The Levels Of Advanced Gastric Cancer Serum MiR-21and Let-7i And Their Relationship To Response And Prognosis Of Oxaliplatin-based Chemotherapy

Objective:To explore level difference of serum miR-21and let-7i between advanced gastriccancer patients, gastric adenoma patients, and healthy people, and to investigate thefeasibility of the levels of serum miR-21and let-7i predicting recent response andprognosis of advanced gastric cancer cases with oxaliplatin-based chemotherapy asfirst-line therapy.Method:Thirty advanced gastric cancer patients treated with mFOLFOX6or XELOXregimen as first-line chemotherapy were analyzed, RT-PCR was used to detect thelevels of miR-21and let-7i in the serum of30(1-30) gastric cancer patients,10(A1-A10) gastric adenoma patients and10(B1-B10) healthy controls. Gastric cancerpatients were divided into high level and low level groups based on the average levelsof miR-21and that of let-7i in30cases, respectively. Relationship of the levels ofserum miR-21and let-7i to clinical features and outcome of the30cases wasanalyzed.Results:1. Compared with gastric adenoma patients and healthy controls, the level ofserum miR-21in advanced gastric cancer patients was significantly up-regulated(P>0.05). No significant difference of serum let-7i was found between these threegroups.2. There is statistical difference of serum miR-21level between differenthistologic grades (P<0.05), different chemotherapy responses (P<0.05), and differentECOG scores (P<0.05), the details are as follows: well differentiated/moderatelydifferentiated<poorly differentiated/undifferentiated, complete response/partialresponse<stable disease/progressive disease, ECOG0~1<ECOG2. No significantdifference of miR-21level was observed between genders, ages, primary sites, anddifferent levels of CEA, CA-199, CA-724(P>0.05). 3. Univariate analysis showed that ECOG, response, serum miR-21werepredictive of prognosis (P<0.05). Multivariate analysis indicated that ECOG andserum miR-21were independent prognostic factors (P<0.05).Conclusion:The level of serum miR-21may be used to predict treatment response andprognosis of advanced gastric cancer patients treated with oxaliplatin-basedchemotherapy.