| Background and purpose: Lung cancer is one of the main causes of cancer relateddeath in China, and the morbidity and mortality increased year by year. About85%ofthe lung cancer patients for non-small cell lung cancer (NSCLC), which is dividedinto the epidermal growth factor receptor (EGFR) mutant and non-mutant. EGFRmutations in exons19and21account for about90%of all mutations, known as theclassic mutation or hot spot mutation. In several randomized controlled studies，it hasbeen confirmed that the objective response rate and progression free survival inEGFR-tyrosine kinase inhibitors(EGFR-TKIs) in the advanced NSCLC weresignificantly better than cisplatin chemotherapy. While recent studies found that theeffect of different subtypes of EGFR mutation with EGFR-TKIs is different and themechanisms for the difference remain unclear. This study retrospectively analyzedEGFR mutations in exons19and21of non-small cell lung cancer patients and tocompare the clinical characteristics and the ORR, OS, PFS with EGFR-TKIs to helpjudging the prognosis, guiding treatment and providing theoretical basis for the studyof EGFR-TKIs application in different subtypes of EGFR mutation with differenteffect.Methods: We retrospectively analyzed86non-small cell lung cancer with EGFRmutations in EGFR exon19or21and accepting EGFR-TKIs (gefitinib, erlotinib oricotinib) therapy from the Affiliated Hospital of Jilin University from January1,2010to January1,2014and regular follow-up, fill in the questionnaire at the same time.According to the different mutation site, the patients were divided into two groups,including exon19deletion mutation group (n=40,46.51%) and exon21L858Rmutation (n=46,53.49%).We compare the clinical features and the objective responserate, progression free survival and overall survival with EGFR-TKIs therapy betweenthe two groups, death as the end event. Clinical data were performed with SPSSversion17.The Mann-Whitney test was used for the data analysis between the twogroups with heterogeneity of variance. Comparisons of categorical variables betweenthe different groups were made by X2test. Cox proportional hazard analysis was used to explore the prognostic factors. Survival analysis was estimated by theKaplan-Meier method. P <0.05was considered significant.Results: This study identified86advanced NSCLC patients harboring EGFR exon19deletion (n=40,46.51%) or21L858R mutation (n=46,53.49%) who were treated withEGFR-TKIs. All the patients with exon19deletion or21L858R mutation were morelikely occurred in female gender(exon19deletion VS21L858R mutation,57.50%VS60.87%), age<60yeas(exon19deletion VS21L858R mutation,65.00%VS58.70%),no smoking(exon19deletion VS21L858R mutation,72.50%VS69.57%),adenocarcinoma(exon19deletion VS21L858R mutation,95.00%VS95.66%), stageIV(exon19deletion VS21L858R mutation,95.00%VS93.48%), lymph nodemetastasis(exon19deletion VS21L858R mutation,97.50%VS100%), ECOG0-1(exon19deletion VS21L858R mutation,82.50%VS80.43%), no cancerhistory(exon19deletion VS21L858R mutation,62.50%VS63.04%). There were nosignificant differences in clinical characteristics above all found between the exon19deletion and21L858R mutation. The prognosis analysis was summarized as follows:Patients with exon19deletion may have higher objective response rate comparedwith patients with21L858R mutation(65.00%VS45.80%， P=0.131).But nostatistical significance was observed. Patients with exon19deletion had significantlylonger PFS, compared with patients with21L858R mutation (10.4vs9.1months,p=0.002). Patients with exon19deletion may have longer overall survival comparedwith patients with21L858R mutation (24.8vs24.1months, p=0.145).But nostatistical significance was observed. Further analysis on the gender,age,smokingstatus,ECOG score,cancer history of PFS, exon19deletion had longer PFS than21L858R mutation under all the cases;But for male, aged greater than60years, nosmoking, no family history of cancer and ECOG score of0-1and2,there wasstatistical significance.For overall survival, patients with exon19deletion may havelonger overall survival compared with patients with21L858R mutation under allcases except family history of cancer; No statistical significance was observed also.Conclusion:1.There were no significant differences between the advanced NSLCL with exons 19deletion and21L858R mutations associated with gender, age, smoking status,histopathology, clinic stage, lymph node metastasis, performance status and cancerhistory.2. Patients with exon19mutation may have higher ORR than exon21mutationwith EGFR-TKIs treatment.3. For male, aged greater than60years, no smoking, no family history of cancerand ECOG score of0-1and2, patients with exon19mutation had longer PFS,compared with those with21L858R mutation. For female, under60years, smoking,family history of cancer,patients with exon19mutation may have longer PFS,compared with those with21L858R mutation.4. For male, patients with exon19mutation had longer OS compared with thosewith21L858R mutation.Patients who had cancer history with exon21mutation mayhave longer OS than those with exon21mutation; For male or female, aged greaterthan60years or under, ECOG score of0-1and2, patients with exon19mutation mayhave longer OS, compared with those with21L858R mutation.5. The exon19mutation may be a more efficient clinical marker for predicting theresponse of patients with NSCLC to EGFR TKIs. |
