Combination of neutrophil-to-lymphocyte ratio and serum CA 19-9 as a prognostic factor in pancreatic cancer.

Background: Traditionally, serum carbohydrate antigen 19-9 (CA 19-9) has been used as a key biomarker for pancreatic cancer and recently other biomarkers which reflect the systemic immune and inflammatory responses also have been explored as potential prognostic factors. The study aims to evaluate the significance of pretreatment neutrophil-to-lymphocyte ratio (NLR) and serum CA 19-9 as prognostic factor in pancreatic cancer patients.

Methods: A retrospective analysis was conducted in 153 consecutive patients with pancreatic cancer in Instituto Nacional de Cancerología from 2013 to 2018. Pretreatment NLR and serum CA 19-9 values were recorded as well as survivals.

Results: The cut-off value determined for NLR was 2.4 and for serum CA 19-9 was 553 U/mL. Survival analysis showed that the 5-year overall survival (OS) was 9% in patients with low-NLR compared with 2% for patients with high-NLR (P=0.008), and 5-year progression-free survival (PFS) was 5.7% in patients with low-NLR compared with 1.3% in patients with high-NLR (P=0.007). For patients with low-CA 19.9, 5-year OS was 8.5% compared with 0% for patients with high-CA 19-9 (P=0.002), and 5-year PFS was 4.1% in patients with low-CA 19-9 compared with 0% in patients with high-CA 19-9 (P=0.005). Classification groups created showed that 5-year OS in Group 1 (low-NLR and low-CA 19-9) was 11.8% compared with 1.9% for patients in Group 2 (either one or both high-NLR or CA 19-9) (P<0.001), and 5-year PFS was 8.6% in Group 1 and 0% in Group 2 (P=0.001).

Conclusions: High-NLR and high-CA 19-9 values used separately are both independently associated with worse OS and PFS in patients with pancreatic cancer. The classification groups created combining both biomarkers showed better prognostic significance than when used separately as demonstrated by survival analysis and multivariate analysis.