Progress of rare epidermal growth factor receptor mutations in non-small cell lung cancer / 肿瘤研究与临床

With the development of biomolecular diagnostic technology and genetic analysis, it has been gradually discovered that some gene abnormalities can drive the occurrence and development of lung cancer. Among them, epidermal growth factor receptor (EGFR) is the most common mutant gene in non-small cell lung cancer (NSCLC). However, most of the current researches focus on the common mutations of EGFR, such as exon 19 deletion (19del) and exon 21 point mutation (L858R). There are few studies on rare EGFR mutations. This article reviews the progress of rare EGFR mutations in NSCLC.

Analysis of online Mendelian inheritance in man / 中国生化药物杂志

Objective To analyze the data from Online Mendelian Inheritance in Man (OMIM) to understand more about it, and provide reference to researchers using this database.Methods 19414 mutations which have definite relevant phenotypes from OMIM were obtained, then these mutations with three databases (1000 Genome Project,GO-ESP,ExAC) which record the mutation frequency in different population were compared.Results Most of the phenotype-related mutations from OMIM are rare mutations whose mutation frequency is less than 1%:18866 in 1000 Genome Project, 18981 in GO-ESP, 18979 in ExAC.The number of mutation whose frequency is more than 1% is 548433435 in 1000 Genome Project, GO-ESP, ExAC, respectively.And there are 320 mutations whose frequency is more than 1% in all databases.In all phenotypes, there are 127 polymorphism phenotypes, 584 susceptibility phenotypes, while in 320 ( 1.6%) phenotypes with common mutations, there are 62 polymorphism phenotypes, 88 susceptibility phenotypes and occupies 48.8%, 15.1%, respectively.Conclusion Approximately 97.5% mutations in OMIM are rare mutations.Polymorphism and susceptibility enrich in common mutations, especially in the mutation whose frequency is more than 10%.

A clinical study of Gefitinib retreatment beyond progression in non-small cell lung cancer patients with rare EGFR mutations / 重庆医学

Objective To evaluate the effectiveness and safety of gefitinib retreatment beyond progression(GRBP)in non-small cell lung cancer(NSCLC)patients with rare EGFR mutations.Methods We retrospectively analyzed six rare-EGFR-mutation NSCLC patients from Jan 2011 to Dec 2015.Those patients had previous disease control and then disease progression according to Response Evaluation Criteria in Solid Tumors version 1.1(RECIST v1.1)after taking oral gefitinib 250 mg once a day.After that,continuing gefitinib was decided by clinicians′ experience at the same treatment option.The primary endpoints were response rate(RR),overall survival(OS),the first and second progression-free survival(PFS-1 and PFS-2).Safety was assessed according to the NCI-CTCAE version 4.0.Results After initial treatment of gefitinib,4 patients achieved partial response(PR)and 2 patients showed stable disease(SD),with RR being 66.7％.The median PFS-1 and PFS-2 were 10 months(95％CI 6.6-13.4)and 9 months(95％CI 6.9-11.1),respectively.The median OS time was 28 months(95％CI 10.4-45.6).The most common treatment-related adverse events were fatigue,diarrhea,rash,itching and elevated transaminases.Conclusion In our study,gefitinib retreatment beyond disease progression is effective with a manageable tolerability profile.

Efficacy of EGFR Tyrosine Kinase Inhibitors in Non-small Cell Lung Cancer Patients Harboring Different Types of EGFR Mutations: A Retrospective Analysis / 华中科技大学学报（医学）（英德文版）

With the development of molecular pathology,many types of epidermal growth factor receptor (EGFR) mutations have been identified.The efficacy of EGFR tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC) patients with different types of EGFR mutations,especially in patients with single rare mutations or complex mutations (co-occurrence of two or more different mutations),has not been fully understood.This study aimed to examine the efficacy of EGFR-TKIs in NSCLC patients with different types of EGFR mutations.Clinical data of 809 NSCLC patients who harbored different types of EGFR mutations and treated from January 2012 to October 2016 at Renmin Hospital and Zhongnan Hospital,Wuhan,were retrospectively reviewed.The clinical characteristics of these patients and the efficacy of EGFR-TKIs were analyzed.Among these patients,377 patients had only the EGFR del-19 mutation,362 patients the EGFR L858R mutation in exon 21,33 patients single rare mutations and 37 patients complex mutations.Among these 809 patients,239 patients were treated with EGFR-TKIs.In all the 239 patients,the disease control rate (DCR) was 93.7％ with two patients (0.2％) achieving complete response (CR),the median progression free survival (PFS) was 13.0 months (95％ confidence interval [CI],11.6-14.4 months),and the median overall survival (OS) was 55.0 months (95％ CI,26.3-83.7 months).Subgroup analysis revealed that the DCR in patients harboring single rare or complex mutations of EGFR was significantly lower than in those with del-19 or L858R mutation (P＜0.001).Patients with classic mutations (del-19 and/or L858R mutations) demonstrated longer PFS (P＜0.001) and OS (P=0.017) than those with uncommon mutations (single rare and/or complex mutations).Furthermore,the patients with single rare mutations had shorter median OS than in those with other mutations.Multivariate Cox regression analysis identified that the type of EGFR mutations was an independent risk factor for PFS (hazard ratio [HR]=0.308,95％ CI,0.191-0.494,P＜0.001) and OS (HR=0.221,95％ CI,0.101-0.480,P＜0.001).The results suggest that the single rare or complex EGFR mutations confer inferior efficacy of EGFR-TKIs treatment to the classic mutations.The prognosis of the single rare EGFR mutations is depressing.EGFR-TKIs may be not a good choice for NSCLC patients with single rare mutations of EGFR.Further studies in these patients with uncommon mutations (especially for the patients with single rare mutations) are needed to determine a better precision treatment.