Relationship between high throughput sequencing for detection of EGFR gene results and clinical features in patients with advanced lung adenocarcinoma

Objective To study the relationship between detection of EGFR gene results and clinical features in patients with advanced lung adenocarcinoma. Methods The paraffin embedded tissues or serum samples of the 53 patients with advanced lung adenocarcinoma were analyzed by high-throughput gene detection, the gene mutation and its correlation with clinic were collected and analyzed. Results Among the 53 patients with lung adenocarcinoma, 25 cases of EGFR gene mutation was detected, 18exon mutation in 0 case, 19exon mutation in 13 cases (52%), 20exon mutation in 1 case (4%), 21exon mutation in 11 cases (44%); 11 cases of female patients with mutations, the mutation rate was 52.9%, which was higher than that of male patients(38.9%, χ2=5.801, P=0.006). There were 40 smokers, mutation of 15 cases, the mutation rate was 37.5%, which was higher than that of non-smokers (30.8%, χ2=2.013, P=0.024). The mutation rate detected from paraffin embedded tissues was 40%, which was higher than the mutation detection rate of the serum(10%, χ2=4.935, P=0.007). Among the 25 patients with gene mutation, the 21exon and 19exon mutation abundance expression levels were 1.0850±0.4228, 0.9650±0.3285, the two groups had no significant difference (P>0.05). After 3 months of gefitinib treatment, according to the evaluation of therapeutic effect solid carcinoma, CR in 3 cases (12%), PR in 17 cases (68%), SD in 4 cases(16%), PD in 1 case(4%). Reviewed the mutation abundances based on curative effect, mutation was found in abundance average expression were 3.6400±0.6288, 0.9458±0.2403, 0.2725±0.0439, the difference among the four groups was significally different (F=59.508, P=0.0014), CR group compared with PR group, SD group, mutation abundance increased significantly (LSD-t=6.370, P=0.0014; LSD-t=4.760, P=0.0004), PR group compared with SD group, the mutation abundance increased significantly (LSD-t=1.578, P=0.1369). The common adverse reactions of EGFR gene mutation were rash and diarrhea, the incidence of rash rate was 52%, and the incidence of diarrhea was 24%, there was significant difference compared with other adverse reactions (χ2=2.762, P=0.048). Conclusions Female patients with lung adenocarcinoma without smoking habit prone to have EGFR gene mutations, and the mutation rate reaches 40%, mainly concentrates in the 19exonDelK746-752 and 21exonL858R; gefitinib on EGFR mutant lung adenocarcinoma patients with good prognosis; the common adverse reactions are rash and diarrhea. Key words: Lung adenocarcinoma; Gene detection; High throughput sequencing; Mutation abundance; Gefitinib; Clinical analysis