MiR 21-5p as a predictor of recurrence in young gastric cancer patients

It is generally assumed that gastric cancer (GC) in young patients has different clinicopathologic characteristics than that of elderly patients. Although recurrence is an important factor in determining prognosis, traditional clinicopathological factors are sometimes inadequate for predicting recurrence in individuals. Therefore, we aimed to identify miRNAs with the potential to predict recurrence in young patients.

Young patients (age <40 years) undergoing gastrectomy for potentially curable GC (stage III) at Asan Medical Center participated in this study. A total of 50 GC patients with (n = 28) and without (n = 22) GC recurrence were selected for analysis. miRNA microarrays were analyzed to screen tissue samples (n = 7), and we validated the selected miRNAs by quantitative PCR in validation samples (n = 43).

Two miRNAs (hsa-miR-21-5p and hsa-miR-451a) identified in the microarray analysis were evaluated in the validation samples. Among the validation samples containing intratumoral stroma ≥ 70 (n = 35), hsa-miR-21-5p was more highly expressed in the recurrence group than in the nonrecurrence group (fold change 1.82, P = 0.03). In the validation samples with intratumoral stroma ≥ 70, the ΔCt of hsa-miR-21-5p, which was >3.35, had a sensitivity and specificity of 86.7% and 65.5%, respectively, for predicting recurrence, with an area under the ROC curve of 0.723.

miR-21-5p may be useful as a predictor of recurrence in young GC patients whose tumors contain a high proportion of intratumoral stroma. The combination of this miRNA with conventional clinicopathological factors should allow patient prognoses to be more accurately predicted.