Inflammatory Biomarkers Predict Local Control and Survival After Escalated High-Dose SBRT in Borderline and Locally Advanced Pancreatic Cancer

<b>Background</b>: Inflammatory biomarkers such as the platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) have been increasingly investigated as prognostic indicators in pancreatic cancer. However, their role in patients receiving high-dose neoadjuvant stereotactic body radiotherapy (SBRT) remains unclear. <b>Methods</b>: Thirty-three patients with borderline resectable (BRPC) or locally advanced pancreatic cancer (LAPC) prospectively included from June 2017 to December 2022 in a multicenter academic SBRT escalated-dose study of neoadjuvant chemotherapy followed by escalated-dose SBRT (50-55 Gy in 5 fractions) were scored according to PLR/NLR expression, before SBRT. Patients were stratified according to the median value for each marker. The primary endpoint was freedom from local progression as the first site of failure (FFLP-FF). Secondary endpoints included cancer-specific survival (CSS) and overall survival (OS). Follow-up was conducted prior to the closing date of 18 July 2025. <b>Results</b>: After a mean follow-up of 24 months (range 6-71 months), the two-year FFLP-FF rate for the entire cohort was 80.2%. High PLR prior to SBRT was significantly associated with lower FFLP-FF (<i>p</i> = 0.038). Similarly, elevated NLR was associated with reduced FFLP-FF (<i>p</i> = 0.014). Patients with both high PLR and high NLR showed the poorest FFLP-FF outcomes (<i>p</i> = 0.001). High pre-SBRT PLR was also correlated with reduced CSS (<i>p</i> = 0.019) and OS (<i>p</i> = 0.018). <b>Conclusions</b>: Pre-treatment inflammatory biomarkers, particularly PLR and NLR, may serve as valuable predictors of local control and survival in patients with borderline or locally advanced pancreatic cancer undergoing escalated high-dose SBRT. Their combination may help identify subgroups with a worse prognosis who may benefit from tailored treatment strategies.