Yanping Mao1, Shunxin Wang1, William Lydiatt2, Jatin P Shah3, A Dimitrios Colevas4, Anne W M Lee5, Brian O'Sullivan6, Rui Guo1, Weijie Luo1, Yupei Chen1, Li Tian7, Linglong Tang1, Ying Sun1, Lizhi Liu7, Jian Ren8, Jun Ma9. 1. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China. 2. Department of Otolaryngology, University of Nebraska Medical Center, Omaha, United States. 3. Department of Head and Neck Surgery, Memorial Sloan Kettering Cancer Center, United States. 4. Department of Medicine, Division of Medical Oncology, Stanford University School of Medicine, United States. 5. Department of Clinical Oncology, The University of Hong Kong and the University of Hong Kong-Shenzhen Hospital, Hong Kong, China. 6. Department of Radiation Oncology, Princess Margaret Cancer Centre, University of Toronto, Canada. 7. Imaging Diagnosis and Interventional Center, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China. 8. School of Life Sciences, Cancer Center, Sun Yat-sen University, Guangzhou, China. 9. Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, China. Electronic address: majun2@mail.sysu.edu.cn.
Abstract
BACKGROUND AND PURPOSE: To explore the prognostic value of different radiologic extranodal extension (rENE) grades and their potential improvement for the 8th edition N category in nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: From 2009 to 2013, a cohort of 1887 patients with NPC was retrospectively enrolled and randomized to the training (n = 955) and validation (n = 932) groups. rENE was categorized as follows: grade 0, nodes without rENE; grade 1, nodes with rENE infiltrating the surrounding fat only; grade 2, matted nodes; grade 3, nodes with rENE infiltrating adjacent structures. RESULTS: The percentage of patients with MRI-positive cervical nodes was 66.5% (1254/1887), of whom grade 0, 1, 2 and 3 rENE cases accounted for 33.2% (416/1254), 14.9% (187/1254), 36.5% (458/1254) and 15.4% (193/1254), respectively. The kappa coefficients for the inter-rater and intra-rater assessments were 0.63, 0.51, 0.65 and 0.93, and 0.76, 0.69, 0.72 and 1.0 in grade 0, 1, 2 and 3 rENE, respectively. Grade 3 rENE rather than grades 0-2 rENE was an independent unfavorable predictor of overall survival and disease-free survival (P < 0.001). Recursive partitioning analysis was applied to refine the N category: eN0 (N0), eN1 (N1 without grade 3), eN2 (N2 without grade 3), and eN3 (N1/N2 with grade 3, N3). Compared to the current system, the proposed N category performed better in hazard consistency, hazard discrimination, sample size balance and outcome prediction. CONCLUSION: Grade 3 rENE was an independent unfavorable indicator of NPC. Upstaging patients in N1-2 with grade 3 rENE to N3 led to a superior prognostic performance.
BACKGROUND AND PURPOSE: To explore the prognostic value of different radiologic extranodal extension (rENE) grades and their potential improvement for the 8th edition N category in nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: From 2009 to 2013, a cohort of 1887 patients with NPC was retrospectively enrolled and randomized to the training (n = 955) and validation (n = 932) groups. rENE was categorized as follows: grade 0, nodes without rENE; grade 1, nodes with rENE infiltrating the surrounding fat only; grade 2, matted nodes; grade 3, nodes with rENE infiltrating adjacent structures. RESULTS: The percentage of patients with MRI-positive cervical nodes was 66.5% (1254/1887), of whom grade 0, 1, 2 and 3 rENE cases accounted for 33.2% (416/1254), 14.9% (187/1254), 36.5% (458/1254) and 15.4% (193/1254), respectively. The kappa coefficients for the inter-rater and intra-rater assessments were 0.63, 0.51, 0.65 and 0.93, and 0.76, 0.69, 0.72 and 1.0 in grade 0, 1, 2 and 3 rENE, respectively. Grade 3 rENE rather than grades 0-2 rENE was an independent unfavorable predictor of overall survival and disease-free survival (P < 0.001). Recursive partitioning analysis was applied to refine the N category: eN0 (N0), eN1 (N1 without grade 3), eN2 (N2 without grade 3), and eN3 (N1/N2 with grade 3, N3). Compared to the current system, the proposed N category performed better in hazard consistency, hazard discrimination, sample size balance and outcome prediction. CONCLUSION: Grade 3 rENE was an independent unfavorable indicator of NPC. Upstaging patients in N1-2 with grade 3 rENE to N3 led to a superior prognostic performance.