Pancreatic cancer has an incidence of 1,401,450 new cases diagnosed annually worldwide
and is the third leading cause of cancer-related death in Spain. This disease is
associated with a poor prognosis, reflected by a 5-year survival rate of less than 5%
when all stages are grouped together.
Several prognostic factors for pancreatic cancer have been identified. The most relevant
include preoperative levels of carbohydrate antigen 19-9 (CA 19.9), surgical margins
after resection, venous and/or arterial vascular involvement, and histopathological
features such as affected locoregional lymph nodes, or perineural and lymphovascular
invasion. Among all these factors, perineural invasion may be the primary independent
factor affecting prognosis, particularly in patients with relatively favorable
pathological features.
The identification of perineural invasion before surgery could influence the clinical
management of these patients. It may facilitate risk stratification, allowing the
identification of patients who would benefit most from neoadjuvant treatments or more
aggressive surgical procedures, such as vascular resections. However, perineural
involvement is very difficult to detect preoperatively.
Only a few studies have analyzed the possible relationship between CA 19.9 and perineural
invasion, and their results are inconsistent. Alternatively, some studies have
demonstrated the utility of preoperative multidetector computed tomography in detecting
extrapancreatic perineural invasion. However, these radiological tests are still not
useful for directly detecting microscopic perineural invasion, especially in early
stages.
On the other hand, in recent years, evidence has supported that the systemic inflammatory
response may play an important role in the prognosis of different malignancies. Among
these inflammatory markers, the neutrophil-to-lymphocyte ratio (NLR) has gained
prominence. Regarding pancreatic cancer, many studies suggest that elevated preoperative
NLR levels are associated with a worse prognosis. However, no studies have yet been
published analyzing a possible relationship between this inflammatory marker and
perineural invasion.
The main objective of this study is to correlate the neutrophil-to-lymphocyte ratio (NLR)
and CA 19.9 with histopathologically confirmed perineural invasion and, in this way,
investigate these data as potential preoperative markers of perineural invasion in
pancreatic cancer. Our working hypothesis is that preoperative NLR and CA 19.9 are
potential markers of perineural invasion.
As secondary objectives, we aim to study the effect of neoadjuvant therapy on
inflammatory markers (NLR) and tumor markers (CEA and CA 19.9) in pancreatic cancer.