Preoperative systemic inflammatory response index as a prognostic marker for distal cholangiocarcinoma after pancreatoduodenectomy.

Background: The relationship between preoperative inflammation status and tumorigenesis as well as tumor progression is widely acknowledged.

Aim: To assess the prognostic significance of preoperative inflammatory biomarkers in patients with distal cholangiocarcinoma (dCCA) who underwent pancreatoduodenectomy (PD).

Methods: This single-center study included 216 patients with dCCA after PD between January 1, 2011, and December 31, 2022. The individuals were categorized into two sets based on their systemic inflammatory response index (SIRI) levels: A low SIRI group (SIRI < 1.5, n = 123) and a high SIRI group (SIRI ≥ 1.5, n = 93). Inflammatory biomarkers were evaluated for predictive accuracy using receiver operating characteristic curves. Both univariate and multivariate Cox proportional hazards analyses were performed to estimate SIRI for overall survival (OS) and recurrence-free survival (RFS).

Results: The study included a total of 216 patients, with 58.3% being male and a mean age of 65.6 ± 9.6 years. 123 patients were in the low SIRI group and 93 were in the high SIRI group after PD for dCCA. SIRI had an area under the curve value of 0.674 for diagnosing dCCA, showing better performance than other inflammatory biomarkers. Multivariate analysis indicated that having a SIRI greater than 1.5 independently increased the risk of dCCA following PD, leading to lower OS [hazard ratios (HR) = 1.868, P = 0.006] and RFS (HR = 0.949, P < 0.001). Additionally, survival analysis indicated a significantly better prognosis for patients in the low SIRI group (P < 0.001).

Conclusion: It is determined that a high SIRI before surgery is a significant risk factor for dCCA after PD.