3538 - Structure-Specific Involvement in Advanced Cervical Lymph Node Extranodal Extension Predicts Prognosis in Nasopharyngeal Carcinoma: A Multi-Center Study
Presenter(s)
J. Liu1,2, C. He1, T. Jin1, T. Bu1,2, T. Qiu1, B. Lu1, H. Zhou3, X. Jiang1,2, J. Wu1, S. Huang1, X. J. Du4, J. Gao5, X. Chen6, Y. Zhu7, X. He1, and L. Wu1,2; 1Department of Radiation Oncology, Nanjing Medical University Affiliated Cancer Hospital, Jiangsu Cancer Hospital and Jiangsu Institute of Cancer Research, Nanjing 210009, Nanjing, Jiangsu, China, 2Jiangsu Key Laboratory of Innovative Cancer Diagnosis & Therapeutics, Nanjing, Jiangsu, China, 3Department of Radiation Oncology, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, China, 4Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer,Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China, 5Department of Radiation Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China, 6Department of Radiation Oncology, Zhejiang Cancer Hospital, Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences, Hangzhou, China, 7Department of Radiology, Nanjing Medical University Affiliated Cancer Hospital, Jiangsu Cancer Hospital and Jiangsu Institute of Cancer Research, Nanjing 210009, Nanjing, Jiangsu, China
Purpose/Objective(s): To further explore the prognostic value of advanced cervical lymph node (CLN) extranodal extension (ENE) involving different structures and whether it may exert synergistic effects with other nodal features.
Materials/Methods:
A total of 1,373 non-metastatic NPC patients at three centers between 2011 and 2021 were enrolled. For advanced CLN ENE, all involved structures, maximum axial diameter (MAD), presence of necrosis, and bilaterality were documented. Adjusted hazard ratios (AHRs) and random survival forests were used to identify the high-risk structure group. Kaplan–Meier methods and multivariable Cox models were applied to analyze overall survival (OS), progression-free survival (PFS), locoregional relapse-free survival (LRRFS), and distant metastasis-free survival (DMFS).
Results:
CLN metastasis was present in 1135 of 1,373 patients (82.7%), among whom 169 (14.9%) had advanced CLN ENE. The high-risk structure group included the hyoid muscles, scalene muscles, longissimus cervicis muscle, interval muscles (obliquus capitis inferior muscle, semispinalis capitis muscle, longus colli muscle, medial pterygoid muscle, trapezius muscle), carotid artery, lower cranial nerves region, and skin. Other potentially involved structures were assigned to the intermediate-risk structure group. Advanced CLN ENE with involvement of high-risk structures (defined as high-risk CLN ENE) was the only independent adverse prognostic factor after adjusting for confounding factors. A significant survival difference was observed between high-risk and intermediate-risk CLN ENE (other advanced CLN ENE). For N1/N2 patients, high-risk CLN ENE was associated with survival similar to N3 (AHRs>1); intermediate-risk CLN ENE had better OS than N3 while PFS/DMFS were comparable (AHRs<1).Conclusion: Compared with necrosis, MAD, or bilateral involvement, stratification based on involved structures more effectively discriminates the prognostic differences of advanced CLN ENE in NPC patients. N1/N2 patients with either high-risk or intermediate-risk CLN ENE have outcomes relatively close to those with N3 disease but exhibit substantial heterogeneity.
| Table. Multivariate analysis of prognostic factors in 1135 patients with positive CLNs | |||||||||
| Characteristic | N | OS | PFS | LRRFS | DMFS | ||||
| AHR (95% CI) a | P-Value | AHR (95% CI) a | P-Value | AHR (95% CI) a | P-Value | AHR (95% CI) a | P-Value | ||
| N3 as reference | 167 | ||||||||
| Other N1 | 523 | 0.34 (0.23-0.50) | p<.001 | 0.38 (0.29-0.51) | p<.001 | 0.60 (0.38-0.95) | p=.029 | 0.31 (0.21-0.44) | p<.001 |
| Other N2 | 349 | 0.43 (0.29-0.64) | p<.001 | 0.50 (0.37-0.67) | p<.001 | 0.68 (0.42-1.10) | p=.115 | 0.37 (0.25-0.54) | p<.001 |
| N1/N2 with intermediate-risk CLN ENE | 49 | 0.31 (0.13-0.72) | p=.007 | 0.67 (0.41-1.08) | p=.102 | 1.17 (0.58-2.36) | p=.656 | 0.62 (0.33-1.13) | p=.117 |
| N1 with high-risk CLN ENE | 14 | 1.71 (0.79-3.74) | p=.176 | 1.10 (0.52-2.30) | p=.803 | 2.34 (0.88-6.16) | p=.087 | 1.10 (0.43-2.82) | p=.840 |
| N2 with high-risk136 CLN ENE | 33 | 1.68 (0.93-3.03) | p=.085 | 1.38 (0.84-2.26) | p=.207 | 1.57 (0.68-3.62) | p=.291 | 1.22 (0.67-2.22) | p=.509 |