Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios inversely correlate to clinical and pathologic stage in patients with resectable pancreatic ductal adenocarcinoma

Background: Post-surgical pathology (SP) staging correlates with long-term survival. Neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) have been shown to predict prognosis and extent of tumor in patients with metastatic pancreatic ductal adenocarcinoma (PDAC). This study aimed to correlate NLR and PLR to radiological clinical staging (CS), carbohydrate antigen (CA) 19-9 tumor marker and SP staging in patients with resectable-PDAC (R-PDAC); and to investigate NLR and PLR as potential markers to guide neoadjuvant therapy.

Methods: Data were collected retrospectively from R-PDAC patients who received upfront surgery from November 2011 to December 2016. NLR and PLR values on the day of diagnosis and surgery were collected. SP, tumor size, location, resected margins (RM), lymphovascular/perineural invasion (LVI/PNI), lymph node involvement, and AJCC/TNM 8th Edition staging were obtained. Associations were assessed using linear, ordinal logistic, and poison regressions or Kruskal Willis Rank Sum Test per the nature of outcome variables, with statistical significance at p-value <0.05.

Results: Fifty-five patients were identified with resectable stage I (61%) and II (38%). They had a mean age of 66 years (48-87 years) and were 47.2% male, 83.6% white, 90.9% non-Hispanic and 89% with ECOG 0-1. NLR/PLR at diagnosis for R0, R1 and R2 were 6.7/241, 4.8/224, and 2.9/147 (P=0.01/0.002), respectively. NLR/PLR for N0 and N1 were 5.1/212 and 2.7/138.3 (P=0.03/0.009) at diagnosis. No other significant association was detected.

Conclusions: These findings suggest that NLR/PLR inversely correlates with RM and lymph node status in patients with R-PDAC, but require prospective evaluation in clinically defined scenarios.