CT Features And Prognostic Factors Of Digestive Neuroendocrine Neoplasms

Object To evaluate the differential CT features of digestive neuroendocrine neoplasms(gastric and pancreatic)from adenocarcinomas,and predict prognosis of pancreatic neuroendocrine cancers(P-NEC)and pancreatic ductal adenocarcinomas(P-DAC)in order to help diagnose and chose optimal treatment options.Methods CT features and clinical data of 15 gastric G-NET,15 G-NEC,and 15 G-ADCs with gastroscopic histological examination or pathological examination after operation between January 2014 and April 2018 were retrospectively reviewed.All patients were examined with CT and multiple CT features were assessed to identify significant differential CT findings of these tumors.Significant variables were assessed using univariate and multivariate analyses.The prevalence of each CT finding between G-NEC and G-NET as well as between G-NEC and gastric ADC were compared using Fisher’s exact test for categorical variables and the independent t-test for continuous variables.Thereafter,binary logistic regression analyses using the backward projection method were performed to determine the most significant differential CT features.CT features and clinical data of 233 patients with pancreatic neoplasms were retrospectively included,according to their pathological results,106 patients of which were diagnosed with P-NEC,the remaining were diagnosed with P-DAC.All patients were examined with CT before surgery or other treatments and followed up for 1-84 months.All follow-up ended on October 31 st,2018.The prevalence of each CT finding and clinical features between P-NEC and P-DAC were compared using chi-square test for categorical variables and the independent t-test for continuous variables.Binary logistic regression analyses were used to determine the most significant differential CT features.Survival times were estimated using the Kaplan–Meier method and log-rank test were used to determine univariate significance of clinical and pathological characteristics.Multivariate analysis was performed using the Cox regression model forvariables that were significantly associated with OS in the univariate analysis,and the corresponding 95% confidence intervals(CI)were calculated.For all statistical analyses methods,a p-value <0.05 was considered to indicate a statistical significance.Result 1.Tumor size(P =0.023)、tumor location(Upper half of the stomachincludes cardia,fundus,and highbody,while lower half of thestomach includes mid body,lowbody,and antrum,P= 0.02)、multiplicity(single,multiple,diffuse,P = 0.003)、tumor margin(P<0.001)、intact overlying mucosa with mucosal tenting(P<0.001)、LNs(Lymph nodes)metastasis(P<0.001)、diameter of the largest LNs(P = 0.008)and LNs necrosis(P = 0.006)were the difference among G-NEC,G-NET and G-ADC;Then compared with G-NET,G-NEC more easily metastasized to LNs(93.3%14/15 VS 20.0%3/15,P=0.001),more often larger(4.72±1.73 cm VS2.08±1.02 cm,P<0.001)and solitary in number(15/15 100% VS 10/15 66.7%,P=0.042),and more often located in mid body,low body,and antrum(9/15 60.0% VS 2/15 13.3%,P=0.021).While intact overlying mucosa(8/15 53.3% VS 1/15 66.7%,P=0.014),well-defined margin(9/15 60.0% VS 0/15 0%,P=0.001)and larger size of metastatic LNs(1.82±0.69 cm VS 1.23±0.65 cm,P =0.045)were the significant CT feature differentiating G-NEC from G-ADC.2.Tumor margin(P=0.000,HR=5.656,95%CI 2.213-14.452),dilatation of pancreatic duct(P=0.000,HR=16.360,95%CI 4.415-60.619),enhancement pattern(P=0.026,HR=3.261,95%CI 1.207-8.808)were the significant CT feature differentiating P-NEC from P-DAC.Followed up for 1-84 months,the median overall(OS)of P-DAC and P-NEC were 19 months and 46 months respectively.The multivariate analysis showed that hepatic metastases,vascular invasion were independent CT factors for OS of P-DAC,meanwhile,hepatic metastases,LN metastases and were independent CT factors for OS of P-NEC.Conclusion 1.CT is of great significance and convenience to differentiate G-NEC from G-NET and G-ADC.Tumor size is proportional to histological grades,lesions of G-NEC is much bigger than G-NET,the optimal cut-off tumor size value for differentiating G-NET from G-NEC is 3.05 cm.Compared with G-NET,G-NEC more frequently locates in upper half of the stomachincludes cardia,fundus,and highbody,more often solitary in number,and more easily metastasized to LNs,metastatic LNs in G-NET tended to show more extensive necrosis.In terms of G-ADC,G-NEC more frequently shows well-defined margins and more often accompanied with intact overlying.In addition,the mean diameter of the largest metastatic LN was significantly larger in G-NEC than in G-ADC 2.CT can play an positive role in diagnosis and predicting survival time of P-NEC and P-DAC.P-DAC often shows ill-defined margin,dilatation of pancreatic duct and less obvious enhancement than P-DAC.Distant metastasis predicts poor prognosis for both P-DAC and P-NEC Accuracy diagnosis and prognosis analyze of these two neoplasms can provide valuable information for tailored decision and then prolong life survival.