patients in whom papillary cancer was found. Morbid events were found in 22/164 (13.4%) patients (17 recurrences and five deaths). All recurrences occurred in patients with the papillary subtype, whereas 4/5 deaths occurred in those with follicular thyroid cancer. Morbid events were found in 14/82 (17.1%) and 8/82 (9.6%) patients in group 1 and group 2, respectively (P=0.1). Comparison of morbid events between group 1 and group 2 showed statistically significant differences with respect to tumor size of 1 cm or more, multifocality, and positivity of the follow-up diagnostic tools at 6-12 months. Kaplan-Meier analysis revealed no significant difference between the two groups (P=0.4) over a mean follow-up period of 125.1±14.6 months. Multivariate Cox analysis showed that development of remote deposits, lymph node metastasis five or more nodes, extracapsular nodal invasion in at least three nodes, and positivity of the follow-up diagnostic tools at 6 months were the significant prognostic factors of morbid events. Our study revealed the impact of CLN metastasis on the occurrence of morbid events in WDTC patients (especially in those with the papillary subtype) with node metastasis five or more, extracapsular nodal invasion in at least three nodes, and positivity of follow-up diagnostic tools at 6 months. Hence, these patients should be optimally managed and more closely monitored.