Purpose: There is an urgent need to discover a predictive biomarker to help patients with advanced pancreatic cancer (APC) choose appropriate chemotherapy regimens. This study aimed to determine whether baseline serum amyloid A (SAA) levels were associated with overall survival (OS), progression-free survival (PFS), and treatment response in patients with APC received chemotherapy.
Patients and Methods: This retrospective study included 268 patients with APC who received first-line chemotherapy at the Sun Yat-Sen University Cancer Center between January 2017 and December 2021. We examined the effect of baseline SAA on OS, PFS and chemotherapy response. The X-Tile program was used to determine the critical value for optimizing the significance of segmentation between Kaplan-Meier survival curves. The Kaplan-Meier curves and Cox regression analyses were used to analyze OS and PFS.
Results: The best cut-off value of baseline SAA levels for OS stratification was 8.2 mg/L. Multivariate analyses showed that SAA was an independent predictor of OS (Hazard Ratio (HR) =  1.694, 95% Confidence Interval (CI) =  1.247– 2.301, p =  0.001) and PFS (HR =  1.555, 95% CI =  1.152– 2.098, p =  0.004). Low SAA was associated with longer OS (median, 15.7 months vs 10.0 months, p < 0.001) and PFS (median, 7.6 months vs 4.8 months, p < 0.001). The patients with a low SAA who received mFOLFIRINOX had longer OS (median, 28.5 months vs 15.1 months, p = 0.019) and PFS (median, 12.0 months vs 7.4 months, p = 0.035) than those who received nab-paclitaxel plus gemcitabine (AG) or SOXIRI, whereas there was no significant difference among the three chemotherapy regimens in patients with a high SAA.
Conclusion: Owing to the rapid and simple analysis of peripheral blood, baseline SAA might be a useful clinical biomarker, not only as a prognostic biomarker for patients with APC, but also as a guide for the selection of chemotherapy regimens.
Keywords: advanced pancreatic cancer, serum amyloid A, chemotherapy, prognosis, biomarker