3694 - Prognostic Value of Necrotic Features in Cervical Lymph Nodes in Stage IB Nasopharyngeal Carcinoma: Base on the 9th Edition AJCC/UICC Staging System
Presenter(s)
J. Zhong1, H. Chen2, X. Chen1, H. Xu2, J. Pan2,3, and Q. Guo2,4; 1Department of Radiology, Clinical Oncology School of Fujian Medical University, Fujian Cancer Hospital, Fuzhou, Fujian, China, 2Department of Radiation Oncology, Clinical Oncology School of Fujian Medical University, Fujian Cancer Hospital, Fuzhou, Fujian, China, 3Oncology Department, Zhangzhou Zhengxing Hospital, Zhangzhou, Fujian, China, 4NHC Key Laboratory of Cancer and Metabolism (Fujian Cancer Hospital), Fuzhou, Fujian, China
Purpose/Objective(s): Lymph node necrosis (LNN) and imaging extranodal extension (iENE) are considered two crucial imaging features of malignant lymph nodes (LNs), serving as key markers of an unfavorable prognosis. The 9th edition of the tumor - node - metastasis (TNM) staging system has upstaged patients with very advanced iENE to the N3 category. However, whether LNN can significantly impact the prognosis of nasopharyngeal carcinoma (NPC) in TNM - 9 remains unknown. This study aimed to investigate the prognostic significance of LNN and its different radiographic features in stage IB nasopharyngeal carcinoma (NPC) patients, according to the TNM - 9. This assessment intends to characterize the association between distinct LNN features and clinical outcomes, with a particular focus on identifying high - risk predictors of treatment failure in stage IB patients.
Materials/Methods: This retrospective study analyzed NPC patients who were restaged as Stage IB according to the TNM - 9 staging system at our institution from January 2017 to December 2019. The presence of LNN and relevant characteristics, including the number of necrotic LNs, the maximum number of necrotic lesions, and the minimum axial diameter (MID) of the largest necrotic area, were recorded. Analyze the impact of lymph node necrosis and its different radiographic features on 5 - year OS, LRC, and DC. Use the Cox proportional hazards model to identify the necrosis indicators that best predict prognosis.
Results:
A total of 318 NPC patients with stage IB were included in this study, of whom 91 (28.6%) had LNN. LNN was an independent prognostic factor for OS and DC. In patients with LNN, multiple LNNs and LNN - MID were more significant prognostic indicators. Patients were divided into four groups based on these two risk factors: Group A (without LNN); Group B (with LNN but no risk factors); Group C (with one risk factor); Group D (with two risk factors). Pairwise comparisons of 5 - year OS among the four groups showed no significant difference between Groups A and B (p = 0.53) and between Groups C and D (p = 0.47). However, there were significant differences between Groups A and B compared with Groups C and D (p < 0.05). Therefore, for further analysis, Groups A and B were combined as the non - high - risk LNN group, and Groups C and D were combined as the high - risk LNN group. Kaplan - Meier analysis confirmed significantly inferior 5 - year OS (82.6% vs. 99.2%, p << 0.001), LRC (88.3% vs. 96.5%, p = 0.02), and DC (82.6% vs. 98.4%, p << 0.001) in the high - risk LNN group. Multivariate analysis results indicated that high - risk LNN is an independent negative prognostic factor for OS and DC.Conclusion: High-risk LNN (multiple LNNs and/or LNN - MID = 5 mm) was validated as an independent prognostic indicator for stage IB NPC, which effectively demonstrated robust prognostic utility for risk stratification in stage IB patients.