Published online Nov 7, 2019. doi: 10.3748/wjg.v25.i41.6248
Peer-review started: May 22, 2019
First decision: June 16, 2019
Revised: July 8, 2019
Accepted: July 19, 2019
Article in press: June 16, 2019
Published online: November 7, 2019
Processing time: 169 Days and 12.4 Hours
Pancreatic neuroendocrine tumor (pNET) is the second most common malignancy among pancreatic tumors. Most studies have primarily concentrated on the significance of tumor cells, but few have focused on the importance of the tumor microenvironment in pNET. Platelets are an important component of the tumor microenvironment. However, the importance of platelets in pNET lacks adequate literature support.
To assess the potential clinical meaning of platelets in pNET and offer evidence concerning a potential anti-platelet therapeutic strategy for pNET.
Tumor-infiltrating platelets are potential independent indicators of survival and recurrence outcome for patients with resectable pNET.
In total, 113 patients who had undergone radical surgical resection were retrospectively enrolled. All the specimens were selected via pathologic diagnosis of pNET without distant metastasis or other tumor history. None of the patients had received any preoperative chemotherapy or radiotherapy or died of postoperative complications within 30 d. Immunohistochemical analysis of CD42b expression in tumor specimens was performed to determine the presence of TIPs. Univariate and multivariate analyses were applied to analyze the prognostic value of tumor-infiltrating platelets.
Tumor-infiltrating platelets were observed in intratumoral areas in 54 patients. Neither basic characteristics nor preoperative platelet count, mean platelet volume, or platelet lymphoid ratio showed a statistical relationship with CD42b expression. Platelet count, mean platelet volume, and platelet-to-lymphocyte ratio determined by preoperative blood tests were not related to overall survival or recurrence-free survival. Tumor-infiltrating platelets were found to be potential independent indicators of survival and recurrence outcome for patients with resectable pNET. The major limitations were that the nature of a retrospective study with a limited sample size restricts the level of evidence and that the mechanism by which platelets influence the recurrence of patients was not thoroughly investigated.
We uncovered a relationship between tumor-infiltrating platelets and the prognosis of patients with pNET following radical resection. We found that tumor-infiltrating platelets were potential pNET prognosis indicators. In addition, therapy targeting platelets in pNET could improve long-term survival. We further provide the clinical meaning of platelets in the tumor microenvironment in pNET.
A further prospective study with a large sample size should be conducted with multicenter cooperation, and additional experiments to assess the mechanism need to be implemented. If possible, we recommend a randomized double-blind controlled clinical trial for platelet-targeted therapy for pNET.