To analyze the correlation between quantitative dynamic contrast-enhanced MRI (DCE-MRI) parameters and molecular typing and related immune proteins in gastric cancer.
Forty-three patients confirmed as gastric adenocarcinoma by histopathology were enrolled in this prospective study. DCE-MRI were performed before surgery, and quantitative DCE parameters (Ktrans, Kep, Ve) were measured. The specimens were stained with biomarkers EBER-ISH, MLH1, PMS2, E-Cadherin, P53 and HER-2. According to the different dyeing results, they were divided into five molecular types and four HER-2 expression grades. The quantitative DCE parameters among five molecular types was compared using the ANOVA or Kruskal-Wallis test, and pairwise comparison was performed using the LSD test. The quantitative DCE parameters between positive and negative expressions of related immune proteins were compared using the Mann-Whitney U test. The correlations between quantitative DCE parameters and HER-2 expression grades were evaluated using Spearman rank correlation test.
Among 43 cases, 3 cases were EBV-positive groups, 9 cases were MSI groups, 2 cases were aberrant E-Cadherin groups, 23 cases were aberrant P53 groups, and 6 cases were normal P53 groups. There were significant differences of quantitative DCE parameters in Ktrans and Kep among five molecular types (P < 0.05). The Ktrans value of Aberrant P53 group was lower than that of EBV-positive group, MSI group and Normal P53 group, the Kep value of E-Cadherin group was lower than that of EBV-positive group, and the Kep value of Aberrant P53 group was lower than that of EBV-positive group and MSI group, and all differences were statistically significant (all P < 0.05). Aberrant E-Cadherin group has the lowest Ktrans value (0.28/min) and Kep value (0.26/min) in five groups, respectively. There were no significant differences in quantitative DCE parameters between positive and negative expressions of all related immune proteins (all P > 0.05). There were no significant correlation between HER-2 expression grades and Ktrans, Kep, Ve values (r=-0.08, -0.03, -0.16, P = 0.63, 0.84, 0.31, respectively).
Quantitative DCE-MRI parameters can assess some molecular types of gastric cancer in a certain extent, and not assess related immune protein expressions, and not related to HER-2 expression grades.