Pancreatic ductal adenocarcinoma contains an effector and regulatory immune cell infiltrate that is altered by multimodal neoadjuvant treatment. PLoS One. 2014;9:e96565. [PMID: 24794217 PMCID: PMC4008589 DOI: 10.1371/journal.pone.0096565]

FOXP3+ lymphocyte density in pancreatic cancer correlates with lymph node metastasis

OBJECTIVE

To determine if the density of FOXP3+ lymphocytes in primary tumors and lymph nodes in pancreatic cancer correlates with the presence of lymph node metastases.

METHODS

FOXP3+ lymphocyte density in primary pancreatic cancer tissue and draining lymph nodes was measured using immunohistochemistry. We analyzed the clinical and pathological aspects associated with the accumulation of FOXP3+ lymphocytes in pancreatic cancer. We also analyzed the correlation of density of FOXP3+ lymphocytes in lymph nodes with the nodal status and distance from the primary tumor.

RESULTS

FOXP3+ lymphocyte density in pancreatic cancer was significantly higher than in paratumoral pancreatic tissue. The density of FOXP3+ lymphocytes in local tumor tissue correlated significantly with the histological grade and overall lymph node status. Furthermore, FOXP3+ lymphocyte density was significantly higher in positive lymph nodes than in negative ones, while it had no correlation with the distance of the lymph node from the primary tumor.

CONCLUSION

FOXP3+ lymphocyte density in primary tumor tissue in patients with pancreatic cancer correlates with lymph node metastasis. Lymph nodes containing metastases having higher FOXP3+ lymphocyte densities than do negative lymph nodes.

The pancreatic cancer microenvironment: an immunologic battleground

Recent studies of human pancreatic cancer challenge the mouse model-derived notion that the pancreas is a site of immune privilege. A heavy infiltration of CD8⁺ T cells expressing programmed cell death 1 (PD-1) and smaller numbers of myeloid cells and regulatory T cells provides rationale for the clinical evaluation of immune checkpoint inhibition as a pancreatic cancer therapeutic strategy.