Purpose: We determined the prognostic value of the systemic inflammation response index (SIRI) in patients with cholangiocarcinoma after surgery and constructed a survival prediction model based on SIRI.
Patients and Methods: We recruited 328 patients with histopathologically confirmed cholangiocarcinoma from 2003 to 2017 and performed Kaplan–Meier survival and Cox analyses to analyze the prognostic value of the SIRI and identify other significant factors. A nomogram involving SIRI and other clinicopathological factors was established based on the training cohort. The concordance index (C-index), decision curve analysis, calibration plots, and Hosmer–Lemeshow test were used to evaluate the clinical utility of the nomogram and to compare it with the traditional TNM staging system. The results were validated using a separate validation cohort.
Results: The patients were randomly divided into the training (n = 232) and validation (n = 96) cohorts. In the training cohort, the independent factors derived from the Cox multivariate analysis were SIRI, platelet-to-lymphocyte ratio, jaundice, γ-glutamyl transpeptidase level, maximal tumor size, N stage, M stage, and radical surgery. Time-dependent receiver operating characteristic (ROC) curves showed higher AUC for SIRI than those for other inflammation-based biomarkers. A nomogram containing all the independent factors showed good discrimination and calibration. The C-index values for overall survival, 0.737 (95% Cl: 0.683– 0.791) and 0.738 (95% Cl: 0.679– 0.797) in the training and validation cohorts, respectively, were significantly better than those for the TNM staging system [0.576 (95% Cl: 0.515– 0.637) and 0.523 (95% Cl: 0.465– 0.581), respectively].
Conclusion: SIRI was an independent prognostic factor for cholangiocarcinoma. A prognostic model based on SIRI might help clinicians to stratify patients more precisely and provide individualized treatment.
Keywords: systemic inflammation response index, cholangiocarcinoma, prognosis, nomogram, survival