Prognostic significance of quantitative metastatic lymph node burden on magnetic resonance imaging in nasopharyngeal carcinoma: A retrospective study of 1224 patients from two centers

• Published in: Radiotherapy and oncology Vol. 151; pp. 40 - 46
• Main Authors: Ma, Huali, Liang, Shaobo, Cui, Chunyan, Zhang, Yu, Xie, Fei, Zhou, Jian, Dong, Annan, Chen, Mingyuan, Xie, Chuanbo, Li, Haojiang, Liu, Lizhi
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.10.2020
• Subjects: Humans; Lymph Nodes - diagnostic imaging; Lymph Nodes - pathology; Lymphatic Metastasis; Magnetic Resonance Imaging; Nasopharyngeal carcinoma; Nasopharyngeal Carcinoma - diagnostic imaging; Nasopharyngeal Carcinoma - pathology; Nasopharyngeal Neoplasms - diagnostic imaging; Nasopharyngeal Neoplasms - pathology; Neoplasm Recurrence, Local; Neoplasm Staging; Nodal staging system; Number of positive lymph node; Prognosis; Retrospective Studies; Survival; NPC; LN; OS; IMRT; MRI; AI; MID; HR; RRFS; Number of positive lymph node; Survival; C-index; Nasopharyngeal carcinoma; Magnetic resonance imaging; DMFS; AJCC; EBV; PFS; ENE; RFS; Nodal staging system
• ISSN: 0167-8140; 1879-0887
• DOI: 10.1016/j.radonc.2020.07.023

•The number of MRI-positive lymph nodes, a critical prognostic factor for NPC.•It surpassed the nodal factors used in current N-staging system.•Patients with more than 9 positive LNs were upgraded from stage N2 to N3.•Revised staging system showed higher predictive ability for NPC patients’ survival. The number of metastatic lymph nodes (LNs) has been demonstrated to be an important prognosticator in some head and neck cancers. This study aimed to examine its prognostic value in nasopharyngeal carcinoma (NPC). Patients with newly-diagnosed, non-distant metastatic NPC from two centers were enrolled in this study. According to the radiologic criteria for involved LNs, the number of positive LNs was assessed on MRI. Univariate and multivariate models were constructed to assess the association between the number of positive LNs and clinical outcomes. Exhaustive method was used to determine the cutoff values of the number of positive LNs. In 1224 patients, the number of MRI-positive LNs was an independent risk factor for overall survival (OS), distant metastasis-free survival (DMFS), relapse-free survival (RFS), progression-free survival (PFS) and regional relapse-free survival (RRFS), surpassing other nodal factors. All the patients were divided into no, low (1–4 positive LNs), moderate (5–9 positive LNs) and high (>9 positive LNs) risk groups. The HRs of high-risk group exceeded the HRs of N3 classification for OS, DMFS, RFS, PFS and RRFS. On upgrading patients with more than 9 positive LNs from N2 to N3, the revised N-staging system showed a higher C-index compared to current N-staging system for predicting OS (0.747 vs. 0.741, P = 0.002), RFS (0.655 vs. 0.640, P = 0.015) and PFS (0.674 vs. 0.669, P = 0.035). The number of MRI-positive LNs was a predominant independent prognostic factor for NPC patients’ survival. It may be incorporated into the future N-staging system to improve its accuracy in predicting outcomes.