Xu-Feng Zhang1,2, Feng Xue1, Zheng Wu1, Alexandra G Lopez-Aguiar3, George Poultsides4, Eleftherios Makris4, Flavio Rocha5, Zaheer Kanji5, Sharon Weber6, Alexander Fisher6, Ryan Fields7, Bradley A Krasnick7, Kamran Idrees8, Paula M Smith8, Cliff Cho9, Megan Beems9, Yi Lyu1, Shishir K Maithel3, Timothy M Pawlik2. 1. Department of Hepatobiliary Surgery and Institute of Advanced Surgical Technology and Engineering, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China. 2. Division of Surgical Oncology, The Ohio State University Wexner Medical Center and James Comprehensive Cancer Center, Columbus, Ohio. 3. Division of Surgical Oncology, Department of Surgery, Winship Cancer Institute, Emory University, Atlanta, Georgia. 4. Department of Surgery, Stanford University, Palo Alto, California. 5. Department of Surgery, Virginia Mason Medical Center, Seattle, Washington. 6. Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin. 7. Department of Surgery, Washington University School of Medicine, St. Louis, Wisconsin. 8. Division of Surgical Oncology, Department of Surgery, Vanderbilt University, Nashville, Tennessee. 9. Division of Hepatopancreatobiliary and Advanced Gastrointestinal Surgery, Department of Surgery, University of Michigan, Ann Arbor, Michigan.
Abstract
OBJECTIVE: To improve the prognostic accuracy of the eighth edition of AJCC staging system for pNETs with establishment and validation of a new staging system. BACKGROUND: Validation of the updated eighth AJCC staging system for pNETs has been limited and controversial. METHODS: Data from the SEER registry (1975-2016) (n = 3303) and a multi-institutional database (2000-2016) (n = 825) was used as development and validation cohorts, respectively. A mTNM was proposed by maintaining the eighth AJCC T and M definitions, and the recently proposed N status as N0 (no LNM), N1 (1-3 LNM), and N2 (≥4 LNM), but adopting a new stage classification. RESULTS: The eighth TNM staging system failed to stratify patients with stage I versus IIA, stage IIB versus IIIA, and overall stage I versus II relative to long-term OS in both database. There was a monotonic decrement in survival based on the proposed mTNM staging classification among patients derived from both the SEER (5-year OS, stage I 87.0% vs stage II 80.3% vs stage III 72.9% vs stage IV 57.2%, all P < 0.001), and multi-institutional (5-year OS, stage I 97.6% vs stage II 82.7% vs stage III 78.4% vs stage IV 50.0%, all P < 0.05) datasets. On multivariable analysis, mTNM staging remained strongly associated with prognosis, as the hazard of death incrementally increased with each stage among patients in the 2 cohorts. CONCLUSION: A mTNM pNETs clinical staging system using N0, N1, N2 nodal categories was better at stratifying patients relative to long-term OS than the eighth AJCC staging.
OBJECTIVE: To improve the prognostic accuracy of the eighth edition of AJCC staging system for pNETs with establishment and validation of a new staging system. BACKGROUND: Validation of the updated eighth AJCC staging system for pNETs has been limited and controversial. METHODS: Data from the SEER registry (1975-2016) (n = 3303) and a multi-institutional database (2000-2016) (n = 825) was used as development and validation cohorts, respectively. A mTNM was proposed by maintaining the eighth AJCC T and M definitions, and the recently proposed N status as N0 (no LNM), N1 (1-3 LNM), and N2 (≥4 LNM), but adopting a new stage classification. RESULTS: The eighth TNM staging system failed to stratify patients with stage I versus IIA, stage IIB versus IIIA, and overall stage I versus II relative to long-term OS in both database. There was a monotonic decrement in survival based on the proposed mTNM staging classification among patients derived from both the SEER (5-year OS, stage I 87.0% vs stage II 80.3% vs stage III 72.9% vs stage IV 57.2%, all P < 0.001), and multi-institutional (5-year OS, stage I 97.6% vs stage II 82.7% vs stage III 78.4% vs stage IV 50.0%, all P < 0.05) datasets. On multivariable analysis, mTNM staging remained strongly associated with prognosis, as the hazard of death incrementally increased with each stage among patients in the 2 cohorts. CONCLUSION: A mTNM pNETs clinical staging system using N0, N1, N2 nodal categories was better at stratifying patients relative to long-term OS than the eighth AJCC staging.