Metastatic Lymph Node Ratio for Predicting Recurrence in Medullary Thyroid Cancer

Abstract

The lymph node ratio (LNR) has been investigated as a prognostic factor in many different types of cancers, including differentiated thyroid cancer; however, reports regarding medullary thyroid cancer (MTC) are limited. Therefore, this study aims to evaluate LNR as a risk factor for structural recurrence in patients with MTC. Medical records of patients treated for MTC in a single tertiary center between 1995 and 2017 were retrospectively reviewed. LNR is defined as the number of metastatic lymph nodes or lymph node metastases (LNM) divided by the number of retrieved lymph nodes or lymph node yield (LNY). In the survival analysis, recurrence-free survival was defined as the time from the date of total thyroidectomy to recurrence or last follow-up. To identify risk factors influencing structural recurrence, univariable and multivariable Cox proportional hazard models were used. A total of 132 patients were enrolled. The mean age of study participants was 49.7 years, and 86 patients (65%) were women. Structural recurrence was identified in 39 patients at the end of the study period, and the median follow-up period was 8.7 years. In univariable analyses, gross extra thyroidal extension, N stage, postoperative serum calcitonin and carcinoembryonic antigen (CEA) levels, and LNR were significant (p < 0.05) predictors of structural recurrence. In multivariable analysis, postoperative serum calcitonin, postoperative serum CEA, and LNR were identified as a predictor of disease-free survival (p < 0.05). LNR can potentially predict structural recurrence as a quantitative evaluation tool for lymph node metastasis in patients with MTC.

Establishment and validation of a nomogram model for predicting distant metastasis in medullary thyroid carcinoma: an analysis of the SEER database based on the AJCC 8th TNM staging system

“…Therefore, 0.3, as our cut-off value, is more clinically applicable than previous studies.In addition to predicting survival, the lymph node ratio can potentially predict recurrence and distant metastases in MTC. 10,34 We came to similar conclusion, LNR>0.3 (OR=2.075, 95%CI:1.030-4.181, P=0.041) was a signi cant predictor of distant metastasis.…”

Genetic and clinical profiles of 160 papillary thyroid cancers with lateral neck lymph node metastasis

“…Nevertheless, no statistical difference was found in LNR between mutation types after PSM matching. LNR, a way to mitigate the effects of surgery, is computed by dividing the number of metastatic lymph nodes by the total number of lymph nodes evaluated ( 13 ). The discrepancy in LNR and absolute values may be related to the insufficient sample size after matching and the limitation of retrospective studies.…”

“…Conventionally, the lymph node ratio (LNR) was calculated as the number of metastatic lymph nodes or lymph node metastases (LNM) divided by the number of retrieved lymph nodes or lymph node yield (LNY) ( 13 ).…”

Establishment and validation of a nomogram model for predicting distant metastasis in medullary thyroid carcinoma: An analysis of the SEER database based on the AJCC 8th TNM staging system

“…Therefore, 0.4, as our cut-off value, is more clinically applicable than previous studies. In addition to predicting survival, the lymph node ratio can potentially predict recurrence and distant metastases in MTC ( 10 , 34 ). We came to a similar conclusion, LNR > 0.4 was an independent significant predictor of distant metastasis.…”