Objective To develop and externally validate a prediction model for survival after curative resection of ampullary adenocarcinoma (AAC).
Summary Background Data AAC is a rare malignancy with great morphological heterogeneity, which complicates predicting individual prognosis and, therefore, clinical decision-making.
Methods An international multicenter cohort study was conducted, including patients who underwent pancreatoduodenectomy for AAC (January 2006-December 2017). A derivation and validation cohort were separately collected from different centers. Predictors were selected from the derivation cohort using a LASSO Cox proportional hazards model. A nomogram was created based on shrunk coefficients. Model performance was assessed in the derivation cohort and subsequently in the validation cohort, by calibration plots and Uno’s C-statistic. Four risk groups were created based on quartiles of the nomogram score.
Results Overall, 1,007 patients were available for development of the model. For external validation, 462 patients were used. Predictors in the final Cox model included age, resection margin, tumor differentiation, pathological T stage and N stage (8th AJCC edition). Internal cross-validation demonstrated a C-statistic of 0.75 (95% CI 0.73-0.77). External validation showed a C-statistic of 0.77 (95% CI 0.73-0.81).
Conclusion A prediction model for survival after curative resection of AAC was developed and demonstrated excellent performance with a C-statistic of 0.77 in a geographically external validation cohort.
Note: The paper describing the development and validation of the prediction model is currently undergoing peer-review.