OBJECTIVETo establish the risk model for predicting the progression within 1 year of patients with gastric neuroendocrine neoplasms(gNEN) and to evaluate its value of prediction.

METHODSClinical data of 127 gENE patients with histologically comfirmed sporadic gNEN from January 1999 to February 2015 in Nanfang Hospital of Southern Medical University(n=63) and The First Affiliated Hospital of Sun Yat-sen University(n=64) were collected retrospectively. Twenty-five patients without follow-up were excluded, so a total of 102 cases were enrolled in the analysis. Tumor size enlargement, lesion number increase, recurrence after resection of primary tumor and emergence of tumor metastasis were defined as tumor progression. Patients were divided into progression group (above definitions occurred within 1 year, n=56) and non-progression group (above definitions did not occur within 1 year, n=46). Logistic regression analysis was used to identify the influencing factors of progression within 1 year and the regression equation was acquired, then the probability of progression within 1 year of gNEN patients was obtained to predict the grading: grade I(: the probability of tumor progression within 1 year was < 25.0%; grade II(: this probability was from ≥25.0% to <50.0%; grade III(: this probability was from ≥50.0% to <75.0%; grade IIII(:this probability was ≥75.0%. Spearman correlation analysis was used to study the correlation between predictive grading and the occurrence of disease progression in patients with gNEN NET within 1 years. The ROC curve of different prediction methods was drawn, then the area under the curve(AUC), sensitivity and specificity were calculated and compared.

RESULTSMultivariate regression analysis showed that tumor size(OR=1.048, 95%CI:1.014-1.083, P=0.005), Ki-67 index(OR=2.045, 95%CI:1.261-3.316, P=0.004), and surgical resection of the primary lesion(OR=0.074, 95%CI:0.011-0.497, P=0.070) were independent influencing factors of the progression of gNET within 1 year. The regression equation was as below: P(Y)=1/[1+ e -(-0.934+0.047a+0.715b-2.597c)]. (a: tumor size, b: Ki-67 grading, c: undergoing the surgical resection of the primary lesion). Prediction grading was based on regression equation: 28 cases (29.2%) belonged to grade I(, 9 cases (9.4%) to grade II(, 24 cases (25.0%) to grade III(, and 35 cases (36.5%) to grade IIII(. The probability of progression within 1 year of patients in grade I(, II(, III( and IIII( was 10.7% (3/28),5/9, 58.3%(14/24), and 91.4%(32/35) respectively, with significant difference (χ=41.236, P=0.000). Prediction grading was positively correlated with the occurrence of tumor progression in gNEN patients within 1 year(r=0.644, P=0.000). The AUC of prediction grading to predict the progression of gNEN within 1 year was 0.857, while the sensitivity was 85.2% and the specificity was 69.0%. DeLong method was used to compare the AUC values of prediction grading, Ki-67 grading and TNM staging. Comparison result revealed that the predictive value of prediction grading was not significantly different with that of TNM staging (P=0.303), but was better than that of Ki-67 grading (P=0.006).

CONCLUSIONSOur grading standard can objectively and accurately reflect the probability of progression within one year in gNEN patients. The later the grading, the higher the probability of progression within 1 year is for gNEN patients.