Expression And Clinical Value Of CXCR4 In High Grade Gastroenteropancreatic Neuroendocrine Neoplasms

Background:Neuroendocrine neoplasms(NENs)are highly heterogeneous solid tumors originating from the diffuse neuroendocrine system.The incidence of NENs has increased remarkably in the past 40 years.The classification of NENs is based on tumor proliferation activity(including Ki-67 index and mitotic rate),pathological morphology,and immunohistochemical staining.2019 WHO Classification of Digestive System Tumors(5th Edition)updated and defined a new subtype,GEP-NET G3.Few studies have been carried out focusing on the similarities and differences between well-differentiated NETs G3 and poorly-differentiated NECs up to now.Accurate identification of GEP-NET G3 and NEC is of great significance for the selection of following treatment.However,the accuracy of existing immunohistochemical diagnostic indicators such as Rb,p53,DAXX/ATRX,and SSTR2 in the identification of NET G3 and NEC is not satisfactory.CXC chemokine receptor 4(CXCR4),which belongs to the CXCR subfamily,is a G protein-coupled sevenfold transmembrane receptor,and is associated with the occurrence,progression,invasion,and metastasis of a variety of malignant tumors.CXCR4 is expected to be a new pathologically assisted diagnostic indicator and therapeutic target.Before its application in clinical practice,many relevant studies are needed to clarify its clinical value.Therefore,our study includes two parts:The first part retrospectively analyzed the clinicopathological characteristics and prognosis of patients with GEP-NENs G3 who underwent surgical treatment in Qilu Hospital of Shandong University;In the second part,the expression level and clinical significance of CXCR4 in GEP-NENs G3 were thoroughly investigated,and the value of CXCR4 in the diagnosis,differential diagnosis,and prognostic prediction of GEP-NENs G3 was evaluated.Dissertation I Clinicopathological features and prognoses of GEP-NEN G3Aims:To retrospectively analyze the clinicopathological features and prognosis of patients with GEP-NENs G3 by focusing on differences in biological behavioral characteristics between NETs G3 and NECs.Methods:The clinical,pathological,and follow-up data of patients with GEP-NENs G3 receiving surgery in Qilu Hospital of Shandong University from January 2013 to April 2021 were collected.SPSS 26.0 software was used for statistical analysis.P<0.05 indicates that the difference was statistically significant.Results:A total of 100 GEP-NEN G3 patients were enrolled in this study,including 25(25.0%)NETs G3 and 75(75.0%)NECs.There were significant differences between NETs G3 and NECs in patients’ age(P=0.028),tumor location(P=0.002),and Ki-67 index(P<0.001).The proportion of CEA elevation(>5ng/ml)in NECs was significantly higher than that in NETs G3(P=0.008).The proportion of elevated CA19-9,CA125,AFP,NSE,and SA in patients with NEC was higher than that in patients with NET G3,but no statistical difference was found.By comparing clinicopathological parameters of GEP-NEN G3 patients with elevated CEA and normal CEA,we found that elevated CEA was significantly correlated with patients’age(P=0.015),tumor classification(P=0.008),tumor size(P=0.023),Ki-67 index(P<0.001),and clinical stage(P=0.027).Multivariate logistic regression showed that age was a risk factor for CEA elevation(P=0.04).Kaplan-Meier survival analysis showed that NET G3 had a better prognosis than NEC,but the difference was not statistically significant(P=0.110).Univariate Cox survival analysis showed that elevated CA19-9(>37U/mL),CA125(>35U/mL),and SA(>75.4mg/dL)were significantly correlated with poor prognosis of patients with GEP-NEN G3;Multivariate Cox survival analysis showed that elevated CA19-9 was an independent risk factor for poor prognosis(P=0.003).Univariate Cox survival analysis showed that elevated CA19-9,NSE,and SA were significantly negatively correlated with prognosis of NEC patients,but multivariate analysis showed that none of the three were independent risk factors.Conclusions:1.There were significant differences between NET G3 and NEC in patients’ age,tumor location,and Ki-67 index.2.The proportion of CEA elevation(>5ng/ml)in NEC was significantly higher than that in NET G3.3.Elevated CA19-9(>37U/mL)was an independent risk factor for poor prognosis in patients with GEP-NEN G3.4.NET G3 patients had better prognoses than NEC,but the difference was not statistically significant.It may due to the small sample size,multiple sources of tumor sites,and large intragroup heterogeneity in this study.The prognosis of NET G3 and NEC needs to be further confirmed by multi-center and large sample size studies.Dissertation Ⅱ Expression and clinical value of CXCR4 in GEP-NEN G3Aims:To explore the expression of CXCR4 in GEP-NEN G3,to study the relationship between CXCR4 expression and clinicopathological features and prognosis of GEP-NEN G3 patients,and to evaluate the value of CXCR4 in the differential diagnosis and prognosis prediction of patients with NET G3 and NEC.Methods:The surgical pathological paraffin blocks of GEP-NEN G3 patients were collected and analyzed by immunohistochemical staining.To investigate the expression of CXCR4 in NET G3 and NEC,and to analyze its correlation with clinicopathological parameters and prognostic data.And to explore the relationship between CXCR4 expression level and the diagnosis,differential diagnosis,and prognosis of NET G3 and NEC.Results:1.CXCR4 is mainly expressed in the membrane and cytoplasm of tumor cells.There were 82 patients(82/100,82.0%)with low CXCR4 expression and 18 patients(18/100,18.0%)with high CXCR4 expression.CXCR4 was low or not expressed in the paracancerous tissues,and there are significant differences between tumor and adjacent tissues(P<0.001).2.NET G3 accounted for 24 cases(29.3%)and NEC accounted for 58 cases(70.7%)in the low expression group of CXCR4.In the CXCR4 overexpression group,there was only 1 case of NET G3(5.6%)and 17 cases of NEC(94.4%).The proportion of NEC in the CXCR4 high expression group was significantly higher than that in the CXCR4 low expression group,and the difference was statistically significant(P=0.038).3.There were significant differences in CXCR4 expression levels among NEC patients with different tumor sites(P=0.013).The proportion of high CXCR4 expression in pancreatic NEC patients was the highest(66.7%),followed by colorectal(57.1%),gallbladder(50.0%),esophagus(25.0%),stomach(15.0%),duodenum and small intestine(0.0%).4.There was no significant correlation between CXCR4 expression level and GEP-NEN G3 patients’ age,gender,tumor location,tumor size,Ki-67 index,lymph node metastasis,liver metastasis,clinical stage,and prognosis.Conclusions:1.CXCR4 was highly expressed only in tumors,and low or no expression was found in the adjacent tissues.2.The expression of CXCR4 in NEC was significantly higher than that in NET G3,which could assist in differential diagnosis.3.CXCR4 expression levels were significantly different in NEC patients with different tumor sites.4.The correlation between high CXCR4 expression and poor prognosis in patients with GEP-NEN G3 or NEC has not been confirmed,and further studies with multi-center,large sample size and longer follow-up are needed.