Low Systemic Inflammation Response Index Predicts Good Prognosis in Locally Advanced Pancreatic Carcinoma Patients Treated with Concurrent Chemoradiotherapy

Abstract

Background . We investigated the prognostic significance of pretreatment systemic inflammation response index (SIRI) in locally advanced pancreatic carcinoma (LAPC) patients treated with concurrent chemoradiotherapy (CRT). Methods . Present retrospective cohort analysis investigated consecutive 154 LAPC patients who received radical CRT. The SIRI was defined as: <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mtext>SIRI</mml:mtext><mml:mo>=</mml:mo><mml:mtext>neutrophil</mml:mtext><mml:mo>×</mml:mo><mml:mtext>monocyte</mml:mtext><mml:mo>/</mml:mo><mml:mtext>lymphocyte</mml:mtext><mml:mtext> </mml:mtext><mml:mtext>counts</mml:mtext></mml:math>. Ideal SIRI cutoff(s) influencing overall survival (OS) and progression-free survival (PFS) results were sought by using receiver operating characteristic (ROC) curve analysis. The primary endpoint was the interaction between the SIRI and OS results. Results . The median follow-up, PFS, and OS durations were 14.3 (range: 2.9-74.6), 7.9 [%95 confidence interval (CI): 5.7-10.1), and 14.7 months (%95 CI: 11.4-18.0) for the entire cohort, respectively. ROC curve analyses determined the ideal SIRI cutoff that exhibiting a significant link with OS and PFS outcomes at the rounded 1.6 point (AUC: 74.3%; sensitivity: 73.8%; specificity: 70.1%).The SIRI &lt;1.6 patients (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mi>N</mml:mi><mml:mo>=</mml:mo><mml:mn>58</mml:mn></mml:math>) had significantly superior median PFS (13.8 versus 6.7 months; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mi>P</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.001</mml:mn></mml:math>) and OS (28.6 versus 12.6 months; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mi>P</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.001</mml:mn></mml:math>) lengths than SIRI ≥1.6 patients (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><mml:mi>N</mml:mi><mml:mo>=</mml:mo><mml:mn>96</mml:mn></mml:math>), respectively. Although the N0 (versus N1; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M6"><mml:mi>P</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.05</mml:mn></mml:math>) and CA 19-9 ≤90 U/mL (versus &gt;90 U/mL) appeared as the other significant associates of better OS and PFS in univariate analyses, yet the results of multivariate analyses confirmed the SIRI &lt;1.6 as the independent indicator of superior OS and PFS (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M7"><mml:mi>P</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.001</mml:mn></mml:math> for each). Conclusion . Pretreatment SIRI is a novel independent prognosticator that may further enhance the conventional tumor-node-metastases staging system in a more precise prediction of the OS and PFS outcomes of LAPC patients after radical CRT.