Abstract: Objective  To analyze the relationship between the expression of RNA (microRNAs) 451 and prognosis in patients with positive expression of epidermal growth factor receptor (EGFR). Methods  A total of 67 lung adenocarcinoma patients with systemic chemotherapy and targeted therapy with positive EGFR expression confirmed by pathological biopsy were enrolled. After RTqPCR (realtime quantitative polymerase chain reaction), the pathological specimens of cancer tissues were examined for microRNA451 expression, and were divided into high expression group and low expression group based on the median expression of microRNA451. The incidence of adverse reactions to chemotherapy was compared between the two groups, as well as their differences in survival.Results  The 3 and 4 degree myelosuppression in the high expression group was lower than that in the low expression group (χ2=5.382, P=0.020; χ2=4.947, P=0.026), and the low expression group was low (χ2=7.208, P=0.007; χ2=6.211, P=0.013)  in the high expression group in the course of chemotherapy with 3 and 4 degrees of digestive tract reaction. In the two groups, the median PFS in the high expression group was 12.3  months, and the middle PFS in the low expression group was 9 months. The two groups had a statistically significant difference (χ2=9.582, P=0.002). The median overall survival (OS) in the high expression group was 12.3 months, while the median OS in the low expression group was 11.5 months, and the difference between the two groups was statistically significant (χ2=5.749, P=0.016).Conclusion  Targeted therapy with positive expression of EGFR combined with systemic chemotherapy in patients with high expression of microRNA451 in lung adenocarcinoma has mild adverse reactions and a long survival time.

Key words: lung adenocarcinoma, receptor, epidermail growth factor, microRNA