Abstract 5177: Lymph node ratio is superior to AJCC N stage for predicting recurrence in papillary thyroid carcinoma

Abstract

Objective: Recently, lymph node ratio (LNR) has emerged as an alternative to American Joint Committee on Cancer (AJCC) N stage, with superior prognostic value. The utility of LNR in Middle Eastern Papillary thyroid carcinoma (PTC) remains unknown. Therefore, we retrospectively analyzed a large cohort of 1407 PTC patients for clinico-pathological associations of LNR. Methods: Receiver operating characteristics (ROC) curve was used to determine the cut-off for LNR. We also performed multivariate logistic regression analysis to determine whether LNR or AJCC N stage was superior in predicting recurrence in PTC. Results: Based on ROC curve analysis, a cut-off of 0.15 was chosen for LNR. High LNR was significantly associated with adverse clinico-pathological characteristics such as male sex, extrathyroidal extension, lymphovascular invasion, multifocality, bilateral tumors, T4 tumors, lateral lymph node (N1b) involvement, distant metastasis, advanced tumor stage, ATA high risk category and tumor recurrence. On multivariate analysis, we found that LNR was a better predictor of tumor recurrence than AJCC N stage (Odds ratio: 1.96 vs. 1.30; p value: 0.0184 vs. 0.3831). We also found that LNR combined with TNM stage and ATA risk category improved the prediction of recurrence-free survival, compared to TNM stage or ATA risk category alone. Conclusions: The present study suggests LNR is an independent predictor of recurrence in Middle Eastern PTC. Integration of LNR with 8th edition AJCC TNM staging system and ATA risk stratification will improve the accuracy to predict recurrence in Middle Eastern PTC and help in tailoring treatment and surveillance strategies in these patients. Citation Format: Sandeep K. Parvathareddy, Abdul K. Siraj, Zeeshan Qadri, Saeeda O. Ahmed, Nabil Siraj, Felisa DeVera, Padmanaban Annaiyappanaidu, Maria A. Sabido, Wael Haqawi, Hassan Aldossari, Khawla S. Al-Kuraya. Lymph node ratio is superior to AJCC N stage for predicting recurrence in papillary thyroid carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5177.

Risk-stratified Distant Metastatic Thyroid Cancer with Clinicopathological Factors and BRAF/TERT Promoter Mutations

“…Ho et al (2021) further evaluated the prevalence of DM in well-differentiated thyroid carcinoma based on their lymph node (LN) burdens and found that the metastasis prevalence increased in a manner dependent on LN numbers 15 . Besides, the metastatic lymph node ratio has been found to be superior to N stage in predicting PTC recurrence 6 .…”

“…To enable early identification of patients with DM risks, several clinic-pathological features have been proposed. Older age 3 , male sex 4 , and pathologic factors like T stage 5 , lymph node metastasis (LNM) 6 , and extrathyroidal extension (ETE) 7 were reported to predict DM. Besides, genetic alterations among candidate genes were also postulated to improve the risk stratification of TC in recent years.…”

Lymph Node Ratio Predicts Recurrence in Patients with Papillary Thyroid Carcinoma with Low Lymph Node Yield

“…A systematic review of nine retrospective studies showed that LNR was an independent predictor of loco-regional recurrence in metastatic PTC [11]. Furthermore, Parvathareddy et al reported that LNR was a better predictor of tumor recurrence than the American Joint Committee on Cancer (AJCC) N stage (odds ratio 1.96 vs. 1.30, p value 0.0184 vs. 0.3831) [12]. The aim of this study was to validate the relationship between LNR and the risk of recurrence in patients with PTC and only one to five LNs examined.…”