A nomogram to preoperatively predict 1-year disease-specific survival in resected pancreatic cancer following neoadjuvant chemoradiation therapy

OBJECTIVE: This study aimed to develop a nomogram to predict the 1-year survival of patients with pancreatic cancer who underwent pancreatectomy following neoadjuvant treatment with preoperatively detectable clinical parameters. Extended pancreatectomy is necessary to achieve complete tumor removal in borderline resectable and locally advanced pancreatic cancer. However, it increases postoperative morbidity and mortality rates, and should be balanced with potential benefit of long-term survival. METHODS: The medical records of patients who underwent pancreatectomy following neoadjuvant treatment from January 2005 to December 2016 at Severance Hospital were retrospectively reviewed. Medical records were collected from five international institutions from Japan and Singapore for external validation. RESULTS: A total of 113 patients were enrolled. The nomogram for predicting 1-year disease-specific survival was created based on 5 clinically detectable preoperative parameters as follows: age (year), symptom (no/yes), tumor size at initial diagnostic stage (cm), preoperative serum carbohydrate antigen (CA) 19-9 level after neoadjuvant treatment (<34/≥34 U/mL), and planned surgery [pancreaticoduodenectomy (PD) (pylorus-preserving PD)/distal pancreatectomy (DP)/total pancreatectomy]. Model performance was assessed for discrimination and calibration. The calibration plot showed good agreement between actual and predicted survival probabilities; the the Greenwood-Nam-D’Agostino (GND) goodness-of-fit test showed that the model was well calibrated (χ(2)=8.24, P=0.5099). A total of 84 patients were used for external validation. When correlating actual disease-specific survival and calculated 1-year disease-specific survival, there were significance differences according to the calculated probability of 1-year survival among the three groups (P=0.044). CONCLUSIONS: The developed nomogram had quite acceptable accuracy and clinical feasibility in the decision-making process for the management of pancreatic cancer.