Ning Pu1, Shanshan Gao2, Ross Beckman3, Ding Ding3, Michael Wright3, Zhiyao Chen3, Yayun Zhu3, Haijie Hu3, Lingdi Yin3, Michael Beckman3, Elizabeth Thompson4, Ralph H Hruban4, John L Cameron5, Michele M Gage5, Kelly J Lafaro5, William R Burns5, Christopher L Wolfgang6, Jin He5, Jun Yu7, Richard A Burkhart8. 1. Division of Hepatobiliary and Pancreatic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of General Surgery, Zhongshan Hospital, Fudan University, Shanghai, China. 2. Division of Hepatobiliary and Pancreatic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Interventional Radiology, Zhongshan Hospital, Fudan University, Shanghai, China. 3. Division of Hepatobiliary and Pancreatic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA. 4. Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center and The Pancreatic Cancer Precision Medicine Program of Excellence, Johns Hopkins University School of Medicine, Baltimore, MD, USA. 5. Division of Hepatobiliary and Pancreatic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA. 6. Division of Hepatobiliary and Pancreatic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center and The Pancreatic Cancer Precision Medicine Program of Excellence, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA. 7. Division of Hepatobiliary and Pancreatic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA. Electronic address: jyu41@jhmi.edu. 8. Division of Hepatobiliary and Pancreatic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, USA. Electronic address: burkhart@jhmi.edu.
Abstract
BACKGROUND: Lymph node (LN) metastasis is associated with decreased survival following resection for pancreatic ductal adenocarcinoma (PDAC). In N0 disease, increasing total evaluated LN (ELN) correlates with improved outcomes suggesting patients may be understaged when LNs are undersampled. We aim to assess the optimal number of examined lymph nodes (ELN) following pancreatectomy. METHODS: Data from 1837 patients undergoing surgery were prospectively collected. The binomial probability law was utilized to analyze the minimum number of examined LNs (minELN) and accurately characterize each histopathologic stage. LN ratio (LNR) was compared to American Joint Committee on Cancer (AJCC) guidelines. RESULTS: As ELN total increased, the likelihood of finding node positive disease increased. An evaluation based upon the binomial probability law suggested an optimal minELN of 12 for accurate AJCC N staging. As the number of ELNs increased, the discriminatory capacity of alternative strategies to characterize LN disease exceeded that offered by AJCC N stage. CONCLUSION: This is the first study dedicated to optimizing histopathologic staging in PDAC using models of minELN informed by the binomial probability law. This study highlights two separate cutoffs for ELNs depending upon prognostic goal and validates that 12 LNs are adequate to determine AJCC N stage for the majority of patients.
BACKGROUND: Lymph node (LN) metastasis is associated with decreased survival following resection for pancreatic ductal adenocarcinoma (PDAC). In N0 disease, increasing total evaluated LN (ELN) correlates with improved outcomes suggesting patients may be understaged when LNs are undersampled. We aim to assess the optimal number of examined lymph nodes (ELN) following pancreatectomy. METHODS: Data from 1837 patients undergoing surgery were prospectively collected. The binomial probability law was utilized to analyze the minimum number of examined LNs (minELN) and accurately characterize each histopathologic stage. LN ratio (LNR) was compared to American Joint Committee on Cancer (AJCC) guidelines. RESULTS: As ELN total increased, the likelihood of finding node positive disease increased. An evaluation based upon the binomial probability law suggested an optimal minELN of 12 for accurate AJCC N staging. As the number of ELNs increased, the discriminatory capacity of alternative strategies to characterize LN disease exceeded that offered by AJCC N stage. CONCLUSION: This is the first study dedicated to optimizing histopathologic staging in PDAC using models of minELN informed by the binomial probability law. This study highlights two separate cutoffs for ELNs depending upon prognostic goal and validates that 12 LNs are adequate to determine AJCC N stage for the majority of patients.